[Our surgical indication for breast-conserving therapy for breast cancer--special reference to extensive intraductal component and mammographic calcifications].

To ascertain accurate indications for breast-conserving therapy, we clinicopathologically examined 597 primary breast cancers. From July 1989 to October 1993, 118 of 597 (19.8%) patients were treated with lumpectomy plus breast radiation therapy. Among 118 of these primary breast cancers, 79 tumors were histologically further investigated with deep cut sections. In 20 of 79 (25.3%) breast cancers, microscopic tumor involvement was observed at resection margins. Most of them showed an extensive intraductal component (EIC). In order to predict EIC, intraductal lesions were histologically examined and classified either as comedo type or non-comedo (e.g., papillary type, cribriform type and solid type). Among 118 primary breast cancer tissues derived from lumpectomy, 66 breast tissues were histologically classified as comedo type. Sixty of 66 (90.9%) of these comedo types showed specific microcalcifications by light microscopic examination. These irregular shaped and relatively large granulated microcalcifications were localized in intraductal lesions with central necrotic ducts. With retrospective mammographic findings, these histological calcifications of comedo type reflected specific mammographic calcifications with columnar and specular formation. These evidences suggested that detection of mammographic calcifications in comedo type breast cancers may be helpful to predict EIC, and this prediction can possibly increase the accuracy of the indication for breast-conserving therapy.