Endometrial cancer: Predictors of peritoneal failure

Objective. To assess determinants of peritoneal failure in endometrial cancer patients after definitive primary treatment. Methods. Of 599 patients with endometrial cancer who had primary surgery at our institution during the decade before 1994, 131 had relapse. We defined "peritoneal failure" as relapse when it occurred in the upper abdomen or involved the pelvic peritoneum (or both). Mean follow-up was 72.8 months. Results. Peritoneal failure was detected in 37 of 599 (6%) patients and represented 28% of identified failures. Stage IV disease, cervical stromal invasion, adnexal involvement, myometrial invasion >50%, primary tumor diameter >2 cm, positive peritoneal cytology, lymph node metastasis, histologic grade 3, nonendometrioid histologic subtype, absence of associated hyperplasia, and lymphovascular invasion correlated significantly (P < 0.01) with peritoneal failure. However, on regression analysis, only stage IV disease (P < 0.001, relative risk [RR] = 7.53), nonendometrioid histologic subtype (P = 0.02, RR = 3.01), and cervical stromal invasion (P = 0.04, RR = 2.83) were independent predictors of peritoneal failure. Because 22 of 37 (59%) peritoneal failures were in patients with stage IV disease, we considered separately the 545 patients with stage I-III disease. On regression analysis, nonendometrioid histologic subtype (P < 0.001, RR = 11.58), positive peritoneal cytology (P = 0.009, RR = 6.72), lymph node metastasis (P = 0.02, RR = 5.10), and cervical stromal invasion (P = 0.04, RR = 3.10) were independent predictors of peritoneal failure. Of the 38 patients in whom at least two of these four predictors were positive, 26% had peritoneal failure at 5 years, compared with 1% of the 507 patients who had none or only 1 predictor (P < 0.001). Conclusion. Patients with stage IV disease and those with stage I-III disease and at least two of the four independent predictors (nonendometrioid histology, positive peritoneal cytology, cervical stromal invasion, and lymph node metastasis) would be candidates for new therapeutic trials incorporating surgical and adjuvant treatment targeting the entire abdominal cavity.