Sinus Tumor Grading and Cancer Staging

The final step before discussing treatment options is a determination of the stage of the cancer. Like for all cancers of the head and neck, doctors in the U.S. use the AJCC Cancer Staging Manual(7th Ed) to determine the stage based on three factors.

Factors that go into determining the stage of the cancer
T	Characteristics of the main tumor mass
N	Status of the lymph nodes in the neck (i.e., evidence of cancer spread)
M	Status of cancer spread to parts of the body outside of the head and neck

This staging applies to all forms of carcinoma. It does not apply to mucosal melanoma, lymphomas and sarcomas.

At first, you will be given a clinical stage based on all of the available information.

• Clinical staging (cTNM) is determined from any information your doctor might have about how extensive the cancer is BEFORE starting any treatment. Stage is determined based on your doctor’s physical exam, imaging studies, laboratory work and biopsies. Classification of clinical stage is described using the lower case prefix c (e.g., cT, cN, cM).

If there is surgical removal of the cancer as part of your treatment, a pathologist will analyze the tumor and any lymph nodes that may have been removed. You will then be assigned a pathologic stage.

• Pathologic staging (pTNM) provides more data. Classification of pathology stage is described using the lower case prefix p (e.g., pT, pN, pM). This may or may not differ from the clinical stage.

There are also a number of other lower-case prefixes that might be used in the staging of your cancer.

• The subscript y (yTNM) is used to assign a cancer stage after some sort of medical, systemic or radiation treatment is given (Posttherapy or Postneoadjuvant Stage). It is typically combined with either a clinical or pathologic stage. For example, ycT2N0M0 indicates that after some sort of non-surgical therapy, the new clinical stage is T2N0M0.
• The subscript r (rTNM) is used when the tumor has recurred after some period of time in which it was gone. This is called Retreatment Classification Stage. Your doctor will use all the available information to assign you a retreatment stage.

T stage: the main tumor mass

Based on a physical examination and review of any imaging, your doctor should be able to give you a T stage that falls within one of the following categories.

Tx	The doctor is unable to assess the primary tumor.
T0	The doctor is unable to find the primary tumor.
Tis	Carcinoma in situ (or severe dysplasia); this means there are cancer type cells, but they have not yet invaded deep into tissue. This is more of a pre-cancer lesion.
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 cribiform 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.

N stage: spread of cancer to the lymph nodes in the neck

Next, your doctor will use all the available information and assign you an N stage. This is based on the assessment as to whether the cancer has spread to lymph nodes in the neck.

Nx	The neck lymph nodes cannot be assessed.
N0	There is no evidence of any spread to the nodes.
N1	There is a single node, on the same side of the main tumor, that is 3 centimeters or less in greatest size.
N2a	Cancer has spread to a single lymph node, on the same side as the main tumor, and it is more than 3 centimeters but less than or equal to 6 centimeters in greatest dimension.
N2b	There are multiple lymph nodes that have cancer, on the same side as the main tumor, but none are more than 6 centimeters in size.
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 centimeters.
N3	There is spread to one or more neck lymph nodes, and the size is greater than 6 centimeters.

M stage: spread of cancer outside the head and neck

Finally, based on an assessment on the entire body, you will be assigned an M stage.

M0	No evidence of distant (outside the head and neck) spread.
M1	There is evidence of spread outside of the head and neck (i.e., in the lungs, bone, brain, etc.).

Your cancer stage

After TNM staging, your doctor can assign a cancer stage based on the following chart.

Stage 0	Tis	N0	M0
Stage I	T1	N0	M0
Stage II	T2	N0	M0
Stage III	T3	N0	M0
	T1	N1	M0
	T2	N1	M0
	T3	N1	M0
Stage IVA	T4a	N0	M0
	T4a	N1	M0
	T1	N2	M0
	T2	N2	M0
	T3	N2	M0
	T4a	N2	M0
Stage IVB	Any T	N3	M0
	T4b	Any N	M0
Stage IVC	Any T	Any N	M1

Mucosal melanoma of the head and neck

Because mucosal melanoma of the head and neck is mostly found in the nasal cavity and paranasal sinuses (67 percent), it is worth mentioning the staging of this type of cancer here.

T stage for mucosal melanoma

You will notice that the lowest T stage you can have is T3 if you have a mucosal melanoma. This indicates that even small tumors of this type can be quite aggressive.

T3	The melanoma is arising in a mucosal site.
T4a	This is moderately advanced local disease. The tumor invades the deep tissue, cartilage, bone or overlying skin.
T4b	This is very advanced local disease. The tumor involves the brain, dura, skull base, lower cranial nerves IX to XII, masticator space, carotid artery, prevertebral space or mediastinal structures.

N stage for mucosal melanoma

Next, your doctor will use all the available information and assign you an N stage. This is based on the assessment as to whether the cancer has spread to lymph nodes in the neck.

Nx	The neck lymph nodes cannot be assessed.
N0	There is no evidence of any spread to the nodes.
N1	There are cancerous lymph nodes present.

M stage: spread of cancer outside the head and neck

Finally, based on an assessment on the entire body, you will be assigned an M stage.

M0	No evidence of distant (outside the head and neck) spread.
M1	There is evidence of spread outside of the head and neck (i.e., in the lungs, bone, brain, etc.).

Your cancer stage for mucosal melanoma

After TNM staging, your doctor can assign a cancer stage based on the following chart.

Stage III	T3	N0	M0
Stage IVa	T4a	N0	M0
	T3-4a	N1	M0
Stage IVb	T4b	Any N	M0
Stage IVc	Any T	Any N	M1

Your clinical stage

Once the diagnostic tests are completed, before deciding what type of treatment you are going to receive, you should be given a clinical stage that will look similar to the example below.

CLINICAL STAGE
	Example
Site	Right Nasal Cavity
Type	Squamous Cell Carcinoma
Grade	Well Differentiated
cT	cT2
cN	cN1
cM	cM0
cStage	cIII

* The lower-case subscript c indicates that this is a CLINICAL STAGE, the stage assigned based on all information available to your doctor before starting treatment.

After surgery, you should get a pathologic stage in regards to your tumor. It will look almost like the clinical stage you received before starting treatment, but notice the “p” that indicates the stage group is based on an analysis of the entire tumor, with or without lymph nodes, under a microscope by a pathologist. In many cases, the pathologic stage will be the same as the clinical stage, but sometimes it will change. You should consider the pathologic stage to be a more accurate assessment of your tumor at the time you start treatment.

After surgery, and after the pathologist has evaluated all of the tumor that was removed, you should be given a pathologic stage that looks something like this:

PATHOLOGIC STAGE
	Example
Site	Right Nasal Cavity
Type	Squamous Cell Carcinoma
Grade	Moderately Differentiated
pT	pT2
pN	pN0
cM	cM0
pStage	pII

* The lower-case subscript p indicates that this is a PATHOLOGIC STAGE, the stage assigned after tumor removal and confirmation of cancer by a pathologist.