Summary
Supported by the MS Society of Canada, the Canadian Institutes of Health Research and the Michael Smith Foundation for Health Research, a research team from UBC conducted a large Canadian retrospective cohort study to compare the incidence of all cancers and specific types of cancers following onset of MS. Findings from this study suggest that the overall cancer incidence, especially colorectal cancer, in people with MS was lower in both males and females and in both relapsing-remitting and primary progressive MS as compared with the general population. [Elaine Kingwell, Chris Bajdik, Norm Phillips, Feng Zhu, Joel Oger, Stanley Hashimoto and Helen Tremlett. Brain (2012) doi: 10.1093/brain/aws148. First published online: June 21, 2012]
Details
UBC researchers conducted a large retrospective cohort study using linkage of prospectively collected data from population-based clinical and administrative databases in British Columbia from the province’s MS clinics, Cancer Registry, Ministry of Health’s Registration and Premium Billing Files and the British Columbia Vital Statistics death database to compare the incidence of all cancers and specific types of cancers following onset of MS. A total of 6917 eligible cases were identified from the British Columbia multiple sclerosis cohort and followed for an average of 16 years. Of these, seventy two per cent were female and twenty eight per cent were male. Eighty nine per cent had a relapsing course at onset, while ten per cent had primary progressive MS. One per cent had an unknown clinical course.
The researchers reported that the overall cancer incidence, especially for colorectal cancer, for persons with MS was lower than expected as compared with the general population. This reduced risk was consistent in females and males and in both relapsing-onset and primary progressive MS. Only non-melanoma skin cancer risk was increased and this was observed only in people with relapsing-onset MS.
The researchers found evidence to suggest that diagnostic neglect might contribute to the apparent reduction in cancer risk in multiple sclerosis. Their findings indicate that the potential for diagnostic neglect of cancer requires further attention by patients, physicians and researchers.