Background: Invasive squamous cell carcinoma (SCC) of the penis is rare in the United States. Although human papillomavirus (HPV) infection is an established etiologic agent in at least 40% of penile SCCs, relatively little is known about the epidemiology of this malignancy.
Methods: Population-based data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program, the Centers for Disease Control and Prevention's National Program for Cancer Registries, and the National Center for Health Statistics were used to examine invasive penile SCC incidence and mortality in the United States. SEER data were used to examine treatment of penile SCC.
Results: From 1998 to 2003, 4967 men were diagnosed with histologically confirmed invasive penile SCC in the United States, representing less than 1% of new cancers in men. The annual, average age-adjusted incidence rate was 0.81 cases per 100,000 men, and rates increased steadily with age. Overall, penile SCC incidence was comparable in whites and blacks, but approximately 2-fold lower in Asians/Pacific Islanders. Rates among Hispanics were 72% higher compared with non-Hispanics. Blacks compared with whites and Asians/Pacific Islanders and Hispanics compared with non-Hispanics were diagnosed at significantly younger ages. Higher rates of mortality were also observed among blacks compared with whites and Hispanics compared with non-Hispanics. Penile SCC incidence and mortality were elevated in Southern states and in regions of low socioeconomic status (SES). Some histologic and anatomic site differences were observed by race and ethnicity. Treatment of penile SCC varied with age, stage, and other tumor characteristics.
Conclusions: There are considerable disparities in invasive penile cancer incidence and mortality in the United States. Key risk factors for excess incidence include Hispanic ethnicity and residence in the South and in low SES regions. Risks for excess mortality include these factors in addition to black race. Decreases in penile cancer incidence and mortality in the United States may be realized in the future as the indirect result of prophylactic HPV vaccination of females. Further research is needed to better understand the epidemiology of penile cancer including the role of HPV.