Therapeutic Benefit of Radiotherapy in Uterine Serous Carcinoma (USC): A Real-World Study
Author(s)
Eleftherios samartzis, MD1, Lucy Gilbert, MD2, Vincent McCarty, MSc3, Neil R. Brett, PhD4, Marielle Bassel, BA4, John S. Sampalis, MSc, PhD4.
1University Hospital Zürich, Zurich, Switzerland, 2Department of Oncology, McGill University, Montreal, QC, Canada, 3Department of Surgery, McGill University, Montreal, QC, Canada, 4PPD™ Observational Studies, Thermo Fisher Scientific, Montreal, QC, Canada.
1University Hospital Zürich, Zurich, Switzerland, 2Department of Oncology, McGill University, Montreal, QC, Canada, 3Department of Surgery, McGill University, Montreal, QC, Canada, 4PPD™ Observational Studies, Thermo Fisher Scientific, Montreal, QC, Canada.
OBJECTIVES: USC accounts for 10% of endometrial carcinomas (EC), but accounts for 40% of EC-related deaths, and is associated with high recurrence/poor prognosis. The potential benefit and optimal timing of adjuvant radiotherapy to treat USC remains unclear. The objective was to understand outcomes of USC patients receiving adjuvant radiotherapy and compare them with patients receiving chemotherapy only.
METHODS: This was a retrospective observational cohort study of patients with USC receiving chemotherapy (C) or chemotherapy and adjuvant external beam radiotherapy (EBRT), at the McGill University Health Center between 2008-2023. Follow-up was ≤5 years. Groups were compared, Cox proportional hazards models and multivariate logistic regression identified EBRT responders.
RESULTS: 50 C and 61 EBRT patients were identified. Mean(SD) age of the two groups were 67.3(9.1) and 69.3(8.0) years (P = 0.219), respectively. Higher proportions in C had stage III/IV disease (74% vs 30%; P<0.001), low albumin (12.5% vs. 2%; P= 0.025), malignant cytology (52.0% vs. 15.5%; P=0.046) and lower deficient mismatch repair status (3.0% vs. 15%; P=0.046). There were no between-group differences for other characteristics. Recurrence (58.5% vs. 29.5%; P=0.003) and mortality (44.0% vs. 20.0%; P=0.007) were higher in C. EBRT was associated with a clinically important (statistically non-significant) reduced adjusted progression rate (HR=0.503; P=0.101) and mortality (HR=0.557; P=0.279). In EBRT patients, longer time to chemotherapy relative to EBRT was associated with increased adjusted mortality risk (HR=1.061; P=0.007) and progression (HR=1.066; P=0.035). Progesterone receptor-positive (PR+) (OR=0.123; P<0.001), FIGO stage III/IV (OR=4.075; P=0.020), malignant cytology (OR=6.626; P=0.006) and older age (OR=1.129; P=0.002) were associated with increased adjusted odds of progression.
CONCLUSIONS: Results suggest EBRT may be recommended for USC patients of older age, PR+, Stage III/IV and malignant cytology, and that chemotherapy should be administered prior to EBRT. Results should be confirmed by additional RWE. This study highlights the importance of RWE in optimizing oncology treatment outcomes.
METHODS: This was a retrospective observational cohort study of patients with USC receiving chemotherapy (C) or chemotherapy and adjuvant external beam radiotherapy (EBRT), at the McGill University Health Center between 2008-2023. Follow-up was ≤5 years. Groups were compared, Cox proportional hazards models and multivariate logistic regression identified EBRT responders.
RESULTS: 50 C and 61 EBRT patients were identified. Mean(SD) age of the two groups were 67.3(9.1) and 69.3(8.0) years (P = 0.219), respectively. Higher proportions in C had stage III/IV disease (74% vs 30%; P<0.001), low albumin (12.5% vs. 2%; P= 0.025), malignant cytology (52.0% vs. 15.5%; P=0.046) and lower deficient mismatch repair status (3.0% vs. 15%; P=0.046). There were no between-group differences for other characteristics. Recurrence (58.5% vs. 29.5%; P=0.003) and mortality (44.0% vs. 20.0%; P=0.007) were higher in C. EBRT was associated with a clinically important (statistically non-significant) reduced adjusted progression rate (HR=0.503; P=0.101) and mortality (HR=0.557; P=0.279). In EBRT patients, longer time to chemotherapy relative to EBRT was associated with increased adjusted mortality risk (HR=1.061; P=0.007) and progression (HR=1.066; P=0.035). Progesterone receptor-positive (PR+) (OR=0.123; P<0.001), FIGO stage III/IV (OR=4.075; P=0.020), malignant cytology (OR=6.626; P=0.006) and older age (OR=1.129; P=0.002) were associated with increased adjusted odds of progression.
CONCLUSIONS: Results suggest EBRT may be recommended for USC patients of older age, PR+, Stage III/IV and malignant cytology, and that chemotherapy should be administered prior to EBRT. Results should be confirmed by additional RWE. This study highlights the importance of RWE in optimizing oncology treatment outcomes.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
CO250
Topic
Clinical Outcomes
Topic Subcategory
Clinician Reported Outcomes
Disease
Oncology