Background: Mistletoe extracts such as Iscador are commonly used as complementary/anthroposophic medications for many cancer indications, particularly for solid cancers. The efficacy of this complementary therapy is still controversial.
Objective: Does long-term therapy with mistletoe extracts Iscador show any effect on survival and psychosomatic self-regulation of patients with ovarian cancer?
Patients and methods: Prospective recruitment and long-term follow-up in controlled cohort studies. (1) Two randomized matched-pair studies: OvarRand (ovarian cancer patients without distant metastases; 21 pairs) and OvarMetRand (ovarian cancer patients with distant metastases; 20 pairs); patients having no mistletoe therapy were matched for prognostic factors. By paired random allocation, one of the patients of each pair was suggested therapy with mistletoe extracts Iscador to be applied by her attending physician. (2) Two non-randomized matched-pair studies: Ovar (ovarian cancer patients without distant metastases; 75 pairs) and OvarRand (ovarian cancer patients with distant metastases; 62 pairs); patients that already received therapy with mistletoe extracts Iscador were matched by the same criteria to control patients without therapy with mistletoe extracts Iscador.
Results: For overall survival in the randomized studies, the effect in favor of therapy with mistletoe extracts Iscador was significant in OvarMetRand but not in OvarRand; hazard ratio estimate and 95% confidence interval: 0.40 (0.15, 1.03) and 0.33 (0.12, 0.92), respectively. In the non-randomized studies Ovar and OvarMet, the results adjusted for relevant prognostic variables were 0.47 (0.31, 0.69) and 0.62 (0.37, 1.05). Psychosomatic self-regulation in the Iscador group increases significantly within 12 months on a scale from 1 to 6 compared with the control group in the randomized study OvarRand as well as in the non-randomized study Ovar on patients with ovarian cancer without distant metastases; estimate of the median difference and 95% confidence interval: 0.58 (0.30, 0.90) and 0.30 (0.05, 0.65), respectively.
Conclusion: Mistletoe extracts Iscador might have the effect of prolonging overall survival of ovarian cancer patients. In the short term, psychosomatic self-regulation increases more markedly under Iscador therapy than under conventional therapy alone.