Conservation therapy for breast cancers other than infiltrating ductal carcinoma.

Pathologic review of 861 Stage I and II breast cancers yielded 152 patients (18%) with histologic types other than invasive ductal carcinoma. All patients had been treated by breast-conserving surgery and radiotherapy, including supplemental radiation to the tumor bed. For 67 patients with predominantly lobular carcinomas, the actuarial overall 5-year survival was 100% and 77% for node-negative and node-positive patients, respectively. The actuarial probability of recurrence in the treated breast (13.5% at 5 years) appeared to be somewhat greater than that observed after treatment of invasive ductal cancers (8.8% at 5 years, P = 0.11). Of 12 mammary recurrences in patients with lobular carcinoma, four occurred at a considerable distance from the original primary and seven were multifocal, involving more than one quadrant in five patients. Of 47 patients with strictly in situ carcinomas, one patient whose axillary nodal status had not been determined subsequently developed distant metastases. Three additional patients developed mammary recurrence, two at the primary tumor site and one in another quadrant. The actuarial 5-year mammary recurrence and overall survival rates were 4% and 98%, respectively. For 27 patients with true medullary cancers, overall survival at 5 years was 90%. One localized mammary recurrence was observed at the site of the original primary. Actuarial mammary recurrence rate was 4% at 5 years. No relapse was observed in ten patients with colloid and one patient with adenoid cystic carcinoma. The authors conclude that, in addition to its well-established efficacy in the treatment of infiltrating ductal carcinomas, the combination of tumor excision and radiotherapy appears to provide adequate local control for other histologic types as well. However, patients with lobular cancer appear to be at somewhat greater risk of mammary failure, and recurrences in such patients tend to be multifocal and multicentric.