The influence of radiation modality and lymph node dissection on survival in early-stage endometrial cancer.

BACKGROUND: The appropriate uses of lymph node dissection (LND) and adjuvant radiation therapy (RT) for Stage I endometrial cancer are controversial. We explored the impact of specific RT modalities (whole pelvic RT [WPRT], vaginal brachytherapy [VB]) and LND status on survival. MATERIALS AND METHODS: The Surveillance Epidemiology and End Results dataset was queried for all surgically treated International Federation of Gynecology and Obstetrics (FIGO) Stage I endometrial cancers; subjects were stratified into low, intermediate and high risk cohorts using modifications of Gynecologic Oncology Group (GOG) protocol 99 and PORTEC (Postoperative Radiation Therapy in Endometrial Cancer) trial criteria. Five-year overall survival was estimated, and comparisons were performed via the log-rank test. RESULTS: A total of 56,360 patients were identified: 70.4% low, 26.2% intermediate, and 3.4% high risk. A total of 41.6% underwent LND and 17.6% adjuvant RT. In low-risk disease, LND was associated with higher survival (93.7 LND vs. 92.7% no LND, p < 0.001), whereas RT was not (91.6% RT vs. 92.9% no RT, p = 0.23). In intermediate-risk disease, LND (82.1% LND vs. 76.5% no LND, p < 0.001) and RT (80.6% RT vs. 74.9% no RT, p < 0.001) were associated with higher survival without differences between RT modalities. In high-risk disease, LND (68.8% LND vs. 54.1% no LND, p < 0.001) and RT (66.9% RT vs. 57.2% no RT, p < 0.001) were associated with increased survival; if LND was not performed, VB alone was inferior to WPRT (p = 0.01). CONCLUSION: Both WPRT and VB alone are associated with increased survival in the intermediate-risk group. In the high-risk group, in the absence of LND, only WPRT is associated with increased survival. LND was also associated with increased survival.

Duke Scholars

Author Junzo Paul Chino Radiation Oncology

Author Andrew Berchuck Obstetrics and Gynecology, Gynecologic Oncology

Author Angeles Alvarez Secord Obstetrics and Gynecology, Gynecologic Oncology

Author Laura Jean Havrilesky Obstetrics and Gynecology, Gynecologic Oncology