Unsustainable Claims

Quality of Life of Patients With Advanced Pancreatic Cancer During Treatment With Mistletoe: A Randomized Controlled Trial by Dr. rer. nat. Wilfried Tröger, Prof. Dr. med. Danijel Galun, Dr. rer. nat. Marcus Reif, Dipl.-Math. Agnes Schumann, Dr. med. Nikola Stanković, Prof. Dr. med. Miroslav Milićević in issue 29–30/2014

Tröger and co-authors assume to have presented evidence proving that mistletoe treatment in patients with locally advanced or metastatic pancreatic carcinoma significantly improves quality of life compared with best supportive care (BSC). In the original publication (1) the authors claim that survival was significantly extended by this therapy. To publish the primary endpoint, survival, and the secondary endpoint, quality of life, separately (2), follows in the tradition of unnecessary multiple publications. Both statements are unsustainable because of the study’s serious methodological shortcomings.

Without blinding, it is not possible to make a valid statement with regard to quality of life and the chosen method of randomization using sealed envelopes does not meet the requirements of good study practice.

The study was terminated early after enrolment of approximately half of the intended number of patients. The authors do not mention that early termination may lead to significant overestimation of treatment effects, especially in small studies (3). The therapy standard at the time of the study was not adequately reported. Best supportive care is here a commonly used “euphemism” for doing without sensible disease-modifying therapies.

The authors declare financial support from the Swiss Cancer Research Association (Verein für Krebsforschung e. V. (VfK), Schweiz) which generates revenues from license fees received from Weleda AG for the preparation of the active substance and, at the same time, state that no conflict of interest exists.

DOI: 10.3238/arztebl.2015.0010b

Dr. med. Monika Lelgemann MSc
Medizinischer Dienst des Spitzenverbandes Bund
der Krankenkassen e.V. (MDS)
Essen

Priv.-Doz. Dr. phil. Claudia Wild
Ludwig Boltzmann Institut für Health Technology Assessment
Wien/Österreich

Prof. Dr. rer. nat. Gerd Antes
Deutsches Cochrane Zentrum
Universitätsklinikum Freiburg 

Dr. rer. nat. Lutz Edler
Deutsches Krebsforschungszentrum
Heidelberg

Prof. Edzard Ernst, MD, PhD, Emeritus Professor
University of Exeter
Exeter, Devon UK

Priv. Doz. Dr. med. Jan Gärtner
Klinik für Palliativmedizin
Universitätsklinikum Freiburg

Prof. Dr. med Norbert Schmacke
Institut für Public Health und Pflegeforschung
Universität Bremen

Conflict of interest statement

The authors declare that no conflict of interest exists.

References

1. Tröger W, Galun D, Reif M, Schumann A, Stankovic N, Milicevic M. Viscum Album extract therapy in patients with locally advanced or metastatic pancreatic cancer: A randomised clinical trial on overall survival. Eur J Cancer 2013; 49; 3788–97.

2. Tröger W, Galun D, Reif M, Schumann A, Stankovic´ N, Milic´ evic´ : M: Quality of life of patients with advanced pancreatic cancer during treatment with mistletoe—a randomized controlled trial. Dtsch Arztebl Int 2014; 111: 493–502.

3. Bassler D, Briel M, Montori VM, Lane M, Glasziou P, Zhou Q et al. Stopping randomized trials early for benefit and estimation of treatment effects: systematic review and meta-regression analysis. JAMA 2010; 303: 1180–7.