The American Joint Committee on Cancer (AJCC) developed the TNM cancer staging system to evaluate three primary factors when it comes to treating cancer, including sinus and other . Below are explanations of what T, N and M mean:
T (tumor): This refers to the size of the primary tumor. It also evaluates to what extent, if any, the cancer has spread to tissues in the nasal cavity and paranasal sinuses and neighboring skull bones. Sometimes, sinus cancers are categorized as T1, T2, etc., instead of by stages.
N (node): This describes the involvement of lymph nodes near the primary tumor. Lymph nodes are small, bean-shaped clusters of immune system cells that are crucial to fighting infections. They are usually one of the first sites in the body where cancer spreads.
M (metastasis): This indicates whether the cancer has spread (metastasized) to other areas of the body. With sinus cancer, the most common site of metastases is the lungs. Bones are the second most common site.
During the sinus cancer staging process, your doctor will assign T, N and M values to the disease based on its microscopic appearance. Your care team at Cancer Treatment Centers of America® (CTCA) will thoroughly review your medical history, family history and other factors to develop an individualized treatment plan for you.
Stages of sinus cancer:
Stage 0: A stage 0 sinus cancer is also known as carcinoma in situ. It means that abnormal cells have been detected in the innermost lining of the maxillary sinus, the nasal cavity or the ethmoid sinus. The abnormal cells could become cancerous and spread to normal tissue.
Stage I (stage 1 sinus cancer): A stage I sinus cancer means the primary tumor is in one sinus, one section of the maxillary sinus mucous membranes, or in the ethmoid sinus or nasal cavity. It also means the cancer could spread to bone.
Stage II (stage 2 sinus cancer): A stage II sinus cancer involves more than one sinus, either in the nasal cavity or the ethmoid sinus. It also means the tumor has spread to bone near to the maxillary sinus. This stage includes the mouth and the nose, but not the bone at the back of the maxillary sinus or the base of the skull.
Stage III (stage 3 sinus cancer): A stage III sinus cancer means the tumor has spread into muscle and tissues under the skin, at the eye socket, the ethmoid sinuses or bone at the back of the maxillary sinus or at the base of the skull. In this stage, cancer cells have spread to one lymph node (3 cm or smaller) on the neck near the cancer and to areas that could include the bone between the eyes, the roof of the mouth, the eye socket, nasal cavity, ethmoid sinus or the maxillary sinus. When a single lymph node is involved, the cancer is automatically identified as stage III sinus cancer.
Stage IV (stage 4 sinus cancer): Stage IV sinus cancer is determined by various factors, including a tumor that has spread to the brain, skin or frontal sinus/sphenoid (center of the forehead). When more than one lymph node is involved, the cancer is automatically defined as stage IV sinus cancer. The sub-stages of stage IV sinus cancer are:
Next topic: How is sinus cancer diagnosed?