UC Irvine

Background: Colorectal cancer (CRC) is a major health problem globally. Among older adults, the burden is particularly substantial, yet there is a lack of evidence comparing clinical presentation, comorbidity burden, and treatment patterns between older-onset colorectal cancer (OLDCRC) and late-onset colorectal cancer (LOCRC).Methods: This study used electronic health record (EHR) data from the University of California Health Data Warehouse (UCHDW). Late-onset CRC patients (50–74 years) and older CRC patients (75–90 years) were identified and matched at a 1:2 ratio based on gender, year of diagnosis, and UCHDW enrollment duration before cancer diagnosis. A secondary 1:2 matched cohort compared older CRC patients to individuals without CRC (NOCRC). Demographic characteristics, tumor location, comorbidity profiles, diagnostic and surgical procedures, and treatment patterns were compared using descriptive statistics and chi-square tests. A loglinear regression was performed to evaluate the association between age cohort and acute clinical presentation, using emergency room visits and inpatient admissions as proxies. Results: Compared with late-onset CRC patients, older CRC patients had a greater burden of several age-related comorbidities but were less likely to undergo diagnostic screening and cancer treatment. Compared with patients without CRC, older CRC patients demonstrated a greater utilization of CRC-related diagnostic screenings. Although no significant difference in acute healthcare utilization was observed between age cohorts after adjusting for comorbidities, several chronic comorbidities, including type II diabetes, obesity, hypertension, hyperlipidemia, myocardial infarction, and stroke were independently associated with increased healthcare utilization, highlighting the importance of overall medical complexity rather than CRC age alone. Conclusion: Older adults with CRC exhibit distinct epidemiologic and clinical characteristics compared with patients with late-onset CRC. These findings improve understanding of CRC in older adults and provide real-world evidence to support more age-appropriate screening, diagnostic evaluation, and treatments.