The prognosis of patients with colorectal cancer (CRC) of different onset ages is controversial.

Data were obtained from a prospective database at Taipei Veterans General Hospital. There were 2,738 newly diagnosed patients with CRC from 2001 to 2006. Two extreme age groups, younger (≤40 years) and elderly (≥80 years), were analyzed to compare clinicopathologic characteristics and prognosis after exclusion of specific cancer syndrome.

A total of 322 patients were enrolled in this prospective study. The younger group consisted of 69 patients with mean age of 33.5 years, and the elderly group consisted of 253 patients with mean age of 83.4 years. Younger patients had a higher incidence of mucinous cell type (14.5% vs 6.3%, P = .05), poorly differentiated adenocarcinoma (26.1% vs 6.3%, P < .001), more advanced disease (82.6% vs 41.9%, P < .001), poorer disease-free survival (67.2% vs 79.3%, P = .048), and cancer-specific survival (44.1% vs 73.1%, P < .001) than elderly patients.

In patients with CRC of younger onset, without relevant predisposing risk factors, younger patients have more advanced stages of disease, more aggressive histopathologic characteristics, and poorer prognoses compared with older patients.