Advertisement

Viscum album [L.] extract therapy in patients with locally advanced or metastatic pancreatic cancer: A randomised clinical trial on overall survival

Open AccessPublished:July 26, 2013DOI:https://doi.org/10.1016/j.ejca.2013.06.043

      Abstract

      Background

      The unfavourable side-effects of late-stage pancreatic cancer treatments call for non-toxic and effective therapeutic approaches. We compared the overall survival (OS) of patients receiving an extract of Viscum album [L.] (VaL) or no antineoplastic therapy.

      Methods

      This is a prospective, parallel, open label, monocentre, group-sequential, randomised phase III study. Patients with locally advanced or metastatic cancer of the pancreas were stratified according to a binary prognosis index, composed of tumour stage, age and performance status; and were evenly randomised to subcutaneous injections of VaL extracts or no antineoplastic therapy (control). VaL was applied in a dose-escalating manner from 0.01 mg up to 10 mg three times per week. Patients in both groups received best supportive care. The primary end-point was 12-month OS, assessed in a group-sequential analysis.

      Findings

      We present the first interim analysis, including data from 220 patients. Baseline characteristics were well balanced between the study arms. Median OS was 4.8 for VaL and 2.7 months for control patients (prognosis-adjusted hazard ratio, HR = 0.49; p < 0.0001). Within the ‘good’ prognosis subgroup, median OS was 6.6 versus 3.2 months (HR = 0.43; p < 0.0001), within the ‘poor’ prognosis subgroup, it was 3.4 versus 2.0 months respectively (HR = 0.55; p = 0.0031). No VaL-related adverse events were observed.

      Conclusion

      VaL therapy showed a significant and clinically relevant prolongation of OS. The study findings suggest VaL to be a non-toxic and effective second-line therapy that offers a prolongation of OS as well as less disease-related symptoms for patients with locally advanced or metastatic pancreatic cancer.

      Keywords

      1. Introduction

      Patients suffering from pancreatic cancer in a locally advanced or metastatic stage do not have many treatment options if their general condition is bad or if standard therapies have failed.
      • Bayraktar S.
      • Bayraktar U.D.
      • Rocha-Lima C.M.
      Recent developments in palliative chemotherapy for locally advanced and metastatic pancreas cancer.
      • Cascinu S.
      • Falconi M.
      • Valentini V.
      • Jelic S.
      Pancreatic cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up.
      • Conroy T.
      • Desseigne F.
      • Ychou M.
      • et al.
      FOLFIRINOX versus gemcitabine for metastatic pancreatic cancer.
      • Richter J.
      • Saif M.W.
      Locally advanced pancreatic adenocarcinoma: where are we and where are we going? Highlights from the “2010 ASCO Gastrointestinal Cancers Symposium”. Orlando, FL, USA. January 22–24, 2010.
      Recent studies on second-line therapies for pancreatic cancer showed benefit
      • Jacobs A.D.
      • Burris III, H.A.
      • Rivkin S.
      • et al.
      A randomized phase III study of rubitecan (ORA) vs. best choice (BC) in 409 patients with refractory pancreatic cancer report from a North-American multi-center study.
      • Pelzer U.
      • Schwaner I.
      • Stieler J.
      • et al.
      Best supportive care (BSC) versus oxaliplatin, folinic acid and 5-fluorouracil (OFF) plus BSC in patients for second-line advanced pancreatic cancer: a phase III-study from the German CONKO-study group.
      ; however, Gemcitabine, 5-FU, capecitabine and combinations of Gemcitabine with capecitabine, erlotinib, oxaliplatin and cisplatin have serious side-effects leading to poor compliance of patients and physicians. Best Supportive Care (BSC) is often the only option,
      • Boeck S.
      • Bruns C.J.
      • Sargent M.
      • et al.
      Current oncological treatment of patients with pancreatic cancer in germany: results from a national survey on behalf of the Arbeitsgemeinschaft Internistische Onkologie and the Chirurgische Arbeitsgemeinschaft Onkologie of the Germany Cancer Society.
      and looking for other therapeutic approaches is desirable.
      Medicinal plants have a long tradition in the treatment of cancer and play a major role in the development of new drugs today. Over 60% of currently used anti-cancer agents originally derive from natural products.
      • Cragg G.M.
      • Newman D.J.
      Plants as a source of anti-cancer agents.
      In central Europe, extracts of Viscum album [L.] (VaL) are registered for parenteral use and are widely used in adjuvant and palliative cancer therapy, alone or in addition to conventional therapies.
      • Kienle G.S.
      • Kiene H.
      Review article: influence of Viscum album L (European mistletoe) extracts on quality of life in cancer patients: a systematic review of controlled clinical studies.
      VaL contains a variety of biologically active constituents such as lectins, viscotoxins and other low-molecular-weight proteins; furthermore, a chitin-binding agglutinin, oligo- and polysaccharides, flavonoids, vesicles, triterpene acids and others.
      • Büssing A.
      Mistletoe. The genus Viscum.
      The manufacturing of VaL adheres to ‘good Medical Practise’ – requirements for injectable medications; the typical proteins of VaL (mistletoe lectins and viscotoxins) are analysed to ensure consistent quantity and quality. Whole VaL extracts as well as several of the compounds are cytotoxic, and the lectins in particular have strong apoptosis-inducing effects via expression of mitochondrial Apo2.7 molecules.
      • Büssing A.
      • Wagner M.
      • Wagner B.
      • et al.
      Induction of mitochondrial Apo2.7 molecules and generation of reactive oxygen-intermediates in cultured lymphocytes by the toxic proteins from Viscum album L.
      VaL and its compounds stimulate the activation of monocytes/macrophages, granulocytes, natural killer cells, T-cells and dendritic cells; they induce granulocyte–macrophage colony-stimulating factor, tumour necrosis factor α, interferon γ and a variety of cytokines, and they enhance endorphins in vivo.
      • Kienle G.S.
      • Kiene H.
      Review article: influence of Viscum album L (European mistletoe) extracts on quality of life in cancer patients: a systematic review of controlled clinical studies.
      • Büssing A.
      Mistletoe. The genus Viscum.
      • Kienle G.S.
      • Kiene H.
      Die Mistel in der onkologie – fakten und konzeptionelle grundlagen.
      Accordingly, low-dose but not high-dose VaL-lectin-I reduces melanoma growth in a mouse model, probably by immunosignalling.
      • Thies A.
      • Dautel P.
      • Meyer A.
      • Pfuller U.
      • Schumacher U.
      Low-dose mistletoe lectin-I reduces melanoma growth and spread in a scid mouse xenograft model.
      Intratumoral injections of VaL result in partial and complete remissions in an animal model using human pancreatic cancer xenografts
      • Rostock M.
      • Huber R.
      • Greiner T.
      • et al.
      Anticancer activity of a lectin-rich mistletoe extract injected intratumorally into human pancreatic cancer xenografts.
      and also in patients with inoperable pancreatic carcinoma.
      • Matthes H.
      • Buchwald D.
      • Schad F.
      • Jeschke E.
      Intratumorale applikation von Viscum album L. (Mistelgesamtextrakt; Helixor M) in der therapie des inoperablen pankreaskarzinom.
      A phase I interaction study of VaL and gemcitabine in patients with advanced solid tumours demonstrated VaL to be safe and well tolerated, allowing a 30% higher gemcitabine dose to be applied. Gemcitabine pharmacokinetics was not affected.
      • Mansky P.J.
      • Blackman M.R.
      • Grem J.
      • Swain S.M.
      • Monahan B.P.
      NCCM/NCI phase I study of mistletoe extract and gemcitabine in patients with advanced solid tumors.
      A recent review of safety data concerning higher VaL dosages confirmed the favourable safety profile
      • Kienle G.S.
      • Grugel R.
      • Kiene H.
      Safety of higher dosages of Viscum album L. in animals and humans – systematic review of immune changes and safety parameters.
      which is particularly desirable for late-stage cancer patients.
      Here we present a phase III, open-label, randomised, group-sequential study (ISRCTN70760582). It investigated whether VaL treatment has an effect on overall survival (OS) in patients with locally advanced or metastatic cancer of the pancreas. Because in countries with widespread use of VaL there is a low patient compliance constraining the conduct of randomised VaL trials,
      • Rostock M.
      • Huber R.
      Randomized and double-blind studies – demands and reality as demonstrated by two examples of mistletoe research.
      we conducted this study in Serbia where VaL therapy is practically unknown. We report the results of the first interim analysis.

