Detection of human papillomavirus (HPV) type 6, 16 and 18 in head and neck squamous cell carcinomas by in situ...

Seventy seven squamous cell carcinomas (10 oral cavity, 15 tongue, 26 pharynx and 26 larynx), with different grading, were analyzed for the presence of HPV DNA by in situ hybridization. Positive signals were found on the nuclei of cancer cells in 25 (32.5%), in the epithelia adjacent to squamous cell carcinomas in 2 (8.7%), and in the resected margins in 1 (4.3%) case. HPV DNA positive signals were obtained in 42% of laryngeal, 34% of pharyngeal, in 20% of oral, and 20% of tongue carcinomas. Out of 25 HPV positive carcinomas a single HPV type was detected in at least 11 (44%), and double or multiple infection in 9 (36%) cases; altogether, HPV 6 DNA was determined in 15 (60%), and HPV 16 and/or 18 DNA in 17 (68%) head and neck tumors. The detection rate of HPV 6 was lower than of HPV 16 and/or 18 for tumors in oral cavity, tongue and larynx. Out of 25 HPV DNA positive carcinomas 21% were graded as G1, 27% as G2, and 44% were G3. The results indicate that HPV may be involved in the pathogenesis of head and neck squamous cell carcinomas.