Progesterone and Estrogen Receptor Expression Are Prognostic Markers for Endometrioid and High-Grade Serous Ovarian Cancer

Blogger's Note: see prior post of the original; (Lancet Oncology); 2nd (easier to read) posting below 

The ASCO Post

Study Details

In the study, 12 studies participating in the Ovarian Tumor Tissue Analysis consortium contributed tissue microarray sections and clinical data from women who had been diagnosed with invasive serous, mucinous, endometrioid, or clear-cell carcinomas of the ovary. For a patient to be eligible, tissue microarrays, clinical follow-up data, age at diagnosis, and tumor grade and stage had to be available. PR and ER status was assessed by central immunohistochemistry analysis done by blinded pathologists. PR and ER staining was defined as negative (< 1% tumor cell nuclei), weak (1% to < 50%), or strong (≥ 50%).
A total of 2,933 women with invasive epithelial ovarian cancer were included in the analysis, consisting of 1,742 with high-grade serous carcinoma, 110 with low-grade serous carcinoma, 207 with mucinous carcinoma, 484 with endometrioid carcinoma, and 390 with clear-cell carcinoma.

PR and ER Expression
PR and ER expression differed among ovarian cancer subtypes. The proportion of tumors that stained positive (weak or strong) for PR was highest for endometrioid carcinoma (67%) and low-grade serous carcinoma (58%), intermediate for high-grade serous carcinoma (31%), and lowest for mucinous carcinoma (17%) and clear-cell carcinoma (8%).
More tumors stained positive for ER than for PR in all subtypes, with the proportion of ER-positive tumors being highest for low-grade serous carcinoma (87%) and high-grade serous carcinoma (81%) and lowest for mucinous carcinoma (21%) and clear-cell carcinoma (20%). For ER-positive tumors, coexpression of PR was most likely for endometrioid carcinoma (82%) and least likely for high-grade serous carcinoma (34%) and clear-cell carcinoma (32%).
The proportion of tumors that were ER- or PR-positive or both was highest for low-grade serous carcinoma (91%), high-grade serous carcinoma (84%), and endometrioid (82%) tumors and lowest for mucinous carcinoma (23%) and clear-cell carcinoma (21%).....

.....They further noted that the magnitude of these effects is similar to the protective effect of germline BRCA mutations on ovarian cancer survival and that the effects were stronger than the observed associations of grade and extent of residual disease with survival in endometrioid carcinoma.
The authors concluded, “PR and ER are prognostic biomarkers for endometrioid and high-grade serous ovarian cancers. Clinical trials, stratified by subtype and biomarker status, are needed to establish whether hormone-receptor status predicts response to endocrine treatment, and whether it could guide personalized treatment for ovarian cancer.”