Cancer Risk with Mitoxantrone

Buttmann M, Seuffert L, Mäder U, Toyka KV. Malignancies after mitoxantrone for multiple sclerosis: A retrospective cohort study. Neurology. 2016 Jun 7;86(23):2203-7.

OBJECTIVE:To assess the therapy-related risk of malignancies in mitoxantrone-treated patients with multiple sclerosis.
METHODS:This retrospective observational cohort study included all mitoxantrone-treated patients with multiple sclerosis seen at our department between 1994 and 2007. We collected follow-up information on medically confirmed malignancies, life status, and cause of death, as of 2010. Malignancy rates were compared to the German national cancer registry matched for sex, age, and year of occurrence.
RESULTS: Follow-up was completed in 676 of 677 identified patients. Median follow-up time was 8.7 years (interquartile range 6.8-11.2), corresponding to 6,220 person-years. Median cumulative mitoxantrone dose was 79.0 mg/m(2) (interquartile range 50.8-102.4). Thirty-seven patients (5.5%) were diagnosed with a malignancy after mitoxantrone initiation, revealing a standardized incidence ratio of 1.50 (95% confidence interval [CI] 1.05-2.08). Entities included breast cancer (n = 9), colorectal cancer (n = 7), acute myeloid leukemia (n = 4, 0.6%), and others (each entity n = 1 or 2). The standardized incidence ratio of colorectal cancer was 2.98 (95% CI 1.20-6.14) and of acute myeloid leukemia 10.44 (95% CI 3.39-24.36). It was not increased for other entities including breast cancer. Multivariate Cox regression identified higher age at treatment initiation but neither cumulative mitoxantrone dose (>75 vs ≤75 mg/m(2)) nor treatment with other immunosuppressive drugs or sex as a risk factor. Fifty-five patients had died, among them 12 of a malignancy and 43 reportedly of other causes.
CONCLUSIONS: While the overall incidence of malignancies was only mildly increased, the risk of leukemia and colorectal cancer was heightened. If confirmed, posttherapy colonoscopy could become advisable.


Mitoxantrone is an anti-cancer drug that is not licenced in the UK ut is sometimes used to treat MS. Its use is limited because it can cause damage to the heart muscles meaning that you can only take a limited number of doses. It is already known that there is a increased risk of cancer. In this German cohort followed for up to a number of years, they report that 5% of people got cancer so that is 1 in 20 people. Whilst life is assocaited with a cancer risk, this appears high and is one of the reasons that our use of ths agent has dwindled. It is strange that there is a resistance against cladribine and I wonder if such people will supply mitoxantrone when the risk of cancer is probably higher.

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