Background:Tongue squamous cell carcinoma (TSCC) is increasing in incidence, especially among young patients and preferably females. Infection with human papilloma virus (HPV) has been suggested as a cause of SCC in the head and neck, and the proportion of oropharyngeal cancers caused by HPV has steadily increased.Methods:Samples from 109 patients with primary TSCC were analysed for the presence of HPV16 by in situ hybridisation and for expression of its surrogate marker p16 and the HPV receptor syndecan-1 by immunhistochemistry.Results:No evidence of HPV16 DNA was observed in the tumours, although one-third showed p16 staining. There was no difference in the expression of the primary HPV receptor, syndecan-1, between TSCC and a group of tonsil SCC.Conclusion:Whereas p16 is expressed in some TSCCs, HPV16 is undetectable, therefore, p16 cannot be used as a surrogate marker for high-risk HPV-infection in this tumour. Despite presence of the HPV-receptor syndecan-1 in TSCC, HPV prefers the tonsillar environment. Lack of p16 associates with worse prognosis primarily in patients aged ⩽40 years with tongue SCC. The improved prognosis seen in p16-positive TSCC can be due to induction of a senescent phenotype or an inherent radiosensitivity due to the ability of p16 to inhibit homologous recombination repair.

Squamous cell carcinoma of the head and neck, SCCHN, is a heterogeneous group of tumours not only concerning the site of origin but also regarding aetiology. The 5-year survival for the whole group of SCCHN tumours has not significantly improved over the last 20-25 years. Apart from tumour spread to lymph nodes, N status, gains and losses of specific chromosomes are the only factors shown to be independent prognostic markers for these tumours. Worldwide, an increasing number of people ≤ 40 years are seen being affected by tongue SCC, the most common tumour within the SCCHN group. Even without any clinical signs of metastasis, up to 30% of all tongue SCC have histologically detectable spread to lymph nodes. In this mini review, field cancerization, tumour microenvironment, the so called EMT (epithelial mesenchymal transition) process and the role of viruses in development of SCCHN are discussed as well as potential new therapeutic targets. For the group of tongue SCC, with the increasing incidence seen in young patients and particularly women, new data with impact on prognosis and treatment are urgently needed. But as long as data from the analyses of several sub sites are presented as valid for the whole group of tumours, this vital point is missed.

The present findings show that expression of c-MYC has prognostic value in squamous cell carcinoma of the tongue, and could be useful in choice of therapy.