Colorectal adenocarcinoma in patients under 45 years of age: Comparison with older patients in a well-defined French population

PURPOSE: Little is known about colorectal cancer in young patients at a pop ulation level, and the behavior, characteristics, and prognosis of such tum ors continue to be debated. METHODS: A population-based series of 4,643 new cases of colorectal adenocarcinomas diagnosed between 1976 and 1996 in Cot e d'Or, France, was used to describe time trends in incidence, predisposing conditions, location, stage, and treatment and to evaluate the prognosis o f such tumors in patients under 45 years of age (n = 146). Prognosis was de termined using relative survival rates and predictive factors using a multi variate relative survival model. RESULTS: Before the age of 45 rears, age-s tandardized incidence rates were 1.9 per 100,000 in males and 1.4 per 100,0 00 in females. Incidence rates almost doubled from 1976 to 1982 and from 19 83 to 1989 in both genders and stabilized thereafter. The frequency of pred isposing conditions was significantly higher before the age of 45 years (11 .7 vs. 0.4 percent; P < 0.001). TNM Stage III tumors were more frequent in younger patients, and Stage II tumors were more frequent in older patients. The postoperative mortality rate was lower in the 0-to-44 age group, 2.1 p ercent, compared with 8.4 percent for the 45-and-over age group (P = 0.004) . Five-year relative survival rates were 51.9, 49.2., and 41.4 percent, res pectively. In both overall and stage-for-stage comparisons, patients before the age of 45 years had a better survival rate than older patients. Gender and stage at diagnosis were the only independent prognostic factors of sur vival for young patients. CONCLUSIONS: This study confirms the high frequen cy of predisposing conditions in young patients and that young age is not a poor prognostic factor for colorectal cancer. This underlines the importan ce of family screening, aggressive surveillance, and treatment in the young with known predisposing conditions.