Effectiveness of Neoadjuvant Chemo-Hormonal Therapy in Patients with Luminal В HER2-Negative Breast Cancer

Introduction. Breast cancer remains the leading cause of cancer morbidity and mortality among women. In hormone-receptor-positive, HER2-negative disease, achieving a pathologic complete response (pCR) after neoadjuvant therapy is an important prognostic factor. Aim. This study evaluates the efficacy and safety of adding tamoxifen to standard neoadjuvant chemotherapy in patients with hormone-sensitive, HER2-negative breast cancer.

Materials and methods. A prospective randomized study included 40 preand postmenopausal patients with indications for neoadjuvant chemotherapy using the 4ddAC → 4T regimen. Patients were assigned to two groups: Group A (n = 20) received additional tamoxifen, while Group B (n = 20) received chemotherapy alone. The primary endpoint was the pCR rate, assessed using the Residual Cancer Burden (RCB) system.

Results and discussion. The pCR rate (RCB-0) was 10% in both groups. The distribution of residual tumor burden across RCB classes was similar, with no statistically significant differences (p > 0.05). Combined chemo-hormonal therapy demonstrated acceptable tolerability; no serious adverse events were reported. All patients completed treatment and subsequently underwent surgery. The addition of tamoxifen did not improve the likelihood of achieving pCR, confirming its limited role in this neoadjuvant regimen.

Conclusion. The study demonstrated comparable efficacy and safety between the two treatment strategies. The absence of benefit from adding tamoxifen highlights the need to explore new therapeutic approaches to improve outcomes in this patient population.

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