A62Effectiveness and resulting surgical behavior after neoadjuvant chemotherapy in locally advanced breast cancer: our experience

Background: The aim of our study was to evaluate how neoadjuvant chemotherapy is able to produce a downstaging in locally advanced breast cancer. Patients and methods: We evaluated all patients, over the last four years, who have undergone neoadjuvant treatment for locally advanced breast cancer, considering the clinical TNM at the time of diagnosis and pathological TNM on the surgical specimen. The baseline assessment was performed with MRI, CT scan and physical examination. Results: We enroled 29 patients treated with neoadjuvant chemotherapy from 2011 to 2014. The mean tumor size was 41.6 mm and median 42 mm (range, 17-86 mm). 8 patients had a multifocal tumor. 10 patients had a clinical nodal staging ≥2a. 12 patients were HER-2 positive; estrogen receptor positivity was in 18 cases, of which 11 were also positive for progesterone receptors. All patients received a sequential scheme with EC ± 5FU, followed by treatment with taxanes ± Trastuzumab. After medical treatment 13 patients had a radiological complete response, 13 patients a partial response and 3 experienced a stabilization disease. The mean tumor size was 11.5 mm and median 3.7 mm (range 0-86). 23 patients were treated with mastectomy anyway, and 6 patients with quadrantectomy. The postoperative staging identified a tumor regression in all patients but two, with a regression to pT0 or pTis in 8 patients; only two patients presented stability compared to diagnosis; only two patients maintained pN = 2a. After surgery, all HER-2 positive patients continued treatment with Trastuzumab till 12 months; 14 patients received hormone therapy, 2 patients were treated with adjuvant chemotherapy. 17 patients underwent radiotherapy. At the time of data only 6 patients had recurrence, including 3 local and 3 remote. Conclusions: Neoadjuvant chemotherapy in locally advanced breast cancer seems to have a major reductive effect on the primary disease and regressive on lymph node involvement. These results do not always entail a change of attitude surgery, despite the confirmation of good pathologic response. There are still cases in which disease control occurs only through a stabilization disease, but predictors of this type of response are not yet clear.