Prevalence of human papillomavirus infection in squamous cell carcinoma of the anal canal in a Northeast City in Brazil: viral genotyping and clinical aspects

ABSTRACT

Background: Anal cancer malignancies comprise about 1.5 to 3% of cancers from the gastrointestinal in which high-risk types of human papillomavirus (HR-HPV) is responsible for >80% of cases. The aim of this work was to detect and perform human papillomavirus (HPV) genotyping in squamous cell carcinoma specimens from the anal canal and to investigate the association between viral infection and histopathological and clinical aspects. Methods: The presence of genotype-specific HPV DNA in formalin-fixed paraffin embedded tissue from 27 anal SCC samples from a reference cancer hospital of São Luís, State of Maranhão, Brazil was performed by Linear Array HPV Genotyping Test and the INNO-LiPA HPV Genotyping Assay. Fisher's Exact test and Chi-square test were performed in order to evaluate the association between HPV type and clinical and morphological variables. P values less than 0.05 were considered statistically significant. Results: Average age of patients at the time of diagnosis was 54.96 years ± 15.81; 74.07% of patients were female. Vegetative ulcers represented the most common type of lesion (22.22%). The lesions ranged in size from 2.1 cm to 5.0 cm and mostly were well-differentiated (70.38%). Lymph node involvement was observed in 26% of the patients. Molecular evaluation revealed that HPV infection was detected in 81.48% of the lesions, and the most common type found was the oncogenic HPV 16. Statistical analysis indicated that the clinical and histopathological variables were not associated with HPV infection. Conclusions: Our results indicate that anal SCC rarely occurs in the absence of HPV and emphasize the predominant role of HPV16. The evaluation about genotype-specific prevalence of HPV in anal SCC is important to assess the potential benefit of HPV vaccination (AU)