Colorectal cancer in young adults.

The clinical and pathologic characteristics of colorectal cancer in patients younger than 30 years are compared with those in patients 30 to 39 years of age. Patients in the two age groups had similar symptoms, predominantly undifferentiated neoplasms, and poor prognoses. However, when the characteristics of these patients were compared with those described for a general patient population with colorectal cancer there was a gradual decrease in the incidence of mucin-producing tumors, poorly differentiated carcinomas, and primary lesions in the right colon, with increasing age at diagnosis. The highest incidences were found in patients less than 30 years old. The degree of tumor anaplasia and stage of tumor at diagnosis significantly influenced the duration of disease-free interval after curative resection of the primary and the duration of survival. Ninety-six percent of patients younger than 40 years had carcinomas extending beyond the colonic wall at diagnosis, adversely affecting long-term survival. The five-year survival of only 25% to 30% in these patients emphasizes the need for early diagnosis and aggressive treatment.