Human epidermal growth factor receptor 2 targeted agents in gynecologic cancers: an updated review

Human epidermal growth factor receptor 2 (HER2) is a well-established oncogenic target across several solid tumor types and is associated with advanced disease and aggressive biology among gynecologic cancers. Experts have recommended HER2 testing algorithms to guide the treatment of advanced or recurrent endometrial cancers, but these guidelines utilize an outdated version of the recommendations for HER2 testing in breast cancers. Additionally, similar consensus guidelines do not exist for HER2 testing and reporting in ovarian or cervical cancers, leading to inconsistent HER2 measurement in clinical trials and real-world practice across all 3 gynecologic cancer types. Nonetheless, accumulating data support the efficacy of HER2-targeted treatment in gynecologic cancers, generating urgency to standardize HER2 measurement for these cancers. Practitioners also need to gain familiarity with the potential impacts on cardiac and respiratory function and the concomitant drug interactions of existing and developing HER2-targeted therapies. This review clarifies HER2 terminology and testing, discusses completed and ongoing clinical trials, and synthesizes recommendations for the use of HER2-directed agents in gynecologic cancers.