What Are the Stages of Cervical Cancer?

The stages of cervical cancer are used to describe how far the cancer has spread in your body. The higher the stage number, the more widespread the cancer is. These stages are important when choosing the best treatments for you. Cervical cancer is usually found in an early stage, either stage 0 or stage I.

TNM System

One way to describe the stages of cervical cancer is to use the TNM system. This system uses three different codes to describe the depth and location of the tumor, whether it has spread to the lymph nodes around the tumor, and whether it can be found in other parts of the body.

In the TNM system, “T” plus a letter or number (0 to 4) is used to describe the depth size and location of the tumor. The tumor stages are:

TX - The primary, or original, tumor cannot be evaluated because of incomplete information.

Tis - Carcinoma (cancer) in situ: the cancer is found only in the lining of the cervix and has not invaded deeper tissues of the cervix.

T1 - The cancer is found only in the cervix.

• T1a - Invasive cancer is diagnosed only by examining cervical tissue or cells under a microscope.
  • T1a1 - A cancerous area no more than 3 millimeters deep and 7 millimeters wide.
  • T1a2 - A cancerous area between 3 millimeters and 5 millimeters deep and less than 7 millimeters wide.
• T1b - A lesion is visible to the doctor and the cancer is found only in the cervix, or a lesion deeper than 5 millimeters or wider than 7 millimeters can only be seen using a microscope. The cancer may have been found because of a physical examination, laparoscopy, or other imaging methods.
  • T1b1 - The tumor is 4 centimeters or smaller.
  • T1b2 - The tumor is larger than 4 centimeters.

T2 - The cancer has grown beyond the uterus (womb) but not to the pelvic wall or to the lower third of the vagina.

• T2a - The tumor has invaded two thirds of the proximal vagina.
• T2b - The tumor has invaded the tissue next to the cervix (the parametrial area).

T3 - The tumor has spread to the pelvic wall; involves the lower third of the vagina; stops the kidney from working properly; or blocks the tubes (ureters) that connect the kidneys to the bladder.

• T3a - The tumor involves the lower third of the vagina but has not grown into the pelvic wall.
• T3b - The tumor has grown into the pelvic wall or stops the kidneys from working properly.

T4 - The tumor has invaded the lining (mucosa) of the bladder or rectum and grown beyond the pelvis.

The "N" in the TNM system stands for node. Lymph nodes are tiny organs shaped like beans that can be found throughout the body. Lymph nodes help the body fight infections. Regional lymph nodes are near the cervix, while distant lymph nodes are in other parts of the body. Lymph node stages are:

NX - The regional lymph nodes cannot be evaluated because of incomplete information.

N0 - The cancer has not spread into the regional lymph nodes.

N1 - The cancer has spread into the regional lymph nodes.

The "M" in the TNM system is used for cancer that has spread, or metastasized, to other parts of the body. The stages for metastatic cervical cancer are:

MX - Distant metastasis cannot be evaluated because of incomplete information.

M0 - The cancer has not metastasized, or spread, to distant organs.

M1 - The cancer has spread to other parts of the body beyond the cervix.

Cancer Stages 0 to IV

The stages of cervical cancer range from Stage 0 to Stage IV based on tumor size, invasiveness (whether the tumor has spread from the lining of the cervix to tissue deeper in the cervix or to other parts of the body), presence in lymph nodes (tiny organs shaped like beans that can be found throughout the body), and whether the cancer has metastasized (spread) to other organs. This staging system was developed by the International Federation of Gynecology and Obstetrics (FIGO). The higher the number, the more serious (advanced) the cancer is.

• Stage 0 (carcinoma in situ) - Precancerous lesion that involves only the cells on the surface of the cervix (Tis, N0, M0).
• Stage 1 - Cancer is found only in the cervix and has not spread anywhere else in the body (T1, N0, M0).
  • Stage IA - A very small amount of cancer that can be seen only under a microscope. The cancer is not deeper than 5 millimeters and not wider than 7 millimeters (T1a, N0, M0).
  • Stage IB - The cancer can either only be seen with a microscope and is deeper than 5 millimeters or less than 7 millimeters wide, or it can be seen without a microscope and may be larger than 4 cm (T1a2, N0, M0).
• Stage II - The cancer has spread beyond the cervix but not outside the pelvis (T2, N0, M0).
  • Stage IIA - The cancer has spread to the upper vagina, but not into lower third of the vagina (T2a, N0, M0).
  • Stage IIB - The cancer has spread to the tissues surrounding the vagina and cervix but not to the pelvic wall (the muscle and connective tissues lining the insides of the pelvic bones) (T2b, N0, M0).
• Stage III - The cancer has spread beyond the cervix to the lower third of the vagina or to the walls of the pelvis and nearby lymph nodes. The cancer might block the flow of urine to the bladder (T3, N0, M0). 
  • Stage IIIA - The cancer has spread to the lower third of the vagina but not to the pelvic wall (T3a, N0, M0).
  • Stage IIIB - The cancer has spread to the pelvic wall and/or the tumor is large enough to block the flow of urine to the bladder. The cancer may also have spread to the lymph nodes in the pelvis (T3b, any N, M0).
• Stage IV -  The cancer has spread to nearby organs or other parts of the body.
  • Stage IVA - The cancer has spread to the bladder or rectum, which are close to the cervix. The cancer may also have spread to lymph nodes in the pelvis (T4, any N, M0).
  • Stage IVB - The cancer has spread to distant organs beyond the pelvic area, such as the abdomen, liver, intestines, or lungs (any T, any N, M1).
• Recurrent or relapsed - Cervical cancer is still detected or has returned (recurred or relapsed) following an initial treatment with surgery, radiation therapy, and/or chemotherapy. The cancer may have returned to the cervix or another place.

This content has been reviewed and approved by Myo Thant, MD.