Comparing trastuzumab-related cardiotoxicity between elderly and younger patients with breast cancer : a prospective cohort study

OBJECTIVE: Trastuzumab is an HER-2 targeted humanized monoclonal antibody that significantly improves metastatic and non-metastatic breast cancer therapeutic outcomes. This study compares trastuzumab outcomes between two age cohorts in the Kuwait Cancer Control Centre (KCCC). PATIENTS AND METHODS: In a prospective comparative observational study, 93 HER-2 positive breast cancer patients undergoing different chemotherapy protocols + trastuzumab between April 2016 and April 2019 were included and divided into two cohorts based on their age (<60 and ≥60 years old). The individual decline in the LVEF from the baseline was calculated and compared between the two age cohorts. Logistic regression analysis was applied to investigate the association between age, comorbidities, BMI, anthracycline treatment, and baseline LVEF value, and trastuzumab-induced cardiotoxicity after adjustments made for the disease stage. RESULTS: The median baseline LVEF was 65% in both age cohorts (IQR 8% and 9% for older and younger patients, respectively). Whereas the median LVEF post-trastuzumab treatment was 51% and 55% in older and younger patients, respectively (IQR 8%; p-value = 0.22), even though older patients had significantly lower exposure to anthracyclines compared to younger patients (60% and 84.1%, respectively; p-value <0.001). 86.7% and 55.6% of older and younger patients, respectively, developed ≥10% decline in their LVEF from the baseline. Statistically, age was the only factor that significantly correlated with developing ≥10% decline in the LVEF (OR 4; p-value