Multiple sclerosis may increase bladder cancer incidence

The incidence of bladder cancer is increased amongst patients with multiple sclerosis (MS), according to a study conducted to determine if the risk of cancer differs in people with and without MS.

In this retrospective matched cohort study, there was no difference in breast cancer risk (pooled hazard ratio [HR] 0.92 [95% confidence interval (CI) 0.78–1.09]) or colorectal cancer risk (pooled HR 0.83 [95% CI 0.64–1.07]) between the cohorts of 53,983 patients with MS and 269,915 controls. There was no difference between cohorts for breast and colorectal cancer mortality rates.

Among patients with MS, bladder cancer incidence and mortality rates were higher.

Differences in the incidence of prostate, uterine, and CNS cancers were found between the cohorts, mortality rates were the same.

“Reported differences in the incidence of some cancers in the MS population may reflect ascertainment differences rather than true differences,” the authors concluded.

Reference
Marrie RA, Maxwell C, Mahar A, et al. Cancer incidence and mortality rates in multiple sclerosis: A matched cohort study. Neurol. 2021; 96 (4) e501-e512; DOI: 10.1212/WNL.0000000000011219.