Precancerous lesions in the anal canal and genital area are more frequent in women with genital warts or a history of genital warts. In 90% of the cases genital warts are caused by low-risk types of HPV 6 and 11. However, a woman with genital warts cannot know if she has also been infected by high-risk types of HPV and must get check-ups with Pap tests or HPV tests, because prevention is the best protection against cancer.