Retrospective study of risk of new-onset hypertension with trastuzumab for breast cancer in adolescents and young adults

Trastuzumab therapy for breast cancer carries a risk of acute cardiotoxicity. A retrospective study among all female AYAs aged 15-39 years diagnosed with first primary invasive breast cancer between 2006 and 2020 in Kaiser Permanente Northern and Southern California, who survived at least 2 years post-diagnosis, investigated the risk of new-onset hypertension with trastuzumab. Among 2382 patients, 33.0% received trastuzumab. The 2-5 year cumulative incidence of hypertension was 6.79% in the trastuzumab group and 7.85% in the non-trastuzumab group. In multivariable analysis, trastuzumab was not associated with hypertension (HR 1.01; 95% CI 0.73-1.38). The authors conclude that trastuzumab was not associated with new-onset hypertension among AYA breast cancer survivors.