Breast cancer incidence and stage at diagnosis in Ontarians with and without intellectual disabilities

Abstract

This thesis examines breast cancer incidence and stage at diagnosis in Ontarians with and without intellectual disabilities. The objectives were 1) To describe and compare the incidence of breast cancer in women with and without intellectual disabilities from 2000 to 2014; 2) To describe and compare breast cancer stage at diagnosis in women with and without intellectual disabilities from 2010-2014. Manuscript 1 (Incidence): Through a retrospective cohort methodology, breast cancer incidence in women with intellectual disabilities was found to be not significantly different from women without intellectual disabilities. Manuscript 2 (Stage): A cross sectional study demonstrated women with intellectual disabilities were significantly more likely to be diagnosed at a later stage (II-IV) (odds ratio 1.6; 95%CI=1.03-2.48) when compared to women without intellectual disabilities. Conclusion: The results of this study suggest women with intellectual disabilities have a comparable incidence of breast cancer to women without intellectual disabilities, but they may have an increased risk of being diagnosed at a later stage.