Cervical cancer begins in the cervix, the lower part of the uterus that connects to the vagina. It is usually caused by human papillomavirus (HPV) infection, particularly strains HPV16 and HPV18. Regular screening tests such as Pap smears or HPV tests can detect precancerous changes in the cervix, allowing for early intervention and prevention of cervical cancer. Treatment may include surgery, chemotherapy, or radiation therapy, depending on the stage and extent of the cancer.