Long-term outcomes in patients with mucinous, medullary, tubular, and invasive ductal carcinomas after lumpectomy

Abstract Background Mucinous, medullary, and tubular carcinomas are uncommon types of breast cancer whose rarity does not permit large single-institution studies or randomized trials to define optimal treatments. In this study, we evaluated the long-term outcomes of breast-conserving therapy (BCT) for these subtypes of breast cancer and compared them with those for invasive ductal carcinoma. Methods In our institutional database of patients who received BCT from 1965 to 1999, 1,643 patients with stage I to II mucinous (61), medullary (37), tubular (60), and invasive ductal (1,485) histologies were identified. The clinical and pathologic features of the 4 groups were evaluated and compared with respect to local-regional recurrence rates, disease-free survival, and overall survival (OS). Results No statistically significant differences were found in the local-regional failure rate among the 4 groups (10.6-year median follow-up). Only patients with tubular carcinoma had better 5- and 10-year OS rates ( P = .013). In multivariable analysis, factors associated with improved OS included age at or below 50 years, negative nodal status, use of chemotherapy or hormonal therapy, and tubular histology. Conclusions BCT for mucinous, medullary, or tubular carcinoma resulted in similar local-regional failure rates to that for invasive ductal carcinoma. Tubular carcinoma patients had the most favorable OS. BCT is an appropriate treatment strategy for early-stage mucinous, medullary, and tubular carcinomas.