As reported in the Journal of Clinical Oncology by Ann H. Klopp, MD, PhD, and colleagues, results from an NRG Oncology/GOG trial showed “excellent” progression-free survival outcomes with radiation therapy alone for local recurrences of endometrial cancer, with the addition of cisplatin in chemoradiation adding no benefit.
Ann H. Klopp, MD, PhD
Study Details
In the U.S. multicenter trial, 156 eligible patients were randomly assigned between February 2008 and August 2020 to receive radiation therapy alone (n = 74) or radiation therapy plus cisplatin (n = 82). All patients received external-beam radiation therapy (EBRT) to the whole pelvis followed by a boost to the recurrent tumor; EBRT was given at 4,500 cGy in 25 fractions to target gross disease, with targeted sites including the vagina and pelvic lymph nodes. In the chemoradiation group, concurrent cisplatin was given at 40 mg/m2 once weekly for a planned total of five cycles. The primary objective of the study was to determine whether chemoradiation improved progression-free survival vs radiation therapy alone.
Key Findings
A total of 82% of patients had recurrences of grade 1 or 2 endometrioid histology. A total of 86% had recurrences confined to the vagina.
Median follow-up for progression-free survival was 62 months (maximum = 128 months). Median progression-free survival was not reached in the radiation therapy group vs 73 months in the chemoradiation group (hazard ratio for chemoradiation vs radiation therapy = 1.25, 95% confidence interval [CI] = 0.75–2.07). At 3 years, 73% of patients in the radiation therapy group vs 62% in the chemoradiation group were alive and free of disease progression.
Grade ≥ 3 toxicity occurred in 57% of patients in the chemoradiation group vs 31% of the radiation therapy group. Rates of acute toxicity of any grade were higher in the chemoradiation group for auditory events (P = .012), constitutional symptoms (P = .016), blood/bone marrow events (P < .001), musculoskeletal events (P = .032), metabolic events (P = .001), ocular events (P = .025), neurologic events (P = .05), and vascular events (P = .014); gastrointestinal events were more common in the radiation therapy group (P = .042). No significant differences were observed for late toxicities.
The investigators concluded, “Excellent outcomes can be achieved for women with localized recurrences of endometrial cancer when treated with radiation therapy. The addition of chemotherapy does not improve progression-free survival for patients treated with definitive radiation therapy for recurrent endometrial cancer and increases acute toxicity. Patients with low-grade and vaginal recurrences who constituted the majority of those enrolled are best treated with radiation therapy alone.”
Dr. Klopp, of the Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by grants from the National Cancer Institute. For full disclosures of the study authors, visit ascopubs.org.
