Increased incidence of penile cancer and high-grade penile intraepithelial neoplasia in Denmark 1978-2008: a nationwide population-based study.

OBJECTIVE: To assess the trends in incidence of penile cancer during 1978-2008 and high-grade penile intraepithelial neoplasia (PIN2/3) during 1998-2008 in Denmark.

METHODS: Using two nationwide registries, we estimated age- and period-specific incidence rates. Log-linear Poisson regression analysis was used to estimate average annual percentage change (AAPC) and 95% confidence intervals (CI).

RESULTS: We identified 1,488 men with penile cancer and 285 men with PIN2/3. The incidence of penile cancer increased from 1.0 to 1.3 per 100,000 men-years in 1978-1979 to 2006-2008; this represented an AAPC of 0.8% (95% CI: 0.17-1.37). Squamous cell carcinoma (SCC) was the most common histological type (91.7%). The median age at diagnosis was 67 years, and the age-specific incidence rate of penile SCC increased with increasing age. The incidence rate of PIN2/3 increased significantly (0.5 to 0.9 per 100,000 men-years) in 1998-1999 to 2006-2008, and this represented an AAPC of 7.1% (95% CI: 3.30-11.05).

CONCLUSIONS: The incidence of penile cancer increased in 1978-2008 in Denmark, and the same applied to PIN2/3 in 1998-2008. A high prevalence of human papillomavirus (HPV) and a low circumcision rate in Denmark may partly explain our results.