RT Journal Article
SR Electronic
T1 Cancer Incidence and Mortality Rates in Multiple Sclerosis
JF Neurology
JO Neurology
FD Lippincott Williams & Wilkins
SP e501
OP e512
DO 10.1212/WNL.0000000000011219
VO 96
IS 4
A1 Ruth Ann Marrie
A1 Colleen Maxwell
A1 Alyson Mahar
A1 Okechukwu Ekuma
A1 Chad McClintock
A1 Dallas Seitz
A1 Colleen Webber
A1 Patti A. Groome
YR 2021
UL http://n.neurology.org/content/96/4/e501.abstract
AB Objective To determine whether cancer risk differs in people with and without multiple sclerosis (MS), we compared incidence rates and cancer-specific mortality rates in MS and matched cohorts using population-based data sources.Methods We conducted a retrospective matched cohort study using population-based administrative data from Manitoba and Ontario, Canada. We applied a validated case definition to identify MS cases, then selected 5 controls without MS matched on birth year, sex, and region. We linked these cohorts to cancer registries, and estimated incidence of breast, colorectal, and 13 other cancers. For breast and colorectal cancers, we constructed Cox models adjusting for age at the index date, area-level socioeconomic status, region, birth cohort year, and comorbidity. We pooled findings across provinces using meta-analysis.Results We included 53,983 MS cases and 269,915 controls. Multivariable analyses showed no difference in breast cancer risk (pooled hazard ratio [HR] 0.92 [95% confidence interval (CI) 0.78–1.09]) or colorectal cancer risk (pooled HR 0.83 [95% CI 0.64–1.07]) between the cohorts. Mortality rates for breast and colorectal did not differ between cohorts. Bladder cancer incidence and mortality rates were higher among the MS cohort. Although the incidence of prostate, uterine, and CNS cancers differed between the MS and matched cohorts, mortality rates did not.Conclusion The incidence of breast and colorectal cancers does not differ between persons with and without MS; however, the incidence of bladder cancer is increased. Reported differences in the incidence of some cancers in the MS population may reflect ascertainment differences rather than true differences.CI=confidence interval; DMT=disease-modifying therapy; HR=hazard ratio; ICD-9=International Classification of Diseases–9; ICD-10=International Classification of Diseases–10; ICD-10-CA=International Classification of Diseases–10–Canada; ICD-O-3=International Classification of Diseases for Oncology; IRR=incidence rate ratio; MCHP=Manitoba Centre for Health Policy; MS=multiple sclerosis; SES=socioeconomic status; SIR=standardized incidence ratio