Trends in use of radiation therapy, chemotherapy, and combination chemoradiotherapy in advanced uterine cancer before, during, and after GOG 258.

OBJECTIVE: To explore the use of Gynecologic Oncology Group 258 (GOG 258) study regimens before, during, and after the study. METHODS: Patients aged 18 years or older with endometrial cancer between 2004-2019 were identified in the National Cancer Database. Inclusion criteria were stage III or IVA of any histology and stage I-IVA clear cell or serous histologies with positive washings that received adjuvant therapy. Adjuvant therapy use was examined in the pre-GOG 258 era (before 2009), during GOG 258 enrollment and maturation (2010-2017), and after results presentation in 2017 (2018-2019). Two-sided Cochran-Armitage tests, Wilcoxen rank sum tests, and χ2 tests were used for continuous and categorical variables. Multi-variable logistic regression assessed factors associated with the receipt of chemoradiotherapy compared with chemotherapy only or radiation therapy only. RESULTS: From 2004 to 2019, 41 408 high-risk endometrial cancer patients received adjuvant therapy (12% radiation therapy, 38% chemotherapy, 50% chemoradiotherapy). Chemoradiotherapy increased over the GOG 258 study period (40% before study opening, 54% during enrollment, and 59% after results). Serous (OR 0.6, 95% CI 0.6 to 0.7) and clear cell histology (0.7, 0.6 to 0.8), higher grade (0.8, 0.7 to 0.9), and lymph node positivity (0.8, 0.7 to 0.9) were negatively associated with receipt of chemoradiotherapy compared with single-modality treatment. Non-Hispanic Black ethnicity (0.8, 0.8 to 0.9) and residing ≥50 miles from the treatment facility (0.8, 0.7 to 0.9) were also negatively associated with chemoradiotherapy. Private insurance (1.2, 1.0 to 1.4) and treatment at community hospitals (1.2, 1.2 to 1.3) were positively associated with chemoradiotherapy. CONCLUSION: Despite the lack of benefit in the GOG 258 experimental arm, chemoradiotherapy use increased during study enrollment and after results publication.