P762 Prevalence association between HPV and fistulising perianal Crohn’s disease

Abstract Background Perianal Crohn’s disease (PCD) is the main risk factor for squamous cells carcinoma (SCC). The incidence of SCC in PCD patients is 0.26 per 1000 patients-years, affects females more than males, develops on average at 42 years of age, which is earlier than general population. Although epidemiological studies have shown that most anal cancers are associated with HPV infection, predominantly oncogenic types 16 and 18.1 prevalence of HPV on perianal Crohn`s disease (PCD) remains unknown. We aimed to estimate the Prevalence of HPV and the subtypes more frequently associated with PCD. Methods Adults with fistulising PCD under immunosuppressed medications who have required surgical intervention, were transversally recruited. A biopsy sample was obtained from perianal fistula tract during under anesthesia exam. INNO-LiPA test was performed on paraffin blocks containing fistula path for HPV testing. Results A total number of 45 PCD patients were recruited and underwent surgical intervention. All patients were under biologic therapy, 42.2% Adalimumab, 40.1% Infliximab, 11.1% Certolizumab, 4.4% Ustekinumab and 2.2% Vedolizumab. The prevalence of fistula tract HPV infection in PCD patients was 37.8% and 22.2% for high-risk HPV in particular. The subtypes more frequently identified were HPV-11 (15.5%), HPV-16 (8.9%) and HPV-53 (6.7%). Conclusion This study shows a high point-prevalence of HPV, specially high-risk subtypes in fistulising PCD population. More studies are necessary to define a screening for cancer in this population.