Incidence and risk of cancer among multiple sclerosis patients: A matched population-based cohort study
Funding information
This study received funding from Merck Healthcare (CrossRef funder ID: 10.13039/100009945)
Abstract
Background and purpose
Studies have not yet found conclusive results on the risk of cancer in patients with multiple sclerosis (MS). This study aimed to compare the incidence of all cancers and of specific types of cancer between MS patients and the general population by age and by sex.
Methods
All prevalent MS patients identified between 2008 and 2014 in the nationwide French health care database (Système National des Données de Santé) and without history of malignancy were included in a cohort study and followed up until cancer occurrence, date of death, or 31 December 2015, whichever came first. MS patients were matched based on sex and year of birth to non-MS controls from the general population without cancer before index date. Incidence rate was reported per 100,000 person-years (PY), and risk of cancer was estimated by type of cancer, age, and sex using a Cox model (hazard ratio [HR] and its 95% confidence interval [CI]).
Results
Overall, 576 cancers per 100,000 PY were observed in MS patients versus 424 per 100,000 PY in the control population. The risk of cancer was higher among MS patients than among population controls whether considered overall (HR = 1.36, 95% CI = 1.29–1.43) or for prostate (HR = 2.08, 95% CI = 1.68–2.58), colorectal and anal (HR = 1.35, 95% CI = 1.16–1.58), trachea, bronchus, and lung (HR = 2.36, 95% CI = 1.96–2.84), and to a lesser extent, breast cancer (HR = 1.12, 95% CI = 1.03–1.23).
Conclusions
MS patients were associated with increased risk of cancer compared to population controls.
CONFLICT OF INTEREST
P.B.-L. is an employee of Bordeaux PharmacoEpi, National Institute of Health and Medical Research (INSERM) of Bordeaux University, an independent nonprofit research organization that works in collaboration with government agencies and pharmaceutical companies. P.B.-L. has received speaker fees from Biogen outside of the submitted work. A.G., C.L., J.J., and P.B. are employees of the Bordeaux PharmacoEpi, INSERM of Bordeaux University. M.S., C.F., and E.B. are full-time employees of Merck Healthcare, Darmstadt, Germany.
Open Research
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are the property of the French health insurance system (Caisse Nationale d’Assurance Maladie). Access to these data is strictly restricted by the law (2016–41) of 26 January 2016 related to the modernization of the French health care system. A request for data reuse may be made and requires the prior approval of the French regulatory authorities (Comité éthique et scientifique pour les recherches, les études et les évaluations dans le domaine de la santé; Commission nationale de l'informatique et libertés).
