Cervical cancer starts in the cells lining the cervix -- the lower part of the uterus (womb). The cervix connects the body of the uterus (the upper part where a fetus grows) to the vagina (birth canal). Cancer starts when cells in the body begin to grow out of control. To learn more about how cancers start and spread, see What Is Cancer?
The cervix is made of two parts and is covered with two different types of cells.
The place where these two cell types meet in the cervix is called the transformation zone. The exact location of the transformation zone changes as you get older and if you give birth. Most cervical cancers begin in the cells in the transformation zone.
Cells in the transformation zone do not suddenly change into cancer. Instead, the normal cells of the cervix first gradually develop abnormal changes that are called pre-cancerous. Doctors use several terms to describe these pre-cancerous changes, including cervical intraepithelial neoplasia (CIN), squamous intraepithelial lesion (SIL), and dysplasia.
When the pre-cancers are checked in the lab, they are graded on a scale of 1 to 3 based on how much of the cervical tissue looks abnormal.
Although cervical cancers start from cells with pre-cancerous changes (pre-cancers), only some of the women with pre-cancers of the cervix will develop cancer. For most women, pre-cancerous cells will go away without any treatment. But, in some women pre-cancers turn into true (invasive) cancers. Treating cervical pre-cancers can prevent almost all cervical cancers.
The goal of cervical cancer screening is to find pre-cancer or cancer early when it is more treatable and curable. Regular screening can prevent cervical cancers and save lives. The tests for cervical cancer screening are the HPV test and the Pap test. Pre-cancerous changes can be detected by the Pap test and treated to prevent cancer from developing. The HPV test looks for infection by high-risk types of HPV that are more likely to cause pre-cancers and cancers of the cervix. HPV infection has no treatment, but a vaccine can help prevent it.
See Can Cervical Cancer Be Prevented? The specific types of treatment for abnormal screening tests are discussed in When Cervical Screening Test Results are Abnormal.
Cervical cancers and cervical pre-cancers are classified by how they look in the lab s with a microscope. The main types of cervical cancers are squamous cell carcinoma and adenocarcinoma.
Although almost all cervical cancers are either squamous cell carcinomas or adenocarcinomas, other types of cancer also can develop in the cervix. These other types, such as melanoma, sarcoma, and lymphoma, occur more commonly in other parts of the body.
Only the more common cervical cancer types are covered here.
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
Eifel P, Klopp AH, Berek JS, and Konstantinopoulos A. Chapter 74: Cancer of the Cervix, Vagina, and Vulva. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2019.
Fontham, ETH, Wolf, AMD, Church, TR, et al. Cervical Cancer Screening for Individuals at Average Risk: 2020 Guideline Update from the American Cancer Society. CA Cancer J Clin. 2020. https://doi.org/10.3322/caac.21628.
Jhungran A, Russell AH, Seiden MV, Duska LR, Goodman A, Lee S, et al. Chapter 84: Cancers of the Cervix, Vulva, and Vagina. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, Pa: Elsevier; 2020.
National Cancer Institute. Physician Data Query (PDQ). Cervical Cancer Treatment – Health Professional Version. 2019. https://www.cancer.gov/types/cervical/hp/cervical-treatment-pdq. Updated February 6, 2019. Accessed on October 30, 2019.
Last Revised: July 30, 2020
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