EXPECTED 10-YEAR MORTALITY IS NOT ASSOCIATED WITH COLORECTAL CANCER SCREENING

Background: Health status and expected mortality are important considerations in assessing the benefits of colorectal cancer (CRC) screening, particularly for older adults given that CRC screening is recommended for adults with life expectancy ≥10 years. We analyzed past-year CRC screening according to a 10-year mortality index among community-dwelling adults aged 65-84 years.
Methods: We estimated 10-year mortality risk using a validated index comprising age, sex, body mass index, smoking history, comorbidities (diabetes, cancer, chronic obstructive pulmonary disease), number of overnight admissions, perceived health status, and functional limitations (difficulty walking several blocks, instrumental activities of daily life dependency) among 40,842 adults aged 65-84 years in the nationwide National Health Interview Survey in survey years 2000, 2003, 2005, 2008, 2010, 2013, 2015, and 2018. The 10-year predicted mortality risk from the lowest to highest quintiles of risk index were 12%, 24%, 39%, 58%, and 79%, respectively. We assessed the receipt of past-year CRC screening, including invasive (colonoscopy and sigmoidoscopy) and non-invasive (CT colonography and stool-based tests) tests, within 12 months according to quintiles of mortality risk.
Results: Among adults aged 65-84 years, prevalence of past-year CRC screening did not differ by quintile of mortality risk index (23.7%, 25.0%, 24.1%, 22.8%, and 22.5%, respectively, from the lowest to highest quintile, p >0.05, Figure 1). Compared to adults in the lowest quintile of mortality index, adults in the highest quintile had similar odds of past-year screening (OR 0.94, 95% CI: 0.85-1.03, p >0.05). About one-quarter (27.9%) of past-year CRC screening occurred in those with 10-year mortality risk >50%. There were some differences in past-year CRC screening by quintiles of mortality risk across strata of age. For example, adults aged 75-79 years in the lowest mortality quintile had lower past-year CRC screening compared to adults aged 70-74 years in the highest mortality quintiles (18.1% vs. 26.5%, p <0.001). This pattern was consistent for invasive and non-invasive screening tests.
Conclusion: Past-year CRC screening does not differ according to expected 10-year mortality risk. Current age-based approaches to CRC screening may result in under-screening for older, healthier adults but over-screening for younger adults with comorbidities. These data have implications for optimal use of limited endoscopic capacity, as well as possible overdiagnosis. Personalized screening with incorporation of individual factors such as life expectancy should be considered when recommending CRC screening.