The prognostic significance of oestrogen and progesterone receptors (ER/PR) in endometrial stromal sarcoma (ESS) has conflicting reports in the literature, and the routine use of adjuvant progestogen is of uncertain efficacy.

To examine the prognostic significance of ER/PR positivity and of primary adjuvant progestogen use with outcome in ESS.

Materials and Methods
All women with a diagnosis of ESS in our tertiary institution and associated private practices over the last 23 years were included. Primary variables were ER/PR positivity and adjuvant progestogen use. Other variables included high‐grade disease and extrauterine disease. The primary outcome was survival, and the secondary outcome was recurrence‐free survival (both overall and at 5 years). Survival was calculated using the Kaplan–Meier method. Univariate analyses were performed with t‐test for means and chi‐squared test for proportions, and multivariate analysis was used to control for age.

35 women were included. ER/PR positivity was associated with a survival benefit (OR death 0.22, P = 0.02), but primary adjuvant progestogen was not. High‐grade disease (OR 13, P = 0.02) and extrauterine disease (OR 8.7, P = 0.04) were associated with decreased survival. No variable significantly affected recurrence‐free survival. Eight of ten cases of recurrence treated with progestogen have survived more than 3 years.

ER/PR positivity appears to be useful for prognosis, but routine administration of primary adjuvant progestogen is not supported. There may be a role for progestogen in ER/PR positive tumours with recurrence or incomplete surgical clearance, but further research is required.