Eligible patients were ≥18 years with squamous cell carcinoma of the oropharynx, oral cavity, nasopharynx, hypopharynx, or larynx with measurable stage IV (T0-4N2b-2c/3M0) and known HPV by p16 status.
Significant differences were found in IGF-1 serum concentrations between patients with p16 positive and p16 negative HNSCC (p=0.0062), with higher IGF-1 levels in p16 positive tumors, between low-grade and high-grade cancers (p=0.0323) only in larynx, with elevated IGF-1 concentrations associated with high-grade and between recurrent and non-recurrent HNSCC (p=0.0354), with lower IGF-1 levels in recurrent tumors.
HPV-AF estimates based on positivity for HPV-DNA, and for either HPV E6*I mRNA or p16(INK4a), were 22.4%, 4.4%, and 3.5% for cancers of the oropharynx, OC, and larynx, respectively, and 18.5%, 3.0%, and 1.5% when requiring simultaneous positivity for all three markers.HPV16 was largely the most common type.
Losses of CDKN2A (9p21) and MLH1 (3p22) and gains of CCND1, EMS1 (both at 11q13), RECQL4 and PTP4A3 (both at 8q24) were the most frequent aberrations in both larynx and pharynx carcinomas.
In order to investigate p16 alterations in head and neck cancer (HNC) we analyzed 70 primary tumors of the larynx, pharynx and oral cavity including their corresponding normal mucosa for mutation inactivation by direct sequencing exon 2.
Recent investigations revealed that 8p, 9p and 17q arms of human chromosomes harbour tumour suppressor genes (TSGs) such as p16 and BRCA1 with an important role in the multistage carcinogenesis of the larynx.
These findings indicate that p16MTS1/CDK4I is frequently inactivated by gene mutation, hypermethylation, and allelic deletions in a significant subset of squamous cell carcinomas of larynx.