Stage IV includes: For squamous cell carcinoma: Any T, Any N, M1, Any G, Tumor location: Any. For adenocarcinoma: Any T, Any N, M1, Any G. M1: Distant metastasis. Tumor location: Location of the primary cancer site is defined by the position of the upper (proximal) edge of the tumor in the esophagus. (AJCC 7th ed.) [from NCI]