Oestrogen receptor beta expression and depth of myometrial invasion in human endometrial cancer

We assessed the relative expression of oestrogen receptor (ER)alpha and oes trogen receptor (ER)beta mRNAs in 36 human endometrial cancers using a mult iplex polymerase chain reaction (PCR). To determine whether or not the expr ession of ER subtypes in endometrial cancers is associated with clinicopath ological parameters, we examined correlations between ER subtypes and age, tumour grade and depth of myometrial invasion. Using multiple regression an alysis, myometrial invasion showed a significant correlation with ER-beta: ER-alpha ratio (r = 0.54, P = 0.0007). The ER-beta :ER-alpha ratio was high in advanced invasive carcinoma. Western blotting analysis showed that ER-b eta proteins were highly expressed in comparison with ER-alpha proteins in endometrial cancer with severe myometrial invasion. Our results suggest tha t ER-beta is important in the progression of myometrial invasion. (C) 2001 Cancer Research Campaign.