Definition Of Staging

A staging system indicates the extent to which a cancer has spread. Staging describes the extent or severity of cancer based on the size of the original (primary) tumor and the extent of it has spread in the body. There are several different staging systems for prostate cancer but the most widely used system in the United States is called the TNM System. It is also known as the Staging System of the American Joint Committee on Cancer (AJCC). 1

General Information on Staging

Staging is based on knowledge of how cancer develops. Cancer cells divide and grow to form a mass of tissue called a growth or tumor. As a tumor grows, it can spread to nearby organs and tissues. Cancer cells may also break away from the tumor and enter the bloodstream or lymphatic system. By moving through the bloodstream or lymphatic system, cancer can spread from the primary site to form new tumors in other organs. The spread of cancer is called metastasis. 2

Purpose of Staging

Staging helps with the cancer diagnosis and treatment process in important ways, including:

  • Helping the doctors to effectively planning a patient’s treatment.
  • Estimating the patient’s prognosis (likely outcome or course of the disease).
  • Helping to identify clinical trials that may be suitable for a particular patient. 3

Staging helps researchers and health care providers exchange information about patients and providing a common language for diagnosis, treatment and clinical trials.

Tests to Determine Kidney Cancer Stage

When a kidney tumor is suspected, a kidney imaging study is obtained.  The first imaging study is usually an ultrasound or CT scan. In some cases, a combination of imaging studies may be needed to completely evaluate the tumor. If cancer is suspected, the patient should be evaluated to see if the cancer has spread beyond the kidney (metastasized). Tests for metastasis include an abdominal CT scan or MRI, chest X-ray and blood tests. A bone scan is also recommended if the patient has bone pain, recent bone fractures, or certain abnormalities on their blood tests. Additional tests may be obtained if your doctor believes it is necessary.

Kidney cancer tends to grow into the renal vein and vena cava. The renal vein is the kidney’s primary draining vein and the vena cava is the vein that takes blood to the heart. The portion of the cancer that extends into these veins is called “tumor thrombus.” Imaging studies, particularly MRI, can help determine if tumor thrombus is present. 4

Staging Kidney Cancer

The AJCC staging system includes the primary kidney tumor (T stage), the lymph nodes near the kidney (N stage) and the presence or absence of metastases (M stage) to determine if the cancer has spread.

In kidney cancer, the lymph nodes near the kidney are referred to as regional lymph nodes. Clinical stage is based on radiographic imaging before surgery. Pathologic stage is based on the analysis of the tissue that has been surgically removed.

Stage Explanation / Description
Stage I The tumor is confined to the kidney. There is no spread to lymph nodes or distant organs.
Stage II The tumor has invaded the fat around the kidney or the adrenal gland above the kidney. There is no spread to lymph nodes or other organs.
Stage III There are several combinations of T and N categories that are included in this stage. These include tumors of any size, with spread into the lymph nodes adjacent to the kidney or into the large veins leading from the kidney to the heart (venous tumor thrombus). This stage does not include tumors that invade other nearby organs or more distant organs.
Stage IV There are several combinations of T, N, and M categories included in this stage. This stage includes any cancers that have invaded into nearby organs such as the colon (large bowel) or the abdominal wall as well as more distant organs in the body.
Primary tumor (T) :
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor 7.0 cm or less, confined to the kidney
T1a Tumor 4.0 cm or less, confined to the kidney
T1b Tumor 4.0-7.0 cm, confined to the kidney
T2 Tumor greater than 7.0 cm, limited to kidney
T3 Tumor extends into major veins/adrenal/tissue; not beyond Gerota’s fascia
T3a Tumor invades adrenal/perinephric fat
T3b Tumor extends into renal vein(s) or vena cava below diaphragm
T3c Tumor extends into vena cava above diaphragm
T4 Tumor invades beyond Gerota’s fascia, into adjacent organ systems
N – Regional lymph nodes
NX Regional nodes cannot be assessed
N0 No regional lymph node metastasis
N1 Metastasis in a single regional lymph node
N2 Metastasis in more than one regional lymph node
M – Distant metastasis
MX Distant metastasis cannot be assessed
M0 No distant metastasis
M1 Distant metastasis

In general, cancers with higher T stage, lymph node metastasis, or distant metastasis have a worse prognosis and shorter survival rates, and these patients need to consider more aggressive treatments. 5

1. “Staging: Questions and Answers,” National Cancer Institute. www.cancer.gov. URL: http://www.cancer.gov/cancertopics/factsheet/Detection/staging
2. Ibid.
3. Ibid.
4. “Kidney Cancer”, American Urological Association Foundation. www.UrologyHealth.org. URL http://urologyhealth.org/adult/index.cfm?cat=04&topic=124:
5. Ibid.

While clinical studies support the effectiveness of the da Vinci® System when used in minimally invasive surgery, individual results may vary. Surgery with the da Vinci Surgical System may not be appropriate for every individual. Always ask your doctor about all treatment options, as well as their risks and benefits.

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