Many Questions Left Open
In a single-center study conducted in Serbia, 220 patients with advanced pancreatic cancer were randomized into two arms: best supportive care (BSC) and mistletoe treatment. A significant survival improvement from 2.7 months to 4.8 months was found and published elsewhere. Now quality-of-life data are presented (1). Here again, mistletoe appears to be superior to BSC. The following questions arise:
- Why was no placebo-control performed? Other mistletoe studies show that even a double-blind design with placebo control is possible (2).
- The method of randomization raises the question whether a violation of allocation concealment may have occurred.
- Is an intent-to-treat analysis available?
- Only in 43 of the 220 patients, histological confirmation was performed. What steps were taken to ensure that no patients with benign or other histologies were included?
- Prior treatments and aftercare were not reported separately.
- Table 4 shows that patients treated with mistletoe had more frequent physician contacts. Thus these patients may have received better palliative care which can extend the lives of patients (3).
- What was the composition of the tumor board?
- Which imaging data are available for each of the two cohorts?
- How was determined that palliative chemotherapy, which can extend survival and quality of life of patients, could not be given?
- The QoL analysis is based on the so-called missing-at-random assumption. Whether patients attend physician appointments is likely to depend on their symptoms (quality of life) at those times. This cast fundamental doubt on the reliability of the QoL analysis.
- Of concern: “The decision of the CCS consultation service was considered final“.
Various studies found quality of life improvements along with mistletoe treatment, for example (2). The molecular causes are manifold and include increased endorphin levels which perhaps could also be achieved with other treatments (4).
Prof. Dr. med. Andreas Neubauer
Klinik für Hämatologie, Onkologie und Immunologie
Universitätsklinikum Gießen und Marburg
Conflict of interest statement
Prof. Neubauer is Head of the Committee on Cancer Therapy of the German Cancer Aid.
|1.||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. VOLLTEXT|
|2.||Semiglazov VF, Stepula VV, Dudov A, Schnitker J, Mengs U. Quality of life is improved in breast cancer patients by Standardised Mistletoe Extract PS76A2 during chemotherapy and follow-up: a randomised, placebo-controlled, double-blind, multicentre clinical trial. Anticancer Res 2006; 26: 1519–29. MEDLINE|
|3.||Temel JS, Greer JA, Muzikansky A, Gallagher ER, Admane S, Jackson VA, et al. Early palliative care for patients with metastatic non-small-cell lung cancer. N Engl J Med 2010; 363: 733–42. CrossRef MEDLINE|
|4.||Melchior JC, Rigaud D, Colas-Linhart N, Petiet A, Girard A, Apfelbaum M. Immunoreactive beta-endorphin increases after an aspartame chocolate drink in healthy human subjects. Physiology & behavior 1991; 50: 941–4. CrossRef|