VEGFA amplification/deletion in human breast tumors.

e21017 Background: The anti-VEGF antibody, bevacizumab, has been FDA approved for the treatment of breast cancer. While germline variability (i.e. single nucleotide polymorphisms) may serve as a predictive marker for anti-VEGF therapy, to date tumor-specific variability has not. More specifically, amplification or deletion of the VEGFA gene has not been studied or evaluated as a predictive or prognostic biomarker for breast cancer. Methods: A VEGFA/centromere enumerization-6 (CEN-6) probe was created and validated using DNA clones and restriction enzyme fragment measurements. The final product contained a RP11-710-L16 probe covering 183 KB including the VEGFA gene and flanking regions. The CEN-6 probe was developed with fluorescein isothiocyanate labeled peptide nucleic acid oligonucleotides. VEGFA and CEN-6 probes were tested on metaphase spreads to exclude cross-hybridization to other chromosomes. A tissue microarray containing 93 breast cancers was analyzed for the presence of VEGFA gene amplification ...