Microscopic Omental Metastasis in Clinical Stage I Endometrial Cancer: A Meta-analysis

A patient with early-stage endometrial cancer may possibly have microscopic metastasis in the omentum, which is associated with a poor prognosis. The purpose of this study was to identify risk factors for microscopic omental metastasis in patients with clinical stage I endometrial cancer to establish the indications for selective omentectomy. We searched the PubMed, EMBASE, and Cochrane Library databases for published studies from inception to August 2014, using terms such as 'endometrial cancer' or 'uterine cancer' for disease, 'omentectomy' or 'omental biopsy' for intervention, and 'metastasis' for outcome. Two reviewers independently identified the studies that matched the selection criteria. We calculated the pooled risk ratios (RRs) with 95 % confidence intervals (CI) of each surgicopathologic finding for microscopic omental metastases in clinical stage I endometrial cancer. We also calculated the prevalence of microscopic omental metastases. Among 1163 patients from ten studies, 22 cases (1.9 %) of microscopic omental metastases were found, which accounted for 26.5 % of all omental metastases. Positive lymph nodes (RR 8.71, 95 % CI 1.38-54.95), adnexal metastases (RR 16.76, 95 % CI 2.60-107.97), and appendiceal implants (RR 161.67, 95 % CI 5.16-5061.03) were highly associated with microscopic omental metastases. Microscopic omental metastases were not negligible in patients with clinical stage I endometrial cancer. Those with a risk factor of microscopic omental metastases were recommended for selective omentectomy.