The amplification of c-erb-B2 in cancer-free surgical margins is a predictor of poor outcome in oral squamous cell carcinoma

Abstract

The tumour subtype, TNM classification, and histopathological data are sometimes not sufficient for understanding and assessing the behaviour of oral cancers. In an attempt to find additional markers of tumour biology and behaviour, this study sought to determine the incidence and consequently the relevance of c-erb-B2, c-Myc, and H-ras gene alterations in tumour-free margins of oral squamous cell carcinoma (OSCC). Fifty samples of OSCC were analyzed for c-erb-B2 and c-Myc amplification by real-time polymerase chain reaction and for H-ras point mutations by sequencing. A relatively high incidence of genetic lesions was detected: 22% of cases had c-erb-B2 and 30% had c-Myc amplification, whilst only 12% harboured H-ras mutations. Kaplan–Meier analysis and the log-rank test showed statistically significant differences in 5-year survival rates and relapse between patients with tumour margins positive for c-erb-B2 amplification and those with margins that were negative (P=0.002). H-ras and c-Myc alterations could not be associated with tumour behaviour. Molecular analysis of margins, targeting cancer genes, could identify additional, independent predictors of risk and outcome in OSCC.