      2. Methods

      This is a prospective randomised open-label study on overall survival. Blinding is not essential in cancer studies with overall survival as primary end-point according to the Food and Drug Administration (FDA) guidelines.

      Guidance for Industry. Clinical Trial Endpoints for the Approval of Cancer Drugs and Biologics. http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM071590.pdf 2007 May.

      The study was conducted at the Hepato-Biliary Surgical Unit of the First Surgical Clinic of the Clinical Centre of Serbia (CCS), Belgrade, Serbia. Patients were referred to the study site from seven different centres in Serbia. The study was conducted according to the Declaration of Helsinki and was approved by the ethics committee of the Clinical Centre of Serbia in Belgrade (No. 60/6 from 04.03.2008) and by the Serbian Drug Agency (No. 587/2008/4000 from 10.11.2008). All patients provided written informed consent before study entry. The study was subject of GCP-conform on-site monitoring. Two independent audits reported no critical or major findings relating to the conduct of the study. Results of the interim analysis were reviewed by an Independent Data Monitoring Committee (IDMC).

      2.1 Patients

      Inclusion criteria for patients were: adults aged ⩾18; with locally advanced or metastatic cancer of the pancreas (Union for International Cancer Control [UICC] stage III/IV); with any history of previous therapies but not eligible for antineoplastic therapies anymore; leucocytes ⩾ 3000 /mm3; platelets ⩾ 100,000 /mm3; serum creatinine ⩽ 2 mg%; serum glutamic oxaloacetic transaminase (SGOT) ⩽ 2.5-fold upper institutional limit; serum glutamic pyruvic transaminase (SGPT) ⩽ 2.5-fold upper institutional limit; negative pregnancy test and contraception (where appropriate); and no other anti-neoplastic therapies planned during the study except 5-fluorouracil (FU)/leucovorin for symptom alleviation. After the first 47 patients, the inclusion criteria SGOT, SGPT and creatinine were omitted by protocol amendment, since many of the screened patients had very advanced disease and failed to meet these criteria.
      Specific exclusion criteria were: life expectancy less than 4 weeks; weight loss ⩾ 20% in the preceding 6 weeks; brain metastasis.

      2.2 Patient assignment

      The Clinical Centre of Serbia (CCS), Belgrade, has about 3700 hospital beds and about 880,000 ambulatory patients. Study centre is the First Surgical Clinic of CCS, the main referral centre for surgical treatment of patients with hepatobiliary and pancreatic malignancies in Serbia. Decisions on treatments of cancer patients are made in a weekly multidisciplinary oncology consultation based on local regulations: inoperable patients with advanced or metastatic pancreatic cancer, not willing to receive chemotherapy or with at least one of the following conditions were candidates for this study: Eastern Cooperative Oncology Group (ECOG) > 2, Bilirubine > 50 μmol/l, transaminases > 100 U/l, leukocytes > 10.0∗109 /l, missing histological confirmation of the disease and therefore not eligible for chemotherapy. After eligibility assessment, signed and witnessed informed consent, and after passing all in- and exclusion criteria, patients were enrolled into the study (Fig. 1).
      Figure thumbnail gr1
      Fig. 1Flow chart according to Consolidated Standards of Reporting Trials (CONSORT). Abbreviation: VaL, Viscum album [L.].
      Patients were stratified into two groups regarding their expected prognosis: ‘Poor prognosis’ was defined as presenting with at least two out of the three following criteria: UICC class = IV; age > 65; and ECOG ⩾ 2. All other patients were classified as having ‘good prognosis’. Within each stratum, patients were randomised 1:1 to either the VaL or control group.

      2.3 Study medication

      The Viscum album (L.) extract (VaL) applied in this study is an approved drug and has a marketing authorisation under the name ‘Iscador® Qu spezial’ in Germany, Switzerland and Austria. It is extracted from the mistletoe of oak trees (Qu = Quercus).The fresh plant is fermented with special starter cultures (lactobacilli). The drug substance Iscador® is then diluted with isotonic saline solution, sterile-filtered and subsequently filled into ampoules as an aseptic injection preparation. The manufacturing adheres to GMP requirements for injectable medications; typical proteins of VaL (mistletoe lectins and viscotoxins) are analysed to ensure consistent quantity and quality.

      2.4 Treatment

      During the course of the study, all patients received best supportive care which was individually tailored to patient needs at the scheduled follow-up visits (at month 1, 2, 3, 6, 9 and 12), at additional intermediate consultation visits of patients in the study centre and by additional telephone consultations.
      Patients in the VaL group received 1 ml subcutaneous injections of VaL three times per week. Patients were taught how to self-administer the subcutaneous injections of VaL. For the time intervals between the follow-up visits at the study centre, patients were provided with sufficient ampoules of VaL and syringes for administration at home or at local health centres. Injections were either self-administered or given by relatives or nurses. VaL dosage was escalating: two injections of 0.01 mg, two of 0.1 mg, five of 1 mg, five of 2 mg and eight of 5 mg, followed by constant doses of 10 mg thrice weekly, maintained throughout the study. In case of local inflammatory skin reactions >5 cm or body temperature >38 °C, Val was to be reduced to the last well tolerated dosage.

