Significant allelic loss of ANX7region (10q21) in hormone receptor negative breast carcinomas

Loss of heterozygosity (LOH) in the 10q21 region that harbors the tumor suppressor gene ANX7-GTPase gene have been found in 35% of prostate tumors. Therefore, the rationale for this study is that this gene could also be implicated in breast pathogenesis as well. We investigated allelic losses in microsatellites of the 10q21 region, and their correlations with ANX7 status, estrogen receptor (ER) status, progesterone receptor (PR) status, Ki-67 status and pathological phenotype in 30 breast carcinomas with matched control specimens. The LOH analysis was performed by amplifying DNA by PCR, using four markers of the 10q21 region (AFMa299ya5, AFM220xe5, AFM 063xc5, AFM200wf4). LOH in at least one marker of the 10q21 region (AFM220xe5 marker close to ANX7) was found in 66% of the first set of informative tumors containing 10 pairs of specimens. Subsequent comparison between 20 carcinomas using AFM220xe5, with and without LOH in terms of pathological parameters showed significant associations with differences in age (P=0.04), ER (P=0.05), Ki-67 (P=0.04) and PR (P=0.01); a trend toward significance was found for tumor size (P=0.06) and histological grade III (P=0.14). These results suggest that the ANX7 gene, or other genes of the 10q21 region, could be functionally related to breast cancer, probably influencing the hormone receptor expression associated with poor prognosis during development.