Pathologic tumor response of invasive lobular carcinoma to neo-adjuvant chemotherapy

Neo-adjuvant chemotherapy is used for locally advanced breast cancer patients with significant variation in tumor response. Our objective is to determine the clinicopathologic effect of neo-adjuvant chemotherapy on invasive lobular carcinoma. A review of a single-institution data base of women diagnosed with breast cancer identified 30 patients from 1999 to 2009 with operable invasive lobular carcinoma who received neo-adjuvant chemotherapy. Patient demographics and clinicopathologic data were reviewed. Cases were reviewed by a single pathologist (NNE). Residual cancer burden class was determined for each case. Median patient age was 50 years (range 25-79). All tumors were hormone receptor positive and clinical stage II or III carcinomas. Most patients (53.3%) had combination anthracycline- and taxane-based chemotherapy. Therapy-related changes were noted within the tumor bed in 25 (83.3%) patients. Six (30%) of 20 patients with residual axillary disease had therapy-related nodal changes. There were 11 patients with moderate residual disease (class II) and 18 (60%) with extensive (class III); there were no complete pathologic responses (class 0). Only one patient (3.3%) converted from mastectomy to breast-conserving surgery. Four (13.3%) patients developed distant metastases; all had pleomorphic-type, clinical stage III tumors with residual cancer burden III classification and developed distant disease in the 2 years after surgery (range 0-26 months). Median follow-up time was 29.5 months (range 7-132). Patients with locally advanced pleomorphic-type lobular carcinoma appear to develop early post-treatment metastatic disease. Neo-adjuvant chemotherapy did not appear to have significant impact on the surgical treatment of patients with invasive lobular carcinoma.