Background: The majority of breast cancer patients in Jordan are diagnosed at a young age and present with metastatic or locally advanced disease. The National Surgical Adjuvant Breast and Bowel Project Protocol B27 (NSABP-B27) (four cycles of adriamycin and cyclophosphamide [AC] followed by four cycles of docetaxel) is a standard neoadjuvant regimen in our institution. In this study, we report the efficacy of adding trastuzumab to docetaxel in this regimen for high-risk human epidermal growth factor receptor 2 (HER2)-positive early-stage disease.
Patients and methods: Consecutive HER2-positive breast cancer patients treated with this regimen were included. Treatment was given at standard doses and schedules as reported in NSABP-B27. Trastuzumab was given with docetaxel and then continued for 1 year.
Results: A total of 121 patients (mean age 45.4 years) were included. The majority had high-risk features including large tumor size, positive axillary lymph nodes, and grade III disease. Three patients did not complete the planned cycles of AC due to a lack of response. Eight (6.6%) patients missed at least one cycle of docetaxel. Following neoadjuvant therapy, 119 patients underwent surgery, of whom 59 (49.6%) patients achieved pathological complete response. The response was higher in node-negative patients (64.0 vs 45.7%; P=0.03) and in hormone receptor-negative disease patients (69.7 vs 41.9%; P=0.018). Breast-conserving surgery was performed in 21.5% of the patients. The median disease-free survival (DFS) for the whole group was not reached while the 3- and 5-year DFS rates were 84.2 and 74.1%, respectively.
Conclusion: Trastuzumab added to the NSABP-B27 regimen is a unique combination. When used in high-risk patients, as in our study, outcomes similar to reported data were achieved without unexpected toxicities.
Keywords: HER2; NSABP-B27; breast cancer; neoadjuvant; trastuzumab.