What is kidney cancer?
You have two kidneys, one on each side of the spine. These organs are responsible for filtering waste products from the blood and regulating fluid levels in the body.
Kidney cancer is cancer that originates in one or both of your kidneys. Smoking, obesity, high blood pressure, and increasing age all raise the risk of kidney cancer.
When a person is diagnosed with kidney cancer, there are many factors that can determine their outlook and life expectancy. These include the kidney cancer type, grade of the tumor, and stage of the cancer. The cancer stage describes how far the cancer has spread. Doctors use this and other information, such as a person’s age and overall health, to make their best guess regarding a person’s survival outlook. This “best guess” is called a prognosis. Generally speaking, when cancer is detected and treated in the early stages the chance of survival is higher.
TNM staging system
Doctors use a variety of diagnostic information to stage kidney cancer. Examples could include imaging studies, like a CT or PET scan, and a biopsy of the cancerous cells. The most frequently used system of describing the stages of kidney cancer is the TNM system developed by the . It’s important to note this staging system is used for all types of kidney cancers except those that affect the renal pelvis of the kidney. A different system is used for these cancer types.
The acronym TNM describes the cancer in this way:
A letter or number is assigned to the T, which describes the size of the tumor.
|TX||There isn’t enough information available to assess the tumor.|
|T0||There is no evidence of a tumor.|
|T1||The tumor is no larger than 7 cm and hasn’t spread past the kidney. T1a is a tumor that’s less than 4 cm, and T2a is between 4 and 7 cm.|
|T2||The tumor is larger than 7 cm and hasn’t spread past the kidney.|
|T3||The tumor is growing into a major vein or into tissue around the kidney.|
|T4||The tumor has spread beyond Gerota’s fascia or into the adrenal gland.|
The letter or number assigned to the N gives information about whether or not the cancer has spread to nearby lymph nodes.
|NX||Information isn’t available to assess nearby lymph nodes.|
|N0||The cancer hasn’t spread to other lymph nodes.|
|N1||The cancer has spread to the lymph nodes.|
The M refers to metastasis, or spread to other organs or tissue in the body. Two additional categories exist: M0 and M1.
|M0||The tumor hasn’t spread to other organs or distant lymph nodes.|
|M1||The cancer has spread to other body parts, such as the lungs, bones, liver, or brain.|
Using the TNM system, doctors will determine a numeric stage 1 through 4. The higher the number is, the more advanced the cancer is.
Like other cancers, kidney cancer is described in four stages, which indicate the following:
- Stage 1: The cancer is small and still only in the kidney. Another name for stage 1 is T1, N0, M0.
- Stage 2: The cancer is confined to the kidney, but the tumor is larger than 7 centimeters across. Another name for this stage is T2, N0, M0.
- Stage 3: The tumor is not in the lymph nodes but is growing into vessels or nearby tissue (T3N0), or the tumor is smaller but is found in the lymph nodes (T1–T3, N1).
- Stage 4: The tumor may have grown into the adrenal gland and spread to nearby lymph nodes but is not in distant organs (T4N1M0), or the cancer is found in distant lymph nodes or organs (any T, any N, M1).
Stage 4 cancer can be treated but is not usually curable. Surgery isn’t always an option, because once the cancer has spread to distant organs or lymph nodes, surgery is not an effective treatment.
Factors affecting survival
According to the , the five-year survival rates for kidney cancer include the following by stage:
- stage 1: 81 percent
- stage 2: 74 percent
- stage 3: 53 percent
- stage 4: 8 percent
However, survival rates for people with kidney cancer are affected by factors other than the stage of the disease. When looking at survival rates, it’s important to remember that these numbers are based off of large groups. They cannot accurately predict the likelihood of survival of any one individual.
Your overall health is an important factor in determining your treatment plan. If you’re in a weakened state of health and unable to care for your self independently that can limit your treatment options and hurt your chances of recovery.
The stage of your kidney cancer at the time of diagnosis will affect your prognosis. Survival rates differ for each stage, and those with a higher stage are less likely to survive for five years after their diagnosis. It is important to understand that these five-year survival rates cannot predict what will happen to any individual.
If there is an aspect of your kidney cancer stage you do not understand, ask your doctor for more information. You can also ask for a second opinion if you feel uncertain. A cancer diagnosis is overwhelming and you may find you need extra support. There are organizations that support kidney cancer patients that you may find helpful. Examples include the or the .