Stage IV is divided into stages IVA, IVB, and IVC. In stage IVA, one of the following is true: (1) cancer has spread through the thyroid cartilage and/or has spread to tissues beyond the larynx such as the neck, trachea, thyroid, or esophagus; cancer may have spread to one lymph node on the same side of the neck as the original tumor and the lymph node is smaller than 3 centimeters; or (2) cancer has spread to one or more lymph nodes anywhere in the neck and the lymph nodes are smaller than 6 centimeters; cancer may have spread to tissues beyond the larynx, such as the neck, trachea, thyroid, or esophagus. Vocal cords may not move normally. In stage IVB, one of the following is true: (1) cancer has spread to the space in front of the spinal column and surrounds the carotid artery, or has spread to parts of the chest and may have spread to one or more lymph nodes anywhere in the neck (the lymph nodes may be any size); or (2) cancer has spread to a lymph node that is larger than 6 centimeters and may have spread as far as the space in front of the spinal column, around the carotid artery, or to parts of the chest. Vocal cords may not move normally. In stage IVC, cancer has spread beyond the larynx to distant parts of the body.