Buzdar AU, et al. - Researchers assessed the long-term outcomes in patients treated with sequential vs concurrent anthracycline plus trastuzumab. Results of the ACOSOG (American College of Surgeons Oncology Group) Z1041 (Alliance) study of 280 patients revealed no differences in disease-free or overall survival between the two approaches of administering trastuzumab with neoadjuvant chemotherapy in patients with HER2-positive breast cancer across a median follow-up of 5.1 years.

Methods

• At 36 centers in the continental US and Puerto Rico, researchers conducted this phase 3 randomized clinical trial.
• They enrolled women 18 years or older with invasive operable HER2-positive breast cancer from September 15, 2007 to December 15, 2011, and randomized them to 1 of 2 treatment arms.
• In arm 1, patients received 500 mg/m² of fluorouracil, 75 mg/m² of epirubicin, and 500 mg/m² of cyclophosphamide (FEC) every 3 weeks for 12 weeks followed by the combination of 80 mg/m² of paclitaxel and 2 mg/kg (except initial dose of 4 mg/kg) of trastuzumab weekly for 12 weeks.
• In arm 2, patients received the same combination of paclitaxel with trastuzumab weekly for 12 weeks followed by FEC every 3 weeks with weekly trastuzumab for 12 weeks.
• Endocrine therapy, and radiotherapy was delivered to women with hormone receptor–positive disease at physician discretion.
• On October 15, 2017, the analysis data set was locked and on December 15, 2017, analysis was concluded.
• Disease-free survival (DFS) and overall survival (OS) and pathologic complete response rate (pCR) in the breast and nodes were assessed as the primary outcomes.

Results

• In this trial, researchers enrolled 282 women with HER2-positive breast cancer, of which, 2 withdrew consent before treatment.
• The remaining 280 women had a median age of 50 years (range, 28-76 years).
• Among these, 232 (82.9%) were white, 29 (10.3%) were black, 8 (2.9%) were Asian, 4 (1.4%) were American Indian or Alaskan Native, and 7 (2.5%) did not report race/ethnicity.
• They reported 22 and 27 disease events in arm 1 and arm 2, respectively.
• No differences in disease-free survival rates with respect to treatment arm were evident (stratified log-rank P=.96; stratified hazard ratio [HR] [arm 2 to arm 1], 1.02; 95% CI, 0.56-1.83).
• With respect to treatment arm, no difference in overall survival was observed (stratified log-rank P=.73; stratified HR [arm 2 to arm 1], 1.17; 95% CI, 0.48-2.88).