Immunohistochemical expression of ER and PR and outcomes in patients with newly diagnosed uterine leiomyosarcoma.

Abstract

5076 Background: To assess the immunohistochemical (IHC) expression of estrogen receptor (ER) and progesterone receptor (PR) in patients with uterine leiomyosarcoma (LMS). To assess the prognostic significance of ER and PR expression in LMS. Methods: We identified all cases of uterine LMS at our institution from 7/82-7/07 for whom ER and PR IHC analysis was performed at initial diagnosis. We only included cases considered high grade and in which IHC was performed at our institution. Cases were also excluded if the only IHC analysis was from tissue obtained at the time of recurrence or progression. ER or PR IHC expression was considered positive (+) if more than 5% of cells stained. Progression-free (PFS) and overall survival (OS) were estimated using Kaplan-Meier estimates and compared with log-rank test where indicated. Results: We identified 43 cases of high-grade LMS. Median age was 52 years (26-73). Disease was confined to the uterine body in 20 cases (47%). Eighteen (42%) of 43 cases were ER+ and 17/42 (41%) were PR+. At last follow-up, 33 (77%) had recurred or progressed and 23 (54%) had died. Median follow-up for survivors was 48.4 months (4-142.4). PR+, but not ER+, was associated with improved PFS (p = 0.002) and OS (p = 0.03). Adjusting for stage, ER expression was associated with PFS (p = 0.01), but not OS (p = 0.3). PR expression maintained its significant association with both PFS (p = 0.002) and OS (p = 0.05) after adjusting for stage. Neither ER or PR expression was associated with outcome in cases with disease outside the uterine body. However, in cases with disease confined to the uterine body, the median PFS for ER+ or PR+ cases was not reached for both compared to 16.9 months (95% CI: 8.1-25.7) for ER- cases (p = 0.03) and 13.5 months (95% CI: 5.9-21.1) for PR- cases (p = 0.001). In the 10 PR+ patients, only 1 recurred and died compared to the 10 PR- patients, in which 9 recurred and 5 died. In the 9 ER+ patients, 2 recurred and died compared to the 11 ER+ patients, in which 8 recurred and 4 died. Conclusions: ER and PR expression is associated with outcome in patients with true high-grade uterine LMS confined to the uterine body. PR expression seems able to identify cases confined to the uterine body that will have the best outcomes. No significant financial relationships to disclose.