473 - RECURRENCE POST-NEOADJUVANT THERAPY IN PATIENTS WITH NODE-POSITIVE BREAST CANCER

Abstract

Introduction: Breast cancer treatment has drastically changed in recent decades due to a better understanding of the
biology of this disease as well as an increase in diagnostic and therapeutic approaches. Objective: We aimed to identify
prognostic factors related to recurrence among patients with node-positive breast cancer who underwent neoadjuvant
chemotherapy (NAC). Methods: We conducted a retrospective review of medical records of node-positive breast cancer
patients treated with NAC at our institution between 2010 and 2016. Clinicopathological variables (such as age, menopausal status, body mass index, tumor type, histological subtype, clinical and pathologic staging, immunohistochemical
profile, type of surgical treatment, and pathologic response to NAC) and its association with axillary or systemic recurrences were investigated using the χ2
test. Results: A total of 131 patients were investigated with a mean age of 49 years.
Most patients (36.6%) presented luminal B subtype, followed by 28.2% with triple negative and 20.6% with HER2 subtype.
Lymphovascular invasion was observed in 42% of the sample, and the median initial breast tumor size was 35 mm. After
NAC, 22.1% of the patients achieved a pathological complete response and tumor size was reduced to a median of 15 mm.
Axillary recurrence was observed in 3.1% of the patients, while systemic recurrence occurred in 28.2% of the patients. None
of the investigated clinicopathological variables were significantly associated with axillary recurrence. However, systemic
recurrence was associated with poor response to NAC and the presence of lymphovascular invasion on pathology analysis.
Conclusion: NAC response and lymphovascular invasion are important predictors of breast cancer systemic recurrence.
Interestingly, histological subtypes were not associated with increased axillary or systemic recurrence rates.