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

Abstract

Objective: Expanded presentation and re-analysis of previously published data of randomized and non-randomized studies on mistletoe therapy with breast cancer patients [3, 4]. The main question is: Does a re-analysis confirm the previously reported effects of prolonging the survival of patients with breast cancer under long-term application of a complementary/anthroposophic therapy with the European mistletoe preparation Iscador?

Data sources: (1) Randomised matched-pairs study: Breast cancer patients with only lymphatic metastases (17 pairs) that had never used mistletoe therapy were matched for several prognostic factors. By paired random allocation, one patient of a pair received a suggestion of mistletoe therapy to be applied by the attending physician. (2) Non-randomised matched-pairs studies: Patients that had already received mistletoe (Iscador) therapy were matched to control patients from the same pool using the same prognostic criteria. Three groups were recruited by this procedure: breast cancer with local recurrences and no metastases (42 pairs), breast cancer with only lymphatic metastases (55 pairs), and breast cancer with distant metastases (83 pairs).

Analysis: Cox proportional hazard models and sensitivity analyses based on subsets of the original data sets according to strict or lose application of the matching criteria.

Results: The results of this re-analysis are consistent with the earlier results, even when comparing different methods and subsets. In the randomised study, the effect of long-term Iscador therapy on overall survival is significantly in favour of the Iscador therapy: Estimate of the median difference and 95 % confidence interval in years 2.5 (0.83, 4.50). The results for the non-randomised studies were also in favour of the Iscador therapy: Breast cancer with local recurrences and no metastases: estimate of hazard ratio and 95 % confidence interval 0.52 (0.23, 1.17); breast cancer with lymphatic metastases: 0.27 (0.15, 0.50); breast cancer with distant metastases: 0.53 (0.32, 0.88). As a short-term effect of this therapy, psychosomatic self-regulation noticeably increases within 3 months in the Iscador group in comparison to the control group in the randomised study: estimate of the median difference 0.90 (0, 1.75).

Conclusion: The re-analysis demonstrates that the effects shown in the previously published data are consistent despite using different analytic methods and different subsets. Overall, the survival of patients receiving mistletoe treatment with Iscador is longer in these studies. In the short term, psychosomatic self-regulation, as a measure of autonomous coping with the disease, rises more under Iscador therapy than under conventional therapy alone.