Objectives: To determine prevalence of E6/E7 for HPV16 and HPV18 in OSCC in Indian population and to determine whether presence of HPV E6/E7 in saliva can be used as marker for HPV associated OSCC.
Methods: OSCC(n=45)cases were divided into two groups. In group1(n=20) tumour tissue and saliva sample were collected; group2(n=25) comprised of archival tumour tissue samples. Nested-multiplex PCR(NMPCR) was used to detect presence of HPV16 and 18 by demonstration of E6/E7proteins in tissue and saliva samples.
Results: HPV16and/or18 was present in 50.74%cases,HPV16 was present in 41.79%cases while HPV18 was present in 26.86%cases. With application of Fisher’s exact test at 1% level of significance, there was no significant difference for HPV16and/or18 presence in OSCC tissue and saliva sample indicating that both saliva and tissue can be used to test HPV positivity in OSCC. Taking lesional tissue sample as standard, sensitivity and specificity for total HPV(16/or18) in saliva by NMPCR was estimated at 62.5%(95%CI:61-84%)and 75%(95%CI:73-97%)respectively. Positive predictive value of NMPCR for detection of “HPV16/HPV18” was 62.5% whereas negative predictive value was 75%.
Conclusions: Study reveals moderate level of prevalence of HPV(16/18) in OSCC in Indian population, suggestive of its role in oral carcinogenesis. E6/E7 proteins of HPV(16/18) can be detected from saliva of patients with HPV associated OSCC by NMPCR. As no significant difference in HPV presence was found in lesional tissue and saliva, the presence of E6/E7 proteins in saliva can be used reliably as predictor for HPV positivity in OSCC.
Keywords: HPV16/18, Microbiology, Neoplasia and Saliva