Survival outcomes with 12 weeks of adjuvant or neoadjuvant trastuzumab in breast cancer

Background: There is limited access to 1 year of adjuvant trastuzumab in resource-constrained settings. Most randomized studies have failed to prove non-inferiority of shorter durations of adjuvant trastuzumab compared to 1 year However, shorter durations are often used when 1 year is not financially viable. We report the outcomes with 12 weeks of trastuzumab administered as part of curative-intent treatment. Methods: This is a retrospective analysis of patients treated at Tata Memorial Centre, Mumbai, a tertiary care cancer center in India. Patients with human epidermal growth factor receptor (HER2)-positive early or locally advanced breast cancer who received 12 weeks of adjuvant or neoadjuvant trastuzumab with paclitaxel and four cycles of an anthracycline-based regimen in either sequence, through a patient assistance program between January 2011 and December 2012, were analyzed for disease-free survival (DFS), overall survival (OS), and toxicity. Results: A total of 102 patients were analyzed with a data cutoff in September 2019. The median follow-up was 72 months (range 6-90 months), the median age was 46 (24-65) years, 51 (50%) were postmenopausal, 37 (36%) were hormone receptor-positive, and 61 (60%) had stage-III disease. There were 37 DFS events and 26 had OS events. The 5-year DFS was 66% (95% Confidence Interval [CI] 56-75%) and the OS was 76% (95% CI 67-85%), respectively. Cardiac dysfunction developed in 11 (10.7%) patients. Conclusion: The use of neoadjuvant or adjuvant 12-week trastuzumab-paclitaxel in sequence with four anthracycline-based regimens resulted in acceptable long-term outcomes in a group of patients, most of whom had advanced-stage nonmetastatic breast cancer.