[Clinicopathologic significance of chromosome 17 polysomy in breast cancer].

OBJECTIVE: To investigate the clinicopathological significance of chromosome 17 polysomy in breast cancer. METHODS: Retrospective study of 200 cases of breast cancer including 106 cases of invasive ductal carcinoma and 94 cases of in-situ carcinoma was performed by fluorescence in-situ hybridization (FISH) to explore the relationship between chromosome 17 polysomy and age, nuclear atypia, lymphatic metastasis, HER2 gene amplification and HER2 protein expression. RESULTS: Twenty-six percent (52/200) of chromosome 17 polysomy was detected in 200 cases of breast ductal carcinoma, all of which were invasive ductal carcinoma. Overall 52. 8% (52/180) of invasive ductal carcinoma cases showed chromosome 17 polysomy, which was correlated to HER2 gene amplification (P = 0.000) and HER-2 protein expression (P=0.000), and to HER2 expression combined with HER2 gene amplification (P=0.001). Chromosome 17 polysomy with or without HER2 gene amplification was also associated with high-grade nuclear atypia (P = 0.012 or P = 0.010) and lymphatic metastasis (P = 0.002 or P = 0.009 ). However, chromosome 17 polysomy with or without HER2 gene amplification was not correlative with the age of patients (P = 1. 000 or P = 0. 415). CONCLUSION: Chromosome 17 polysomy may be related to the nuclear atypia, metastasis, HER2 gene amplification of invasive ductal carcinoma and thus a worse prognosis of the patients.