Treatment of noninvasive carcinoma: fifteen-year results at the National Cancer Center Hospital in Tokyo.

The introduction of screening mammography (MMG) will lead to increased detection of preclinical early breast cancer in Japan. It has become more important to understand the nature of these lesions. We tried to elucidate the long term prognosis and clinical and pathological characteristics of noninvasive cancers. A total of 336 (5.4%) ductal carcinoma in situ (DCIS) and 32 (0.5%) lobular carcinoma in situ (LCIS) were diagnosed in 6 277 breast carcinomas at the National Cancer Center Hospital from 1962 to 1995. Most (80%) LCIS occurred in premenopausal women. LCIS has significantly higher bilaterality than that of DCIS. Local recurrence occurred in approximately 10% of patients after breast conserving surgery for DCIS and LCIS. Four patients died of breast carcinoma, which were initially diagnosed as noninfiltrating carcinoma. The 15-year cause specific survival rates of patients with DCIS and LCIS were 98.5 % and 100 %, respectively.