Surgical considerations in preoperative chemotherapy of breast cancer

Primary systemic chemotherapy for breast cancer was initially directed at downsizing tumors to make them acceptable candidates for breast-conserving surgery. Later trials used this approach in the hope of improving disease-free survival and overall survival. Results from NSABP protocol B-18 indicate significant initial tumor response and downstaging of lymph nodes in 30% of patients. Patients with small tumors were more likely to experience complete clinical response and complete pathologic response. Patients with larger tumors whose surgeons would have chosen mastectomy often responded with tumor decrease to a size at which lumpectomy was considered feasible. The local recurrence rate in these patients was higher than in those patients selected for lumpectomy primarily. Nevertheless, even with a higher rate of ipsilateral breast tumor recurrence, approximately 90% of women older than 50 years and 83% of younger women had successful breast-conserving surgery. There was no difference in disease-free survival or overall survival between preoperative and postoperative chemotherapy groups. The response of patients to initial chemotherapy can be a useful tool in exploring the biology of breast cancer.