Objective: To explore the possibility of nonsurgical treatment of primary breast cancers by a sequential treatment of chemotherapy and radiotherapy.
Methods: We conducted a safety and efficacy trial of chemotherapy and radiation therapy sequentially as primary therapy in patients with stage I-IIIA breast cancer. All patients underwent mastectomy or lumpectomy 12-16 weeks after the completion of radiation therapy to maximize the effect of radiation therapy. The primary endpoint was the pathological complete response (pCR) rate.
Results: Between June 2004 and April 2005, one hundred eight patients were enrolled. Thirty six percent of the entire population achieved a pCR, which could not reject the null hypothesis. The pCR rate was 57% in patients with hormone receptor (HR)-negative/HER-2-positive tumors and 52% in patients with triple-negative tumors. While 7% of the HR-negative/HER2-positive patients recurred, a higher incidence of recurrence (24%) was observed in triple-negative tumors in a follow-up of 4.5 years. The rate of breast-conserving surgery was 88.9% (96/108).
Conclusion: The pCR rate was not high enough, even though preoperative sequential chemoradiation therapy did not increase the risk of operative complications and could achieve a high rate of breast-conserving surgery.