Stage

The stage of a cancer is determined by the TNM staging system:

  • The ‘T’ stands for tumour 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

American Joint Committee on Cancer, 8th Ed. 2017

Nasal Cavity TNM Definitions

Definition
TX The primary tumour cannot be evaluated.
Tis The cancer is in situ, meaning it has not invaded into deeper layers.
T1 The tumour is in just one sub-site, and there is no bone invasion or destruction.
T2 The tumour is involved in two sub-sites in a single region or an adjacent site within the nasoethmoid complex, with or without bone invasion.
T3 The tumour 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 tumour 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 tumour 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 tumour, 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 tumour, 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 tumour, 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 present (tumour has spread outside of the lymph node based on examination of tumour under the microscope)
ENE (-) = extranodal extension is absent (tumour has not spread outside of the lymph node based on examination of tumour 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 tumour, 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 tumour, 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 tumour, 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 tumour, 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 tumour, and the size is greater than 3 cm and ENE (+)or There 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 present (tumour has spread outside of the lymph node based on examination of tumour under the microscope)
ENE (-) = extranodal extension is absent (tumour has not spread outside of the lymph node based on examination of tumour under the microscope)

M Definition
M0 No evidence of distant spread
M1 Distant spread

Maxillary Sinus TNM Definitions

Definition
TX The primary tumour cannot be evaluated.
Tis The cancer is in situ, meaning it has not invaded into deeper layers.
T1 The tumour is totally within the lining of the maxillary sinus. There is no destruction of any of the bone of the maxillary sinus.
T2 The tumour is in the maxillary sinus and has caused the bone to become eroded or destroyed. The tumour is in this stage even if it extends into the hard palate or into the nose under the middle turbinate.
T3 The tumour 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 tumour 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 tumour 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 tumour, 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 tumour, 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 tumour, 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 present (tumour has spread outside of the lymph node based on examination of tumour under the microscope)
ENE (-) = extranodal extension is absent (tumour has not spread outside of the lymph node based on examination of tumour 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 tumour, 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 tumour, 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 tumour, 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 tumour, 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 tumour, and the size is greater than 3 cm and ENE (+)or There 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 present (tumour has spread outside of the lymph node based on examination of tumour under the microscope)
ENE (-) = extranodal extension is absent (tumour has not spread outside of the lymph node based on examination of tumour under the microscope)

M Definition
M0 No evidence of distant spread
M1 Distant spread

Ethmoid Sinus TNM Definitions

Definition
TX The primary tumour cannot be evaluated.
Tis The cancer is in situ, meaning it has not invaded into deeper layers.
T1 The tumour is in just one sub-site, and there is no bone invasion or destruction.
T2 The tumour is involved in two sub-sites in a single region or an adjacent site within the nasoethmoid complex, with or without bone invasion.
T3 The tumour 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 tumour 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 tumour 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 tumour, 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 tumour, 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 tumour, 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 present (tumour has spread outside of the lymph node based on examination of tumour under the microscope)
ENE (-) = extranodal extension is absent (tumour has not spread outside of the lymph node based on examination of tumour 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 tumour, 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 tumour, 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 tumour, 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 tumour, 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 tumour, and the size is greater than 3 cm and ENE (+)or There 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 present (tumour has spread outside of the lymph node based on examination of tumour under the microscope)
ENE (-) = extranodal extension is absent (tumour has not spread outside of the lymph node based on examination of tumour under the microscope)

M Definition
M0 No evidence of distant spread
M1 Distant spread