Clinicopathological Features and Survival Outcomes of Colorectal Cancer in Young Versus Elderly: A Population-Based Cohort Study of SEER 9 Registries Data (1988-2011).

The incidence of colorectal cancer (CRC) in young adults is rising. We aimed to analyze the clinicopathological characteristics and survival outcomes of young versus elderly CRC patients. All patients diagnosed with CRC in the Surveillance, Epidemiology, and End Results program data (1988-2011) from the United States were evaluated. They were divided into 3 groups by age at diagnosis: group 1 (20-40 years old), group 2 (41-50 years old), and group 3 (>50 years old). The clinicopathological characteristics and CRC-specific survival (CRC-SS) were evaluated and compared among the 3 groups. A total of 279,623 CRC patients were included: 6700 (2.4%) in group 1, 19,385 (6.9%) in group 2, and 253,538 (90.7%) in group 3. Young CRC patients had more tumors located in rectum, fewer cases with multiple tumors, later stage, more mucinous carcinoma and signet ring-cell carcinoma, more poor differentiated tumors, and more lymph nodes (no. ≥12) examined. The 5-year CRC-SS rates of patients in groups 1, 2, and 3 were 65.1%, 67.1%, and 62.8%, respectively (group 1 vs group 2, P = 0.001; group 1 vs group 3, P < 0.001; group 2 vs group 3, P < 0.001). Multivariate analysis revealed older (>50 years old) age was an independent predictor of poor prognosis (hazard ratio, 1.545; 95% confidence interval, 1.456-1.639; P < 0.001). Young CRC patients had later stage presentation and more aggressive pathological features, but better survival. CRC patients aged 41 to 50 years had best CRC-SS in contrast to patients in another 2 age groups.