The different stages of cancer are stages zero, 1, 2, 3 and 4, according to the American Society of Clinical Oncology. However, most cancers only have the latter four stages, and doctors determine the cancer stage using the tumor, node and metastasis, or TNM, system of classification.
Stage zero cancer is highly curable, and the term is used to describe cancer that has not invaded any nearby tissues, notes the American Society of Clinical Oncology. Doctors typically treat this stage of cancer by removing the tumor with surgery. Stage 1 cancer has not spread to the lymph nodes or other parts of the body; however, it may have grown into nearby tissues. Cancer that is stage 2 or 3 has not spread to other parts of the body, but it has grown deep into nearby tissues and spread to the lymph nodes. Stage 4 cancer is advanced and has spread to other parts of the body.
Each type of cancer has its own TNM system, with the letter T plus a number describing the location and size of a tumor, the letter N plus a number noting whether or not cancer has spread to the lymph nodes, and the letter M noting whether or not cancer has spread to other parts of the body, explains the American Society of Clinical Oncology. Once doctors diagnose the stage of a cancer, the stage does not change over time. If the cancer progresses or goes into remission, doctors simply note the change next to the original stage of cancer.