Prevalence, trends, and survival impact of human papillomavirus on oropharyngeal cancer in Indian population.

Abstract

5540 Background: Among oropharyngeal squamous cell carcinoma (OSCC), the true prevalence of HPV remains variable and studies have estimated that up to 60% may be HPV positive. Patients with HPV positive tumor are usuallyyounger in age, less likely to have history of tobacco or alcohol consumption and associated with a better prognosis but this information for Indian patients is largely unknown. Methods: 105 newly diagnosed patients of OSCC were enrolled. HPV genotyping was done on the biopsy specimen by consensus polymerase chain reaction and reverse line-blot hybridization assay. HPV prevalence was studied according to gender, age, tobacco and alcohol use and high risk sexual behavior. Results: Overall HPV prevalence was 22.8%. HPV positive patients were younger by 8 years as compared to negative patients (P=0.003). No significant correlation between tobacco consumption, alcoholic habits, and HPV status was observed. The mean number of life time sexual partners in HPV positive patients was 1.66 while, it was 1.33 in HPV negative patients (P=0.049). Incidence of high risk sexual behaviors was more in HPV positive patients (P<0.001). There were no significant associations between the two groups with respect to tumor size, nodal stage and the overall stage of the tumor. 16% of the base of tongue cancers and 40% of tonsillar carcinoma were positive (P = 0.02). Among positive samples, HPV 16 was the commonest (79%) followed by HPV 18 (12%). 96% of patients received treatment. At 18.8 months there was no significant difference in OS, EFS between HPV positive and negative OSCC (P = 0.97 and P= 0.51 respectively). Conclusions: The current study reconfirms that HPV positive OSCC patients are younger with high risk sexual behavior. Impact of smoking and alcohol consumption on HPV status was not found in this study. HPV positive rates were significantly higher for tonsillar cancer. Contrary to literature, we did not find any differences in OS or EFS between two groups. Small numbers of patients in the study group, short follow up period and significant tobacco smoking in HPV group may be the one of the reason for this.