RT Journal Article SR Electronic T1 HER2, TOP2A, CCND1, EGFR and C-MYC oncogene amplification in colorectal cancer JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 768 OP 772 DO 10.1136/jcp.2006.038281 VO 60 IS 7 A1 Al-Kuraya, Khawla A1 Novotny, Hedvika A1 Bavi, Prashant A1 Siraj, Abdul K A1 Uddin, Shahab A1 Ezzat, Adnan A1 Sanea, Nasser Al A1 Al-Dayel, Fouad A1 Al-Mana, Hadeel A1 Sheikh, Salwa S A1 Mirlacher, Martina A1 Tapia, Coya A1 Simon, Ronald A1 Sauter, Guido A1 Terracciano, Luigi A1 Tornillo, Luigi YR 2007 UL http://jcp.bmj.com/content/60/7/768.abstract AB Aim: Recent studies had suggested substantial molecular differences between tumours from different ethnic groups. In this study, the molecular differences between the incidences of colorectal carcinoma in Saudi and Swiss populations are investigated. Method: 518 cases of colon cancer tumours (114 from Saudi Arabia and 404 from Switzerland) were analysed in a tissue microarray format. Fluorescence in situ hybridisation (FISH) was used to estimate frequencies of copy number changes of known oncogenes, including HER2, TOPO2A, CCND1, EGFR and C-MYC. Results: Using FISH, amplifications were mostly low level (gene-to-centromere ratio 2 to 4), which is in contrast with other tumour types with more frequent gene amplifications. The amplifications were particularly frequent for MYC (Saudi 9% and Swiss 14.2%) but unrelated to clinical outcome and pathological information. Remarkably, there were four tumours exhibiting classic high-level gene amplification for HER2 (Swiss 1.3%), a pattern often accompanied by response to trastuzumab (Herceptin) in breast cancer. Occasional high-level amplifications were also observed for CCND1 (Saudi 1/106, 0.9%; Swiss 2/373, 0.5%) and EGFR (Swiss 2/355; 0.6%). Conclusions: Rare high-level amplifications of therapeutic target genes were found in patients with colon cancer. Although no molecular differences were found between incidences of colon cancer cases in Swiss and Saudi populations, these observations emphasise the urgent need for clinical studies investigating the effect of targeted therapies.