Long-term results from the phase III NRG258 trial indicate that adjuvant chemoradiation (C-RT) does not improve overall survival compared to chemotherapy (CT) alone in patients with locally advanced endometrial carcinoma. The study, a multicenter trial conducted across the U.S., followed 736 patients with International Federation of Gynecology and Obstetrics (FIGO) stage III or IVA endometrial cancer. The findings, published in the Journal of Clinical Oncology, challenge the role of adjuvant C-RT in this patient population, suggesting CT remains a standard treatment option.
The NRG258 trial, led by Daniela E. Matei, MD, of Northwestern University, randomly assigned patients between June 2009 and July 2014 to either C-RT (cisplatin and volume-directed radiation therapy followed by carboplatin and paclitaxel) or CT alone (carboplatin and paclitaxel). The primary endpoint was recurrence-free survival. While initial reports suggested a benefit of C-RT in reducing local recurrence, this did not translate into improved recurrence-free or overall survival.
Key Findings on Survival Rates
With a median follow-up of 112 months (maximum, 155 months), the median overall survival was not reached in either group. The number of deaths were 134 in the C-RT group and 125 in the chemotherapy group (HR = 1.05, 95% CI = 0.82–1.34, P = .72). These results indicate no statistically significant difference in overall survival between the two treatment arms.
Previously reported data showed that C-RT did not significantly improve recurrence-free survival compared to CT alone (HR = 0.90, 90% CI = 0.74–1.10).
Subgroup Analysis
Subgroup analyses revealed no significant benefit of C-RT across various clinical and pathological factors, including FIGO stage, patient age, race, gross residual disease, histology, lymph-vascular space invasion, and body mass index. This suggests that the lack of overall survival benefit with C-RT is consistent across different patient subgroups.
Implications for Clinical Practice
The trial's results suggest that while C-RT may reduce local recurrence rates, it does not translate into a survival advantage for patients with stage III/IVA endometrial cancer. "Although C-RT reduced the rate of local recurrence compared with CT, it did not increase [overall survival or recurrence-free survival] in stage III/IVA [endometrial cancer]," the investigators concluded. These findings support the continued use of chemotherapy alone as a standard treatment approach for this patient population, potentially sparing patients the added toxicity associated with radiation therapy without compromising survival outcomes.
