Breast Cancer Survival in Canadians with Multiple Sclerosis

According to a recent study by Dr. Ruth Ann Marrie (University of Manitoba) and colleagues, multiple sclerosis (MS) does not affect cancer-specific survival of women with breast cancer for up to 10 years following diagnosis. However, the researchers also found that having MS was associated with a higher risk (28%) of death from other causes not related to cancer.

Breast cancer is one of the most common cancer types among people with MS, therefore it is important to understand how survival after cancer diagnosis differs between MS and non-MS populations. When looking at the number of people who died specifically of cancer, the survival rates of breast cancer patients did not differ between those with and without MS. However, the fatality rates related to factors other than cancer was 28% higher in people with MS compared to those without the disease. Researchers speculate that this difference may be due to complications associated with MS, including greater disability at the time of breast cancer diagnosis which may lead to less aggressive cancer treatment or greater susceptibility to treatment complications and other factors.

This study used population-based health records of 779 people with MS and 3116 people without MS (matched controls) from Manitoba and Ontario, Canada, of which both patient populations had a confirmed diagnosis of breast cancer. The researchers adjusted for factors such as age at cancer diagnosis, period of cancer diagnosis, and socioeconomic status. Note that the study did not account for race or ethnicity, differences in cancer care and treatment, and health behaviours that may influence cancer survival.


The scientific article was published in Neurology – link.

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