MS was associated with a 28% increased hazard for all-cause mortality (HR 1.28, 95% CI 1.08-1.53), but not with cancer-specific survival (HR 0.98, 95% CI 0.65-1.46), reported Ruth Ann Marrie, MD, PhD, of the University of Manitoba in Winnipeg, and colleagues in Neurology.
“Although multiple sclerosis and its complications remain the most common cause of death in people with MS, cancer is the second or third most common cause of death,” Marrie said in a statement. “Our study looked at whether survival rates for women after a breast cancer diagnosis were different for those with MS and those without it.”
Earlier Canadian research showed the incidence of breast and colorectal cancers was similar between people with and without MS. Breast cancer incidence is of particular interest since several cases of breast cancer had been reported in ocrelizumab (Ocrevus) phase III clinical trials. The drug, which was approved for MS in 2017 in the U.S., carries a breast cancer warning.
In their study, Marrie and colleagues identified female MS patients in population-based administrative data in Manitoba and Ontario from 1994 through 2016, linking the MS cohorts to cancer registries. For each woman with MS and breast cancer, the researchers selected four breast cancer controls without MS, matched on birth year, cancer diagnosis year, and region.
The analysis included 779 MS cases (691 from Ontario and 88 from Manitoba) and 3,116 controls with a mean age of 58 at diagnosis. Most women were diagnosed with stage I or II breast cancer. About half of the study group was diagnosed in 2010 or later, and most lived in urban areas. To read this aerticle in its entireity click here: Breast Cancer and MS