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New Study Looks at Lifespan After Women with MS are Diagnosed with Breast Cancer

May 21, 2021

A study funded in part by the MS Society of Canada shows that women with MS who were diagnosed with breast cancer had similar cancer survival rates compared to women who did not have MS. However, ten years after their breast cancer diagnosis, women with MS had slightly increased chances of mortality from any cause. These findings need further research to be confirmed, and explored for possible mechanisms underlying this difference.
  • Background: Multiple sclerosis involves an abnormal immune response that damages the brain, spinal cord, and optic nerve. Since some emerging cancers can be eliminated by the immune system, there is a chance that people with MS could have an increased risk for cancer. Over the years, studies have examined the risk for cancer in people with MS. Recent results from this team showed that the rates of most cancers were not increased compared with people without MS.
  • This study: The researchers examined healthcare databases in Manitoba and Ontario, and identified 779 people with MS who had experienced breast cancer, and 3,116 controls without MS, but who had experienced breast cancer.
  • Cancer survival rates were similar between people with MS and people without MS. However, for unexplained reasons, they found that about ten years later, the rates of death from any cause among women with MS and breast cancer were slightly higher (28%) than those who did not have MS.
  • This study did not look at race or ethnicity, which are factors that can affect breast cancer survival. Findings in the Ontario province indicate that the increase in mortality in people with MS might be related to increased physical disability. Further research is necessary to understand and confirm these findings. 
“Breast Cancer Survival in Multiple Sclerosis: A Matched Cohort Study” by Ruth Ann Marrie, MD, PhD (University of Manitoba, Winnipeg, Canada), Patti Groome, PhD (University, Kingston, Ontario, Canada) and colleagues is published in Neurology (May 19, 2021).
Read the press release from the American Academy of Neurology

About Multiple Sclerosis

Multiple sclerosis is an unpredictable disease of the central nervous system. Currently there is no cure. Symptoms vary from person to person and may include disabling fatigue, mobility challenges, cognitive changes, and vision issues. An estimated 1 million people live with MS in the United States. Early diagnosis and treatment are critical to minimize disability. Significant progress is being made to achieve a world free of MS.


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