Etiologic fraction of HPV-attributed anal and penile squamous cell carcinoma: study in specialized hospitals, Sri Lanka
摘要
The Human Papillomavirus (HPV) infection is known to cause anogenital cancers. Male HPV prevalence and Population Attributable Risk (PAR) are important to plan future HPV preventive strategies for HPV-driven anogenital cancers in males.
MethodsA hospital-based case-control study was carried out to determine the etiologic fraction attributed to HPV-driven anal and penile(anogenital) cancers among male patients presenting to specialised hospitals in Gampaha district and Apeksha Hospital (cancer specialised) in Sri Lanka and to calculate the PAR percentage on anogenital Squamous Cell Cancer (SCC) among the study population where HPV prevalence was 5.7%. New or recently diagnosed anal and penile SCC patients (August 2022–June 2023) were included as cases. For each case, four controls were selected from sexually active, clinically normal men aged 20–70 years residing in Gampaha district. Additional etiological factors that were checked included the presence of sexually transmitted infections, phimosis, anogenital injury, and the use of tobacco, alcohol or illegal drugs. The Chi-square test was used at the significant level of p < 0.05 and the Fisher’s exact test was applied when expected cell counts were low. Bivariate and multivariable binary logistic regression analyses were used to calculate Odds Ratios (ORs).
ResultsA significantly associated factor for getting anal or penile SCC was HPV infection (Adjusted OR(AOR) = 27.7; 95% CI: 4.3-177.8; P < 0.001). For any HPV genotype & High-Risk (HR) HPV genotype, the prevalence was 55% & 50% among cases, and 5% & 2.5% among controls, respectively. Assuming prevalence among controls as the population prevalence, the calculated PAR% was 60.3% for any HPV genotype and 39.4% for the HPV 16 h genotype.
Conclusions60% of the anal and penile SCCs were attributed to any HPV genotype and a significant proportion (more than one-third) of anal and penile SCCs could potentially be prevented by introducing the HPV 16 genotype-containing vaccine to males.
Clinical trialNot applicable.