Combined use of endometrial sample and magnetic resonance imaging in the preoperative risk-stratification of endometrial carcinomas

Abstract

Objective To compare two treatment strategies in women undergoing surgery for endometrial carcinoma. Design Retrospective cohort study. Setting Tertiary care center. Population 1166 patients. Uterine biopsy/curettage was obtained in 1140 women, of whom 229 also had pelvic magnetic resonance imaging (MRI). Methods We compared two strategies: (i) routine pelvic lymphadenectomy and (ii) selective pelvic lymphadenectomy for women with high-risk carcinomas as determined from preoperative histology and MRI. High-risk carcinomas included grade 1-2 endometrioid carcinomas with ≥50% myometrial invasion, grade 3 endometrioid carcinomas, and nonendometrioid carcinomas. Others were considered low-risk carcinomas. Main outcome measures Diagnostic indices, treatment algorithms. Results Of the women who underwent lymphadenectomy, positive pelvic nodes were found in 2.3% of low-risk carcinomas and 18.3% of high-risk carcinomas. The combination of preoperative histology and MRI detected high-risk carcinomas with a sensitivity of 85.7%, a specificity of 75.0%, a positive predictive value of 74.4%, and a negative predictive value of 86.1%. Area under curve was 0.804. In the routine lymphadenectomy algorithm, 54.1% of lymphadenectomies were performed for low-risk carcinomas. In the selective lymphadenectomy algorithm, 14.3% of women with high-risk carcinomas did not receive lymphadenectomy. Missed positive pelvic nodes were estimated to occur in 2.1% of patients in the selective strategy. Similarly, the estimated risk for isolated para-aortic metastasis was 2.1%, regardless of treatment strategy. Conclusions The combination of preoperative histology and MRI is moderately sensitive and specific in detecting high-risk endometrial carcinomas. The clinical utility of the method is hampered by the relatively high proportion of high-risk cases that remain unrecognized preoperatively.