Differential response of triple‐negative breast cancer to a docetaxel and carboplatin‐based neoadjuvant treatment

BACKGROUND:

In this study, the authors evaluated whether a pathologic complete response (pCR) or a clinical complete response (cCR) to neoadjuvant treatment in patients with locally advanced breast cancer differed among the 3 subtypes of breast cancer: triple‐negative breast cancer (TNBC), human epidermal growth factor receptor 2 (HER2)‐positive breast cancer, and hormone receptor‐positive/HER2‐negative breast cancer. Whether a cCR or a pCR was correlated with fewer recurrences and better survival also was investigated.

METHODS:

Patients with stage II/III breast cancer received 4 cycles of neoadjuvant docetaxel and carboplatin (TC) every 3 weeks. Patients with HER2‐positive tumors were randomized to receive either additional weekly trastuzumab preoperatively or TC alone. Postoperatively, all patients received 4 cycles of TC, and all HER2‐positive patients received a total of 52 weeks of trastuzumab. The recurrence‐free survival (RFS) and overall survival (OS) rates at 2 years were reported.

RESULTS:

Seventy‐four patients were enrolled, including 11 patients with TNBC, 30 patients with HER2‐positive tumors, and 33 patients with hormone receptor‐positive/HER2‐negative tumor. The cCR rates were 45.4%, 50% and 40.6% in TNBC, HER2‐positive, and hormone receptor‐positive/HER2‐negative groups, respectively. The pCR rate for the entire group was 26.8%, and patients with TNBC had the best response (54.6%) followed by patients with HER2‐positive tumors (24.1%) and patients with hormone receptor‐positive/HER2‐negative tumors (19.4%; P = .0126). The pCR rate for patients with HER2‐positive tumors improved from 7% to 40% if trastuzumab was added (P = .08). Infiltrating ductal cancer, TNBC, negative estrogen receptor and/or progesterone receptor status, tumor classification predicted a pCR (P ≤ .05). Multivariate analysis using a logistic regression test indicated that tumor type was an independent predictor. The RFS rate for patients who did versus patients who did not achieve a pCR was 93.8% versus 78.4% at 2 years, respectively, and 83.3% versus 58% at 3 years, respectively (P = .1227); whereas, for patients who did versus patients who did not achieve a cCR, the RFS rate was 80.9% versus 83.9%, respectively, at 2 years and 65% versus 64.3%, respectively, at 3 years (P = .999).

CONCLUSIONS:

The current results indicated that the TC combination is promising for the treatment of TNBC. The addition of trastuzumab to TC improved the pCR rate significantly in patients with HER2‐positive breast cancer. Cancer 2010. © 2010 American Cancer Society.