      2.5 End-points

      Our primary hypothesis was: Advanced pancreatic cancer patients receiving VaL will show an improvement of 12-month OS. Reference point for OS was the date of inclusion into the study. Primary end-point was the date of death from any reason, obtained from family members and cross-checked by the Serbian residents’ registration office. This first interim analysis included 220 patients enrolled in the study, using the intention-to-treat approach.
      The secondary end-points of this study were: quality of life parameters, vital signs, performance status, weight and concomitant medication. The respective results will be published elsewhere.

      2.6 Safety

      All 220 enrolled patients were included in the safety evaluation.
      At each visit, patients were asked for adverse events which were documented according to the Common Toxicity Criteria for Adverse Events (CTCAE).
      After the inclusion of the first 47 patients, a more consistent record of all adverse events was considered desirable, and a standardised documentation of disease-related symptoms was additionally provided in the case report form. These disease-related symptoms consisted of weight loss, pain, loss of energy, nausea/emesis, diarrhoea, anxiety, vertigo, jaundice and abnormal values of bilirubin, SGOT and SGPT. Their severity was rated according to CTCAE as: none, mild, moderate, severe and life-threatening or disabling. All patients received diaries to document episodes of fever. VaL patients were additionally asked to document the applied dose and the occurrence of local skin reactions at the injection site which are considered a desirable immune response and not classified as an adverse event in this study if less than 5 cm in diameter.

      2.7 Determination of the sample size

      Previous VaL studies in patients with advanced pancreatic cancer showed a prolongation in median OS from 5 to 7 months, from which a hazard ratio of 0.714 could be deduced.
      • Matthes H.
      • Friedel W.E.
      • Bock P.R.
      • Zanker K.S.
      Molecular mistletoe therapy: friend or foe in established anti-tumor protocols? A multicenter, controlled, retrospective pharmaco-epidemiological study in pancreas cancer.
      • Schaefermeyer G.
      • Schaefermeyer H.
      Treatment of pancreatic cancer with Viscum album (Iscador): a retrospective study of 292 patients 1986–1996.
      For a two-sided group-sequential hypothesis test with two pre-planned interim analyses including 50% and 75% of the foreseen total sample size, respectively, assuming a power of 85% and 5% level of significance as well as an accrual period of 53 months with an additional follow-up time of 12 months and an even allocation scheme, it was estimated that 173 evaluable patients per group would be needed to confirm a statistically significant treatment effect according to Freedman’s formula.
      • Freedman L.S.
      Tables of the number of patients required in clinical trials using the logrank test.
      To account for dropouts the study was designed for a maximum of 428 patients.

      2.8 Randomisation

      A special department of the data management created for each of the two prognosis strata a separate, evenly balanced randomisation list with variable permutation block sizes of 4, 6 and 8 using SAS® version 9.1 (SAS® Institute, Cary, NC, USA). Following these two randomisation lists, one for each prognosis stratum, two series of opaque and sealed consecutively numbered allocation letters were produced and stored at the study centre. When a patient had been included and attributed to one of the prognosis strata, the investigator opened the next consecutive allocation letter of that stratum and assigned the patient, as determined in this letter, either to the Val or the control group. The monitor checked the sealed as well as the opened random letters at each monitoring visit.

      2.9 Statistical methods

      The study design is based on a group-sequential test procedure with pre-planned analyses after 220, 320 and 428 patients meeting one of the off-study criteria. An alpha-spending approach as suggested by Lan and DeMets
      • Lan K.K.
      • DeMets D.L.
      Discrete sequential boundaries for clinical trials.
      with an O’Brien/Fleming-like alpha spending function was used to define the test boundaries of the group-sequential procedure. The primary analysis regarding OS uses a Cox Proportional Hazard Model with treatment and prognosis groups as predictor variables to calculate the Z score needed for the group-sequential procedure. Stagewise ordering was used to compute the unbiased median estimate and confidence limits for the prognosis-group-adjusted hazard rates.
      • Emerson S.S.
      • Fleming T.R.
      Parameter estimation following group sequential hypothesis testing.
      The non-parametric Kaplan–Meier product-limit estimator of the survival function was used to visualise differences between treatment groups and to calculate median survival times.
      The Wilcoxon rank sum test and Fisher’s exact test were used to check the balance of demographic and clinical baseline characteristics. Prognosis-group-adjusted odds ratios for the occurrence of at least one adverse event during the course of the study were calculated by logistic regression. The worst reported post-baseline CTCAE grade of a patient for each item of the disease-related symptom section was analysed by a Cochran–Mantel–Haenszel test stratified for its baseline value. All tests were two-sided, and a p-value of 0.05 was considered statistically significant. The statistical analysis was performed with SAS® version 9.2.

      3. Results

      3.1 Patients’ characteristics

      This first interim analysis referred to 238 screened patients, of whom 220 had been enrolled into the study between January 2009 and December 2010 (Fig. 1). Eighteen patients were not enrolled because their condition was too bad (major weight loss, life expectancy <4 weeks). All enrolled patients had locally advanced or metastatic pancreatic cancer: 195 patients were diagnosed during surgery and 25 were diagnosed by imaging methods only. Baseline patient characteristics were well balanced between VaL and control groups (Table 1). Seven patients dropped out: two in the VaL group and five in the control group (Fig. 1). None of the dropouts were related to treatment with VaL. The recruitment into this study was stopped due to proven efficacy after obtaining the decision of the IDMC in May 2012.
      Table 1Demographic and clinical baseline-characteristics of 220 patients with locally advanced or metastatic pancreatic cancer, treated with VaL extracts or no antineoplastic therapy (control).
      Patient characteristicGroup
      Control (n = 110)VaL (n = 110)Test (2-sided)
      Gender
       Male63 (57.3%)65 (59.1%)p = 0.891 FET
       Female47 (42.7%)45 (40.9%)
      Age (years)
       Median6561p = 0.097 Wilcoxon
       Range27–9024–87
      Race
       Caucasian110 (100%)110 (100%)
      ECOG
       0–156 (50.9%)56 (50.9%)p = 1.000 FET
       2–454 (49.1%)54 (49.1%)
      UICC
       III64 (58.2%)57 (51.8%)p = 0.416 FET
       IV46 (41.8%)53 (48.2%)
      Prognosis group
       Poor56 (50.9%)55 (50.0%)p = 1.000 FET
       Good54 (49.1%)55 (50.0%)
      Tumor-related surgery
       No9 (8.2%)6 (5.5%)p = 0.594 FET
       Yes101 (91.8%)104 (94.5%)
      Affected part of pancreas
       Head56 (50.9%)58 (52.7%)p = 0.564 FET
       Body12 (10.9%)12 (10.9%)
       Tail3 (2.7%)7 (6.4%)
       Head and body18 (16.4%)18 (16.4%)
       Body and tail21 (19.1%)14 (12.7%)
       Head, body and tail- (-%)1 (0.9%)
      TNM (T)
       31 (0.9%)2 (1.8%)p = 0.622 FET
       4109 (99.1%)107 (97.3%)
       X- (-%)1 (0.9%)
      TNM (N)
       01 (0.9%)- (-%)p = 1.000 FET
       113 (0.9%)14 (12.7%)
       X96 (87.3%)96 (87.3%)
      TNM (M)
       064 (58.2%)57 (51.8%)p = 0.416 FET
       146 (41.8%)53 (48.2%)
      Abbreviations: Wilcoxon, Wilcoxon rank sum test; FET, Fisher’s Exact test; ECOG, Eastern Cooperative Oncology Group (performance scale); UICC, Union for International Cancer Control (for grading); TNM, TNM classification according to UICC; VaL, Viscum album [L.].

