Molecular Beacon Reverse Transcription-PCR of Human Chorionic Gonadotropin- -3, -5, and -8 mRNAs Has Prognostic Value in Breast Cancer

Background: The -subunit of human chorionic gonadotropin (hCG) is encoded by four genes, of which expression of the hCG -3, -5, and -8 genes could have prognostic value in breast cancer. Methods: Applying a new, modified Molecular Beacon reverse transcription-PCR assay, we investigated the prognostic value of the hCG -3, -5, and -8 gene transcripts in 129 sporadic unilateral breast cancer samples from patients with a median follow-up of 62.3 months. Results: Expression of hCG -3, -5, -8 was significantly (P 0.020) associated with relapse-free survival (RFS). In multivariate survival analysis, hCG -3, -5, and -8 maintained prognostic value for RFS, with high expression predicting shorter RFS (P 0.015; hazard ratio, 2.25; 95% confidence interval, 1.17–4.34). Only 1 of 24 (4%) node-negative patients with low hCG -3, -5, -8 expression relapsed, in contrast to 7 of 26 (27%) patients with high expression (P 0.046). Conclusions: Expression of hCG -3, -5, -8, which differ by only one nucleotide from other hCG genes, can be assessed by our modified Molecular Beacon assay in breast cancer tissues. Expression of hCG -3, -5, -8 has independent, prognostic value for RFS in breast cancer and may help identify node-negative patients with poor prognosis. © 2003 American Association for Clinical Chemistry