Use of Iscador, an extract of European mistletoe (Viscum album), in cancer treatment: prospective nonrandomized and randomized matched-pair studies nested within a cohort study.

CONTEXT In anthroposophical medicine, total extracts of Viscum album (mistletoe) have been developed to treat cancer patients. The oldest such product is Iscador. Although Iscador is regarded as a complementary cancer therapy, it is the most commonly used oncological drug in Germany. OBJECTIVE To determine whether Iscador treatment prolongs survival time of patients with carcinoma of the colon, rectum, or stomach; breast carcinoma with or without axillary or remote metastases; or small cell or non-small-cell bronchogenic carcinoma; and to explore synergies between Iscador treatment and psychosomatic self-regulation. DESIGN Prospective nonrandomized and randomized matched-pair studies nested within a cohort study. SETTING General community in Germany. PARTICIPANTS 10,226 cancer patients involved in a prospective long-term epidemiological cohort study, including 1668 patients treated with Iscador and 8475 who had taken neither Iscador nor any other mistletoe product (control patients). INTERVENTION Iscador. MAIN OUTCOME MEASURE Survival time. RESULTS In the nonrandomized matched-pair study, survival time of patients treated with Iscador was longer for all types of cancer studied. In the pool of 396 matched pairs, mean survival time in the Iscador groups (4.23 years) was roughly 40% longer than in the control groups (3.05 years; P < .001). Synergies between Iscador treatment and self-regulation manifested in a longer survival advantage for Iscador patients with good self-regulation (56% relative to control group; P = .03) than for patients with poor self-regulation. Results of the 2 randomized matched-pair studies largely confirmed the results of the non-randomized studies. CONCLUSION Iscador treatment can achieve a clinically relevant prolongation of survival time of cancer patients and appears to stimulate self-regulation.