The term "cancer" refers to an abnormal growth of cells in an organ, which can destroy tissue and spread to other organs. Cancer progresses through a stage system. Each stage is associated with different properties. As each cancer is different, it is often difficult to classify it in one stage or another. Therefore, a system called TNM (Tumor, lymph Node, and Metastasis) has come about to allow oncologists to place the cancer in several different stages at a time. However, the stages are basically the same.
Stage I
Stage I cancers are defined by small (less than 2 centimeters) tumors located in one part of the body. Many cancers of this type are very treatable as the cancer is small and localized. This type of cancer may be cured by surgery and a small dose of radiation therapy. As the tumor is still small and has not spread, it usually can be entirely extracted from the body.
Stage II
Stage II cancers are slightly more serious than the Stage I types. If a cancer is at Stage II, the tumor has increased in size (usually two to five centimeters) but has not spread to the surrounding tissues and lymph nodes (although it may be approaching that point). The tumor can still be extracted via surgery and radiation can help ensure the cancer will not return.
Stage III
A Stage III cancer is one which has begun to move from the local organ to the surrounding lymph nodes. Once this occurs, it is more difficult to cure. Treatment typically involves surgery to remove the tumor and radiation and chemotherapy to kill the cancer cells that have moved to the lymph nodes and surrounding tissue.
Stage IV
Stage IV, or metastatic cancer, is the most challenging form of cancer. This type of cancer is characterized by the largest tumors that have spread to surrounding organs. Once cancer has metastasized, it generally cannot be completely removed through surgery. This form of cancer is the most serious and requires the heaviest doses of chemotherapy and other drugs.
