HER-2/neu amplification detected by fluorescence in situ hybridization in fine needle aspirates from primary breast cancer

• Published in: Annals of oncology Vol. 13; no. 9; pp. 1398 - 1403
• Main Authors: Bozzetti, C., Nizzoli, R., Guazzi, A., Flora, M., Bassano, C., Crafa, P., Naldi, N., Cascinu, S.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-09-2002
• Subjects: Biological and medical sciences; Biopsy, Needle; Breast Neoplasms - epidemiology; Breast Neoplasms - genetics; Breast Neoplasms - pathology; Culture Techniques; Female; fluorescence in situ hybridization; Gene Amplification; Genes, erbB-2 - genetics; Gynecology. Andrology. Obstetrics; HER-2/neu; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence - methods; Key words: breast cancer; Mammary gland diseases; Medical sciences; Paraffin Embedding; Reproducibility of Results; Sensitivity and Specificity; Tumors; Human; Tumoral tissue; Gene overexpression; breast cancer; Malignant tumor; Gene expression; Fine needle aspiration biopsy; fluorescence in situ hybridization; Mammary gland diseases; Gene amplification; Female; HER-2/neu; Mammary gland; Onc gene; Protooncogene
• ISSN: 0923-7534; 1569-8041
• DOI: 10.1093/annonc/mdf217

Background: The HER-2/neu gene is amplified in 20–30% of human breast cancers and has been shown to have prognostic and predictive value for treatment with chemotherapy, hormone therapy and antibodies against the HER-2/neu domain (trastuzumab). The aim of our study was to evaluate the reliability of HER-2/neu determination by fluorescence in situ hybridization (FISH) on fine-needle aspirates (FNAs) from primary breast cancer patients by comparison with the results obtained by FISH and immunohistochemistry (IHC) on the corresponding histological sections. Materials and methods: HER-2/neu amplification was determined by FISH on 66 breast cancer FNAs. Twenty-three and 36 corresponding formalin-fixed, paraffin-embedded sections were assayed by FISH and by IHC, respectively, in order to detect HER-2/neu amplification and HER-2/neu protein expression. Results: Twenty-seven per cent (18/66) of breast cancer FNAs showed amplification of HER-2/neu by FISH. Paired results by FISH cytology and FISH histology were available in 22 cases. Concordance was 91% (20/22). Paired results by FISH cytology and IHC were available in 36 cases. Concordance was 92% (33/36). Eighteen of 66 breast cancer FNAs were also submitted to flow cytometric DNA analysis. None of the diploid cases showed HER-2/neu amplification by FISH. Six out of the eight aneuploid cases were amplified and two were polysomic. Conclusions: HER-2/neu gene amplification can be reliably estimated by FISH on breast cancer FNAs and a good correlation has been found between FISH and IHC results from the corresponding histological sections.