Clinicopathologic characteristics of early-onset colorectal cancer

Purpose: The aim of this study was to analysis of the clinicopathological characteristics and prognosis of colorectal cancer (CRC) under the age of 50 years.Methods: Between January 2009 and December 2018, 1,126 primary CRC patients were included from National Health Insurance Service Ilsan Hospital. The patients were divided into group 1 (n =111, <= 50 years) and group 2 (n =1,015, > 50 years). The clinicopathologic features and prognostic outcomes were compared. In addition, to analyze whether there were any differences of those characteristics in 3 groups, patients aged under 50 years were divided into their 20s, 30s, and 40s.Results: Group 1 had a slightly higher distribution in the left colon and rectum, lower T stage I and higher T stage IV rate, and a significantly higher distribution in stage N2 than group 2 (30.6%:16.3%, P < 0.001). Poor histological differentiation of tumors was significantly high in group 1 (P =0.003). The 5-year survival rate for those in their 30s (69.2%) and 40s (91.6%) was higher than those in their 20s who died immediately after surgery (P < 0.001). The 5-year disease-free sur-vival rate was also confirmed to be meaningful for each age group, with 0% in their 20s, 53.8% in their 30s, 79.2% in their 40s (P < 0.001).Conclusion: Although the age was not an independent prognostic factor for overall survival in this study, the early onset group of CRCs is more advanced at the time of diagnosis and has a more aggressive histologic type.