Trastuzumab Deruxtecan (T-DXd) is a humanized anti-HER2 monoclonal antibody covalently linked to DXd, which is a topoisomerase 1 inhibitor. T-DXd has been approved for the treatment of HER2-positive breast cancer, HER2-mutated lung cancer, HER2-positive gastric cancer, and HER2-low breast cancer in Taiwan. Aside from clinical benefits in the above cancers, the DESTINY-PanTumor02 (NCT04482309) Phase II trial showed that T-DXd continued to demonstrate clinically meaningful and durable responses and survival benefits in previously treated patients across multiple HER2-expressing advanced solid tumors. Among multiple types of solid tumors in the DESTINY-PanTumor02 trial, T-DXd showed a high confirmed objective response rate in heavily treated HER2 IHC 3+ endometrial cancer (EC, 84.6%, 11/13), ovarian cancer (OC, 63.6%, 7/11), and cervical cancer (CC, 75%, 6/8). Previous evidence showed that HER2-expressing gynecologic cancers have limited treatment options and have poor prognoses under standard therapies. Data from DESTINY-PanTumor02 therefore serve as supporting evidence for T-DXd to become a potential therapeutic option for these HER2-expressing gynecologic cancers. In August 2023, T-DXd received the FDA-designated breakthrough therapy designations and was approved in April 2024 for treating unresectable and metastatic HER2 IHC 3+ solid tumors that have progressed after prior treatment or lack satisfactory alternative options. The National Comprehensive Cancer Network (NCCN) has included T-DXd as a treatment option for HER2-positive endometrial, ovarian, and cervical carcinomas in their guidelines as of V1 2024. However, the prevalence rate of HER2 IHC 3+ in recurrent advanced endometrial, ovarian, and cervical cancers in Taiwan remains unclear. Limited information is available regarding the HER2 amplification rate by ISH for specific cancer types. In this retrospective, non-interventional study, the investigators aim to explore the prevalence of HER2 IHC 3+ in recurrent advanced endometrial, ovarian, and cervical cancers in Taiwan. The clinicopathologic characteristics will also be described, using information abstracted from the medical charts, to better understand and characterize the patient profiles of recurrent advanced endometrial, ovarian, and cervical cancers in Taiwan.