Cancer, the disease that claims the lives of over 600,000 Americans every year, begins when cells in the body begin growing out of control. Almost any part of the body can fall victim to its cells becoming cancer, and often the cancer can spread to other areas. 

Cervical cancer begins in the cells lining the cervix, the lower part of the uterus, which has two different parts and covered with two different types of cells:

  • The part of the cervix closest to the body of the uterus is called the endocervix and is covered with glandular cells.
  • The part next to the vagina is the exocervix (or ectocervixand is covered in squamous cells.

These two cell types meet in the transformation zone, where most cervical cancer begins.

The change is not immediate. Instead, the normal cells of the cervix start by developing pre-cancerous changes, including cervical intraepithelial neoplasia (CIN), squamous intraepithelial lesion (SIL), and dysplasia. These changes can be detected by the Pap test and treated to prevent cancer from developing. 

Although cervical cancers start from cells with those pre-cancerous changes, only a portion of the women with those pre-cancers will develop cancer. Usually, it takes several years for the pre-cancer to develop into cervical cancer, but sometimes it can occur in less than a year. For the majority of women, pre-cancerous cells may go away without treatment, but in some cases they turn into truly invasive cancers. Treatment of pre-cancers can prevent almost all cervical cancers. 

There are several types of cervical cancers. Cervical cancers and cervical pre-cancers are classified by how they look under a microscope. According to the American Cancer Society, the main types of cervical cancers are squamous cell carcinoma and adenocarcinoma.

  • Most (up to 9 out of 10) cervical cancers are squamous cell carcinomas. These cancers develop from cells in the exocervix and the cancer cells have features of squamous cells under the microscope. Squamous cell carcinomas most often begin in the transformation zone (where the exocervix joins the endocervix).
  • Most of the other cervical cancers are adenocarcinomas. Adenocarcinomas are cancers that develop from gland cells. Cervical adenocarcinoma develops from the mucus-producing gland cells of the endocervix. Cervical adenocarcinomas seem to have become more common in the past 20 to 30 years.
  • Less commonly, cervical cancers have features of both squamous cell carcinomas and adenocarcinomas. These are called adenosquamous carcinomas or mixed carcinomas.

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.

To stay on top of your cervical health, continue to receive regular Pap tests and report any changes you notice to your body. If you are in need of a gynecologist, UAB Medical West’s Obstetrics & Gynecology is here to help. Call (205)996-WEST or visit to learn more!

Sources: American Cancer Society,