Stage I-IV colorectal cancer

Colorectal cancer staging (Stages I-IV) describes how advanced the cancer is and how far it has spread. Stage I means the cancer is limited to the innermost layers of the colon or rectum and hasn't spread beyond. Stage II indicates the cancer has grown deeper or through the wall but still hasn't reached nearby lymph nodes. Stage III involves spread to nearby lymph nodes but not distant sites. Stage IV is the most advanced, with cancer spreading to other parts of the body, like the liver or lungs. Staging helps determine the best treatment approach and prognosis.