Role of conservation therapy for invasive lobular carcinoma of the breast.

BACKGROUND: Invasive lobular carcinoma (ILC) accounts for 5% to 10% of all invasive breast cancers. Although breast conservation therapy using local excision and postoperative irradiation is a standard therapy for early invasive ductal breast cancer, the result of this strategy in ILC is not well documented. We sought to determine the rate of locoregional recurrence after breast conservation therapy in patients with ILC.

METHODS: A retrospective review of 74 patients with ILC treated with breast conservation therapy at The University of Texas M. D. Anderson Cancer Center (n = 43) or The John Wayne Cancer Institute (n = 31) between 1977 and 1993 was performed.

RESULTS: The median age of patients was 60 years, and median follow-up was 56 months (range 1 to 207 months). Thirty-nine patients had American Joint Committee on Cancer stage I disease, 30 had stage IIa disease, and five had stage IIb disease. All patients underwent surgical resection and postoperative radiation therapy. Twelve patients received postoperative adjuvant chemotherapy, and 27 patients were treated with adjuvant hormonal therapy. The 5-year actuarial locoregional recurrence rate was 9.8%, and the median time to recurrence was 77 months (range 41 to 113 months). Patients with positive or close (< or = 1 mm) surgical margins were at increased risk for local recurrence on univariate analysis (p = 0.034). Of the nine patients with breast recurrence, six underwent salvage therapy with total mastectomy and are disease free at the time of this writing, two patients died of distant disease, and one is alive with local disease at the time of this report. The 5-year disease-specific survival rate was 93.7%.

CONCLUSIONS: Breast conservation therapy for ILC achieves locoregional control in the majority of patients. However, long-term follow-up of patients is important because many local recurrences following breast conservation therapy are late events.