Adjuvant radiotherapy for FIGO 2023 stage IC endometrial carcinoma

Within the International Federation of Gynecology and Obstetrics (FIGO) 2023 staging framework, stage IC endometrial carcinoma denotes tumors with aggressive histology confined to the endometrium, without myometrial invasion. This study evaluated treatment outcomes and survival following adjuvant radiotherapy (RT).

Twenty-eight patients diagnosed with FIGO 2023 stage IC endometrial carcinoma who were treated with adjuvant RT were retrospectively analyzed.

The most common histologic subtype was serous carcinoma (39%), followed by clear cell carcinoma (25%), high-grade endometrioid carcinoma (25%), carcinosarcoma (7%), and undifferentiated carcinoma (4%). Half of the patients received RT alone, while the remainder received combined RT and chemotherapy. Vaginal brachytherapy was the predominant adjuvant RT technique (86%). The median duration of observation was 59 months. The 2-and 5-year overall survival (OS) rates were 96% and 87; locoregional recurrence-free survival (LRRFS) rates were 96% and 82; and distant metastasis-free survival (DMFS) rates were 92% and 80%, respectively. The presence of malignant peritoneal cytology during surgical staging predicted significantly poorer 5-year OS (93% vs. 33%), LRRFS (86% vs. 33%), and DMFS (90% vs. 0%). Within this limited cohort, the addition of chemotherapy to adjuvant RT did not confer a clear survival advantage. No severe treatment-related toxicities were observed.

While patients with FIGO 2023 stage IC endometrial carcinoma typically achieve favorable outcomes after adjuvant RT, malignant peritoneal cytology remains an adverse prognostic factor. In this subgroup, escalation of adjuvant therapy, such as combination chemotherapy, may be appropriate.