Multi-institutional study on the role of post-operative radiotherapy in elderly patients with endometrial cancer

To investigate the prognostic factors for survival and toxicities in elderly (≥65 years) patients with endometrial cancer who underwent post-operative radiotherapy. Additionally, to compare the treatment outcomes between the older elderly (≥75 years) and younger elderly (65-74 years) patients.

Medical records of patients with enometrial cancer treated between January 1998 and July 2019 were reviewed. Patients with stage IA to IIIC2, all histology subtypes, and any grade were included. All patients underwent total abdominal hysterectomy and received adjuvant radiotherapy with or without chemotherapy. All but 67 (8.4%) of 801 patients had lymph node dissection. Clinicopathological factors and treatment strategies were compared between the two age groups. The prognostic factors for overall survival and progression-free survival were investigated.

A total of 801 patients with enometrial cancer, 627 patients (78.3%) younger elderly and 174 patients (21.7%) in the older elderly group were included. Median follow-up was 74.3 months (range 0.4-224.6). The older elderly patients had significantly higher rates of grade 3 tumors (51.7% vs 40.8%; p=0.04), cervical glandular involvement (21.8% vs 14.0%; p=0.03), and cervical stromal invasion (34.5% vs 27.9%; p=0.04) than the younger elderly patients. The rates of lymph node dissection (p=0.2), radiotherapy modalities (p=0.92), and systemic chemotherapy (p=0.2) did not differ between the two groups. The 5-year locoregional control and distant metastasis rates were 88.3% and 23.8%, respectively. The 5-year cause-specific survival and progression-free survival rates for younger and older elderly patients, were 79.8% vs 74.3% (p=0.04) and 67.5% vs 57.8% (p<0.001), respectively. In multivariate analysis, larger tumor size, non-endometrioid histology, cervical stromal involvement, and stage III disease were associated with poor cause-specific survival and progression-free survival. Age was an independent predictor of worse progression-free survival, but not of cause-specific survival. There was no significant difference in acute and late gastrointestinal and genitourinary toxicities between age groups.

Post-operative radiotherapy for elderly patients with endometrial cancer is effective and well tolerated. Advanced age should not preclude appropriate treatment, especially in those with adequate quality of life, life expectancy, and functional status.