Expression of estrogen receptor beta isoforms in pancreatic adenocarcinoma

// Mamoun Younes 1 , Charles J. Ly 1 , Kanchan Singh 2 , Atilla Ertan 2 , Pamela S. Younes 1 and Jennifer M. Bailey 2 1 Departments of Pathology and Laboratory Medicine, University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, USA 2 Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition, University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, USA Correspondence to: Mamoun Younes, email: mamoun.younes@uth.tmc.edu Keywords: estrogen receptor; proliferative activity; quantitative biomarker analysis; image analysis; pancreas Received: August 29, 2018      Accepted: December 13, 2018      Published: December 28, 2018 ABSTRACT Limited studies have shown that some patients with pancreatic adenocarcinoma (PAC) may benefit from treatment with tamoxifen. PAC has been shown to be largely negative for estrogen receptor alpha (ER-alpha). The aim of this pilot study was to investigate ER-beta expression in human PAC. Sections of tissue microarray with 18 evaluable cases of human PAC were stained by immunohistochemistry (IHC) for ER-beta1, ER-beta2, ER-beta5, and Cyclin A. The levels of ER-beta isoform expression and the S-phase fraction (SPF) were determined using quantitative digital image analysis. Higher mean and median ER-beta2 levels correlated with male sex ( p = 0.057 and p = 0.035, respectively), older age ( p = 0.005 and p = 0.006, respectively), and lower pT stage ( p = 0.008 and p = 0.009). Mean and median ER-beta5 levels correlated negatively with SPF ( p = 0.021 and p = 0.047, respectively). Mean ER-beta1 expression did not correlate with any of the above mentioned clinicopathologic factors. The findings in this pilot study, although should be considered preliminary, suggest that some ER-beta isoforms may play a role in the biology of PAC. Additional larger studies are needed to confirm our findings, and to determine whether ER-beta may be considered for future targeted therapy.