For patients with low- and moderate-risk HER2-positive breast cancer, carboplatin may be safely omitted from the neoadjuvant regimen without compromising outcomes at surgery, a Chinese trial has shown.
Published in the Journal of Clinical Oncology, the phase III neoCARHP trial results show that neoadjuvant THP for six cycles is noninferior to TCHP in achieving pathologic complete response for stage II-III human epidermal growth factor receptor 2–positive (HER2+) breast cancer, with reduced toxicity.
The trial, led by Professor Gao Hongfei of the Guangdong Provincial People’s Hospital, recruited 776 women age 18 years or older with previously untreated, stage II and III, HER2-positive invasive breast cancer. Patients were randomly assigned (1:1) to receive six 3-week cycles of taxane (docetaxel, paclitaxel, or nab-paclitaxel) plus trastuzumab and pertuzumab, with carboplatin (TCbHP) or without carboplatin (THP).
The primary end point was pathologic complete response (pCR) rate in the breast and axilla (ypT0/is ypN0).
The trial met its primary end point, with pCR rates of 64.1% for THP versus 65.9% for TCHP, meeting the prespecified –10% noninferiority margin (difference, –1.8%.
The results were consistent across hormone receptor–positive (pCR rates 56% v 59%) and hormone receptor–negative (78% v 78%) subgroups, as well as across stage II and III disease and across taxane choices.
Notably, THP demonstrated substantially fewer grade 3-4 adverse events (20.7% v 34.6%) and fewer serious adverse events (1.3% v 4.7%), with marked reductions in anemia, nausea, vomiting, neutropenia, and thrombocytopenia compared with TCHP.
“These findings suggest that omitting carboplatin may serve as an alternative neoadjuvant strategy in combination with dual HER2 blockade for patients with early-stage HER2-positive breast cancer,” the study authors concluded.
The study was conducted at 15 cancer centres in China and led by researchers at Department of Breast Cancer, Cancer Center, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou.
An accompanying commentary article welcomed the findings but urged caution, noting that although pCR is prognostic at the individual patient level, its surrogacy for survival in treatment comparisons is modest.
It would therefore be important to await mature data from neoCARHP and related data sets, it advised.
The article also noted that nearly all THP trials enrolled patients with stage II disease, warranting caution in translating their results into practice for patients with stage III disease, for which a more intensive neoadjuvant regimen should be recommended at present.



