Differential Expression of ER-α and ER-β in Pancreatic Neoplasms: A Case-Matched Study

Abstract

Introduction: The discovery of two forms of estrogen receptors, has mandated to reconsider findings of earlier studies and re-examine their expression in tumours that were previously thought negative. This study aimed to assess the expression of the two estrogen receptor types in benign and malignant pancreatic lesions. Method: A case-matched study was performed between benign and malignant pancreatic lesions of patients with similar age, gender and tumour size. ER-αand ER-β expression was assessed by immunohistochemistry and scored using two established scoring systems. Statistical analysis was performed between the two groups as well as with other histological factors and oncological outcomes. Results: A total of 209 patients were identified. After implementation of matching criteria, 16 benign lesions and 32 malignant lesions were analysed. ER-α was detected in 31,25% of benign tumours but in no malignant tumour (p=0,003). ER-β was positive in 31,25% of benign and 37,5% of malignant tumours (p=0,757). No statistically significant correlation was found between ER-β expression and other histological or clinical parameters. Conclusions: Pancreatic adenocarcinomas do not express ER-α, which might explain failure of relevant earlier clinical trials, but do express ER-βat a considerable rate, which supports the need for further targeted studies. Tabled 1EP02C-028Full cohortMatched casesTotaln=209Pancreatic Adenocarcinomas n=129Benign lesions n=22Pancreatic Adenocarcinomas n=32Benign lesions n=16P value**Age*66 (24-87)67 (45-87)63 (24-82)64 (45-87)63 (49-82)0,734gender†91 (43,54)96 (74,42)17 (77,27)24 (75)12 (75)1,000size‡4 (1,2-17)3,5 (1,2-8)5 (1,8-17)3,5 (1,2-9)4,5 (1,8-10)0,187Grade§I29 (22,48)4 (12,5)II60(46,51)22 (68,75)III40 (31,01)6 (18,75)*in years, median (range)†female, n (percentage)‡in cm, median (range)§n (percentage)**comparison between case-match groups Open table in a new tab *in years, median (range) †female, n (percentage) ‡in cm, median (range) §n (percentage) **comparison between case-match groups