A Clinico-pathological Study of Adenomas and Early Invasive Carcinomas Removed by Colonoscopic Polypectomy and Hot Biopsy

Abstract

1242 adenomas and early invasive carcinomas removed by colonoscopy at St. Mark's Hospital were studied. Among the lesions 0.5-1.0 cm, the percent of adenomas with severe dysplasia plus early invasive carcinomas (what is generally considered to be early carcinoma of the large bowel in Japan) was 8, 5%, which is a greater value than those previously reported on surgical cases. Adenomas smaller than 5 mm. showed relatively even distribution throughout the entire colon, on the other hand those larger than 5 mm showed the highest incidence in the sigmoid colon. Adenomas with moderate or severe dysplasia also showed the highest incidence in the sigmoid colon. Consequently, adenomas of the sigmoid colon are considered to have the highest risk of developing carcinoma, The greater number of adenomas per patient indicates increased cancer risk, which should be taken into consideration in the treatment and follow up of the patients with multiple adenomas. Female adenomas have slightly higher risk of developing carcinomas than male adenomas. Possible involvement of sex hormons in the carcinogenesis is suggested. Further epidemiological study, comparing British and Japanese adenomas, may produce epidemiologically interesting results.