Abstract
Six hundred and thirty-five colorectal polyps were diagnosed among 312 cases by endoscopy during the past six years (1980-1985). All but 22 early cancers in 16 cases excised by operation were excised endoscopically. The histopathological study of the polyps were identified 433 lesions (68.2 per cent) as adenoma, 78 lesions (12.3 per cent) as early cancer (m: 53 lesions, sm : 25 lesions) and 124 lesions (19.5 per cent) as others. The following results were obtained. 1) The ratio of early cancer to adenoma was slightly elevated in female compared to that in male. 2) The age was distributed highest in the fifties in both adenoma and early cancer. 3) The larger the size of polyp was, the higher the frequency of early cancer was. 4) The ratio of early cancer to adenoma was higher in the rectum, the sigmoid, and the ascending colon than the descending and transverse colon. 5) The frequency of early cancer with adenoma was 89.7 per cent and that without adenoma was 10.3 per cent. 6) Among early cancers with adenoma, m cancer dominated in cancer in adenoma and sm cancer dominated in adenoma in cancer. 7) Both m and sm cancers were found most in the shape of Is. “m” cancer was found in the next in the shape of Ip while sm cancer was found in the shape of II a or IIa+IIc. 8) All the early cancers without adenoma were sm cancers and had the shape of IIa+IIc or IIa. Most of results was consistent with the concept of adenoma-carcinoma sequence. However, further meticulous analyses of accumulated cases were needed in order to clarify the natural course of cancer including the process of malignant change.
