Impact of Adjuvant Radiotherapy on Survival of Patients with Stage I-II Endometrial Cancer

Abstract

Introduction: Endometrial cancer is the most common gynecological neoplasm in developed countries. Most cases are diagnosed early, and surgical treatment is usually curative. The role of adjuvant radiotherapy is controversial, especially for patients with intermediate or high-risk factors. The increasing variety of therapies and emphasis on personalized treatment underscore the need to critically assess the impact of radiotherapy on patient outcomes. Therefore, this study aims to evaluate the impact of adjuvant radiotherapy on clinical outcomes in patients with endometrial cancer who have intermediate or high-risk factors. Methods: The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The protocol was registered on the PROSPERO platform. A literature search was conducted in PubMed/MEDLINE, Embase, Scopus, Web of Science, Lilacs, and SciELO. The search covered publications up to August 2025. Controlled descriptors (MeSH) and free keywords were used, combined with Boolean operators. Original studies with clinical data on patients undergoing adjuvant radiotherapy, published in Portuguese, English, or Spanish, were included. Results: After screening and evaluating the full texts, 12 studies were included, totaling 18,975 patients. The studies analyzed different radiotherapy modalities, such as external beam radiotherapy, vaginal brachytherapy, and combination therapy with chemotherapy. The results demonstrated that adjuvant radiotherapy significantly contributes to reducing locoregional recurrence and improving disease-free survival, especially in patients with risk factors such as high tumor grade, lymphovascular invasion, or malignant peritoneal cytology. Vaginal brachytherapy showed similar efficacy to external beam radiotherapy in many cases, with less toxicity. Recent studies propose selective treatment deintensification and the use of molecular profiles to guide radiotherapy indications, as evidenced in the PORTEC-4a clinical trial. Conclusions: Adjuvant radiotherapy plays a relevant role in the management of early-stage endometrial cancer and should be indicated selectively based on clinical, histological, and molecular criteria.