Stage
The stage of a cancer is determined by the TNM staging system:
- The ‘T’ stands for tumor size.
- The ‘N’ stands for lymph node involvement.
- The ‘M’ stands for distant metastases, or cancer spread to other areas of the body.
Staging helps doctors determine how serious the cancer is and how best to treat it. Staging systems often reference very specific anatomical structures. Please reference the anatomy page to learn more about these terms.
Staging is generally based on the American Joint Committee on Cancer (AJCC) 8th edition guidelines. The ‘T’ staging is different depending on what subsite of the sinonasal cavity is involved. It is separated by nasal cavity, maxillary sinus, and ethmoid sinus which are provided below. To learn more, see the AJCC TNM Staging Tables and definitions below.
TNM Staging Table, from the American Joint Committee on Cancer (AJCC)
| T | N | M | Stage |
| Tis | N0 | M0 | 0 |
| T1 | N0 | M0 | I |
| T2 | N0 | M0 | II |
| T3 | N0 | M0 | III |
| T1,2,3 | N1 | M0 | III |
| T4a | N0 or N1 | M0 | IVA |
| T1,2,3,4a | N2 | M0 | IVA |
| Any T | N3 | M0 | IVB |
| T4b | Any N | M0 | IVB |
| Any T | Any N | M1 | IVC |
Nasal Cavity TNM Definitions
| T | Definition |
| TX | The primary tumor cannot be evaluated. |
| Tis | The cancer is in situ, meaning it has not invaded into deeper layers. |
| T1 | The tumor is in just one subsite, and there is no bone invasion or destruction. |
| T2 | The tumor is involved in two subsites in a single region or an adjacent site within the nasoethmoid complex, with or without bone invasion. |
| T3 | The tumor has grown to involve the inner wall or floor of the eye socket, or the maxillary sinus, hard palate or cribriform plate. |
| T4a | This is moderately advanced local disease. The tumor has invaded any of the following: the front of the eye socket, skin of the nose or cheek, minor extension into the anterior cranial fossa, pterygoid plates, sphenoid sinus or frontal sinus. |
| T4b | This is very advanced local disease. The tumor has invaded into any of the following: the back part of the eye socket (orbital apex), the dura, brain, middle cranial fossa, cranial nerves (except V2), nasopharynx or clivus. |
Clinical N (cN)
| N | Definition |
| NX | The neck lymph nodes cannot be assessed (for example, they were removed for another reason in the past). |
| N0 | There is no evidence of any spread to the lymph nodes. |
| N1 | There is a single node, on the same side of the main tumor, that is 3 cm or less in greatest size and ENE (-) |
| N2 | N2a – Cancer has spread to a single lymph node, on the same side as the main tumor, and it is more than 3 cm but less than or equal to 6 cm in greatest dimension and ENE (-) N2b – There are multiple lymph nodes that have cancer, on the same side as the main tumor, but none are more than 6 cm in size and ENE (-) N2c – There are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck, but none are more than 6 cm and ENE (-) |
| N3 | N3a – There is spread to one or more neck lymph nodes, and the size is greater than 6 cm and ENE (-) N3b – There is spread to any lymph nodes with clinical appearance of ENE (+) |
ENE (-) = extranodal extension is absent (tumor has not spread outside of the lymph node based on examination of tumor under the microscope)
Pathologic N (pN)
N Definition NX The neck lymph nodes cannot be assessed (for example, they were removed for another reason in the past). N0 There is no evidence of any spread to the lymph nodes. N1 There is a single node, on the same side of the main tumor, that is 3 cm or less in greatest size and ENE (-) N2 N2a – Cancer has spread to a single lymph node, on the same side as the main tumor, and it is more than 3 cm but less than or equal to 6 cm in greatest dimension and ENE (-)or Cancer has spread to a single lymph node, on the same side as the main tumor, and it is less than 3 cm in greatest dimension and ENE (+)
N2b – There are multiple lymph nodes that have cancer, on the same side as the main tumor, but none are more than 6 cm in size and ENE (-)
N2c – There are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck, but none are more than 6 cm and ENE (-)N3 N3a – There is spread to one or more neck lymph nodes, and the size is greater than 6 cm and ENE (-)
N3b – There is spread to a single lymph node, on the same side as the main tumor, and the size is greater than 3 cm and ENE (+)orThere are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck with ENE (+)
ENE (-) = extranodal extension is absent (tumor has not spread outside of the lymph node based on examination of tumor under the microscope)M Definition M0 No evidence of distant spread M1 Distant spread
Maxillary Sinus TNM Definitions
| T | Definition |
| TX | The primary tumor cannot be evaluated. |
| Tis | The cancer is in situ, meaning it has not invaded into deeper layers. |
| T1 | The tumor is totally within the lining of the maxillary sinus. There is no destruction of any of the bone of the maxillary sinus. |
| T2 | The tumor is in the maxillary sinus and has caused the bone to become eroded or destroyed. The tumor is in this stage even if it extends into the hard palate or into the nose under the middle turbinate. |
| T3 | The tumor invades through bone or any of the following: the bone at the back wall of the maxillary sinus, into the deep layers of the skin, into the inner floor of the eye socket, the pterygoid fossa (a space behind and to the side of the nose on the other side of the sphenoid bone), or the ethmoid sinuses. |
| T4a | This is moderately advanced local disease. The tumor has invaded into the contents of the eye socket in the front, the outer skin of the cheek, pterygoid plates, infratemporal fossa, cribriform plate, sphenoid or frontal sinuses. |
| T4b | This is very advanced local disease. The tumor has invaded into any of the following: the back part of the eye socket (orbital apex), the dura, brain, middle cranial fossa, cranial nerves (except V2), nasopharynx or clivus. |
