Are Individuals With Multiple Sclerosis at Higher Risk of Developing Breast Cancer?
Posted: Wednesday, January 20, 2021
Patients with multiple sclerosis may not be at higher risk of developing breast or colorectal cancer compared with patients who do not have multiple sclerosis, according to research published in the journal Neurology. However, the retrospective study did find that patients with multiple sclerosis may be at higher risk of developing bladder cancer.
“This is good news for people with [multiple sclerosis], because earlier studies have shown a link between [multiple sclerosis] and breast and colorectal cancers,” noted Ruth Ann Marrie, MD, PhD, of the University of Manitoba, in a press release from the American Academy of Neurology.
The study collected and analyzed health records of 53,984 patients with multiple sclerosis and 266,920 people without multiple sclerosis. For each identified patient with multiple sclerosis, five people of comparable age, sex, and region who did not have multiple sclerosis were included. Enrolled participants were linked to cancer registries to determine the incidence and mortality rates of 13 cancers, including breast, bladder, and colorectal.
Differences between the multiple sclerosis and control cohorts in breast cancer risk and colorectal risk were not significant (pooled hazard ratio [HR] = 0.92, 95% confidence interval [CI] = 0.78–1.09, and 0.83, 95% CI = 0.64–1.07, respectively). Bladder cancer was more commonly occurring and more commonly fatal among patients with multiple sclerosis. Though differences in the incidence rates of prostate, uterine, and central nervous system cancers were observed between the two cohorts, mortality rates for those cancers remained similar.
Of note, study limitations included the fact that the investigators could not account for differences in health behaviors such as smoking, diet, and physical activity. In addition, the study did not account for the possibility that specific multiple sclerosis–modifying therapies might have contributed to the cancer risk.
Disclosure: The study authors reported no conflicts of interest.