Adjuvant chemotherapy with external beamradiation therapy for high-grade, node-positive endometrial cancer

The objective of this study was to evaluate clinical outcomes including disease-free survival (DFS) and overall survival (OS) for women with node-positive, high-grade adenocarcinoma of the uterus.

Database review identified 73 patients with International Federation of Gynecology and Obstetrics stage IIIC 1/2 grade 3 endometrial cancer diagnosed from 1995 to 2009. Study inclusion required total abdominal hysterectomy/bilateral salpingo-oophorectomy and negative chest imaging. Histologic subtypes were endometrioid (22, 30%), papillary serous (20, 27%), clear cell (9, 12%), mixed (21, 29%), and undifferentiated (1, 1%). Adjuvant treatment was chemotherapy with external beam radiation therapy (EBRT) in 55 patients (75%), EBRT alone in 14 (19%), chemotherapy in 2 (3%), and no adjuvant therapy in 2 (3%).

With a median follow-up of 50 months, DFS/OS rates at 5 years were 44%/53%, respectively. Intraperitoneal relapse was more common in patients with positive cytology (30% vs 6%, P = 0.02) and nonendometrioid histology (16% vs 4%, P = 0.3). By histologic subtype, 5-year DFS/OS rates were 59%/82% for grade 3 endometrioid, 25%/30% for serous, 22%/17% for clear cell, and 50%/51% for mixed histology (P = 0.1/P < 0.001). The 5-year DFS/OS rates were 56%/68% for those who received both chemotherapy and EBRT. Among patients treated with adjuvant EBRT, pelvic control was 93%.

For node-positive, high-grade endometrial cancer, patients with endometrioid and mixed histologic subtypes had better clinical outcomes than did those with serous and clear cell cancers. Distinct patterns of relapse were observed with a greater risk of intraperitoneal failure for nonendometrioid histologic subtypes. Future studies are needed to define the optimal chemotherapy regimen and radiation fields.