      3.2 Treatment administration

      During the study, patients in the VaL group received three 1 ml subcutaneous injections of VaL per week. In total, 8136 subcutaneous injections were recorded for 110 patients (per patient median = 61.5; minimum = 3; maximum = 156). For all patients in the VaL group, dose escalation followed the planned scheme without any need for dose reduction. No patients in the control group received VaL. All patients in both groups were provided with best supportive care and none of them received 5-FU/Leucovorin or any other antineoplastic therapies.

      3.3 Overall survival

      Median OS for patients was 4.8 months in the VaL group and 2.7 months in the control group (Fig. 2). A prognosis-group adjusted hazard ratio (HR) of 0.49 (95% confidence interval (CI) = 0.36–0.65, p < 0.0001) was estimated by the group-sequential procedure.
      Figure thumbnail gr2
      Fig. 2Kaplan–Meier estimates of 12-month overall survival of 220 patients with advanced or metastatic pancreatic cancer assigned to a therapy with extract of VaL or to no antineoplastic therapy (Control). Abbreviations: Cox, Cox regression adjusted for prognosis state; VaL, Viscum album [L.]. Note: All patients surviving for more than 12 months are censored and therefore not at risk any more.
      Subgroup analysis for patients with ‘good prognosis’ showed a median OS of 6.6 months in the VaL group compared to 3.2 months in the control group (Chi2 = 15.5, HR = 0.43; 95% CI = 0.28–0.65, p < 0.0001) (Fig. 3). For patients with ‘poor prognosis’ the median OS was 3.4 months and 2.0 months, respectively (Chi2 = 8.8, HR = 0.55; 95% CI = 0.37–0.82, p = 0.0031) (Fig. 4). Seventeen patients in the VaL group and no patient in the control group ended the study with a regular exit visit after 12 months. Two patients in the control group dropped out without an exit visit, but survived study day 360. Subgroup analyses showed superiority for the VaL group in all analysed subsets (Fig. 5).
      Figure thumbnail gr3
      Fig. 3Kaplan–Meier estimates of 12-month overall survival of 109 patients with advanced or metastatic pancreatic cancer assigned to a therapy with extract of VaL or to no antineoplastic therapy (Control) and good prognosis. Abbreviations: Cox, Cox regression; VaL, Viscum album [L.].
      Figure thumbnail gr4
      Fig. 4Kaplan–Meier estimates of 12-month overall survival of 111 patients with advanced or metastatic pancreatic cancer assigned to a therapy with extract of VaL or to no antineoplastic therapy (Control) and poor prognosis. Abbreviations: Cox, Cox regression; VaL, Viscum album [L.].
      Figure thumbnail gr5
      Fig. 5Forest plot (multivariate cox regression including interactions) of the treatment effect on 12-month overall survival of 220 patients with advanced or metastatic pancreatic cancer assigned to a therapy with extract of VaL or to no antineoplastic therapy (Control). Abbreviations: ECOG, Eastern Cooperative Oncology Group (performance scale); VaL, Viscum album [L.]. The squares represent the hazard ratio and their sizes are proportional to the sizes of the subgroups. The horizontal lines show the confidence intervals.

      3.4 Safety

      In the VaL group, 16 adverse events and one serious adverse event (cerebral infarction) occurred in 11 patients; in the control group, 53 adverse events occurred in 34 patients. The odds ratio of 0.25 (95% CI = 0.12–0.52) calculated by logistic regression adjusted for the prognosis group was in favour of the VaL group. The most frequent adverse event (AE) was back pain (four in the VaL group and 20 in the control group; Table 2). None of the adverse events was causally related to VaL.
      Table 2Summary of adverse event analysis: number of AEs by MedDRA preferred term and CTCAE grade with total frequency ⩾2 in patients with locally advanced or metastatic pancreatic cancer assigned to a therapy with extract of VaL or to no antineoplastic therapy (Control).
      Adverse eventGradeControl n = 53 (100%)VaL n = 17 (100%)
      Back painCTC 28 (15%)4 (24%)
      CTC 312 (23%)0
      DyspepsiaCTC 211 (21%)2 (12%)
      DehydrationCTC 26 (11%)1 (6%)
      HeadacheCTC 11 (2%)0
      CTC 31 (2%)0
      Metastases to liverCTC 12 (4%)0
      Urinary tract infectionCTC 102 (12%)
      Abdominal pain/upper abdominal painCTC 11 (2%)1 (6%)
      CTC 21 (2%)1 (6%)
      Note: None of the adverse events was related to the therapy with VaL.
      Abbreviation: VaL, Viscum album [L.].
      The Medical Dictionary for Regulatory Activities (MedDRA).
      Local side-effects of VaL injections such as erythema or swellings were reported in the diaries of 67 VaL patients but were always below the AE-defining size of 5 cm in diameter. The validity of the diary data, however, seemed questionable, since substantial number of diary entries could not undoubtedly be attributed to patients but may have been done by relatives or nurses.
      Prevalence of pre-specified post-baseline disease-related symptoms in patients was: pain (96.9%); loss of energy (70.9%); abnormal SGPT (55.4%); abnormal SGOT (50.6%); weight loss (42.5%); abnormal bilirubin (38.1%); jaundice (26.0%); nausea/emesis (18.9%); diarrhoea and anxiety (both 2.4%). No cases of vertigo were reported. In the VaL group, the frequency and severity of post-baseline disease-related symptoms was significantly lower for: pain, weight loss, loss of energy, nausea/emesis (p < 0.0001 for all parameters), diarrhoea (p = 0.0033) and anxiety (p = 0.046) (Table 3).
      Table 3Summary of maximum post-baseline CTCAE grade of disease related symptoms of patients
      Patients with symptom documentation that survived at least until visit 2 (=100%).
      with locally advanced metastatic pancreatic cancer assigned to a therapy with extract of VaL or to no antineoplastic therapy (Control).
      SymptomGradeGroup
      Control n = 51 (100%)VaL n = 76 (100%)Mantel–Haenszel
      Cochran–Mantel–Haenszel test, stratified for baseline value.
      Chi2/p (2-sided)
      Weight lossCTC 018 (35.3%)74 (97.4%)52.23/p < 0.0001
      CTC 125 (49.0%)2 (2.6%)
      CTC 28 (15.7%)0
      PainCTC 004 (5.3%)26.90/p < 0.0001
      CTC 112 (23.5%)46 (60.5%)
      CTC 238 (74.5%)26 (34.2%)
      CTC 31 (2.0%)0
      Loss of energyCTC 0037 (48.7%)40.39/p < 0.0001
      CTC 144 (86.3%)39 (51.3%)
      CTC 27 (13.7%)0
      Nausea/emesisCTC 029 (56.9%)74 (97.4%)32.06/p < 0.0001
      CTC 122 (43.1%)2 (2.6%)
      DiarrheaCTC 048 (94.1%)76 (100%)4.54/p = 0.0331
      CTC 13 (5.9%)0
      AnxietyCTC 048 (94.6%)76 (100%)4.00/p = 0.0455
      CTC 13 (5.9%)0
      VertigoCTC 051 (100%)76 (100%)–/–
      JaundiceCTC 036 (70.6%)58 (76.3%)0.34/p = 0.5578
      CTC 112 (23.5%)12 (15.8%)
      CTC 23 (5.9%)6 (7.9%)
      BilirubinCTC 043 (59.7%)61 (63.5%)1.03/p = 0.3097
      CTC 19 (12.5%)14 (14.6%)
      CTC 29 (12.5%)12 (12.5%)
      CTC 37 (9.7%)8 (8.3%)
      CTC 44 (5.6%)1 (1.0%)
      SGOTCTC 032 (44.4%)51 (53.1%)1.86/p = 0.1730
      CTC 124 (33.3%)31 (32.3%)
      CTC 212 (16.7%)11 (11.5%)
      CTC 34 (5.6%)3 (3.1%)
      SGPTCTC 031 (43.1%)44 (45.8%)0.92/p = 0.3382
      CTC 129 (40.3%)43 (44.8%)
      CTC 29 (12.5%)8 (8.3%)
      CTC 33 (4.2%)1 (1.0%)
      Abbreviations: CTCAE, common terminology for adverse events; SGOT, serum glutamic oxaloacetic transaminase; SGPT, serum glutamic pyruvic transaminase; VaL, Viscum album [L.].
      low asterisk Patients with symptom documentation that survived at least until visit 2 (=100%).
      low asterisklow asterisk Cochran–Mantel–Haenszel test, stratified for baseline value.

