Comparison of IHC and FISH for HER-2/neu Status of Breast Cancer in Indian Women

Breast cancer is one of the most common malignancies in the world. According to the global cancer statistics, Europe and America have the high incidence and mortality (Parkin et al., 2005). The incidence of breast cancer is 20 per 100,000 populations, and the incidence is growing (Zheng et al., 2001). Research has shown that about 20% 30% of the breast cancer patients have HER-2/neu amplification or overexpression, which is associatedf with a more aggressive phenotype and decreased survival (Paterson et al., 1991; Seshadri et al., 1993; Press et al., 1993; 1997; Ross and Fletcher, 1999). The benefit of humanized anti-HER-2/neu monoclonal antibody trastuzumab (Herceptin) in HER-2/ neu -positive breast cancers has been well documented as noted by prolonged survival (Dean-Colomb and Esteva, 2008). But this therapy is effective only if the detection of HER-2/neu status is accurate. There are several methods available to detect the HER-2/neu status like polymerase chain reaction (PCR), immunohistochemistry (IHC), fluorescence-in-situ hybridization (FISH), Chromogenic in situ hybridization (CISH) (Tanner et al., 2000; Sáez et al., 2006). Protein overexpression detected by IHC or amplification of HER-2/neu gene analyzed by FISH are the two main methods used to detect HER-2/neu status