Objective: The purpose of this study was to determine whether para-aortic lymphadenectomy improves disease-related survival (DRS) in stage IIIc endometrial cancer.
Methods: A total of 63 patients with stage IIIc endometrial carcinoma underwent primary radical surgery in the Tohoku Gynecologic Cancer Unit from 1993 to 2004. All patients had modified radical hysterectomy, bilateral salpingo-oophorectomy, systemic pelvic lymph node (PLN) adenectomy, and with or without para-aortic lymph node (PAN) adenectomy, followed by adjuvant chemotherapy. DRS was analyzed using Kaplan-Meier curves and the log-rank test. Independent prognostic factors were determined by multivariate Cox regression analysis using a forward stepwise selection.
Results: There were no statistical differences in age distribution and histopathological prognostic factors between PLN adenectomy group (n=25) and PLN+PAN adenectomy group (n=38). On univariate analysis, architectural grade (p=0.026), peritoneal cytology (p=0.033), and the number of PLN positive sites (</=1 or >/=2) (p=0.010) were related to poor DRS. On multivariate Cox regression analysis, the number of positive PLN sites was related to DRS (p=0.040). In positive PLN>/=2 sites group (n=33), PAN adenectomy significantly improved DRS compared to PLN adenectomy alone (p=0.011). The incidence of initial PAN recurrence was higher in the PLN adenectomy group (6/25) than in the PLN+PAN adenectomy group (1/38) (p=0.013, Odds Ratio=11.68).
Conclusions: The number of positive PLN site is an independent prognostic factor in stage IIIc endometrial cancer. PAN adenectomy decreased the incidence of PAN recurrence and may improve DRS in patients with >/=2 positive PLN sites. A large prospective clinical trial needs to be conducted to establish the strategy of PAN adenectomy before or intra-operative treatment.