A study to assess expression of human papillomavirus types 16 and 18 in oral squamous cell carcinoma using polymerase chain reaction

OBJECTIVE: The diverse subset of oral squamous cell carcinoma (OSCC) with different clinical appearance and outcome, independent of traditional risk factors has led to increasing attention in human papillomavirus (HPV) infection. MATERIALS AND METHODS: The investigation followed a case–control design. Information pertaining to the subjects was retrieved from hospital records. Twenty cases of OSCC and twenty age-matched controls were analyzed to ascertain the prevalence of HPV types 16 and 18. DNA was extracted from the blocks of formalin-fixed paraffin embedded tissues, and HPV-DNA was amplified using HPV type-specific primers by polymerase chain reaction (PCR) method. Data analysis was carried out using Chi-square test. RESULTS: HPV-DNA was detected in 55% of cases (11/20; HPV 16 = 6, HPV 18 = 3 and HPV 16 and 18 = 2) and 30% of controls (6/20; HPV 16 = 3, HPV 18 = 1 and HPV 16 and 18 = 2) indicating higher percentage of HPV presence among OSCC cases. No significant association was found between the presence of HPV and gender, age, site and grade of differentiation of OSCC. CONCLUSION: Although the presence of HPV was higher in cases compared to controls, none of these differences were statistically significant. HPV 16 and 18 are commonly found in normal oral mucosa mandating the need for distinguishing clinical, subclinical and latent HPV infections.