Clinical N (cN)
N Definition NX The neck lymph nodes cannot be assessed (for example, they were removed for another reason in the past). N0 There is no evidence of any spread to the lymph nodes. N1 There is a single node, on the same side of the main tumor, that is 3 cm or less in greatest size and ENE (-) N2 N2a – Cancer has spread to a single lymph node, on the same side as the main tumor, and it is more than 3 cm but less than or equal to 6 cm in greatest dimension and ENE (-)
N2b – There are multiple lymph nodes that have cancer, on the same side as the main tumor, but none are more than 6 cm in size and ENE (-)
N2c – There are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck, but none are more than 6 cm and ENE (-)N3 N3a – There is spread to one or more neck lymph nodes, and the size is greater than 6 cm and ENE (-)
N3b – There is spread to any lymph nodes with clinical appearance of ENE (+)
ENE (-) = extranodal extension is absent (tumor has not spread outside of the lymph node based on examination of tumor under the microscope)
Pathologic N (pN)
N Definition NX The neck lymph nodes cannot be assessed (for example, they were removed for another reason in the past). N0 There is no evidence of any spread to the lymph nodes. N1 There is a single node, on the same side of the main tumor, that is 3 cm or less in greatest size and ENE (-) N2 N2a – Cancer has spread to a single lymph node, on the same side as the main tumor, and it is more than 3 cm but less than or equal to 6 cm in greatest dimension and ENE (-)or Cancer has spread to a single lymph node, on the same side as the main tumor, and it is less than 3 cm in greatest dimension and ENE (+)
N2b – There are multiple lymph nodes that have cancer, on the same side as the main tumor, but none are more than 6 cm in size and ENE (-)
N2c – There are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck, but none are more than 6 cm and ENE (-)N3 N3a – There is spread to one or more neck lymph nodes, and the size is greater than 6 cm and ENE (-)
N3b – There is spread to a single lymph node, on the same side as the main tumor, and the size is greater than 3 cm and ENE (+)orThere are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck with ENE (+)
ENE (-) = extranodal extension is absent (tumor has not spread outside of the lymph node based on examination of tumor under the microscope)M Definition M0 No evidence of distant spread M1 Distant spread
Ethmoid Sinus TNM Definitions
| T | Definition |
| TX | The primary tumor cannot be evaluated. |
| Tis | The cancer is in situ, meaning it has not invaded into deeper layers. |
| T1 | The tumor is in just one subsite, and there is no bone invasion or destruction. |
| T2 | The tumor is involved in two subsites in a single region or an adjacent site within the nasoethmoid complex, with or without bone invasion. |
| T3 | The tumor has grown to involve the inner wall or floor of the eye socket, or the maxillary sinus, hard palate or cribriform plate. |
| T4a | This is moderately advanced local disease. The tumor has invaded any of the following: the front of the eye socket, skin of the nose or cheek, minor extension into the anterior cranial fossa, pterygoid plates, sphenoid sinus or frontal sinus. |
| T4b | This is very advanced local disease. The tumor has invaded into any of the following: the back part of the eye socket (orbital apex), the dura, brain, middle cranial fossa, cranial nerves (except V2), nasopharynx or clivus. |
Clinical N (cN)
N Definition NX The neck lymph nodes cannot be assessed (for example, they were removed for another reason in the past). N0 There is no evidence of any spread to the lymph nodes. N1 There is a single node, on the same side of the main tumor, that is 3 cm or less in greatest size and ENE (-) N2 N2a – Cancer has spread to a single lymph node, on the same side as the main tumor, and it is more than 3 cm but less than or equal to 6 cm in greatest dimension and ENE (-)
N2b – There are multiple lymph nodes that have cancer, on the same side as the main tumor, but none are more than 6 cm in size and ENE (-)
N2c – There are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck, but none are more than 6 cm and ENE (-)N3 N3a – There is spread to one or more neck lymph nodes, and the size is greater than 6 cm and ENE (-)
N3b – There is spread to any lymph nodes with clinical appearance of ENE (+)
ENE (-) = extranodal extension is absent (tumor has not spread outside of the lymph node based on examination of tumor under the microscope)
Pathologic N (pN)
N Definition NX The neck lymph nodes cannot be assessed (for example, they were removed for another reason in the past). N0 There is no evidence of any spread to the lymph nodes. N1 There is a single node, on the same side of the main tumor, that is 3 cm or less in greatest size and ENE (-) N2 N2a – Cancer has spread to a single lymph node, on the same side as the main tumor, and it is more than 3 cm but less than or equal to 6 cm in greatest dimension and ENE (-)or Cancer has spread to a single lymph node, on the same side as the main tumor, and it is less than 3 cm in greatest dimension and ENE (+)
N2b – There are multiple lymph nodes that have cancer, on the same side as the main tumor, but none are more than 6 cm in size and ENE (-)
N2c – There are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck, but none are more than 6 cm and ENE (-)N3 N3a – There is spread to one or more neck lymph nodes, and the size is greater than 6 cm and ENE (-)
N3b – There is spread to a single lymph node, on the same side as the main tumor, and the size is greater than 3 cm and ENE (+)orThere are lymph nodes in the neck on either the opposite side as the main cancer, or on both sides of the neck with ENE (+)
ENE (-) = extranodal extension is absent (tumor has not spread outside of the lymph node based on examination of tumor under the microscope)M Definition M0 No evidence of distant spread M1 Distant spread
