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What Is Cervical Cancer?

Cervical cancer is cancer that starts in the cells of the cervix. The cervix is the lower, narrow end of the uterus (womb). The cervix connects the uterus to the vagina (birth canal). Cervical cancer usually develops slowly over time. Before cancer appears in the cervix, the cells of the cervix go through changes known as dysplasia, in which abnormal cells begin to appear in the cervical tissue. Over time, if not destroyed or removed, the abnormal cells may become cancer cells and start to grow and spread more deeply into the cervix and to surrounding areas.

EnlargeAnatomy of the female reproductive system; drawing shows the uterus, myometrium (muscular outer layer of the uterus), endometrium (inner lining of the uterus), ovaries, fallopian tubes, cervix, and vagina.
Anatomy of the female reproductive system. The organs in the female reproductive system include the uterus, ovaries, fallopian tubes, cervix, and vagina. The uterus has a muscular outer layer called the myometrium and an inner lining called the endometrium.

The cervix has two main parts:

  • The ectocervix (also called exocervix) is the outer part of the cervix that can be seen during a gynecologic exam. The ectocervix is covered with thin, flat cells called squamous cells.
  • The endocervix is the inner part of the cervix that forms a canal that connects the vagina to the uterus. The endocervix is covered with column-shaped glandular cells that make mucus.

The squamocolumnar junction (also called the transformation zone) is the border where the endocervix and ectocervix meet. Most cervical cancers begin in this area.

EnlargeDrawing of the anatomy of the cervix showing the internal OS, endocervical canal, endocervix, ectocervix, and external OS. The uterus and vagina are also shown. There is also a pullout that shows a close up of the squamocolumnar junction (the area where the endocervix and ectocervix meet) and the cells that line the endocervix and ectocervix.
Anatomy of the cervix. The cervix is the lower, narrow end of the uterus that connects the uterus to the vagina. It is made up of the internal OS (the opening between the cervix and the upper part of the uterus), the endocervix (the inner part of the cervix that forms the endocervical canal), the ectocervix (the outer part of the cervix that opens into the vagina) and the external OS (the opening between the cervix and vagina). The area where the endocervix and ectocervix meet is called the squamocolumnar junction, which contains both glandular cells (column-shaped cells that make mucus) from the endocervix and squamous cells (thin, flat cells) from the ectocervix. The squamocolumnar junction is sometimes referred to as the transformation zone.

Types of cervical cancer

Cervical cancers are named after the type of cell where the cancer started. The two main types are:

  • Squamous cell carcinoma: Most cervical cancers (up to 90%) are squamous cell carcinomas. These cancers develop from cells in the ectocervix.
  • Adenocarcinoma: Cervical adenocarcinomas develop in the glandular cells of the endocervix. Clear cell adenocarcinoma, also called clear cell carcinoma or mesonephroma, is a rare type of cervical adenocarcinoma.

Sometimes, cervical cancer has features of both squamous cell carcinoma and adenocarcinoma. This is called mixed carcinoma or adenosquamous carcinoma. Very rarely, cancer develops in other cells in the cervix.

Learn more about cervical cancer


Many cervical cancer symptoms are also seen with other, less serious conditions. These are the warning signs you shouldn’t ignore.

Causes, Risk Factors, and Prevention

Long-lasting HPV infection causes almost all cervical cancers. Learn about HPV infection and other risk factors for cervical cancer and what you can do to lower your risk.


If you have a cervix, screening for cervical cancer is an important part of routine health care. Learn when to get screened and what to expect during and after screening.

HPV and Pap Test Results

Learn what HPV and Pap test results mean and next steps if a test result is abnormal.


Learn about the tests that are used to diagnose and stage cervical cancer.

Prognosis and Survival Rates

Learn about cervical cancer survival rates and why this statistic doesn't predict exactly what will happen to you.


Stage refers to the extent of your cancer, such as how large the tumor is and if it has spread. Learn about cervical cancer stages, an important factor in deciding your treatment plan.


Learn about the different ways cervical cancer can be treated.

Childhood Cervical and Vaginal Cancers

Cervical cancer and vaginal cancer are very rare in children. Learn about the signs and symptoms, diagnosis, and treatment options.

Coping and Support

Certain aspects of cervical cancer diagnosis and treatment are of special concern. Gain a greater sense of control by knowing what to expect and what resources are available to help you cope.

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