Evaluation of immunotherapy response in the radiated field in patients with recurrent endometrial and cervical cancer

OBJECTIVES: Historical data suggest chemotherapy responses are poor in gynecologic cancer patients with recurrence in previously radiated fields, but the effectiveness of immunotherapy (IO) in this setting remains unclear. This study evaluated IO response and survival in patients with endometrial (EC) and cervical cancer (CC) with recurrence within or outside the radiated field. METHODS: A retrospective, single-institution cohort study was conducted in EC and CC patients treated with IO between 2017 and 2023. Patients were categorized by recurrence site: (1) within the radiated field, (2) both in and out of the radiated field, and (3) outside the radiated field. Descriptive and univariate analyses were performed. Progression-free survival (PFS) was defined from IO initiation to progression or death, and overall survival (OS) from diagnosis to death. Kaplan-Meier methods assessed survival. RESULTS: Seventy-four patients with EC and 59 with CC were included. In EC, 12% recurred within the radiated field, 32% both in and out, and 55% outside. In CC, 20% recurred within the radiated field, 44% both in and out, and 36% outside. Complete response rates (CRR) and survival outcomes were similar across groups. For EC, CRRs were 44.4%, 20.8%, and 25.6% (p = 0.58) with median PFS of 86.5, 9.7, and 6.8 months, respectively. For CC, CRRs were 16.7%, 24%, and 10% (p = 0.31) with median PFS of 12.2, 4.6, and 3.4 months. CONCLUSIONS: IO response and survival outcomes did not differ by recurrence location relative to prior radiation fields in recurrent EC or CC.