Quantitative profile of estrogen receptor variants/isoforms in Taiwanese women with breast cancer

Aim To quantify ER variants/isoforms for women with breast cancer in Taiwan, an area with remarkably low breast cancer rates, but with an early onset and poor prognosis. Methods Real-time PCR technology was exploited to quantify mRNAs of ERα, ERαE3Δ, ERαE5Δ, ERαE7Δ and ERβ, in 49 breast cancer and paired adjacent normal tissues. Clinical parameters were assembled and tested for assocation with the ER expression. Results Comparison of cancer and matched normal samples showed significantly decreased ERβ (p<0.001) in cancer tissues, and constant amounts of ERα and their variants. The results revealed significantly lower ERαE7Δ/ERα (p=0.030) and ERβ/ERα (p=0.035) ratios in patients with lymph node (LN) metastasis than in those without LN metastasis. Conclusion Our data suggests that ERαE7Δ and ERβ may regulate ERα in normal human breast tissue.