The cervix is a female reproductive organ that forms the lower portion of the uterus or womb. The uterus and cervix lie in the pelvis, on top of the vagina, in between the rectum and bladder. The cervix forms the part of the birth canal that opens to the vagina.
The surface layer of the cervix is mostly composed of squamous cells. The squamous cells of the cervix merge with the glandular cells lining the cervical canal of the uterus. The area of merging is called the squamo-columnar junction and the area on the cervix outside of this junction is called the transformation zone. Cervical cancer occurs when cervical cells grow out of control, typically in the transformation zone. When cells grow out of control, they spread and grow throughout the cervix and may invade and destroy neighboring organs or break away and spread through the bloodstream and lymphatic system to other parts of the body.
Doctors who care for women routinely perform pelvic examinations and a Papanicolaou (Pap) smear to screen for cancer in the cells on the surface of the cervix. During a Pap smear, a sample of cells from the cervix is taken with a small wooden spatula or brush and examined under the microscope. Women may first become aware that they have cervical cancer when a suspicious area is identified during a pelvic examination or an abnormal Pap smear. If a suspicious or a precancerous lesion is found, additional tests will be recommended to determine whether a precancerous lesion or invasive cancer exists.
Cells taken from the surface of the cervix can appear abnormal, but may not be cancer. These abnormal cells, however, may be the first step in a series of changes that lead to cancer. Doctors refer to the abnormal cells as "precancerous" and have used different terms to refer to them, such as squamous intraepithelial lesions, dysplasia, cervical intraepithelial neoplasia or carcinoma in situ. Precancerous disease involves only the surface of the cervix. When the abnormal cells begin to spread deeper into the cervix, they are referred to as invasive cancer of the cervix.
If physicians feel they need more information following an abnormal Pap smear, they may use a colposcope (lighted microscope) to better visualize the cervix or to perform a biopsy, which is the removal of a sample of tissue from the cervix in order to evaluate cervical cells under a microscope. If the doctor cannot determine whether the abnormal cells are only on the surface of the cervix, an endocervical curettage or conization may be recommended. During an endocervical curettage, a small spoon-shaped instrument called a curette is used to scrape cells away from inside the cervical opening. A conization or cone biopsy removes a cone-shaped sample of tissue from the cervical canal. Conization can also serve as the primary treatment of precancerous cervical cancer.
Infrequently, it may still remain unclear whether the abnormal cells are confined to the cervix or arise from inside the uterus. In this situation, a dilatation and curettage (D and C) may be recommended. During a D and C, the cervical opening is stretched (dilated) and a curette is inserted to remove cells from the lining of the uterus and cervical canal. In order to learn more about the most recent information available concerning the treatment of cervical cancer, click on the appropriate stage.
Stage 0: Precancerous lesion involves only the cells on the surface of the cervix.
Stage I: Cancer is confined to the cervix, and may be evident only under microscopic evaluation (stage IA) or apparent by visible or physical examination (stage IB).
Stage II: Cancer has spread beyond the cervix to involve the tissues surrounding the cervix (parametria) or the upper portion of the vagina.
Stage III: Cancer spreads beyond the cervix to the lower vagina or to the sides of the pelvis, or causes a blockage of drainage from the kidney, a condition called hydronephrosis.
Stage IV: Cancer invades structures adjacent to the cervix such as the bladder or rectum or has spread to other parts of the body such as the liver or lungs.
Recurrent/Relapsed: Cervical cancer is still detected or has returned (recurred/relapsed) following an initial treatment with surgery, radiation therapy, and/or chemotherapy.