Lobular carcinoma of the breast: outcome of 205 patients

Introduction

Invasive lobular carcinoma (ILC) is the second most common type of invasive breast cancer (BC), which comprises approximately 10% of BC and appears to have distinct biologic and epidemiologic characteristics.

Methods

We analyzed data of 205 BC patients diagnosed with ILC who were diagnosed between January 1994 and December 2007. The objective was to determine the clinicopathological features, treatment and patterns of recurrence of ILC.

Results

Median age was 58.5 (range: 29.6 to 87.3). One hundred and thirty-six patients (66.3%) were postmenopausal, 131 patients (63.9%) underwent mastectomy and 74 (36.1%) a conservative surgical procedure. Pathological features were: T1: 79 patients (38.5%); T2: 84 patients (41%); T3: 19 patients (9.3%); T4: seven patients (3.4%); multifocal: 16 patients (7.8%). Nodal status N0: 131 patients (63.9%); N1: 41 patients (20%); N2: 16 patients (7.8%); N3: 17 patients (8.3%). Regarding phenotype, 90 patients (43.9%) were luminal A; 82 patients (40%) luminal B; 14 patients (6.8%) HER2⁺/RE⁺; two patients (1%) HER2⁺/RE^-; and seven patients (3.4%) were triple negative. Sixty-seven patients (32.7%) did not receive adjuvant chemotherapy (CT). Most frequent adjuvant QT received was anthracycline-based (61 patients, 29.8%) followed by CMF (42 patients, 20.5%) and anthracycline + taxane-based CT (35 patients, 17.1%). A total of 185 patients (90%) received adjuvant hormonal treatment, the most commonly used being tamoxifen (111 patients, 60%) followed by up-front aromatase inhibitors (AI). With a median follow-up of 97.3 months, 47 patients (22.9%) had a relapse, with a median disease-free survival (DFS) of 184 months. Five-year and 10-year DFS rates were 81.8% and 69.1%, respectively. T1, N0 tumors that received CT/HT/RT had a significantly lower recurrence rate (P < 0.05). The most frequent metastatic site at recurrence was bone (18 patients, 38%), followed by pleuropulmonar (seven patients, 15%), liver (five patients, 11%) and ganglionar (five patients, 11%). Median overall survival (OS) was not achieved; 5-year and 10-year OS rates were 94.4% and 81%, respectively. OS was significantly better (P < 0.05) for T1, N0 tumors.

Conclusion

In this review of ILC patients, the most common phenotype was luminal A. Recurrence and death rates were low, bone being the most common site of relapse.