Evidence of chromosome regions and gene involvement in inflammatory breast cancer

Inflammatory breast cancer (IBC) is a rare but particularly aggressive form of primary breast cancer. In contrast to noninflammatory breast cancer (non IBC), the molecular alterations underlying IBC are poorly known. We postulated that the kind and frequency of these alterations might differ between IBC and non IBC and account for its particular aggressiveness. We investigated allelic losses associated with primary breast cancer (on chromosome arms 1p, 3p, 6p, 6q, 7q, 8p, 9p, 11p, 11q, 16q, 17p and 17q) by analyzing 71 microsatellite markers in 66 cases of IBC. Loss of heterozygosity (LOH) was frequent, with a mean fractional allelic loss (FAL) index of 52%. Relative to published data on non IBC, allelic loss was particularly frequent at 3p21-p14, 6p, 8p22, 11q, 13q14 and 17q21, suggesting the presence of genes that are markedly altered in IBC. In contrast, the DNA amplification levels of ERBB2, MYC and CCND1, as measured by real-time quantitative PCR, did not differ between IBC and non IBC.