Staging Of Kidney Cancer


There are actually 2 types of staging for kidney cancer. The clinical stage is your doctor's best estimate of the extent of your disease, based on the results of the physical exam, lab tests, and any imaging studies you have had. If you have surgery, your doctors can also determine the pathologic stage, which is based on the same factors as the clinical stage, plus what is found during surgery and examination of the removed tissue. This means that if you have surgery, the stage of your cancer might actually change afterward (for example, if cancer was found to have spread further than was suspected). Pathologic staging is likely to be more accurate than clinical staging, because it allows your doctor to get a first hand impression of the extent of your disease.

AJCC (TNM) staging system (the most common used) explained more

A staging system is a standardised way in which the cancer care team describes the extent of the cancer. The most commonly used staging system is that of the American Joint Committee on Cancer (AJCC), sometimes also known as the TNM system. The TNM system describes 3 key pieces of information:

"T" Categories For Kidney Cancer

TX: The primary tumour cannot be assessed.

T0: No evidence of a primary tumour.

T1a: The tumour is 4 cm (<2½") across or smaller and is limited to the kidney.

T1b: The tumour is larger than 4 cm (<2½") but not larger than 7 cm (about 2¾") across and is limited to the kidney.

T2: The tumour is larger than 7 cm (2¾") across but is still limited to the kidney.

T2a: The tumour is more than 7 cm (2¾") but not more than 10 cm (about 4") across and is limited to the kidney.

T2b: The tumour is more than 10 cm (4") across and is limited to the kidney.

T3: The tumour is growing into a major vein or into tissue around the kidney, but it is not growing into the adrenal gland (on top of the kidney) or beyond Gerota's fascia (the fibrous layer that surrounds the kidney and nearby fatty tissue).

T3a: The tumour has invaded into the adrenal gland, perinephric fat or renal sinus fat, tumour confined within Gerota’s fascia.

T3b: The tumour invaded the renal vein or the inferior vena cava below the diaphragm.

T3c: The tumour has grown into the part of the inferior vena cava that is within the chest or it is growing into the wall of the inferior vena cava.

T4: The tumour has spread beyond Gerota's fascia, the fibrous layer that surrounds the kidney and nearby fatty tissue. The tumour may have grown into the adrenal gland, on top of the kidney.

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"N" Categories For Kidney Cancer

NX: Regional (nearby) lymph nodes cannot be assessed.

N0: No spread to nearby lymph nodes.

N1: Tumour has spread to 1 nearby lymph node.

N2: Metastasis to more than one regional lymph node.

"M" Categories For Kidney Cancer

MX: Presence of distant metastasis cannot be assessed.

M0: There is no spread to distant lymph nodes or other organs.

M1: Distant metastasis is present; includes spread to distant lymph nodes and/or to other organs such as the lungs, bones, or brain.

Stage grouping

Once the T, N, and M categories have been assigned, this information is combined to assign an overall stage of I, II, III, or IV. The stages identify cancers that have a similar prognosis and thus are treated in a similar way. Patients with lower stage numbers tend to have a better prognosis.

Stage I: T1, N0, M0: The tumour is 7 cm across or smaller and is only in the kidney (T1). There is no spread to lymph nodes (N0) or distant organs (M0).

Stage II: T2, N0, M0: The tumour is larger than 7 cm across but is still only in the kidney (T2). There is no spread to lymph nodes (N0) or distant organs (M0).

Stage III: Either of the following:

T3, N0, M0: The tumour is growing into a major vein, like the renal vein or the vena cava or into tissue around the kidney, but it is not growing into the adrenal gland or beyond Gerota's fascia (T3). It has not spread beyond Gerota's fascia. There is no spread to lymph nodes (N0) or distant organs (M0).

T1 to T3, N1, M0: The main tumour can be any size and may be outside the kidney, but it has not spread beyond Gerota's fascia (T1 to T3). The cancer has spread to nearby lymph nodes (N1) but has not spread to distant lymph nodes or other organs (M0).

Stage IV: Either of the following:

T4, any N, M0: The main tumour is growing beyond Gerota's fascia and may be growing into the adrenal gland on top of the kidney (T4). It may or may not have spread to nearby lymph nodes (any N). It has not spread to distant lymph nodes or other organs (M0).

Any T, Any N, M1: The main tumour can be any size and may have grown outside the kidney (any T). It may or may not have spread to nearby lymph nodes (any N). It has spread to distant lymph nodes and/or other organs (M1).

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Staging of disease at presentation

Staging of disease at presentation refers to the amount that the cancer has grown and spread by the time it is diagnosed. See staging above. Staging is the most important factor in deciding the likely outcome of the kidney cancer. The quoted survival rates below are guidelines only and should be discussed further with your doctor.

Prognosis for RCC based on stage is as follows:

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Histological grade of the tumour

Histological grade refers to how aggressive the cancer looks based on viewing its cells under a microscope in a laboratory. There are 4 grades, with 1 having the best prognosis (five year survival 89%), and 4 being the worst (46% five year survival). Less important than the stage or grade of the tumour is the subtype, which was discussed in classification. Some subtypes however, such as sarcomatoid clear cell carcinoma, renal medullary carcinoma and collecting duct carcinoma are known to be more aggressive and tend to be associated with poorer prognosis.

Clear Cell Renal Cell Carcinoma: Fuhrman Nuclear Grade

Histopathology of Kidney