• A new study found that people with colorectal cancer and multiple sclerosis (MS) had a higher death rate in the year following their cancer diagnosis than those without MS.
• After a year passed, people with colorectal cancer and MS had similar mortality rates as those who didn’t have MS.
• The findings could lead to further research into how cancer treatments can affect people living with MS.

A new research study on people living with colorectal cancer — also known as colon or rectal cancer — found that those who also had MS had a 45 percent higher chance of dying from any cause within six months of their cancer diagnosis.

The study, conducted in Canada, also discovered that at one year after a colorectal cancer diagnosis, the risk of death was 34 percent higher in those with MS than those without it. After a year, the mortality risk was approximately the same in both groups, the study authors noted.

Overall death rates as well as cancer-related death rates were higher in people living with MS at six months and one year following their cancer diagnosis. However, the researchers were unable to pinpoint what put individuals with MS at a higher risk of mortality at those timepoints.

“Are people with MS less likely to receive cancer treatment? Or are they less able to tolerate the effects of chemotherapy? Are factors specific to MS involved? How accommodating is the cancer care system for people with disabilities?” asked study author Dr. Ruth Ann Marrie of Canada’s University of Manitoba in a news release about the study results.

Marrie said researchers will need to further investigate these areas to find out more information about what could be driving the higher death rates among those with MS and colorectal cancer.

“Understanding more about the factors involved in treating cancer in people with MS and their outcomes will be helpful for people with MS and their doctors as they balance the benefits of cancer treatment with the potential adverse effects and consider life expectancy and quality of life,” Marrie said.

The study results, published on Sept. 15 in Neurology, were based on data from 1,690 people (338 with MS and 1,352 without) who had colorectal cancer. The average age at cancer diagnosis among study participants was 65.