Predictors of lymphatic failure in endometrial cancer

Objective. The aim of this study was to identify determinants of lymphatic failure in patients with endometrial cancer after definitive primary treatment. Methods. We observed 142 relapses in endometrial cancer patients who had primary surgery at our institution during the decade before 1994. We defined lymphatic failure as a relapse occurring on the pelvic sidewall (PSW), para-aortic area (PAA), or other node-bearing area (i.e., groin, axilla, supraclavicular, mediastinal). Mean follow-up was 72.8 months. Results. We observed 44 instances of lymphatic failure - 6 on the PSW only, 16 in the PAA only, 12 concomitantly in the PAA and on the PSW, and 10 confined in other node-bearing areas. By univariate analysis, body mass index ≥30 kg/m², para-aortic lymph node biopsy, cervical stromal invasion (CSI), positive adnexa, myometrial invasion ≥50%, primary tumor diameter ≥2 cm, positive peritoneal cytology, positive lymph nodes (pelvic and/or para-aortic), radiotherapy, grade 3 tumor, nonendometrioid histology, and lymph-vascular invasion (LVI) significantly (P ≤ 0.05) correlated with lymphatic failure. However, on Cox regression analysis, only LVI (P < 0.01, relative risk [RR] = 4.27), nodal involvement (P = 0.02, RR = 3.43), and CSI (P = 0.049, RR = 2.26) were independent predictors of lymphatic failure. Moreover, lymph node metastases (P = 0.01, RR = 19.82) and CSI (P = 0.050, RR = 3.57) independently predicted failure on the PSW, and only lymph node involvement (P < 0.01, RR = 10.15) predicted relapse in the PAA. Conclusion. LVI, positive lymph nodes, and CSI were the strongest predictors of lymphatic failure in endometrial cancer (31% of patients with at least one of the above three variables had a failure at 5 years). Patients with none of the above three factors had an extremely low (<1%) risk of lymphatic failure.