An epidemiological retrospective cohort study  on the use of mistletoe in this type of cancer was published in 2005. It investigated the therapeutic efficacy and harmlessness of long-term mistletoe therapy with Iscador P in 686 patients with malignant melanoma at medium to high risk during aftercare compared to a control group that was only observed ("watchful waiting").
The study showed mistletoe therapy can significantly prolong survival time during treatment and follow-up time. The main reason seems to be that mistletoe therapy lasts long enough (over one year. Furthermore, pine mistletoe extract (Iscador P) seems to work even better than Iscador M (extract from apple tree mistletoe), which is also frequently used. You can read more about this study here.
Last update: July 15th, 2020/AT