Postoperative Radiotherapy for Endometrial Cancer in Elderly (≥80 Years) Patients: Oncologic Outcomes, Toxicity, and Validation of Prognostic Scores

SIMPLE SUMMARY: As population ages, understanding of frailty in cancer patients becomes all the more important. Due to the rarity of elderly patients in randomized prospective trials, only limited data exist regarding safety and feasibility of postoperative radiotherapy for very elderly women of 80 years or older in a curative treatment intent. Further, geriatric assessments and prognostic scores for these women are not sufficiently validated. In a homogenous cohort of very elderly women with endometrial cancer, we confirmed that, despite older age, adjuvant radiotherapy can achieve excellent local control and overall survival with minimal high-grade toxicity. The geriatric G8 screening score was a highly applicable tool for prognostic evaluation of overall survival in our review. ABSTRACT: Endometrial cancer is a common malignancy in elderly women that are more likely to suffer from limiting medical comorbidities. Given this narrower therapeutic ratio, we aimed to assess the oncologic outcomes and toxicity in the adjuvant setting. Out of a cohort of 975 women, seventy patients aged ≥ 80 years, treated with curative postoperative radiotherapy (RT) for endometrial cancer between 2005 and 2021, were identified. Outcomes were assessed using Kaplan–Meier-analysis and comorbidities using the Charlson Comorbidity Index and G8 geriatric score. The overall survival at 1-, 2- and 5-years was 94.4%, 82.6%, and 67.6%, respectively, with significant correlation to G8 score. At 1- and 5-years, the local control rates were 89.5% and 89.5% and distant control rates were 86.3% and 66.9%, respectively. Severe (≥grade 3) acute toxicity was rare with gastrointestinal (2.9%), genitourinary (1.4%), and vaginal disorders (1.4%). Univariate analysis significantly revealed inferior overall survival with lower RT dose, G8 score, hemoglobin levels and obesity, while higher grading, lymphangiosis, RT dose decrease and the omission of chemotherapy reduced distant control. Despite older age and additional comorbidities, elderly patients tolerated curative treatment well. The vast majority completed treatment as planned with very low rates of acute severe side-effects. RT offers durable local control; however, late distant failure remains an issue.