fluorescent in situ hybridization and real-time quantitative polymerase chain reaction to evaluate her2/neu status in breast cancer

Background: breast cancer remains the most common and second lethal cancer in females. her-2/neu is one of the most important amplified oncogene in breast cancer. the amplification of her-2 is correlated with decreased survival, metastasis, and early recurrence. the amplification of her-2/neu gene and synthesis of the protein are reported in 10%-34% of breast cancer cases associated with tumor size, advanced tumor stage, high-grade tumor, young age at diagnosis, absence of steroid hormone receptor, and lymph node involvement. methods: fluorescence in situ hybridization (fish) and immunohistochemistry (ihc) methods are options to evaluate her-2 expression. the current study aimed at identifying the correlation between fish and real-time polymerase chain reaction (pcr) in measuring her-2 expression. results: the study investigated the performance of the real-time pcr as measured against fish method in ihc +2 borderline cases. in a total of 120 ihc 2+ samples, 58.3% were negative and 41.6% positive for her-2 gene, confirmed by fish as a gold standard method. the real-time pcr ratio was <1.8 for a majority (82.8%) of the tumor samples with unamplified her-2 gene by fish as a gold standard assay. conclusion: despite the fact that real-time pcr is a promising method to evaluate her-2 over expression and a supplementary array to fish, according to the results of the present study it cannot be utilized instead of gold standard techniques; therefore, additional studies should be carried out to appraise the value of this method to evaluate her-2 over expression.