user: What are the stages of Gallbladder Cancer ?

assistant: Key Points
                    - Tests and procedures to stage gallbladder cancer are usually done at the same time as diagnosis.     - There are three ways that cancer spreads in the body.    - Cancer may spread from where it began to other parts of the body.    - The following stages are used for gallbladder cancer:         - Stage 0 (Carcinoma in Situ)     - Stage I     - Stage II     - Stage IIIA     - Stage IIIB     - Stage IVA     - Stage IVB        - For gallbladder cancer, stages are also grouped according to how the cancer may be treated. There are two treatment groups:         - Localized (Stage I)      - Unresectable, recurrent, or metastatic (Stage II, Stage III, and Stage IV)
                
                
                    Tests and procedures to stage gallbladder cancer are usually done at the same time as diagnosis.
                    See the General Information section for a description of tests and procedures used to detect, diagnose, and stage gallbladder cancer.
                
                
                    There are three ways that cancer spreads in the body.
                    Cancer can spread through tissue, the lymph system, and the blood:         - Tissue. The cancer spreads from where it began by growing into nearby areas.     - Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.     - Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.
                
                
                    Cancer may spread from where it began to other parts of the body.
                    When cancer spreads to another part of the body, it is called metastasis. Cancer cells break away from where they began (the primary tumor) and travel through the lymph system or blood.         - Lymph system. The cancer gets into the lymph system, travels through the lymph vessels, and forms a tumor (metastatic tumor) in another part of the body.    - Blood. The cancer gets into the blood, travels through the blood vessels, and forms a tumor (metastatic tumor) in another part of the body.        The metastatic tumor is the same type of cancer as the primary tumor. For example, if gallbladder cancer spreads to the liver, the cancer cells in the liver are actually gallbladder cancer cells. The disease is metastatic gallbladder cancer, not liver cancer.
                
                
                    The following stages are used for gallbladder cancer:
                    Stage 0 (Carcinoma in Situ)    In stage 0, abnormal cells are found in the inner (mucosal) layer of the gallbladder. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.       Stage I    In stage I, cancer has formed and has spread beyond the inner (mucosal) layer to a layer of tissue with blood vessels or to the muscle layer.       Stage II    In stage II, cancer has spread beyond the muscle layer to the connective tissue around the muscle.       Stage IIIA    In stage IIIA, cancer has spread through the thin layers of tissue that cover the gallbladder and/or to the liver and/or to one nearby organ (such as the stomach, small intestine, colon, pancreas, or bile ducts outside the liver).       Stage IIIB    In stage IIIB, cancer has spread to nearby lymph nodes and:            -  beyond the inner layer of the gallbladder to a layer of tissue with blood vessels or to the muscle layer; or     -  beyond the muscle layer to the connective tissue around the muscle; or     - through the thin layers of tissue that cover the gallbladder and/or to the liver and/or to one nearby organ (such as the stomach, small intestine, colon, pancreas, or bile ducts outside the liver).              Stage IVA    In stage IVA, cancer has spread to a main blood vessel of the liver or to 2 or more nearby organs or areas other than the liver. Cancer may have spread to nearby lymph nodes.       Stage IVB    In stage IVB, cancer has spread to either:            -  lymph nodes along large arteries in the abdomen and/or near the lower part of the backbone; or      - to organs or areas far away from the gallbladder.
                
                
                    For gallbladder cancer, stages are also grouped according to how the cancer may be treated. There are two treatment groups:
                    Localized (Stage I)      Cancer is found in the wall of the gallbladder and can be completely removed by surgery.        Unresectable, recurrent, or metastatic (Stage II, Stage III, and Stage IV)     Unresectable cancer cannot be removed completely by surgery. Most patients with gallbladder cancer have unresectable cancer.      Recurrent cancer is cancer that has recurred (come back) after it has been treated. Gallbladder cancer may come back in the gallbladder or in other parts of the body.     Metastasis is the spread of cancer from the primary site (place where it started) to other places in the body. Metastatic gallbladder cancer may spread to surrounding tissues, organs, throughout the abdominal cavity, or to distant parts of the body.