[Increasing incidence of anal cancer in the Netherlands].

Anal cancer is a rare malignancy with a rapidly rising incidence. The most important risk factor for anal cancer is persistent infection with Human papillomavirus (HPV). In the Netherlands, the incidence of anal cancer increased from 71 to 149 new patients each year over the period 1989-2006. There has been a corresponding overall increase in mortality, although the exact level differs per year. Not enough research has been done to date to clarify why the incidence of anal cancer is increasing.