Stage IV cancer is a cancer that has spread to distant organs and tissues in the body, according to Cancer.Net. Other stages of cancer include stage 0, which is carcinoma in situ or the earliest stage of cancer, states the National Cancer Institute. Stage I, stage II and stage III cancers describe the size and location of cancer, with higher-numbered stages indicating larger, more extensive tumors.Continue Reading
Cancers are typically classified using the TNM staging system based on the size and location of a tumor, whether or not the lymphatic system is involved and if the cancer is metastatic. In the TMN classification system, "T" represents the size of the primary tumor. A T0 classification, for example, means that there is no evidence of a tumor, according to the National Cancer Institute. If the classification shows M1, distant metastasis has been found, as "M" represents the spread of cancer tumors in the body. The "N" represents the lymphatic system and indicates the number and location of any involved lymph nodes. Different TNM combinations correspond to different stages of cancer.
Several methods are used to determine the classification and stage of cancer, according to the National Cancer Institute. Laboratory tests, physical examinations, CT and PET scans, surgical reports and pathology reports are used to classify the stage of a tumor.Learn more about Cancer