CRC can also be grouped into stages as shown on this chart. Stage 0 is associated with Tis, or carcinoma in situ, which indicates that the tumor is found only in the tissue where it started, such as a polyp. In Stage 0 disease, there is no nodal involvement or distant metastases. Stage I disease, is characterized by a T1 or T2 tumor component, while Stage II disease is characterized by a T3 or T4 tumor. Both Stage I and Stage II disease have no nodal involvement or distant metastases. Stage III disease is any T with spread to a lymph node, while Stage IV disease indicates the presence of at least one distant metastasis. The graph shows survival statistics by stage.