Nasal & Sinus Cavity Stages | Georgia Radiation Therapy

After a nasal and sinus cavity cancer diagnosis, it’s necessary to determine if cancer cells have spread within the paranasal sinuses and nasal cavity or to other parts of the body. This process, called staging, is an important step in helping your doctor design the most effective treatment plan.

The TNM system, created by the American Joint Committee on Cancer (AJCC), is the most common staging system used for nasal and sinus cavity cancer. This system is based on 3 key pieces of information:

Tumor (T): the size and primary location of the tumor
Node (N): if the cancer has spread to the lymph nodes
Metastasis (M): whether the cancer has metastasized (spread) to other areas of the body

Numbers or letters after T, N, and M provide more details about each of these factors, such as the size and location of the tumor. Lower numbers mean that the cancer is in an early stage. Higher numbers mean the cancer is more advanced.

Tumor (T)

Primary tumor (T) in the maxillary sinus

TX: The primary tumor cannot be evaluated.

Tis: This is a very early stage cancer in which cancer cells are found only in 1 layer of tissue. It is also called carcinoma (cancer) in situ.

T1: The tumor is limited to the inside of the sinus and does not erode or invade bone.

T2: The tumor erodes or invades the bone surrounding the sinuses.

T3: The tumor invades the surrounding bone, the skin of the cheek, or the other sinuses.

T4a: The tumor invades the bone surrounding the eye, the skin of the cheek, or the bones in the back of the throat.

T4b: The tumor invades any of the following: the back of the eye, the brain area, or the bones of the skull, other than those behind the nose and the back of the head.

Primary tumor (T) in the nasal cavity and ethmoid sinus

TX: The primary tumor cannot be evaluated.

Tis: This is a very early stage cancer in which cancer cells are found only in 1 layer of tissue. It is also called carcinoma (cancer) in situ.

T1: The tumor is limited to the inside of the sinus.

T2: The tumor extends into the nasal cavity.

T3: The tumor extends into the maxillary sinus or to the bone surrounding the eye.

T4a: The tumor has spread throughout the facial bones or into the base of the skull.

T4b: The tumor invades any of the following: the back of the eye, the brain area, or the back of the head.

Node (N)

Lymph node evaluation can be clinical or pathological. Clinical evaluations are ones done by an oncologist in the clinic. Pathological evaluations are ones performed by a pathologist in a lab.

Clinical definition

NX: The regional lymph nodes cannot be evaluated.

N0 (N plus zero): There is no evidence of cancer in the regional lymph nodes.

N1: The cancer has spread to 1 lymph node on the same side as the primary tumor. The cancer found is 3 centimeters (cm) or smaller. It does not extend into the tissue beyond the involved lymph node, called extranodal extension (ENE).

N2a: The cancer has spread to 1 lymph node on the same side as the primary tumor. It is between 3 cm and 6 cm in size. There is no ENE.

N2b: The cancer has spread to more than 1 lymph node on the same side as the primary tumor, and all are smaller than 6 cm. There is no ENE.

N2c: The cancer has spread to more than 1 lymph node on either side of the body, and all are smaller than 6 cm. There is no ENE.

N3a: The cancer is found in at least 1 nearby lymph node and is larger than 6 cm. There is no ENE.

N3b: The cancer has spread to any node, and it has spread to the tissue surrounding the lymph node (ENE).

Pathological definition

NX: The regional lymph nodes cannot be evaluated.

N0 (N plus zero): There is no evidence of cancer in the regional lymph nodes.

N1: The cancer has spread to 1 lymph node on the same side as the primary tumor. The cancer found is 3 cm or smaller. It does not extend into the tissue beyond the involved lymph node, called extranodal extension (ENE).

N2a: The cancer has spread to 1 lymph node on either side of the primary tumor. It is smaller than 3 cm, and ENE is present. Or, it has spread to 1 lymph node on the same side of the primary tumor, it is between 3 cm and 6 cm in size, and there is no ENE.

N2b: The cancer has spread to more than 1 lymph node on the same side as the primary tumor, and all are smaller than 6 cm. There is no ENE.

N2c: The cancer has spread to more than 1 lymph node on either side of the body, and all are smaller than 6 cm. There is no ENE.

N3a: The cancer is found in at least 1 nearby lymph node and is larger than 6 cm. There is no ENE.

N3b: The cancer is found in 1 lymph node on the same side as the primary tumor, it is larger than 3 cm, and there is ENE. Or, the cancer has spread to many nodes on either side of the body, and there is ENE.

Metastasis (M)

M0 (M plus zero): The cancer has not spread to other parts of the body.

M1: The cancer has spread to another part(s) of the body.

Grade (G)

Nasal cavity and paranasal sinus cancer is also described by its grade (G). The grade describes how much cancer cells look like healthy cells when viewed under a microscope. When cancer cells resemble normal cells, it is called “differentiated” or “low-grade tumor.” These tumors tend to grow slowly and offer a better prognosis. Cancer cells that look very different from normal cells are called “poorly differentiated” or “high-grade tumors.” These tumors tend to grow faster and are more likely to spread.

GX: The grade cannot be evaluated.

G1: The cells look more like healthy tissue and are well differentiated.

G2: The cells are only moderately differentiated.

G3: The cells don’t resemble healthy tissue and are poorly differentiated.

Stage groups for nasal cavity and paranasal sinus cancer

The T, N, and M information is combined to determine what stage the cancer is. The standardized stages of nasal and sinus cavity cancer are:

Stage 0: This is a very early cancer (Tis) with no spread to lymph nodes (N0) or distant metastasis (M0).

Stage I: This is a noninvasive cancer (T1) with no spread to lymph nodes (N0) and no distant metastasis (M0).

Stage II: This is an invasive cancer (T2) that has not spread to lymph nodes (N0) or to distant parts of the body (M0).

Stage III: This includes invasive cancer (T3) with no spread to regional lymph nodes (N0) and no metastasis (M0), as well as invasive cancer (T1, T2, T3) that has spread to regional lymph nodes (N1) but shows no sign of metastasis (M0).

Stage IV

Stage IVA: This is an invasive cancer (T4a) that either has no lymph node involvement (N0) or has spread to only 1 same-sided lymph node (N1) but with no metastasis (M0). It is also used for any cancer that is not considered very advanced (T1, T2, T3, T4a) with more significant nodal involvement (N2) but with no metastasis (M0).
Stage IVB: This is an invasive cancer (any T) that has spread to lymph nodes (N3) but has no metastasis (M0). It is also used for very advanced cancer (T4b) that has not metastasized (any N, M0).
Stage IVC: This refers to any tumor (any T, any N) when there is evidence of distant spread (M1).

Recurrent: Recurrent cancer is cancer that has come back after treatment. If the cancer does return, there will be another round of tests to learn about the extent of the recurrence. These tests and scans are often similar to those done at the time of the original diagnosis.

The staging information leads to a personalized treatment plan. Some patients will need more treatments or different treatments than others based on the type, location and stage of the cancer as well as the patient’s overall health condition.