A Retrospective Multicenter Study of the Clinicopathological Characteristics and Prognosis of Young Adult Patients with Colorectal Cancer: Effects of Chemotherapy on Prognosis

Background: The objective of this study was to evaluate clinicopathologic features of young patients with colorectal cancer (CRC) and to compare their prognosis with those of older patients Methods: We retrospectively reviewed the medical records of patients who underwent surgery for stage 0-III CRC at four university-affiliated hospitals between January 2011 and December 2020. The patients were divided into two groups, the young adult group (<= 45 years) and the older group (>45 years). Results: Of 1992 patients, 93 (4.6%) were young adults and 1899 (95.3%) were older patients. Young patients showed more symptoms (p = 0.014) and more poorly or undifferentiated adenocarcinoma (p = 0.047) than older patients. The young adult patients were more likely to receive adjuvant chemotherapy (p < 0.001) and multidrug agents (p = 0.029), and less likely to cease chemotherapy (p = 0.037). The five-year RFS (recurrence-free survival) rate was better in the young adults than in the older patients (p = 0.009). In the multivariable analysis, young age was a significant prognostic factor for better RFS (p = 0.015). Conclusions: Young patients with CRC had more symptoms, aggressive histological features than older patients. They received more multidrug agents and discontinued chemotherapy less often, resulting in better prognosis.