Evaluation of c-myc and CCNE2 amplification in breast cancer with quantitative multi-gene fluorescence in-situ hybridization

Abstract

To investigate c-myc and CCNE2 gene amplifications and their relationship in breast cancer. Sixty-six infiltrating ductal breast carcinomas with foci of ductal carcinoma in situ components collected from January 2005 to December 2007 were selected for tissue microarray and quantitative multi-gene FISH for c-myc and CCNE2 gene amplification, and the relationship with the clinicopathologic features was analyzed. Of the 66 cases, 18 (27.3%) showed c-myc amplification and 23 (34.8%) showed CCNE2 amplification. A strong correlation was found between c-myc and CCNE2 amplification (P < 0.01). The breast cancers showing c-myc and CCNE2 amplifications were all aneuploidy, and were HER2 positive (P < 0.05). Tumors with c-myc amplification also showed higher Ki-67 index (P < 0.05). C-myc and CCNE2 amplifications are common events in breast cancer, and they often coexist. C-myc and CCNE2 genes may play critical roles in the pathogenesis and development of breast cancer through unique and overlapping signaling pathways.