Survival effect of para-aortic lymphadenectomy in endometrial cancer (SEPAL study): a retrospective cohort analysis

Background: In response to findings that pelvic lymphadenectomy does not have any therapeutic benefit for endometrial cancer, we aimed to establish whether complete, systematic lymphadenectomy, including the para-aortic lymph nodes, should be part of surgical therapy for patients at intermediate and high risk of recurrence.

Methods: We selected 671 patients with endometrial carcinoma who had been treated with complete, systematic pelvic lymphadenectomy (n=325 patients) or combined pelvic and para-aortic lymphadenectomy (n=346) at two tertiary centres in Japan (January, 1986-June, 2004). Patients at intermediate or high risk of recurrence were offered adjuvant radiotherapy or chemotherapy. The primary outcome measure was overall survival.

Findings: Overall survival was significantly longer in the pelvic and para-aortic lymphadenectomy group than in the pelvic lymphadenectomy group (HR 0.53, 95% CI 0.38-0.76; p=0.0005). This association was also recorded in 407 patients at intermediate or high risk (p=0.0009), but overall survival was not related to lymphadenectomy type in low-risk patients. Multivariate analysis of prognostic factors showed that in patients with intermediate or high risk of recurrence, pelvic and para-aortic lymphadenectomy reduced the risk of death compared with pelvic lymphadenectomy (0.44, 0.30-0.64; p<0.0001). Analysis of 328 patients with intermediate or high risk who were treated with adjuvant radiotherapy or chemotherapy showed that patient survival improved with pelvic and para-aortic lymphadenectomy (0.48, 0.29-0.83; p=0.0049) and with adjuvant chemotherapy (0.59, 0.37-1.00; p=0.0465) independently of one another.

Interpretation: Combined pelvic and para-aortic lymphadenectomy is recommended as treatment for patients with endometrial carcinoma of intermediate or high risk of recurrence. If a prospective randomised or comparative cohort study is planned to validate the therapeutic effect of lymphadenectomy, it should include both pelvic and para-aortic lymphadenectomy in patients of intermediate or high risk of recurrence.

Funding: Japanese Foundation for Multidisciplinary Treatment of Cancer, and the Japan Society for the Promotion of Science.