The development of cervical cancer

Cervical intraepithelial neoplasia (CIN) is the precursor of cervical cancer. It means that the cervical cells on the surface of the cervix are abnormal. Even if the entire surface layer of the cervix is abnormal, it is not cancer at this time. When the deeper cells begin to show abnormalities, it can be defined as cancer. Cervical cancer can be divided into the following four stages:
Stage 1: Cancer cells begin to appear in subcutaneous cells, and the cancer cells are still confined to the location of the cervix.
Stage 2: Cancer cells have extended to the nearby tissues of the cervix and the upper part of the vagina, but have not yet spread to the pelvic cavity and the lower part of the vagina.
Stage III: Cancer cells have extended to the pelvic cavity and reached the lower part of the vagina.
Stage IV: Cancer cells have spread to other parts of the body, such as the rectum, lungs, and bones.