      4. Discussion

      In this randomised phase III study on patients with locally advanced or metastatic cancer of the pancreas, patients in the VaL group had a significant longer OS. No VaL-related side-effects were observed, and fewer disease-related symptoms were reported for patients in the VaL group.
      Based on the findings of this interim analysis, the IDMC recommended the termination of the study, and to give all study patients unrestricted access to VaL therapy. However, due to the lack of a marketing authorisation in Serbia, legal restrictions prohibit the provision of any patient with VaL outside of the clinical trial. Therefore, the local ethics committee allowed to stop the recruitment after 376 patients and to treat patients with VaL within the study.
      The non-blinding of study treatment always is a concern in confirmatory clinical trials. However, according to a FDA-guideline blinding is not essential in cancer studies with overall survival as primary end-point. And apart from that a recent Cochrane review
      • Hrobjartsson A.
      • Gotzsche P.C.
      Placebo interventions for all clinical conditions.
      on controlled trials comparing placebo groups with untreated groups found no significant effects on continuous or binary outcomes. Regarding our study, it may be of concern that different qualities of BSC may influence the patients’ OS. To prevent such bias, we centralised the medical care (BSC) during the study, guaranteeing a high and equal standard of BSC for both patient groups and prompting the patients to come to the follow-up visits at the study centre. The very low drop-out rate in both groups may be a sign of the effectiveness of this measure. Up to the point of time of this interim analysis no differences in BSC in the two groups were found.
      Previous VaL studies on OS of cancer patients had either an epidemiologic design
      • Matthes H.
      • Friedel W.E.
      • Bock P.R.
      • Zanker K.S.
      Molecular mistletoe therapy: friend or foe in established anti-tumor protocols? A multicenter, controlled, retrospective pharmaco-epidemiological study in pancreas cancer.
      • Grossarth-Maticek R.
      • Ziegler R.
      Randomised and non-randomised prospective controlled cohort studies in matched-pair design for the long-term therapy of breast cancer patients with a mistletoe preparation (Iscador): a re-analysis.
      ; had a small number of participants or were not properly randomised
      • Kienle G.S.
      • Berrino F.
      • Büssing A.
      • et al.
      Mistletoe in cancer – a systematic review on controlled clinical trials.
      • Kienle G.S.
      • Kiene H.
      Systematic reviews on mistletoe in cancer – what implications for future research can be drawn?.
      ; or, as criticised,
      • Kienle G.S.
      • Berrino F.
      • Büssing A.
      • et al.
      Mistletoe in cancer – a systematic review on controlled clinical trials.
      • Kienle G.S.
      • Kiene H.
      Systematic reviews on mistletoe in cancer – what implications for future research can be drawn?.
      may have had unbalanced baseline characteristics and a large number of dropouts and verum patients not receiving VaL,
      • Kleeberg U.R.
      • Suciu S.
      • Bröcker E.B.
      • et al.
      Final results of the EORTC 18871/DKG 80–1 randomised phase III trial: rIFN-a2b versus rIFN-g versus Iscador M versus observation after surgery in melanoma patients with either high-risk primary (thickness >3 mm) or regional lymph node metastasis.
      or too low doses.
      • Steuer-Vogt M.K.
      • Bonkowsky V.
      • Ambrosch P.
      • et al.
      The effect of an adjuvant mistletoe treatment programme in resected head and neck cancer patients: a randomised controlled clinical trial.
      Strengths of the present study are its prospective randomised study design, a sufficient number of participants, OS as primary end-point, baseline characteristics balanced between groups, a small number of dropouts, all patients in the verum group receiving VaL treatment and sufficient VaL dosage.
      The absence of a histopathological confirmation of the diagnosis for tumour identification is justified by the high risk of pancreatic fistula for the patients when direct tumour biopsy is taken and represents the institutional policy: a histopathological examination is considered unnecessary in local non-resectable stage of the disease (infiltration of both superior mesenteric artery and vein, infiltration of mesentery root and infiltration of retroperitoneal space and major blood vessels) and in patients not consenting in chemotherapy. Imaging of the tumour in the pancreatic body and/or tail, and metastasis in the liver and/or spread in the peritoneum is also considered to be a sufficient diagnosis.
      To assess the external validity, we compared the outcome of our control group with that of untreated patients as reported in the literature. The literature search outcome of a previous review
      • Fung M.C.
      • Takayama S.
      • Ishiguro H.
      • et al.
      Chemotherapy for advanced or metastatic pancreatic cancer: analysis of 43 randomized trials in 3 decades (1974–2002).
      was updated in January 2013 yielding 20 publications with OS times in a total of 754 untreated patients with advanced or metastatic pancreatic cancer.
      • Fung M.C.
      • Takayama S.
      • Ishiguro H.
      • et al.
      Chemotherapy for advanced or metastatic pancreatic cancer: analysis of 43 randomized trials in 3 decades (1974–2002).
      • Andersen J.R.
      • Friis-Moller A.
      • Hancke S.
      • et al.
      A controlled trial of combination chemotherapy with 5-FU and BCNU in pancreatic cancer.
      • Andren-Sandberg A.
