Preprint · Sep 2, 2023
Association of Cancer Diagnosis with Disability Status among Older Survivors of Colorectal Cancer: A Population-Based Retrospective Cohort Study
By Swartz MC
Background: Older adults with cancer often experience declines in physical function due to the cancer diagnosis and treatments, increasing their risk of disability and early mortality. While prior studies have focused on surgical complications and mortality, less is known about factors associated with the development of disability in cancer survivors without pre-existing disability. We aimed to identify factors associated with developing disability in older colorectal cancer (CRC) survivors compared to a non-cancer cohort. Methods: Using the Texas Cancer Registry Medicare-linked database, this retrospective cohort study included 13,229 CRC survivors diagnosed during 2005-2013 and 13,225 age-sex matched non-cancer controls. Disability status was determined using Medicare claims 12 months after diagnosis per Davidoff's method. Cox regression was conducted to identify factors associated with developing disability.Results: Majority of CRC survivors (97%) were aged ≥65 years. Over 9 years, 54% developed disability. Factors associated with the development of disability status included older age at diagnosis (HR=3.50 for >80 years), female sex (HR=1.50), Hispanic (HR=1.34) or Black (HR=1.21) race/ethnicity, distant stage (HR=2.26), >1 comorbidity (HR=2.18), and radiation therapy (HR=1.21). Cancer diagnosis (HR=1.07) was associated with developing disability in pooled cohorts of those with and without cancer; age and race/ethnicity were also significant factors. Conclusions: CRC diagnosis increases disability risk independent of other factors. Older age, female sex, Hispanic/Black race/ethnicity, advanced stage, comorbidities, and radiation were associated with developing disability in CRC survivors. Routine physical function assessment, especially in higher-risk subgroups, may prevent development of disability status in older CRC survivors.