Oestrogen receptor-alpha variant mRNA expression in primary human breast tumours and matched lymph node metastases

We have shown previously that the relative expression of a truncated oestro gen receptor-alpha variant mRNA (ER clone 4) is significantly increased in axillary node-positive primary breast tumours compared with node-negative t umours, In this study, we have examined the relative expression of clone 4- truncated, exon 5-deleted and exon 7-deleted oestrogen receptor-alpha varia nt mRNAs in 15 primary breast tumour samples and in synchronous axillary ly mph node metastases. Overall, there were no significant differences between the primary tumours and the matched metastases in the relative expression of these three specific variant mRNAs. Furthermore, the pattern of all dele ted oestrogen receptor-alpha Variant mRNAs appeared conserved between any p rimary and its matched secondary tumour.