Increase in the Rate of HPV Positive Oropharyngeal Cancers During 1996-2011 in a Case Study in Turkey

Background: Primary aim of this study is to assess whether or not there is an increase at rate of HPV positive oropharyngeal cancers during 1996-2011 in Turkey, for comparison with prior reports from Western countries. Materials and Methods: A total of 138 newly diagnosed patients with oropharyngeal cancer were identified, 39 of which had no primary tumor specimen available and 18 patients with invalid HPV status, therefore HPV status for remaining 81 patients was evaluated. The presence and type of HPV DNA were determined with formalin-fixed paraffin embedded specimens, using an HPV DNA-based multiplex PCR assay. Associations between HPV status and clinicopathological characteristics were evaluated using a two-sample t-test for the continuous variables and the categorical variables were compared by chi-square test. Overall survival (OS) periods were calculated with Kaplan-Meier method. Results: The proportion of HPV-positive cancer has continued to increase during 2004-2011 as compared with 1996-2003. Notably, 33% (6/18) of the cases were HPV-positive in 1996-1999, 43% (9/21) in 2000-2003, 55% (11/20) in 2004-2007 and 70% (16/23) in 2008-2011. Thus, when we compared the results obtained during the 2004-2011with results of 1996-2003 period, we found that increase at HPV-positivity ratio was statistically significant (38% vs 64% p=0.012). Conclusions: This study demonstrated that HPV positive oropharyngeal cancers are increasing in Turkish patients as in the Western world.