For women with breast cancer, those with multiple sclerosis (MS) have an increased risk for allcause mortality compared with those without MS, according to a study published in Neurology. Researchers identified female MS cases and linked MS cohorts to cancer registries to identify women with breast cancer. Four matched breast cancer controls without MS were selected; data were included for 779 MS cases and 3,116 controls with breast cancer. All-cause survival and cancerspecific survival were compared between cohorts. Most patients with stage data were diagnosed with stage I or II breast cancer, with a mean age at diagnosis of 57.8. MS was associated with an increased risk for all-cause mortality (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.08- 1.53) but was not associated with any difference in cancer-specific survival (HR, 0.98; 95% CI, 0.65-1.46). “Women with MS have lower survival after breast cancer than women without MS. A clear understanding of prognosis is important for clinical decision-making, thus our findings provide information that may inform women with MS and their health care providers,” the authors write. “Future studies should identify MS-specific factors associated with worse prognosis.”