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. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (chance of recovery). There are different stage descriptions for different types of cancer.
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 stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments.
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, the "T" plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Some stages are divided into smaller groups that help describe the tumor in even more detail. Specific tumor stage information is listed below.
TX: The primary tumor cannot be evaluated.
T0: There is no evidence of cancer in the vagina.
Tis: The tumor is carcinoma in situ, an early cancer found only in one layer of cells that has not spread to nearby tissue.
T1: The tumor is in the vagina and has not spread through the vaginal wall or to other parts of the body.
T2: The tumor has spread through the vaginal wall and surrounding tissue, but not to the walls of the pelvis.
T3: The tumor has spread to the pelvic wall.
T4: The tumor has spread to the bladder, rectum, or other areas of the body.
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 pelvis and groin are called regional lymph nodes. Depending on the exact location of the tumor (upper third, middle third, or lower third of the vagina), the lymph nodes near the hips or upper thighs may also be involved. Lymph nodes in other parts of the body are called distant lymph nodes.
NX: The lymph nodes cannot be evaluated.
N0: Cancer has not spread to the regional lymph nodes.
N1: Cancer has spread to the regional lymph nodes.
Distant metastasis. The "M" in the TNM system indicates whether the cancer has spread to other parts of the body.
MX: Metastasis cannot be evaluated.
M0: The cancer has not spread to other parts of the body.
M1: The cancer has spread to another part of the body.
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. In other words, the cancer is found only in the first layer of cells lining the vagina, not in the deeper tissue (Tis, N0, M0).
Stage I: The tumor has not spread through the vaginal wall or to other parts of the body (T1, N0, M0).
Stage II: The tumor has spread through the vaginal wall, but not to the walls of the pelvis (T2, N0, M0).
Stage III: Vaginal cancer is called stage III in either of these conditions:
- Cancer has spread to the lymph nodes in the pelvis (T1, T2, or T3; N1, M0).
- Cancer has spread to the pelvic wall (except the bladder), but not the lymph nodes (T3, N0, M0).
Stage IVA: Cancer has spread to the bladder, rectum, or beyond the pelvis. The lymph nodes may or may not be involved (T4, any N, M0).
Stage IVB: Any cancer that has spread to a distant part of the body (any T, any N, M1).
Recurrent: Recurrent cancer is cancer that comes back after treatment. If there is a recurrence, the cancer may need to be staged again (called re-staging) using the system above.
Tumor grade (G). In addition to the TNM system, doctors also describe a primary tumor by its grade, which is determined using a microscope to examine tissue from a tumor. The doctor compares the tumor tissue with normal tissue. Normal tissue contains many different types of cells grouped together, which is called differentiated. Tissue from a tumor usually has cells that look more alike, called poorly differentiated. Generally, the more differentiated the tissue, the better the prognosis.
GX: The tumor grade cannot be evaluated.
G1: The tumor cells are well differentiated (contain many healthy-looking cells).
G2: The tumor cells are moderately differentiated (more cells appear abnormal than healthy).
G3: The tumor cells are poorly differentiated (most of the cells appear abnormal).
G4: The tumor cells are undifferentiated (the cells barely resemble healthy cells).
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.