Her-2/neu amplification determined by real-time quantitative PCR and its association with clinical outcome of breast cancer in Thailand.

HER-2/neu has been found to be amplified or overexpressed in about 20-30% of breast cancers, in association with negative prognosticators and shortened survival. Determination of HER-2/neu status in breast-cancer patients, to select for adjuvant treatment with trastuzumab, is becoming standard breast-cancer clinical practice. This study aimed to investigate HER-2/neu status in breast-cancer by real-time quantitative polymerase chain reaction (PCR), allowing accurate and precise quantification of HER-2/neu amplification in tumor tissues. We evaluated 112 breast-cancer samples, of which 42 (37.5%) had HER-2/neu amplification. After a mean follow-up period of 71 months, HER-2/neu amplification was found to be significantly associated with increased risk of death (HR = 6.367, 95% CI = 1.787-22.684), even after adjusting for age, clinical stage, tumor size, lymph-node status, and histologic grade. These findings support a negative prognostic role for HER-2/neu in breast-cancer survival. We suggest that real-time quantitative PCR analysis of HER-2/neu amplification represents an alternative technique for establishing HER-2/neu status in routine clinical practice.