February 16, 2021

Cancer Risk in Canadians Living with Multiple Sclerosis

A study by Dr. Ruth Ann Marrie (University of Manitoba) and colleagues found no difference in the incidence and mortality rates of breast and colorectal cancers between people with and without multiple sclerosis (MS) in Canada. These findings suggest that people with MS may not be at higher risk of developing breast or colorectal cancer, which are two of the most common cancer types among MS patients.

The group also reported increased incidence and mortality rates of bladder cancer among people with MS. This increased risk could be attributed to more frequent presence of bladder cancer risk factors among MS patients, including urinary tract infections or use of chronic indwelling catheters.

Since cancer is a common co-existing health condition in MS, it is important to understand how often people with MS develop certain types of cancer and whether they are at higher risk compared to the general population. This study highlights the need for establishing guidelines for how often healthcare providers should monitor or screen for cancer-related indications among the MS population, particularly urinary symptoms.

This study looked at population-based health records of over 53,000 people with MS and over 269,000 people without MS (matched controls) from Manitoba and Ontario, Canada. The researchers used cancer registries to estimate the incidence of a total of 15 cancers and adjusted for factors such as age, sex, socioeconomic status, and comorbidity. Note that the study did not account for differences in health behaviours, such as smoking, diet, and physical activity. The effect of disease-modifying therapies (DMT) on cancer incidence also warrants further investigation.


The scientific article was published in Neurology – link.

For more information on Dr. Marrie’s MS Society funded research, please click here.