Cervical cancer starts in a woman's cervix. The cervix is the lower, thin opening of the uterus that connects the vagina (or birth canal) to the uterus (womb). Cervical cancer grows slowly over time and usually starts with abnormal changes to the cells on the cervix, known as dysplasia. Removing these abnormal cells can prevent cervical cancer.
Cervical cancer screening tests can find the cells that lead to cancer before it starts or find cancer early when it is most easily treated. The Papanicolaou (Pap) test screens for abnormal cells that may develop into cancer, and the HPV test screens for the human papillomavirus virus (HPV) that causes these cell changes. Nearly all cervical cancer is caused by the human papillomavirus (HPV). As many as 93% of cervical cancers could be prevented by screening and HPV (human papillomavirus) vaccination.