Clinicopathological application of fluorescence in situ hybridization technique to diagnose and analyse HER-2 gene amplification and chromosome 17 polysomy in invasive ductal breast cancer tissues

OBJECTIVE: To summarize and analyze the experience and clinicopathological significance in application of fluorescence in situ hybridization(FISH) technique to diagnose HER-2 gene amplification and chromosome 17 polysomy in large sample of invasive ductal breast cancer.METHODS: Status of HER-2 gene amplification and chromosome 17 polysomy was diagnosed by FISH technique and analyzed with other biomarkers and clincopathological data in 1 699 cases of invasive ductal breast cancer.RESULTS: The positive rate for HER-2 gene amplification and chromosome 17 polysomy was 52.6%(894/1 699) and 12.7%(216/1 699),respectively.Amplification of HER-2 gene was correlated positively with HER-2 protein expression(P=0.000 1),chromosome 17 polysomy(P=0.009),tumor size(P=0.008),grade(P=0.025),lymphatic metastasis(P=0.015) and Ki-67(P=0.004),whereas negatively with ER(P=0.002),PR(P=0.001) and Bcl-2(P=0.028).Prognosis of HER-2 amplified breast cancer was obviously better in cases treated with Herceptin than that in those treated without(Log-rank=38.5;P=0.000 1).Recurrences of breast cancer showing chromosome 17 polysomy was statistically lower in cases treated with Herceptin than that in those treated without(P=0.022).CONCLUSION: Clinical application of FISH technique to diagnose the target of HER-2 gene amplification and to direct molecular targeting therapy can obviously improve the prognosis in breast cancer patients,therefore,it is worthy to further expand its application in departments of clinical pathology of hospital.