ABSTRACT
PURPOSE: The aim of this study was to examine the risk of HPV-associated oral cavity, oropharyngeal or anal cancer in men with penile cancer to test the hypothesis of an increased risk to develop a second HPV-associated cancer later in life. MATERIAL AND METHODS: We conducted a population-based register study including all men in Sweden diagnosed with penile cancer between 2000 and 2012. For each patient, six men without penile cancer were matched based on age and county of residence. Data were retrieved from Swedish cancer and population registers, to assess the risk of oral cavity, oropharyngeal or anal cancer in patients with penile cancer. Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Risks in men with penile cancer were also compared with the background Swedish male population by use of standardized incidence ratios. RESULTS: In total, 1634 men with and 9804 without penile cancer were included in the study. Among men with penile cancer, four men were subsequently diagnosed with oral cavity cancer, one with oropharyngeal cancer and one with anal cancer. Corresponding numbers among the penile cancer-free men were ten, two and three, respectively. There was evidence of an increased risks of all three cancers under study with an HR of 2.84 (95% CI 0.89-9.06) for oral cavity cancer, 3.66 (95% CI 0.33-40.39) for oropharyngeal cancer and 2.34 (95% CI 0.24-22.47) for anal cancer. When comparing the incidence of these malignancies between penile cancer patients and the background population, the patterns of association were similar. CONCLUSIONS: Our findings indicate that men with penile cancer are at an increased risk of a second HPV-associated cancer of the oral cavity, oropharynx and anal canal. Considering that our study was based on small numbers reflecting the rarity of these cancers, larger studies are needed to confirm our findings.
