Mucinous differentiation of endometrioid endometrial carcinoma: Impact on pathology features and survival outcomes

Abstract

Objective: Mucinous differentiation of endometrioid adenocarcinoma refers to the presence of a mucinous component that does not exceed 50% of the surface of the tumor. It has been associated with improved survival outcomes. In the present systematic review, we summarize the evidence to provide a robust result concerning the prognostic significance of this histologic variant. Methods: We systematically searched Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar databases in our primary search along with the reference lists of electronically retrieved full-text papers. Results: Four retrospective observational studies were included in the present meta-analysis that involved 1.501 patients. Patients with mucinous differentiation of endometrioid carcinomas had similar odds of deep myometrial invasion compared to patients with endometrioid carcinoma (OR 1.00, 95% CI 0.62, 1.59) as well as of developing lymphovascular space invasion (OR 1.00, 95% CI 0.59, 1.71) or lymph node metastases (OR 0.89, 95% CI 0.39, 2.05). Recurrence free survival of these patients (OR 0.59, 95% CI 0.03, 10.42) were also similar to those of patients with endometrioid endometrial carcinoma. Conclusion: Mucinous differentiation of endometrioid endometrial carcinoma does not appear to be associated with significantly increased risk of lymph node metastases, lymphovascular space invasion or deep myometrial invasion. Concurrently, there is no evidence to support its association with decreased progression free or overall survival rates.