Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all of the tests are finished. In addition, doctors may need information based on samples of tissue from surgery, so staging may not be complete before surgery to remove the tumor (see Treatment). Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a woman's prognosis (chance of recovery). There are different stage descriptions for different types of cancer.
The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments. One tool that doctors use to describe the stage is the TNM system. This system judges three factors: the tumor itself, the lymph nodes around the tumor, and if the tumor has spread to other parts of the body. The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero) and stages I through IV (one through four).
The Roman numerals are stages used in another widely used staging system from the Federation Internationale de Gynecologie et d'Obstetrique, or FIGO. The FIGO system is the standard system used by most doctors to stage uterine cancer.
TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:
- How large is the primary tumor and where is it located? (Tumor, T)
- Has the tumor spread to the lymph nodes? (Node, N)
- Has the cancer metastasized to other parts of the body? (Metastasis, M)
Tumor. Using the TNM system, "T" plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Some stages are also divided into smaller groups that help describe the tumor in even more detail.
TX: The primary tumor cannot be evaluated due to a lack of information. More tests may be needed.
T0 (T plus zero): There does not seem to be a primary tumor in the uterus.
Tis: This condition is called carcinoma (cancer) in situ, which means that the cancer is found only in the layer of cells lining the uterus and has not spread to deeper tissues of the uterus.
T1/FIGO I: The tumor is found only in the corpus uteri (the body of the uterus).
T1a/FIGO IA: The tumor is found only in the endometrium has spread to less than one-half of the myometrium.
T1b/FIGO IB: The tumor has spread to one-half or more of the myometrium.
T2/FIGO II: The tumor has spread to the cervical stroma (the connective tissue of the cervix) but has not spread beyond the uterus.
T3a/FIGO IIIA: The tumor involves the serosa (the layer of tissue that covers the outer surface of the uterus) and/or the tissue of the fallopian tubes and ovaries.
T3b/FIGO IIIB: The tumor has spread to the vagina or next to the uterus.
T4/FIGO IVA: The tumor has spread to the lining of the bladder mucosa (lining of the bladder) and/or the bowel mucosa (lining of the bowel).
Node. The "N" in the TNM staging system stands for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph nodes near the uterus are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes.
NX: The regional lymph nodes cannot be evaluated.
N0 (N plus zero): There is no spread to regional lymph nodes.
N1/FIGO IIIC1: The cancer has spread to the regional pelvic lymph node(s).
N2/FIGO IIIC2: The cancer has spread to the para-aortic lymph nodes, which are located in the mid and upper abdomen, with or without spread to the regional pelvic lymph nodes.
Distant metastasis. The "M" in the TNM system describes whether the cancer has spread to other parts of the body.
M0 (M plus zero): The cancer has not metastasized.
M1/FIGO IVB: There is distant metastasis.
Cancer stage grouping
Doctors assign the stage of the cancer by combining the T, N, and M classifications.
Stage 0: The tumor is called carcinoma in situ, which means it is very early stage cancer. It is found only in one layer of cells and has not spread (Tis, N0, M0).
Stage I: The cancer is found only in the uterus or womb and has not spread to other parts of the body (T1, N0, M0).
Stage IA: The cancer is found only in the endometrium or less than one-half of the myometrium (T1a, N0, M0).
Stage IB: The tumor has spread to one-half or more of the myometrium (T1b, N0, M0).
Stage II: The tumor has spread from the uterus to the cervical stroma but not to other parts of the body (T2, N0, M0).
Stage III: The cancer has spread beyond the uterus, but it is still only in the pelvic area (T3, N0, M0).
Stage IIIA: The cancer has spread to the serosa of the uterus and/or the tissue of the fallopian tubes and ovaries but not to other parts of the body (T3a, N0, M0).
Stage IIIB: The tumor has spread to the vagina or next to the uterus (T3b, N0, M0).
Stage IIIC1: The cancer has spread to the regional pelvic lymph nodes (T1 to T3, N1, M0).
Stage IIIC2: The cancer has spread to the para-aortic lymph nodes with or without spread to the regional pelvic lymph nodes (T1 to T3, N2, M0).
Stage IVA: The cancer has spread to the mucosa of the rectum or bladder (T4, any N, M0).
Stage IVB: The cancer has spread to lymph nodes in the groin area, and/or it has spread to distant organs, such as the bones or lungs (any T, any N, M1).
In addition to the stage, doctors may also use the term “grade,” which is how similar the tumor is to normal tissue. Tumor grade is determined by examining the tumor tissue under a microscope. In a tumor that resembles healthy tissue, doctors can clearly see different types of cells grouped together (called well-differentiated). In a higher-grade cancer, the cancer cells usually look less like healthy cells, or “wilder” (called poorly differentiated or undifferentiated). In general, patients with a lower-grade tumor have a better prognosis.
The letter "G" is used to define a grade for uterine cancer.
GX: The grade cannot be evaluated
G1: The cells are well differentiated
G2: The cells are moderately differentiated
G3: The cells are poorly differentiated
G4: The cells are undifferentiated
Recurrent uterine cancer
Recurrent cancer is cancer that comes back after treatment. Uterine cancer may come back in the uterus, pelvis, lymph nodes of the abdomen, or another part of the body. Approximately 70% of recurrent uterine cancer happens within three years of initial treatment. Some symptoms of recurrent cancer are similar to those experienced when the disease was first diagnosed.
- Vaginal bleeding or discharge
- Pain in the pelvic area, abdomen, or back of the legs
- Difficulty or pain when urinating
- Weight loss
- Chronic cough
If there is a recurrence, the cancer may need to be staged again (called re-staging) using the system above.
Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer-Verlag New York, www.cancerstaging.net.