Clinicopathological analysis of HER-2 gene amplification and chromosome 17 polysomy in 335 cases of breast carcinoma

Objective To investigate the clinicopathological significance of HER-2 gene amplification and chromosome 17 polysomy in breast carcinoma.Methods A retrospective study in 335 cases of breast carcinoma based on fluorescence in situ hybridization(FISH) was performed to analyze the relationship between HER-2 gene amplification or chromosome 17 polysomy and age,histological grade,lymphatic metastasis,and HER-2 protein expression.Results One hundred fifty-six cases(44.6%)of HER-2 gene amplification and 73 cases(21.8%)of chromosome 17 polysomy were detected in 335 cases of breast ductal carcinoma,in which all of them were invasive ductal carcinoma and thus the percentage of HER-2 amplification and chromosome 17 polysomy for invasive ductal carcinoma was up to 53.4%(156/292)and 25.0%(73/292),respectively.In this study HER-2 gene amplification was associated with HER-2 expression(P0.001),and chromosome 17 polysomy was corresponding to HER-2 gene amplification(P0.001)and HER-2 protein expression(P0.001).It was suggested that HER-2 gene amplification or chromosome 17 polysomy was correlated with histological grade(P=0.002 or P=0.002)and lymphatic metastasis(P=0.002 or P=0.021),and therefore,with the poor prognosis of breast cancer patients.It was also showed that either HER-2 amplification or chromosome 17 polysomy was not related to the age of patients(P=0.222 or P=0.502).Conclusion Both HER-2 gene amplification and chromosome 17 polysomy may be correlated to the histological grade,metastasis and HER-2 expression in breast carcinoma.