Distinct features of colorectal cancer in children and adolescents: a population-based study of 159 cases.

BACKGROUND: Colorectal cancer is exceedingly rare in children and adolescents. Reports from small series indicate that poor prognostic factors are more common in children than in adults, resulting in worse outcome for the pediatric population. METHODS: The Surveillance, Epidemiology, and End Results database was searched for records of children/adolescents with colorectal cancer, and the features and outcomes were compared with those of adults. RESULTS: From January 1973 through December 2005, only 159 children/adolescents (ages 4-20 years) were reported with a diagnosis of colorectal cancer. The most common sites of involvement were the rectum (27%) and the transverse colon (26%). Adenocarcinoma was the most common histotype in both adults and pediatric patients; however, children/adolescents had more unfavorable histotypes (ie, mucinous adenocarcinoma [22%] and signet ring cell carcinoma [18%]) when compared with adults (10% and 1%, respectively; P < .001). Poorly differentiated and undifferentiated tumors (grades III and IV, respectively) and distant stage were more common in children/adolescents (P < .001). The 5-year relative survival estimates in children/adolescents and adults were 40% +/- 4.2% and 60% +/- 0.10%, respectively, confirming a worse outcome in the pediatric age group (P < .001). CONCLUSIONS: Children/adolescents represent a minority of patients with colorectal cancer and have high-risk features and worse outcome than adults. The small number of patients in this age group was an impediment to the development of meaningful clinical trials. Thus, the principles of management for adult colorectal cancer should be used in the treatment of children and adolescents.