For most people who have HPV, it will either go away on its own or remain but not cause harm. Only specific varieties of HPV can cause cancer and even if you have those varieties, the chances of developing cancer are very small.
Among those who do develop HPV-related cancer, HPV 16 and HPV 18 varieties are most likely to blame. Both HPV 16 and HPV 18 strains cause 70% of cervical cancers and 80% of anal cancers worldwide.
Although anal cancer is rare, affecting 1 of 100,000 people, anal cancer rates are highest among guys into guys. Men who have sex with men are 20 times more likely than heterosexual men to develop anal cancer, and HIV-positive men who have sex with men are 100 times more likely.