Predictors of complete pathological response to neoadjuvant TCHP therapy in patients with early HER2-positive breast cancer: a single-center experience

Neoadjuvant chemotherapy with dual anti-HER2 blockade is the standard of care for early HER2-positive breast cancer (BC), leading to a complete pathological response (pCR) in a significant proportion of patients. However, the response to therapy is heterogeneous, and the identification of accessible clinicopathological predictors of pCR remains a key challenge for treatment personalization and efficacy prediction.

Purpose of the study. To evaluate the efficacy of the TCHP (docetaxel, carboplatin, trastuzumab, pertuzumab) neoadjuvant regimen and to identify independent clinicopathological predictors of achieving pCR in patients with stage IIA–IIIA HER2-positive BC.

Patients and methods. A single-center retrospective study was conducted at the P.A. Hertsen Moscow Oncology Research Institute. The analysis included data from 120 patients with stage IIA–IIIA HER2-positive BC who received neoadjuvant TCHP therapy between 2022 and 2025. The primary endpoint was the rate of pCR (ypT0/is ypN0). Univariate comparative analysis and multivariate binary logistic regression were used to identify predictors of response. ROC analysis was used to determine the optimal cutoff value for the predictor.

Results. Complete pathological response was achieved in 70 out of 120 patients (58.3 %). In the multivariate analysis, estrogen receptor (ER) expression level was the only independent predictor of pCR. For each one-point increase in the Allred score for ER expression, the odds of achieving pCR decreased by 16.1 % (OR 0.839; 95 % CI 0.753–0.934; p = 0.001). ROC analysis identified an optimal cutoff value for ER expression of ≤ 6 points for predicting pCR (AUC = 0.665; p = 0.001).

Conclusion. ER expression level is a key independent predictor of response to neoadjuvant TCHP therapy in patients with HER2-positive breast cancer. ER expression assessment can be used in clinical practice as an accessible biomarker for patient stratification and for identifying a group with a lower likelihood of achieving pCR who may require alternative or intensified therapeutic regimens.

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