Some types of HPV are referred to as ?low-risk? viruses because they rarely develop into cancer. HPV types that are more likely to lead to the development of cancer are referred to as ?high-risk.? Both high-risk and low-risk types of HPV can cause the growth of abnormal cells, but generally only the high-risk types of HPV may lead to cancer.
Sexually transmitted, high-risk HPVs include types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 69, and possibly a few others. These high-risk types of HPV cause growths that are usually flat and nearly invisible, as compared with the warts caused by types HPV?6 and HPV?11. It is important to note, however, that the majority of high-risk HPV infections go away on their own and do not cause cancer.