Mult Scler. 2018 May 1:1352458518774444. doi: 10.1177/1352458518774444. [Epub ahead of print]
Spontaneous regression of tumor-stage cutaneous T-cell lymphoma in a multiple sclerosis patient after discontinuing fingolimod.
Despite the side effects of MS treatments, I still believe that without them we’d be a lot worse off. The damage done by MS, the visible and not so visible, are such that the risks in a majority are justified. But, I am no stranger to doubt; it comes and goes. A fleeting shadow that slips from the mind, only to resurface with the publication of another adverse event.
Fingolimod, is a relatively safe drug as far as highly active MS drugs go. Around two years ago, a signal with skin cancers (basal cell carcinomas) became apparent. Now Froehlich et al. in a letter to the editor report a second case of cutaneous CD30+ anaplastic large-cell T-cell lymphoma. A case similar to this one was reported back in 2016 by Papathemeli et al. (Development of a primary cutaneous CD30(+) anaplastic large-cell T-cell lymphoma during treatment of multiple sclerosis with fingolimod). In both instances, they have followed initiation of fingolimod and resolved after its discontinuation. I have also blogged on cutaneous lymphomas on fingolimod before: http://multiple-sclerosis-research.blogspot.com/2017/12/blood-cancers-after-fingolimod-treatment.html
The authors point out that such skin cancers are not unusual and seen in organ transplant recipients under long-term immunosuppression. Unlike other MS disease modifying-drugs fingolimod keeps the lymphocytes in the lymph nodes, it is therefore possible that this mode of action prevents tumour controlling T-lymphocytes from reaching the skin where tumor cells are proliferating. The reduction in immune surveillance with fingolimod is likely to throw up other cases in the future, over and above those that simply escape immune surveillance (i.e. in the presence of an apparent normal immune system). On a separate note, the occurrence of secondary malignancies with chronic immunosupression needs to be investigated in greater detail, together with workable strategies on how to overcome them in the near future.