Cancer Risk Among Patients With Multiple Sclerosis: A 10-Year Nationwide Retrospective Cohort Study

Area of Science:

• Epidemiology
• Oncology
• Neurology

Background:

• Divergent literature exists on cancer risk in people with multiple sclerosis (PwMS).
• This study addresses the need for a clear comparison of cancer risk between PwMS and the general population.

Purpose of the Study:

• To compare the incidence of cancer in PwMS versus a matched general population sample in France.
• To investigate cancer risk variations by cancer type, age, and sex in PwMS.

Main Methods:

• A 10-year nationwide retrospective matched cohort study (2012-2021) using French administrative health care data.
• PwMS identified via long-term disease status, hospitalizations, and MS-specific drug reimbursements; controls matched 4:1.
• Cancer incidence and hazard ratios (HRs) analyzed using Fine and Gray models; cancer screening participation compared.

Main Results:

• Overall cancer incidence was slightly higher in PwMS (799/100,000 PYs) compared to controls (736/100,000 PYs), with an HR of 1.06.
• Increased risk observed for bladder, brain, and cervical cancers; decreased risk for prostate, breast, and colorectal cancers.
• Risk was higher in younger PwMS (<55 years) and lower in older PwMS (≥65 years); lower screening participation noted in PwMS.

Conclusions:

• Cancer risk is slightly elevated in PwMS, particularly for certain cancer types, potentially influenced by surveillance bias.
• Age-related fluctuations in risk suggest interplay between generational screening practices and risk factors.
• Further research into surveillance bias and age-specific risk factors is warranted.