Sampling in Atypical Endometrial Hyperplasia: Which Method Results in the Lowest Underestimation of Endometrial Cancer? A Systematic Review and Meta-analysis

Our objective was to identify the most accurate method of endometrial sampling for the diagnosis of complex atypical hyperplasia (CAH), and the related risk of underestimation of endometrial cancer. We conducted a systematic literature search in PubMed and EMBASE (January 1999-September 2013) to identify all registered articles on this subject. Studies were selected with a 2-step method. First, titles and abstracts were analyzed by 2 reviewers, and 69 relevant articles were selected for full reading. Then, the full articles were evaluated to determine whether full inclusion criteria were met. We selected 27 studies, taking into consideration the comparison between histology of endometrial hyperplasia obtained by diagnostic tests of interest (uterine curettage, hysteroscopically guided biopsy, or hysteroscopic endometrial resection) and subsequent results of hysterectomy. Analysis of the studies reviewed focused on 1106 patients with a preoperative diagnosis of atypical endometrial hyperplasia. The mean risk of finding endometrial cancer at hysterectomy after atypical endometrial hyperplasia diagnosed by uterine curettage was 32.7% (95% confidence interval [CI], 26.2-39.9), with a risk of 45.3% (95% CI, 32.8-58.5) after hysteroscopically guided biopsy and 5.8% (95% CI, 0.8-31.7) after hysteroscopic resection. In total, the risk of underestimation of endometrial cancer reaches a very high rate in patients with CAH using the classic method of evaluation (i.e., uterine curettage or hysteroscopically guided biopsy). This rate of underdiagnosed endometrial cancer leads to the risk of inappropriate surgical procedures (31.7% of tubal conservation in the data available and no abdominal exploration in 24.6% of the cases). Hysteroscopic resection seems to reduce the risk of underdiagnosed endometrial cancer.