As per estimates, 79 percent of cervical cancers are due to a common group of viruses called human papillomavirus (HPV). There are over 100 types of HPV, but the types most commonly associated with abnormal cervical changes and the development of cancer are called high risk HPV. Many types of HPV can be easy to catch. Most people clear the virus spontaneously, but a small number have persistent infection and are at risk of developing abnormal changes. If left untreated, these changes can lead to cancer.