Breast Cancer
Posted: Fri May 21, 2021 5:17 am
2021 May 19
Department of Internal Medicine, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, CAN
Breast Cancer Survival in Multiple Sclerosis: A Matched Cohort Study
https://pubmed.ncbi.nlm.nih.gov/34011575/
Abstract
Objective: We tested the hypotheses that overall survival and cancer-specific survival after breast cancer diagnosis would be lower in persons with multiple sclerosis (MS) as compared to persons without MS using a retrospective matched cohort design.
Methods: We applied a validated case definition to population-based administrative data in Manitoba and Ontario, Canada to identify female MS cases. We linked the MS cohorts to cancer registries to identify women with breast cancer. Then we selected 4 breast cancer controls without MS matched on birth year, cancer diagnosis year and region. We compared all-cause survival between cohorts using Cox proportional hazards regression adjusting for age at cancer diagnosis, cancer diagnosis period, income quintile, region, and Elixhauser comorbidity score. We compared cancer-specific survival between cohorts using a multivariable cause-specific hazards model. We pooled findings between provinces using meta-analysis.
Results: We included 779 MS cases and 3116 controls with breast cancer. Most subjects with stage data (1976/2822, 70.0%) were diagnosed with stage I or II breast cancer, and the mean (SD) age at diagnosis was 57.8 (10.7) years. After adjustment for covariates, MS was associated with a 28% increased hazard for all-cause mortality (hazard ratio [HR] 1.28; 95%CI: 1.08-1.53), but was not associated with altered cancer-specific survival (HR 0.98; 95%CI: 0.65-1.46).
Conclusion: Women with MS have lower all-cause survival after breast cancer diagnosis than women without MS. Future studies should confirm these findings in other populations and identify MS-specific factors associated with worse prognosis.
Department of Internal Medicine, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, CAN
Breast Cancer Survival in Multiple Sclerosis: A Matched Cohort Study
https://pubmed.ncbi.nlm.nih.gov/34011575/
Abstract
Objective: We tested the hypotheses that overall survival and cancer-specific survival after breast cancer diagnosis would be lower in persons with multiple sclerosis (MS) as compared to persons without MS using a retrospective matched cohort design.
Methods: We applied a validated case definition to population-based administrative data in Manitoba and Ontario, Canada to identify female MS cases. We linked the MS cohorts to cancer registries to identify women with breast cancer. Then we selected 4 breast cancer controls without MS matched on birth year, cancer diagnosis year and region. We compared all-cause survival between cohorts using Cox proportional hazards regression adjusting for age at cancer diagnosis, cancer diagnosis period, income quintile, region, and Elixhauser comorbidity score. We compared cancer-specific survival between cohorts using a multivariable cause-specific hazards model. We pooled findings between provinces using meta-analysis.
Results: We included 779 MS cases and 3116 controls with breast cancer. Most subjects with stage data (1976/2822, 70.0%) were diagnosed with stage I or II breast cancer, and the mean (SD) age at diagnosis was 57.8 (10.7) years. After adjustment for covariates, MS was associated with a 28% increased hazard for all-cause mortality (hazard ratio [HR] 1.28; 95%CI: 1.08-1.53), but was not associated with altered cancer-specific survival (HR 0.98; 95%CI: 0.65-1.46).
Conclusion: Women with MS have lower all-cause survival after breast cancer diagnosis than women without MS. Future studies should confirm these findings in other populations and identify MS-specific factors associated with worse prognosis.