Salivary detection of human Papilloma virus 16 & 18 in pre-malignant and malignant lesions of oral cavity: Is it feasible in Pakistani context of Socio-Cultural Taboos?

Objective: To evaluate salivary detection of HPV-16 & 18 would be feasible and informative biomarker for oral pre-malignant and malignant lesion in our population.

Methods: This non-interventional, case control study was carried out at department of E.N.T, Head and Neck Surgery, Dow University of Health Sciences, Dow Medical College and Civil Hospital Karachi, Pakistan between July 2011 to December 2012. Total of 105 cases were recruited. These were divided in three groups 'A', 'B' & 'C' having 35 subjects each. Group'A' constitutes patients having strong clinical evidence of oral pre-malignant lesions (PML). Group 'B' includes histologically proven oral squamous cell carcinoma (OSCC) and Group 'C' comprised disease free subjects as controls. After taking informed consent, relevant clinical history was recorded on institutional approved performa. Saliva from all subjects was procured by standard 'drooling method'. Samples were stored at +4°C and later transferred to Laboratory to store at-20°C before further process. Samples were centrifuged at 4500 rpm for 15 minutes at 4°C. Cell pellets sediments were used for identification of HPV-16 & 18 by real-time PCR method. Data was entered and analysed using SPSS version 16. P-value of 0.05 was taken as standard.

Results: In group 'A', HPV-16 was detected in 3 (8.6%) cases while HPV-18 was not detected in any of the subject. In group 'B', HPV-16 was detected in 07 (20%) while HPV-18 was found in 06 (17.1%) cases. Mixed HPV-16 and HPV-18 were found in 02 (5.7%) cases. In group 'C', HPV-16 was detected in 03(8.6%) while HPV-18 was not detected in any of the subjects. Significant relationship was observed between the groups for HPV-18 detection (P= 0.002) while for HPV-16, no significant association was found (P= 0.245).

Conclusion: HPV infection for the causation of oral cancer cannot be fully established possibly due to small sample size. More over differences in genetic makeup, environment, indulgence in peculiar risk factor habits, sexual practices and difficult evaluation of the acquisition of viral load due to socio-cultural and religious restrictions could be the reason.