ON THIS PAGE: You will learn about how doctors describe a cancer’s growth or spread. This is called the stage. To see other pages, use the menu on the side of your screen.
Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting other parts of the body. Doctors use diagnostic tests to find out the cancer's stage, so staging may not be complete until all 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, which is the chance of recovery. There are different stage descriptions for different types of cancer.
TNM staging system
One tool that doctors use to describe the stage is the TNM system. Doctors use the results from diagnostic tests and scans to answer these questions:
Tumor (T): How large is the primary tumor? Where is it located?
Node (N): Has the tumor spread to the lymph nodes? If so, where and how many?
Metastasis (M): Has the cancer metastasized to other parts of the body? If so, where and how much?
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.
Here are more details on each part of the TNM system for gallbladder cancer:
Using the TNM system, the "T" plus a letter or number (0 to 4) is used to describe the amount of cancer found in the gallbladder. Some stages are also divided into smaller groups that help describe the tumor in even more detail. This helps the doctor develop the best treatment plan for each patient. Specific tumor stage information is listed below.
TX: The primary tumor cannot be evaluated.
T0: No evidence of cancer was found in the gallbladder.
Tis: This refers to carcinoma (cancer) in situ, which means that the tumor remains in a pre-invasive state and its spread, if any, is very confined.
T1: The tumor is only in the gallbladder and has only invaded the lamina propria (a type of connective tissue found under the thin layer of tissue covering a mucous membrane) or muscle layer.
T1a: The tumor has invaded the lamina propria.
T1b: The tumor has invaded the muscle layer.
T2: The tumor has invaded the perimuscular connective tissue (the layer between the muscle layer and the serosa) but has not extended beyond the serosa (the outer layer) or into the liver.
T3: The tumor extends beyond the gallbladder and/or has invaded the liver and/or one other adjacent organ or structure, such as the stomach, duodenum (part of the small bowel), colon, or pancreas.
T4: The tumor has invaded the main portal vein or hepatic artery or has invaded more than one organ or structure beyond the liver.
The “N” in the TNM staging system stands for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph nodes near the gallbladder 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 regional lymph node metastasis.
N1: There is regional lymph node metastasis.
N2: There is distant lymph node metastasis.
The “M” in the TNM system indicates whether the cancer has spread to other parts of the body.
M0 (M plus zero): There is no distant metastasis.
M1: There is metastasis to one or more other parts of the body.
Cancer stage grouping
Doctors assign the stage of the cancer by combining the T, N, and M classifications.
Stage 0: Describes cancer in situ (Tis, N0, M0).
Stage I: A tumor is only in the gallbladder and has not spread (T1, N0, M0).
Stage II: A tumor has extended to the perimuscular connective tissue but has not spread elsewhere (T2, N0, M0).
Stage IIIA: A tumor has spread beyond the gallbladder but not to nearby arteries or veins. It has not spread to any lymph nodes or other parts of the body (T3, N0, M0).
Stage IIIB: A tumor of any size has spread to nearby lymph nodes but not to nearby arteries and/or veins or to other parts of the body (T1, T2, T3; N1; M0).
Stage IVA: A tumor has spread to nearby arteries, veins, and/or nearby lymph nodes, but it has not spread to other parts of the body (T4, N0 or N1, M0).
Stage IVB: Describes any tumor that has spread to other parts of the body (any T, any N, M1) or any tumor that has distant lymph node spread, even if it has not spread to distant organs (any T, N2, M0).
Recurrent: Recurrent gallbladder cancer is cancer that has come back after treatment. If there is a recurrence, the cancer may need to be staged again (called re-staging) using the system above. If the cancer does return, there will be another round of tests to learn about the extent of the recurrence. These tests and scans are often similar to those done at the time of the original diagnosis .
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 published by Springer-Verlag New York, www.cancerstaging.net 
Information about the cancer’s stage will help the doctor recommend a specific treatment plan. The next section in this guide is Treatment Options.  Or, use the menu on the side of your screen to choose another section to continue reading this guide.