      • Holmberg J.T.
      • Ihse I.
      Treatment of unresectable pancreatic carcinoma with 5-fluorouracil, vincristine, and CCNU.
      • Ciuleanu T.E.
      • Pavlovsky A.V.
      • Bodoky G.
      • et al.
      A randomised phase III trial of glufosfamide compared with best supportive care in metastatic pancreatic adenocarcinoma previously treated with gemcitabine.
      • Gilliam A.D.
      • Broome P.
      • Topuzov E.G.
      • et al.
      An international multicenter randomized controlled trial of G17DT in patients with pancreatic cancer.
      • Glimelius B.
      • Hoffman K.
      • Sjoden P.O.
      • et al.
      Chemotherapy improves survival and quality of life in advanced pancreatic and biliary cancer.
      • Huguier M.
      • Barrier A.
      • Valinas R.
      • et al.
      Randomized trial of 5-fluorouracil, leucovorin and cisplatin in advanced pancreatic cancer.
      • Koeppler H.
      • Duru M.
      • Grundheber M.
      • et al.
      Palliative treatment of advanced pancreatic carcinoma in community-based oncology group practices.
      • Mallinson C.N.
      • Rake M.O.
      • Cocking J.B.
      • et al.
      Chemotherapy in pancreatic cancer: results of a controlled, prospective, randomised, multicentre trial.
      • Matsumoto K.
      • Miyake Y.
      • Kato H.
      • et al.
      Effect of low-dose gemcitabine on unresectable pancreatic cancer in elderly patients.
      • Negi S.S.
      • Agarwal A.
      • Chaudhary A.
      Flutamide in unresectable pancreatic adenocarcinoma: a randomized, double-blind, placebo-controlled trial.
      • Palmer K.R.
      • Kerr M.
      • Knowles G.
      • et al.
      Chemotherapy prolongs survival in inoperable pancreatic carcinoma.
      • Rosenberg L.
      • Barkun A.N.
      • Denis M.H.
      • Pollak M.
      Low dose octreotide and tamoxifen in the treatment of adenocarcinoma of the pancreas.
      • Shimoda M.
      • Katoh M.
      • Kita J.
      • Sawada T.
      • Kubota K.
      The Glasgow Prognostic Score is a good predictor of treatment outcome in patients with unresectable pancreatic cancer.
      • Shinchi H.
      • Takao S.
      • Noma H.
      • et al.
      Length and quality of survival after external-beam radiotherapy with concurrent continuous 5-fluorouracil infusion for locally unresectable pancreatic cancer.
      • Takada T.
      • Nimura Y.
      • Katoh H.
      • et al.
      Prospective randomized trial of 5-fluorouracil, doxorubicin, and mitomycin C for non-resectable pancreatic and biliary carcinoma: multicenter randomized trial.
      • Taylor O.M.
      • Benson E.A.
      • McMahon M.J.
      Clinical trial of tamoxifen in patients with irresectable pancreatic adenocarcinoma. The Yorkshire Gastrointestinal Tumour Group.
      • Tsavaris N.
      • Tentas K.
      • Tzivras M.
      • et al.
      Combined epirubicin, 5-fluorouracil and folinic acid vs no treatment for patients with advanced pancreatic cancer: a prospective comparative study.
      • Wang P.
      • Meng Z.Q.
      • Chen Z.
      • et al.
      Survival rate of pancreatic cancer in elderly patients.
      • Weinerman B.H.
      • MacCormick R.E.
      A phase II survival comparison of patients with adenocarcinoma of the pancreas treated with 5-fluorouracil and calcium leucovorin versus a matched tumor registry control population.
      The range of median survival times from 2.1 to 7.0 months (median = 3.9; weighted mean = 3.7; SD = 1.5 months) reported there also encloses the median OS of 2.4 months observed in the control patients of this study.
      At present, the exact pharmacological working principle of VaL is unclear as VaL contains a wide variety of biologically active constituents (lectins, viscotoxins, other low-molecular-weight proteins, a chitin-binding agglutinin, oligo- and polysaccharides, flavonoids, vesicles and triterpene acids) exerting cytotoxic, apoptosis-inducing and immunostimulatory effects. For the subcutaneous injections used in this study, some immunosignalling can be assumed, induced by perhaps a variety of substances.
      The study findings suggest VaL may be a non-toxic and effective second-line therapy that offers a prolongation of OS as well as fewer disease-related symptoms for patients with locally advanced or metastatic pancreatic cancer. Further research on non-toxic and effective cancer therapies is warranted.

      Authors’ financial disclosure

      This work was supported by the Society for Cancer Research (Verein für Krebsforschung e.V.; VfK), Switzerland. It was the only funding source. Wilfried Tröger, Marcus Reif and Agnes Schumann are carrying out other studies for the VfK. All authors declare not to have employments, consultancies, stock ownerships, honoraria, paid expert testimonies, patent applications, travel grants or other supports.

      Independent Data Monitoring Committee (IDMC)

      Patrick J. Mansky (Chair; Belin Health, Green Bay, Wisconsin), Volker Diehl (University of Cologne), Ulrich Mansmann (University of Munich).
      The members of the IDMC confirmed in writing their independence from the sponsor with regard to any financial or commercial interest.

      Authors contributions

      Conception and design: W. Tröger, M. Reif.
      Administrative support: W. Tröger, N. Stanković.
      Provision of study materials or patients: M. Milićević, D. Galun.
      Collection and assembly of data: D. Galun, N. Stanković, M. Reif.
      Data analysis and interpretation: A. Schumann, M. Reif, W. Tröger.
      Manuscript writing: W. Tröger.
      Final correction and approval of manuscript: W. Tröger, D. Galun, M. Reif, A. Schumann, N. Stanković, M. Milićević.

      Conflict of interest statement

      None declared.

