A possible divergent role for the oestrogen receptor alpha and beta subtypes in clinical breast cancer

✍ Scribed by Janice M. Knowlden; Julia M.W. Gee; John F.R. Robertson; Ian O. Ellis; Robert I. Nicholson

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: French
• Weight: 70 KB
• Volume: 89
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(20000320)89:2<209::aid-ijc17>3.0.co;2-6

✦ Synopsis

We have examined the relative levels of oestrogen receptor beta (ER␤) mRNA in 94 breast cancer specimens using a semi-quantitative RT-PCR procedure. We correlated its expression with ER␣ and various clinical, pathological and biochemical features of the disease. The level of ER␤ mRNA expression in these samples was found to be much lower than ER␣. Although ER␣ mRNA species were found to be most frequently associated with histological grade I and II tumours, displaying tubular differentiation, low grades of nuclear pleomorphism and low mitotic activity, such features were not characteristic of ER␤ positive samples. Indeed, application of the Spearman rank correlation test revealed that there was an inverse association between ER␤ normalised levels and ER␣ protein HScore. Also ER␤ mRNA positive cancers were more frequently EGFR protein positive than their negative counterparts (p ‫؍‬ 0.016), a feature normally associated with endocrine-insensitive disease. Our data suggest that although ER␤ levels are most likely lower than ER␣, they may influence the biological behaviour of breast cancers containing low levels of ER␣.