Are sporadic colorectal cancers in young patients distinct from those in elderly patients?

The aim of this study was to compare the clinicopathological and oncological characteristics of sporadic colorectal cancer (CRC) between young and elderly patients without any genetic mutations that cause hereditary CRC.

In this cross-sectional, retrospective study conducted at three tertiary referral hospitals, we enrolled 1599 patients with CRC who underwent surgery between January 2010 and December 2017, including 157 young patients (age ≤ 40 years; yCRC) and 1442 elderly patients (age ≥ 70 years; eCRC). The clinicopathological and oncological outcomes were compared between the two groups.

The median age at diagnosis was 37 years in the yCRC group (range 33.0-39.2 years) and 76 years in the eCRC group (range 72.0-79.0 years). The yCRC group did not present with advanced stages at diagnosis compared with the eCRC group, and the distribution of tumour stages was similar between the two groups. Microsatellite instability (MSI) testing revealed no difference in the frequency of tumours with high MSI (7.8% in yCRC, 5.8% in eCRC), and the frequency of mutations in the KRAS, NRAS and BRAF genes was also similar. The 3-year overall survival was better in the yCRC group than in the eCRC group (97.4% vs. 83.5%, p < 0.001); however, no such difference was observed in cancer-specific survival.

Genetically proven sporadic CRCs did not differ significantly between young and elderly patients in terms of tumour stage, tumour location and various molecular features.

The study was retrospectively registered with Clinical Trials.gov (no. NCT05601609).