Stage IV is divided into stages IVA, IVB, and IVC. In stage IVA, (1) the tumor has spread through tissue in the lip or oral cavity into nearby tissue and/or bone (jaw, tongue, floor of mouth, maxillary sinus, or skin of chin or nose); cancer may have spread to one lymph node that is 3 centimeters or smaller, on the same side of the neck as the tumor; or (2) the tumor is any size or has spread through tissue in the lip or oral cavity into nearby tissue and/or bone (jaw, tongue, floor of mouth, maxillary sinus, or skin of chin or nose). Cancer has spread to one lymph node on the same side of the neck as the tumor and the lymph node is larger than 3 centimeters but not larger than 6 centimeters, or to more than one lymph node on the same side of the neck as the tumor and the lymph nodes are not larger than 6 centimeters, or to lymph nodes on the opposite side of the neck as the tumor or on both sides of the neck, and the lymph nodes are not larger than 6 centimeters.