[Problems in the Japanese general rules for studies on cancer of the colon, rectum and anus and TNM classification and follow-up studies].

Five-year survival rate of the anal cancer on stage classification has been analyzed using Japanese Research Society (J.R.S.) and TNM classification. On studying of 73 consecutive patients who had abdominoperineal resection of the rectum for anal cancer at the Health Insurance Central Hospital, Tokyo, 5-year survival rate of stage II was lower than that of stage III in the J.R.S. while appropriate distribution of survival rate was seen in the TNM classification. On the anal cancer, size or rate of infiltration to circumference of the anal canal of the tumor has an important effect on prognosis. We recommend to add infiltration to circumference of the anal canal as a factor on the stage classification.