Doctors stage tumors based on their T,N and M grading. Stage 0: Carcinoma in situ (Tis, N0, M0). Stage I: the tumor is confined to the gallbladder and has not spread to the surrounding area (T1, N0, M0). Stage II: the tumor invades the peri-muscular hoof tissue and does not invade other parts of the body (T2, N0, M0). Stage IIIA: Tumor invades the extracellular tissues of the gallbladder but does not invade the adjacent arteries, veins, lymph nodes, or other organs and tissues. Stage IIIB: Tumor of any size invades peripheral lymph nodes but not surrounding arteries or veins and other organs and tissues (T1, T2, T3; N1; M0); Stage 4A: Tumor invades peripheral arteries, veins, or lymph nodes but not other organs and tissues (T4, N0 or N1, M0). Stage 4B: Tumor invades other organs and tissues (any T, any N, M1) or tumor has distant lymph node invasion even though there is no distant organ invasion (any T, N2, M0). Recurrence: the reappearance of a tumor after treatment of gallbladder cancer becomes a recurrence. If recurrence occurs, the tumor needs to be restaged (in-staging) according to the system described above. If the tumor does recur, a series of tests are needed to assess the extent of the recurrence. These tests are similar to those used for the first diagnosis. The staging of gallbladder cancer can be divided into 4 stages, and the treatment of gallbladder cancer needs to be based on the staging. Therefore, before treatment, patients need to undergo a careful examination to determine the stage and then make a treatment plan.