[Stage A prostate cancer: comparison of subclassification between Japanese rule and TNM, and outcome]

Between 1980 and June, 2002, transurethral resection of prostate was performed against 3294 cases of benign prostatic hyperplasia, and 144 cases of stage A cancer were detected (4.4%). Among these cases, 136 cases which had complete records of examination were studied. Annual number of stage A and A1:A2 ratio were not influenced by introducing PSA determination from 1991, although the number of T1c has been increasing gradually. Since subclassification of stage A is different between Japanese rules (A1; 3 chips of cancer with well-differentiated adenocarcinoma, A2; others) and TNM (T1a; 5% of less number of chips with cancer, T1b; others), two criteria were compared. Coincidence was found with 93.7%, and disagreement was due to ratio of number of chips with cancer to whole number resected, or different grade. The former difference was caused by a larger or smaller prostate. Most cases of A1 and A2 were subjected to watchful waiting or subsequent therapy. PSA was elevated in 10 cases (7%), two of which died from progression of cancer. Other cases were disease-free. Individual pathological findings are important for subclassification of stage A.