The stage of a cancer tells you how far the cancer has spread in your body. Exams and scans are done to find out the size of the cancer and where it is. Some of them can also show if the cancer has spread into nearby tissues and to other parts of the body. But CLL is cancer in the blood cells. Tumor size and spread aren't part of staging. Instead, blood and bone marrow tests plus spleen and lymph node size are used to stage this type of cancer.

The stage of cancer is one of the most important things to know when deciding how to treat it.

Doctors use different systems to stage CLL. The Rai and Binet staging systems are the most common and may be used together. The system used most often in the U.S. is the Rai system. It uses stage groupings that have a value of 0 or 1 through 4 using Roman numerals I, II, III, and IV. The higher the number, the more advanced the cancer is. The Rai system then groups CLL into low (stage 0), intermediate (stages I and II), and high (stages III and IV) risk groups.

Here are the Rai stages and what they mean:

Stage 0.

• There are too many white blood cells called lymphocytes in the blood. (This is called lymphocytosis.)
• The other blood counts are close to normal.
• There are no symptoms of leukemia.

Stage 0 CLL is slow growing, and low risk. This means people tend to have longer survival rates and have no or few symptoms.

Stage I.

• There are too many lymphocytes in the blood.
• The lymph nodes are larger than normal.
• Other organs, like the spleen and liver, are normal size.
• The red blood cell and platelet counts are close to normal.

Stage I CLL is medium (intermediate) risk.

Stage II.

• There are too many lymphocytes in the blood.
• The spleen is swollen or enlarged. This is called splenomegaly.
• The liver might be swollen. This is called hepatomegaly.
• There might be swollen lymph nodes.
• Red blood cell and platelet counts are close to normal.

Stage II CLL is medium (intermediate) risk.

Stage III.

• There are too many lymphocytes in the blood.
• The red blood cell count is low. This is called anemia.
• Platelet counts are close to normal.
• The liver, spleen, or lymph nodes might be bigger than normal.

Stage III CLL is high risk.

Stage IV.

• There are too many lymphocytes in the blood.
• The platelet count is low. This is called thrombocytopenia.
• There might be too few red blood cells in the blood (anemia).
• The liver, spleen, or lymph nodes might be bigger than normal.

Stage IV CLL is high risk.

The 3 Binet stages A, B, and C are classified by number of lymphoid tissue groups affected and whether or not too few red blood cells or too few blood platelets are present. Here are the Binet stages and what they mean:

• Binet stage A: Is considered low risk. It has less than 3 areas of lymphoid tissue enlarged and the red blood cell and platelet counts are normal.
• Binet stage B: Is considered intermediate risk. It has at least 3 areas of lymphoid tissue enlarged and the red blood cell and platelet counts are normal.
• Binet stage C: Is considered high risk. Any number of lymphoid tissue areas may be enlarged. One or both of the red blood cell and the platelet counts are low.

Along with the stage of your CLL, these factors matter when your doctor is looking at your treatment choices:

• Your age
• The amount of your normal bone marrow that's been replaced by leukemia cells
• Blood levels of beta-2 microglobulin and certain other substances
• How fast your lymphocytes are growing
• Chromosome changes (mutations) found in the cancer cells
• The time it's taking for your lymphocyte count to double

Your doctor can tell you more about these factors, what they mean, and how they affect your treatment plan.

Once your leukemia is staged, your doctor will talk with you about what the stage means for your treatment. Ask questions and talk about your concerns.