Majority of endometrial cancer patients present with early - stage disease and generally carries an overall good prognosis. Treatment typically consists of surgery and the need for adjuvant therapy is based primarily on the stage of the disease and other prognostic factors. Lower uterine segment (LUS) involvement though not currently included in the FIGO staging for endometrial cancer and prognostic factors for adjuvant treatment, may play a role in the managementof early stage endometrial cancer.

The aim of the study is to investigate the overall survival (OS) and recurrence free survival (RFS) of early stage endometrioid endometrial cancer (EEC) with LUS involvement and to detect its association with other prognostic factors.

This is a retrospective study which included patients diagnosed with stage l EEC who underwent surgical staging at a single institution from January 2004 – December 2014. The 5 year OS and RFS of patients with or without LUS involvement were documented and analyzed. Of the 142 cases, 36 (25.4%) had LUS involvement. The 5 year OS of patients with positive and negative LUS involvement were significantly different at 83.8% and 95.4% respectively (p value = 0.039). There was no significant difference in their RFS at 87.5% and 87.8% respectively (p value = 0.807). LUS involvement was significantly associated with deeper myometrial invasion, presence of lymphovascular space invasion and larger tumor size of euqal to or greater than 2 cm. LUS involvement warrants consideration when deciding upon surgical staging and giving adjuvant treatment in patients with stage l EEC.