Clinical and pathological response to neoadjuvant chemotherapy (NCT) in patients with triple-negative breast cancer (TNBC).
e12616 Background: Neoadjuvant chemotherapy (NCT), Triple-negative breast cancer (TNBC) including anthracyclines and taxanes for early stages of TNBC, allows to achieve pathological complete response (pCR) in 25-36% of patients. Pathological complete response (pCR) significantly correlates with an increase in disease-free survival (DFS) and overall survival (OS). Methods: Randomized, monocentric trial was conducted in NN Petrov National Medical Research Center of Oncology from 2016 to 2019. 99 patients aged from 28 to 68 years with confirmed TNBC were included in trial: 96 had invasive ductal carcinoma G3, 3 - metaplastic cancer, negative BRCA mutations (a test for Founder mutations was performed).Patients were randomized in 3 groups, depending on the NCT regimen:1st subgroup (24 patients) - Eribulin in combination with Carboplatin AUC 5 x 4 cycles 2nd subgroup (37 patients) - Paclitaxel in combination with Carboplatin AUC 5 x 4 cycles 3rd subgroup (38 patients) –Carboplatin AUC5 + Doxorubicin + Paclitaxel x 6 cycles. Patients 1 and 2 subgroups in an adjuvant mode received 4 cycles of AC. Results: Clinical complete response (cCR) by physical examination (palpation) was achieved in 44 out of 99 patients (44.4%). Clinical complete response (cCR) by ultrasound and MG - in 27 (27.2%) patients. Miller-Payne V regression stage was achieved in 55 out of 99 cases (55.6%). In clinical cT1-T2 stage (n = 70), ypCR was achieved in 49 cases (70%), cT3-T4 (n = 29) ypCR in 6 patients (20.68%). Before NCT, 71 patients had status cN0-N1. Conversion to ypN0 occurred in 57 patients (80.2%). In 28 patients with cN2-N3 status, conversion to ypN0 occurred in 7 patients (25%). The median follow-up was 58 months. Progression was observed in 15.1% of patients, mortality – 6%. Local recurrence - 6 patients (6%), all patients were with residual tumor after NCT. Distant recurrence – 8 patients (8.1 %). Local recurrence rate and distant recurrence rate did not correlate with type of surgery (BCS or ME), but correlated with ypCR. Conclusions: NCT for TNBC is advisable both for locally advanced breast cancer and early breast cancer BC. De-escalation of BC surgery is possible in the future, especially in cT1-T2 stage patients (n = 70) where ypCR rate reaches 70%. It is planned to continue the trial with the vacuum aspiration biopsy of the tumor bed and SLNB after NCT.SLNB after NCT is advisable only in cN0-N1 group of patients (n = 71), since conversion to ypN0 was achieved in 57 patients - 80.2%.