Cervical cancer is a cancer that starts in the cervix, which is the lower part of womb. It is an invasive tumour affecting the cervix. 'Invasive' means that the tumour can spread from the surface of cervix into the deeper tissues, which in turn may spread to adjacent structures (e.g. vagina, nerve, pelvis and kidney) and finally to distant organs such as liver, lung and brain.
Almost all cervical cancers are caused by persistent infection with one of the cancer-causing or high-risk human papillomavirus (HPV) types. HPV infection is common in any person who has been sexually active. Most people with HPV infection will not have any symptoms and will clear the infection on their own. Some females with persistent high-risk HPV infection in the cervix will develop pre-cancerous cell changes. While the majority of these changes will regress to normal, some may progress to cancer over years. The following figure illustrates the natural course of the development of pre-cancerous cell changes to cervical cancer.