QS101 - Improving Colon Cancer Outcomes in Patients over 75: The Role of Routine Screening in the Elderly

Purpose/Background: As the US population ages, we see a disproportionate increase in use of medical resources by elderly patients. In 2020, the rate of colorectal cancer (CRC) amongst 85 plus year old patients was 199.6/100,000 people, more than two times the rate of patients in the 60-64 age group (76.7/100,000 people). Numerous studies suggest that the geriatric population undergoes higher rates of urgent/ emergent operations, less often receive standard of care treatment interventions, and experience higher disease-specific mortality. Unfortunately, current colorectal cancer screening guidelines are non-specific regarding recommendations for the over 75 group. We aim to examine if continuing routine colon cancer screening reduces the odds of being diagnosed with high stage colon cancer (CC) after age 75, for the general population as well as underserved subgroups. Furthermore, we examine post-operative outcomes and mortality rates among patients aged 75 and above who have undergone colectomy for a diagnosis of colon cancer with or without pre-diagnostic screening.

Methods/Interventions: Using data from Surveillance, Epidemiology and End Results (SEER)-Medicare, we identified adults >75 years of age undergoing a colectomy for a diagnosis of CC between 2015-2017. Records were assessed for colon cancer screening (colonoscopy, fecal occult blood test, fecal immunohistochemistry, flexible sigmoidoscopy, virtual colonoscopy, and barium enema) in the 10 years to 6 months preceding the colectomy. Patient demographics (gender, age, Yost Index, marital status, insurance, source of admission), comorbidities and tumor stage at diagnosis were assessed. Operative factors, post-operative outcomes, and mortality were obtained. Bivariate and multivariate analyses were employed to examine relationships between patients receiving routine CC screening and those without.

Results/Outcomes: Among 18,671 patients with an average age of 82.2 undergoing colectomy for CC, 8,724 (41.8%) underwent CC screening in the 10 years preceding the colectomy. For patients who underwent screening, the most recent screening occurred 4.1 years prior to colectomy. 3486 (45.5%) of patients underwent urgent/emergent surgery, compared to 5988 (54.4%) of those who were not screened. At the time of diagnosis, 39.1% patients were Stage I, 18.7% Stage II, 27.6% Stage III, and 12.6% Stage IV. Patients who underwent routine screening were more likely to be diagnosed at an earlier stage (I/II) of disease compared to those who were not screened (63.5% vs. 59.1%, p< 0.01). Among patients who were screened, Black patients were significantly more likely to be diagnosed at late stage as compared to whites (43.5% vs. 35.5%, p< 0.01). Residing in higher poverty areas was further associated with higher rates of late-stage diagnosis (p < 0.01). Higher SES status was associated with higher chances of receiving colonoscopy for white (p < 0.01), but not for Black/ other race patients (p=0.14).

Conclusion/Discussion: Colorectal cancer screening amongst patients aged ≥75 is well below the screening rates for the general population. Our findings indicate that routine screening past age 75 is associated with reduced risk of being diagnosed with late-stage CC. Lower SES and Black/other race further exacerbate this difference in diagnosis rates with less utilization of CRC screening. Future research should focus on understanding the role of demographic and social factors as a barrier to screening among older adults and to optimize CRC screening guidelines for patients ≥75 years of age.