A Phase II Study of Adjuvant Chemotherapy of Tegafur-Uracil for Patients with Breast Cancer with HER2-negative Pathologic Residual Invasive Disease After Neoadjuvant Chemotherapy.

There is no consensus on the need for adjuvant chemotherapy for patients with pathological residual invasive breast cancer (non-pCR) after neoadjuvant chemotherapy (NAC). We evaluated the tolerability and safety of tegafur-uracil (UFT) as adjuvant chemotherapy for patients with human epidermal growth factor receptor 2-negative breast cancer that resulted in non-pCR after NAC.

We treated patients with 270 mg/m2 UFT per day for 2 years after definitive surgery and radiotherapy, if necessary. In cases with hormone-sensitive cancer, patients received concurrent endocrine therapy. The primary end-point was the rate of completion of scheduled UFT therapy. Secondary end-points included safety and disease-free survival.

Twenty-one out of 29 patients (72%) completed the scheduled therapy. Eight patients discontinued the study treatment because of disease recurrence, toxicities, and patients' wish. Excluding liver dysfunction, adverse events were quite mild.

Adjuvant UFT therapy after NAC was feasible and safe.