Efficacy of systematic pelvic lymphadenectomy in endometrial cancer (MRC ASTEC trial): a randomised study

Abstract

Background: Hysterectomy and bilateral salpingo-oophorectomy (BSO) is the standard surgery for stage I endometrial cancer. Systematic pelvic lymphadenectomy has been used to establish whether there is extra-uterine disease and as a therapeutic procedure; however, randomised trials need to be done to assess therapeutic efficacy. The ASTEC surgical trial investigated whether pelvic lymphadenectomy could improve survival of women with endometrial cancer.

Methods: From 85 centres in four countries, 1408 women with histologically proven endometrial carcinoma thought preoperatively to be confined to the corpus were randomly allocated by a minimisation method to standard surgery (hysterectomy and BSO, peritoneal washings, and palpation of para-aortic nodes; n=704) or standard surgery plus lymphadenectomy (n=704). The primary outcome measure was overall survival. To control for postsurgical treatment, women with early-stage disease at intermediate or high risk of recurrence were randomised (independent of lymph-node status) into the ASTEC radiotherapy trial. Analysis was by intention to treat. This study is registered, number ISRCTN 16571884.

Findings: After a median follow-up of 37 months (IQR 24-58), 191 women (88 standard surgery group, 103 lymphadenectomy group) had died, with a hazard ratio (HR) of 1.16 (95% CI 0.87-1.54; p=0.31) in favour of standard surgery and an absolute difference in 5-year overall survival of 1% (95% CI -4 to 6). 251 women died or had recurrent disease (107 standard surgery group, 144 lymphadenectomy group), with an HR of 1.35 (1.06-1.73; p=0.017) in favour of standard surgery and an absolute difference in 5-year recurrence-free survival of 6% (1-12). With adjustment for baseline characteristics and pathology details, the HR for overall survival was 1.04 (0.74-1.45; p=0.83) and for recurrence-free survival was 1.25 (0.93-1.66; p=0.14).

Interpretation: Our results show no evidence of benefit in terms of overall or recurrence-free survival for pelvic lymphadenectomy in women with early endometrial cancer. Pelvic lymphadenectomy cannot be recommended as routine procedure for therapeutic purposes outside of clinical trials.

Figure 1

ASTEC trial design

Figure 2

Profile of ASTEC surgical trial We did not collect logs of patients assessed for eligibility. TAH=total abdominal hysterectomy. BSO=bilateral salpingo-oophorectomy. H=hysterectomy.

Figure 3

Overall survival (A), disease and treatment-related deaths (B), and recurrence-free survival (C) by treatment group

Figure 4

Kaplan-Meier plots for the two treatment groups for overall and recurrence-free survival together with the model curves from fitting the Royston-Parmar parametric model A and B show Kaplan-Meier estimates, with Royston-Parmar parametric model fitted. C and D show the absolute difference over time (95% CI) in survival from Royston-Parmar parametric model.

Figure 5

Effect of lymphadenectomy on overall survival (A) and recurrence-free survival (B) in women in different risk groups of recurrence O–E=observed minus expected. Outer bars show 99% CI, inner bars show 95% CI.