Cervical cancer is largely preventable, thanks to the availability of Pap tests. And because of widespread preventative measures, cervical cancer is fairly uncommon in the United States. It's the 14th most common cancer among women in the United States, but it is the second most common cancer among women worldwide. Nevertheless, every year more than 12,000 women in the United States are diagnosed with cervical cancer and nearly 3,700 die of the disease. About half of women diagnosed with cervical cancer in the United States have not had a Pap test in 10 years or longer. Most of these women are over 30 years old. Unfortunately, those women with high-risk lifestyles are those most likely to develop cervical cancer but least likely to be screened for it.

Making Sense of Test Results

One of the most common test used to screen for cervical cancer includes a pelvic examination a Pap test, in which a sample of cells taken from the cervix and the cervical canal. The cell sample is determined to be either negative (no cell abnormalities detected) or positive (abnormal cells seen in the sample). Positive results can be confusing, so they are explained below. Click here to learn more about pap tests

Squamous Intraepithelial Lesion (SIL)

The word squamous means "plate like" or "scaly" and refers to squamous cells, the relatively flat cells that make up the outer layers of the cervix. The prefix intra- means "within" and the word epithelial refers to the cells of the epithelium, the membranous tissue that covers the cervix. SIL is further categorized as either low grade or high grade.

  • Low-grade SIL (LSIL) indicates mild changes to the cells (known as dysplasia) that might resolve without treatment but could lead to more ominous precancerous changes.
  • High-grade SIL (HSIL) indicates premalignant changes that are likely to become cancerous without treatment. High-grade lesions are determined to represent moderate dysplasia, severe dysplasia, or carcinoma in situ (CIS or noninvasive cancer).

These designations are part of the Bethesda system of classification and are used to describe abnormal Pap test results.

Dysplasia and Cervical Intraepithelial Neoplasia (CIN)

The word dysplasia comes from the prefix dys-, meaning bad, and the Greek word plasia, meaning formation. And as we've just learned, the prefix intra- means within, and epithelial refers to the tissue that covers the cervix. Finally, the prefix neo- means new, and plasia refers to formation. Putting it all together, intraepithelial neoplasia means the new formation of a dysplastic lesion within the cervical tissue. The lesion, or tumor, will be labeled as follows:

  • CIN 1 for mild dysplasia
  • CIN 2 for moderate dysplasia
  • CIN 3 for severe dysplasia or CIS

It's important to note that CIN is not cancer; it only designates the presence of abnormal cells. If discovered early enough, it can be treated.

Cancer Staging

If your doctor determines that you do have cervical cancer, the next step will be to determine whether the cancer has spread and, if so, to what extent. This process is known as "staging." Physicians use one of two classification systems. The first is the FIGO (Federation Internationale de Gynecologie et d'Obstetrique, or International Federation of Gynecology and Obstetrics) system. The other, which is more common in the United States, is the American Joint Committee on Cancer's TNM system.

The TNM system assigns a stage from 0 to IV to indicate the general state of the cancer, and adds additional letters and numbers indicate specific features of the tumor. Number-letter combinations with the letter T indicate the extent of the tumor; number-letter combinations with the letter N indicate if the cancer has spread to nearby lymph nodes; and number letter combinations with the letter M indicate metastases—if the cancer has spread to any distant parts of the body. 

For example, "Stage IB2 (T1b2, N0, M0)" indicates that the lesion measures 3 to 5 mm but less than 7 mm (T1b2), is confined to the cervix and has not spread to regional lymph nodes (N0), and has not metastasized to distant sites (M0). If you or a loved one is diagnosed with cervical cancer, ask your doctor to tell you the TNM or FIGO stage so that you can research information that applies specifically to that stage. The overall prognosis for the patient will depend largely on the stage of the cancer and how amenable it is to surgery and/or medical treatments.

Here are is a generalized overview of the stages:

Stage 0: This very early cancer is small and confined to the surface of the cervix. It is sometimes referred to as "carcinoma in situ" or "non-invasive cancer."

Stage I: In Stage I, the cancer has invaded the cervix, but is confined there.

  • Stage IA: This is the earlier form of Stage I, and refers to a cancer that can only be seen under a microscope.
  • Stage IB: This refers to a Stage I cancer that can be seen without a microscope, or cancer that can only be seen with a microscope but has spread deeper than 5mm into the connective tissue of the cervix.

Stage II: At this stage, the cancer has moved beyond the cervix, but not to the pelvic wall or to the lower third of the vagina. Stage II is divided into Stages IIA and IIB, depending on how far the cancer has spread.

  • Stage IIA: This is a Stage II cancer that has spread to the upper two-thirds of the vagina, but not beyond.
  • Stage IIB: This is a Stage II cancer that has spread to both the upper two-thirds of the vagina and to the uterus, but not beyond.

Stage III: In stage III, the cancer has spread beyond the cervix and uterus and may have reached the pelvic wall and/or the lower part of the vagina. Stage III is divided into Stages IIIA and IIIB, depending on how far the cancer has spread.

  • Stage IIIIA: This is a Stage III cancer that has invaded the lower third of the vagina, but not the pelvic wall.
  • Stage IIIIB: This is a Stage III cancer that has spread to the pelvic wall and/or has resulted in a tumor large enough to block the tubes connecting the kidneys to the bladder. Bladder failure may have occurred as a result. Cancer cells in this stage may also have reached the pelvic lymph nodes.

Stage IV: At Stage IV, the cancer has spread to organs nearby the cervix, such as the bladder or  rectum, or it has spread to other areas of the body such as the liver, abdomen, or lungs. Stage IV is divided into Stages IVA and IVB, which indicate where the cancer can now be found.

  • Stage IVA: This is a Stage IV cancer that has spread to the bladder or to the rectal wall. It may also have spread to lymph nodes in the pelvis.
  • Stage IVB: This is a Stage IV cancer that has spread to distant organs beyond the pelvic region. It may have reached the bones, lungs, abdomen, liver, or intestinal tract, for example.