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 ER alpha, ER alpha E3 Delta, ER alpha E5 Delta, ER alpha E7 Delta and ER beta, 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 ER beta (p < 0.001) in cancer tissues, and constant amounts of ERa and their variants. The results revealed significantly lower ER alpha E7 Delta/ER alpha (p = 0.030) and ER beta/ER alpha (p = 0.035) ratios in patients with lymph node (LN) metastasis than in those without LN metastasis. Conclusion: Our data suggests that ER alpha E7 Delta and ER beta may regulate ER alpha in normal human breast tissue. (C) 2006 Elsevier Ltd. All rights reserved.