Prostate cancer in young men: An emerging young adult and older adolescent challenge.

<bold>Background: </bold>Recent observations suggest that prostate cancer is an increasing disease among older adolescents and young adults.<bold>Methods: </bold>Incidence, mortality, and survival data were obtained from the US National Cancer Institute Surveillance, Epidemiology, and End Results program and the Institute for Health Metrics and Evaluation Global Burden of Disease database.<bold>Results: </bold>Worldwide, the incidence of prostate cancer has increased in all groups between ages 15 and 40 years and increased globally at a steady rate averaging 2% per year since 1990 (P < .01). In the United States, this age group was >6 times more likely than older men to have distant disease at diagnosis. Stage for stage, their survival rate improved less than in older men. Whereas the overall 5-year relative survival rate in the United States for men diagnosed between ages 40 and 80 years was between 95% and 100%, it was 30% in those aged 15 to 24 years, 50% in those aged 20 to 29 years, and 80% in those aged 25 to 34 years.<bold>Conclusions: </bold>Prostate cancer in older adolescent and young adult men has increased in most countries. There is some evidence that this may be caused in part by underdiagnosis, prostate-specific antigen screening, and overdiagnosis. It also may be caused by trends in obesity, physical inactivity, HPV infection, substance exposure, environmental carcinogens, and/or referral patterns. How the biology of these cancers differs from that in older men and how the etiologies vary from country to country remain to be determined. [ABSTRACT FROM AUTHOR]