      Acknowledgements

      We thank participants in the study, Dr. D. Basarić for assistance, K. Stokuća (study nurse), the nurses in CCS, R. Beutke and S. Weippert (Data management) and the physicians, sending patients with the confirmation of the diagnosis and the report of surgery for the study: Prof. Dr. S. Knežević, Prof. Dr. S. Ostojić, Prof. Dr. M. Petrović, Doc. Dr. D. Radenković, Prof. Dr. M. Kerkez, Doc. Dr. S. Matić, Dr. P. Bulajić, Dr. Z. Đorđević, Dr. I. Pavlović, Dr. D. Knežević, Dr. N. Grubor, Dr. M. Jagodić, Dr. I. Pejović, Dr. Z. Ražnatović, Dr. M. Jovanović, Dr. N. Zarić, Dr. D. Jezdić, Dr. D. Veličković, Dr. G. Barišić, Dr. A. Antić, and Dr. V. Dugalić from different departments of the First Surgical Clinic of CCS; Prof. Dr. Ž. Laušević, Dr. M. Gvozdenović, Dr. G. Kaljević, Dr. P. Savić, and Dr. V. Resanović from the different departments of the Urgent Centre of CCS; Prof. Dr. D. Bilanović, Dr. B. Tošković, and Dr. V. Kovčin from KBC Bežanijska Kosa; Dr. A. Filipović, Dr. V. Cijan, and Dr. Z. Bokun from KBC Zvezdara, as well as Dr. R. Marković from CC Kragujevac, Dr. D. Dabić from ZC Čačak, and Dr. B. Jovanović from ZC Požarevac.

      References

        • Bayraktar S.
        • Bayraktar U.D.
        • Rocha-Lima C.M.
        Recent developments in palliative chemotherapy for locally advanced and metastatic pancreas cancer.
        World J Gastroenterol. 2010; 16: 673-682
        • Cascinu S.
        • Falconi M.
        • Valentini V.
        • Jelic S.
        Pancreatic cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up.
        Ann Oncol. 2010; 21: v55-v58
        • Conroy T.
        • Desseigne F.
        • Ychou M.
        • et al.
        FOLFIRINOX versus gemcitabine for metastatic pancreatic cancer.
        N Engl J Med. 2011; 364: 1817-1825
        • Richter J.
        • Saif M.W.
        Locally advanced pancreatic adenocarcinoma: where are we and where are we going? Highlights from the “2010 ASCO Gastrointestinal Cancers Symposium”. Orlando, FL, USA. January 22–24, 2010.
        JOP. 2010 Mar 5; 11: 139-143
        • Jacobs A.D.
        • Burris III, H.A.
        • Rivkin S.
        • et al.
        A randomized phase III study of rubitecan (ORA) vs. best choice (BC) in 409 patients with refractory pancreatic cancer report from a North-American multi-center study.
        J Clin Oncol. 2004; 22: 4013
        • Pelzer U.
        • Schwaner I.
        • Stieler J.
        • et al.
        Best supportive care (BSC) versus oxaliplatin, folinic acid and 5-fluorouracil (OFF) plus BSC in patients for second-line advanced pancreatic cancer: a phase III-study from the German CONKO-study group.
        Eur J Cancer. 2011; 47: 1676-1681
        • Boeck S.
        • Bruns C.J.
        • Sargent M.
        • et al.
        Current oncological treatment of patients with pancreatic cancer in germany: results from a national survey on behalf of the Arbeitsgemeinschaft Internistische Onkologie and the Chirurgische Arbeitsgemeinschaft Onkologie of the Germany Cancer Society.
        Oncology. 2009; 77: 40-48
        • Cragg G.M.
        • Newman D.J.
        Plants as a source of anti-cancer agents.
        J Ethnopharmacol. 2005; 100: 72-79
        • Kienle G.S.
        • Kiene H.
        Review article: influence of Viscum album L (European mistletoe) extracts on quality of life in cancer patients: a systematic review of controlled clinical studies.
        Integr Cancer Ther. 2010; 9: 142-157
        • Büssing A.
        Mistletoe. The genus Viscum.
        Hardwood Academic Publishers, Amsterdam2000 (p. 1–265)
        • Büssing A.
        • Wagner M.
        • Wagner B.
        • et al.
        Induction of mitochondrial Apo2.7 molecules and generation of reactive oxygen-intermediates in cultured lymphocytes by the toxic proteins from Viscum album L.
        Cancer Lett. 1999; 139: 79-88
        • Kienle G.S.
        • Kiene H.
        Die Mistel in der onkologie – fakten und konzeptionelle grundlagen.
        Schattauer Verlag, Stuttgart2003 (p. 1–749)
        • Thies A.
        • Dautel P.
        • Meyer A.
        • Pfuller U.
        • Schumacher U.
        Low-dose mistletoe lectin-I reduces melanoma growth and spread in a scid mouse xenograft model.
        Br J Cancer. 2008; 98: 106-112
        • Rostock M.
        • Huber R.
        • Greiner T.
        • et al.
        Anticancer activity of a lectin-rich mistletoe extract injected intratumorally into human pancreatic cancer xenografts.
        Anticancer Res. 2005; 25: 1969-1975
        • Matthes H.
        • Buchwald D.
        • Schad F.
        • Jeschke E.
        Intratumorale applikation von Viscum album L. (Mistelgesamtextrakt; Helixor M) in der therapie des inoperablen pankreaskarzinom.
        Z Gastroenterol. 2007; 45 (http://dx.doi.org/10.1055/s-2007-988162)
        • Mansky P.J.
        • Blackman M.R.
        • Grem J.
        • Swain S.M.
        • Monahan B.P.
        NCCM/NCI phase I study of mistletoe extract and gemcitabine in patients with advanced solid tumors.
        J Clin Oncol. 2010; 28: 2559
        • Kienle G.S.
        • Grugel R.
        • Kiene H.
        Safety of higher dosages of Viscum album L. in animals and humans – systematic review of immune changes and safety parameters.
        BMC Complement Altern Med. 2011; 11: 72
        • Rostock M.
        • Huber R.
        Randomized and double-blind studies – demands and reality as demonstrated by two examples of mistletoe research.
        Forsch Komplementärmed Klass Naturheilkd. 2004; 11: 18-22
      1. Guidance for Industry. Clinical Trial Endpoints for the Approval of Cancer Drugs and Biologics. http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM071590.pdf 2007 May.

