Condyloma (genital warts) is a common outcome of HPV infection and has a high likelihood of reoccurrence. Therefore, treatment is associated with high medical expenditures. Thus, determining condyloma incidence, the HPV genotypes detected in condyloma, and the rate of HPV progression to disease is clinically important, and contributes significantly to cost-effectiveness modeling of prevention and treatment interventions in each country. The purpose of this study was to assess whether the incidence of histopathologically confirmed condyloma and penile intraepithelial neoplasia (PeIN) and rates of genital HPV infection progression to these lesions differs by country among men residing in Brazil, Mexico, and the U.S.
HPV Infection in Men (HIM) Study participants were men aged 18-70 years living in Tampa, Florida (U.S.), Cuernavaca (Mexico), and Sao Paulo (Brazil). At each visit, condyloma and PeIN lesions were biopsied. Biopsy specimens were categorized by pathologic diagnoses. The Linear Array genotyping method was used to identify HPV genotypes from genital swabs, while the INNO-LiPA HPV Genotyping Extra method was used for biopsy tissue specimens. Age-specific analyses were conducted for lesion incidence by country, with Kaplan–Meier estimation of cumulative incidence by country. The proportion of HPV infections that progressed to condyloma and PeIN, the median time to condyloma and PeIN development, and the incidence rates were estimated by country.
When comparing demographic and sexual characteristics across the three countries, sexual orientation (p=0.008) and lifetime number of female sexual partners (p<0.0001) were differentially associated with lesion incidence in the three countries. Condyloma incidence rates overall by country were 1.6 per 100 person-years (p-y) in Brazil, 1.8 per 100 p-y in Mexico, and 1.9 per 100 p-y in U.S. Condyloma incidence in Brazil and the U.S. decreased with age, while incidence remained fairly constant across the lifespan in Mexico. No differences by country were observed when comparing PeIN incidence rates across age categories. HPV types 6 and 11 were the most common types to progress to condyloma, and HPV types 16, 6, and 11 were the most common types to progress to PeIN in all three countries.
The continuous risk of condyloma and PeIN across all age groups and countries in this study emphasizes the need to ensure that strong HPV immunity, such as that obtained through vaccination, is maintained across the lifespan of males.