Adjuvant Chemotherapy for Node-Positive Breast Cancer

Patients meeting the following characteristics were chosen from electronically archived medical records: (1) Curative resection of breast cancer at Seoul National University Hospital, Korea between 1999 and 2004; (2) Pathologically determined involvement of 4 or more lymph nodes; (3) The administration of AC/T as an adjuvant chemotherapy; (4) No trastuzumab adjuvant therapy; and (5) Sufficient tissue samples available for immunohistochemical analysis.
Adjuvant chemotherapy consisted of 60 mg/m² doxorubicin and 600 mg/m² cyclophosphamide every 3 weeks for 4 cycles followed by 175 mg/m² paclitaxel every 3 weeks for 4 cycles [3 (link)]. Adjuvant radiotherapy or hormonal therapy was performed as appropriate.
One hundred and fifty one patients, including 3 male patients, met these inclusion criteria and were included in this study. Patients with stage IIIB disease (T4 by AJCC staging) were not included in this study, because these patients were treated with a neoadjuvant chemotherapy protocol. Thus, all 151 patients were at stage IIIA or IIIC disease. Surgical treatment was radical modified mastectomy, without removal of the pectoralis muscles, in 120 cases (79.5%) and breast conserving surgery including quadrantectomy in 31 cases (20.5%). A level II axillary dissection was performed in all patients and the mean number of lymph nodes removed was 22.9 (range 7–54). Of the 151 patients, 89 (58.9%) were ER and/or PR positive, and 87 (97.8%) of these patients received 5 years of adjuvant tamoxifen. Thirty-one patients received breast-conserving surgery and all, except one lost to follow-up, received adjuvant radiotherapy. Of the 120 patients who underwent modified radical mastectomy, 108 received adjuvant radiotherapy. Patient characteristics are listed in Table 1.