        • Matthes H.
        • Friedel W.E.
        • Bock P.R.
        • Zanker K.S.
        Molecular mistletoe therapy: friend or foe in established anti-tumor protocols? A multicenter, controlled, retrospective pharmaco-epidemiological study in pancreas cancer.
        Curr Mol Med. 2010; 10: 430-439
        • Schaefermeyer G.
        • Schaefermeyer H.
        Treatment of pancreatic cancer with Viscum album (Iscador): a retrospective study of 292 patients 1986–1996.
        Complement Ther Med. 1998; 6: 172-177
        • Freedman L.S.
        Tables of the number of patients required in clinical trials using the logrank test.
        Stat Med. 1982; 1: 121-129
        • Lan K.K.
        • DeMets D.L.
        Discrete sequential boundaries for clinical trials.
        Biometrika. 1983; 70: 659-663
        • Emerson S.S.
        • Fleming T.R.
        Parameter estimation following group sequential hypothesis testing.
        Biometrika. 1990; 77: 875-892
        • Hrobjartsson A.
        • Gotzsche P.C.
        Placebo interventions for all clinical conditions.
        Cochrane Database Syst Rev. 2010; 20: CD003974
        • Grossarth-Maticek R.
        • Ziegler R.
        Randomised and non-randomised prospective controlled cohort studies in matched-pair design for the long-term therapy of breast cancer patients with a mistletoe preparation (Iscador): a re-analysis.
        Eur J Med Res. 2006; 11: 485-495
        • Kienle G.S.
        • Berrino F.
        • Büssing A.
        • et al.
        Mistletoe in cancer – a systematic review on controlled clinical trials.
        Eur J Med Res. 2003; 8: 109-119
        • Kienle G.S.
        • Kiene H.
        Systematic reviews on mistletoe in cancer – what implications for future research can be drawn?.
        Phytomedicine (Jena). 2007; 14: 11
        • Kleeberg U.R.
        • Suciu S.
        • Bröcker E.B.
        • et al.
        Final results of the EORTC 18871/DKG 80–1 randomised phase III trial: rIFN-a2b versus rIFN-g versus Iscador M versus observation after surgery in melanoma patients with either high-risk primary (thickness >3 mm) or regional lymph node metastasis.
        Eur J Cancer. 2004; 40: 390-402
        • Steuer-Vogt M.K.
        • Bonkowsky V.
        • Ambrosch P.
        • et al.
        The effect of an adjuvant mistletoe treatment programme in resected head and neck cancer patients: a randomised controlled clinical trial.
        Eur J Cancer. 2001; 37: 23-31
        • Fung M.C.
        • Takayama S.
        • Ishiguro H.
        • et al.
        Chemotherapy for advanced or metastatic pancreatic cancer: analysis of 43 randomized trials in 3 decades (1974–2002).
        Gan To Kagaku Ryoho. 2003; 30: 1101-1111
        • Andersen J.R.
        • Friis-Moller A.
        • Hancke S.
        • et al.
        A controlled trial of combination chemotherapy with 5-FU and BCNU in pancreatic cancer.
        Scand J Gastroenterol. 1981; 16: 973-975
        • Andren-Sandberg A.
        • Holmberg J.T.
        • Ihse I.
        Treatment of unresectable pancreatic carcinoma with 5-fluorouracil, vincristine, and CCNU.
        Scand J Gastroenterol. 1983; 18: 609-612
        • Ciuleanu T.E.
        • Pavlovsky A.V.
        • Bodoky G.
        • et al.
        A randomised phase III trial of glufosfamide compared with best supportive care in metastatic pancreatic adenocarcinoma previously treated with gemcitabine.
        Eur J Cancer. 2009; 45: 1589-1596
        • Gilliam A.D.
        • Broome P.
        • Topuzov E.G.
        • et al.
        An international multicenter randomized controlled trial of G17DT in patients with pancreatic cancer.
        Pancreas. 2012; 41: 374-379
        • Glimelius B.
        • Hoffman K.
        • Sjoden P.O.
        • et al.
        Chemotherapy improves survival and quality of life in advanced pancreatic and biliary cancer.
        Ann Oncol. 1996; 7: 593-600
        • Huguier M.
        • Barrier A.
        • Valinas R.
        • et al.
        Randomized trial of 5-fluorouracil, leucovorin and cisplatin in advanced pancreatic cancer.
        Hepatogastroenterology. 2001; 48: 875-878
        • Koeppler H.
        • Duru M.
        • Grundheber M.
        • et al.
        Palliative treatment of advanced pancreatic carcinoma in community-based oncology group practices.
        J Support Oncol. 2004; 2: 159-163
        • Mallinson C.N.
        • Rake M.O.
        • Cocking J.B.
        • et al.
        Chemotherapy in pancreatic cancer: results of a controlled, prospective, randomised, multicentre trial.
        Br Med J. 1980; 281: 1589-1591
        • Matsumoto K.
        • Miyake Y.
        • Kato H.
        • et al.
        Effect of low-dose gemcitabine on unresectable pancreatic cancer in elderly patients.
        Digestion. 2011; 84: 230-235
        • Negi S.S.
        • Agarwal A.
        • Chaudhary A.
        Flutamide in unresectable pancreatic adenocarcinoma: a randomized, double-blind, placebo-controlled trial.
        Invest New Drugs. 2006; 24: 189-194
        • Palmer K.R.
        • Kerr M.
        • Knowles G.
        • et al.
        Chemotherapy prolongs survival in inoperable pancreatic carcinoma.
        Br J Surg. 1994; 81: 882-885
        • Rosenberg L.
        • Barkun A.N.
        • Denis M.H.
        • Pollak M.
        Low dose octreotide and tamoxifen in the treatment of adenocarcinoma of the pancreas.
        Cancer. 1995; 75: 23-28
        • Shimoda M.
        • Katoh M.
        • Kita J.
        • Sawada T.
        • Kubota K.
        The Glasgow Prognostic Score is a good predictor of treatment outcome in patients with unresectable pancreatic cancer.
        Chemotherapy. 2010; 56: 501-506
        • Shinchi H.
        • Takao S.
        • Noma H.
        • et al.
        Length and quality of survival after external-beam radiotherapy with concurrent continuous 5-fluorouracil infusion for locally unresectable pancreatic cancer.
        Int J Radiat Oncol Biol Phys. 2002; 53: 146-150
        • Takada T.
        • Nimura Y.
        • Katoh H.
        • et al.
        Prospective randomized trial of 5-fluorouracil, doxorubicin, and mitomycin C for non-resectable pancreatic and biliary carcinoma: multicenter randomized trial.
        Hepatogastroenterology. 1998; 45: 2020-2026
        • Taylor O.M.
        • Benson E.A.
        • McMahon M.J.
        Clinical trial of tamoxifen in patients with irresectable pancreatic adenocarcinoma. The Yorkshire Gastrointestinal Tumour Group.
        Br J Surg. 1993; 80: 384-386
        • Tsavaris N.
        • Tentas K.
        • Tzivras M.
        • et al.
        Combined epirubicin, 5-fluorouracil and folinic acid vs no treatment for patients with advanced pancreatic cancer: a prospective comparative study.
        J Chemother. 1998; 10: 331-337
        • Wang P.
        • Meng Z.Q.
        • Chen Z.
        • et al.
        Survival rate of pancreatic cancer in elderly patients.
        Hepatogastroenterology. 2008; 55: 681-686
        • Weinerman B.H.
        • MacCormick R.E.
        A phase II survival comparison of patients with adenocarcinoma of the pancreas treated with 5-fluorouracil and calcium leucovorin versus a matched tumor registry control population.
        Am J Clin Oncol. 1994; 17: 467-469