to arrive at their findings, researchers analyzed the health records of 338 people with ms and colorectal cancer residing in manitoba and ontario. participants were matched with four people of the same age, sex and year of cancer diagnosis but not ms — a total of 1,352 subjects. study participants had an average age of 65 at the time of diagnosis.
after passing the one-year mark, researchers found the risk of all-cause death for ms patients with cancer became the same for cancer patients without ms. the team adjusted for other factors that can increase the risk of all-cause death, including age, socioeconomic status and comorbidities. with regards to death from cancer specifically, ms patients were only more likely to die at the six-month mark, at which point they faced 29 per cent greater risk.
over a five-year period, the all-cause rate of death for ms patients in ontario was 16.4 per 100 person-years — a metric that takes into account the number of people in a study as well as time spent in the study. this number was 11.5 per 100 person-years for those without ms. in manitoba, these numbers were 19.8 and 15.4, respectively.
when it comes to deaths caused by cancer, the fatality rate in ontario was 12.7 per 100 person-years for those with ms compared to 9.9 for those without ms. in manitoba, it was 13.6 for those with ms and 13.0 for those without.
the study, which researchers said may not have accounted for all other conditions participants may have had in addition to ms or cancer, sheds light on the unique challenges faced by people fighting life-threatening battles on multiple fronts.
“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.