Chromogenic in situ hybridisation (CISH) should be an accepted method in the routine diagnostic evaluation of HER2 status in breast cancer

• Published in: Journal of clinical pathology 2007-09, Vol.60 (9), p.1067-1068
• Main Authors: Di Palma, S, Collins, N, Faulkes, C, Ping, B, Ferns, G, Haagsma, B, Layer, G, Kissin, M W, Cook, M G
• Format: Article
• Language: English
• Subjects: Antibodies, Monoclonal - therapeutic use; Antibodies, Monoclonal, Humanized; Antineoplastic Agents - therapeutic use; Biological and medical sciences; Breast cancer; Breast Neoplasms - diagnosis; Breast Neoplasms - drug therapy; Breast Neoplasms - genetics; Carcinoma, Ductal, Breast - diagnosis; Carcinoma, Ductal, Breast - drug therapy; Carcinoma, Ductal, Breast - genetics; Chromogenic Compounds; Chromosomes; Female; Funding; Genes, erbB-2; Gynecology. Andrology. Obstetrics; Histopathology; Humans; In Situ Hybridization - methods; Investigative techniques, diagnostic techniques (general aspects); Laboratories; Mammary gland diseases; Medical sciences; Microscopy; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Patient Selection; Proteins; Short Reports; Trastuzumab; Tumors
• ISSN: 0021-9746; 1472-4146
• DOI: 10.1136/jcp.2006.043356

Table 1 HER2 1HC and FISH versus CISH data IHC FISH 3+ 2+ 0/1+ + - CISH + 29 4 1 CISH + 5 0 - 7 12 108 - 0 19 CISH, chromogenic in situ hybridisation; FISH, fluorescence in situ hybridisation; IHC, immunohistochemistry; Discussion FDA (Food and Drug Administration) approved HercepTest IHC analysis has been adopted as the frontline test for identifying patients eligible for trastuzumab therapy. Chromogenic in situ hybridisation (CISH) is as sensitive and as specific as fluorescence in situ hybridisation (FISH) CISH is more cost-effective than FISH Other FISH/CISH discrepancies have been due to inadequate use of chromosome 17 correction and difficult histology. 3, 6 By using chromosome 17 correction in all low amplified cases, light microscopy for assessment of HER2 in the histological context of the tumour sample and having experienced histopathologists analysing all the slides, we have not encountered these discrepancies between FISH and CISH results leading us to believe that CISH can reliably be used to assess breast tumour samples for patient eligibility for trastuzumab therapy.