Carcinoma of the colon in childhood; report of 2 cases expressing p53 without K-ras mutation.

We report on 2 children with colonic carcinoma and also review 62 cases of Japanese children with colonic carcinoma including ours. Although the dismal prognosis in colonic cancer in children is possibly due to the predominance of poorly differentiated carcinoma, there is no significant difference in the 5-year survival rates among well, moderately and poorly differentiated carcinomas in children. Positive staining with p53 in tumor cells was observed in each, but K-ras mutations were not detected in any. Therefore, these carcinomas possibly developed from de-novo carcinoma. The development pathway of colonic carcinoma may relate to the prognosis in children, and be different from that in adults.