Pathological complete response rate (pCR) in thirty-three women with triple-negative breast cancer (TNBC) treated with a neoadjuvant carboplatin-based regimen.

Abstract

e12099 Background: The purpose of this retrospective case series was to assess pCR rate, progression-free survival and prognostic factors in TNBC. Methods: We reviewed medical records for 33 consecutive female patients with TNBC (41% node+) treated between July 2015 and April 2018 with neoadjuvant paclitaxel 80 mg/m2 IV weekly plus concurrent carboplatin (AUC 4) every 3 weeks for a total of 12 weeks followed by dose-dense doxorubicin 60 mg/m2 plus cyclophosphamide 600 mg/m2 every 2 weeks for a total of 4 cycles. Surgical pathology was studied to determine the presence or absence of residual disease at surgery. Age at treatment, tumor stage, subsequent hospitalizations, and genetic testing were recorded. Patients with residual disease were treated with adjuvant capecitabine 1500 mg PO BID, one week on, one week off, for 6 monthly cycles ± radiation; some patients with a complete pathological response also received postoperative radiation. Results: Among 33 patients, 17 patients had pCR (52%, median age 58 yrs), 10 had a partial response and 6 had no response or progression (median age 63.5). After surgery 24 patients received radiation therapy (XRT). There were 6 hospitalizations, 3 that were treatment related, 2 for neutropenic fever and one for renal failure induced by carboplatin; all 3 resulted in chemotherapy dose reductions; all 3 had pCR. 3 progressions/recurrences were recorded: 2 after treatment and 1 progression during treatment. Two deaths occurred, 1 secondary to progressive disease. Median progression free survival time was 8.5 months (range 0.1 to 24.0 mos). Median time since diagnosis is 16.7 months (range 8.1 to 37.6 mos). There was no significant difference in the median age of patients who had a pCR compared with patients with residual disease. Conclusions: We observed pCR in patients with TNBC treated with a pre-operative carboplatin-containing regimen (superior to historical pCR rates in patients receiving taxanes and anthracyclines only). Although there are insufficient data to demonstrate increased overall survival, we show an improvement in prognosis with a carboplatin-containing regimen for TNBC.