Staging for CLL is used primarily for treatment planning. Two frequently used staging systems are the Rai system and the Binet system. The Rai staging system was introduced in the mid 1970's, and a modified version was introduced in 1987. Both the original Rai staging system and the modified version are still in use. The Rai staging system is used primarily in North America while the Binet staging system is commonly used in other parts of the world.

In any stage, treatment planning is different for disease that has not responded to treatment (refractory disease) than for newly diagnosed and untreated disease. Details of the Rai and Binet staging systems are:

Stage 0 - There are too many lymphocytes in the blood, but there are usually no other symptoms of leukemia. Lymph nodes and the spleen and liver are not swollen, and the number of red blood cells and platelets is normal.

Stage I - There are too many lymphocytes in the blood and lymph nodes are swollen (lymphadenopathy). The spleen and liver are not swollen and the number of red blood cells and platelets is normal.

Stage II - There are too many lymphocytes in the blood, lymph nodes are swollen, and either the liver is swollen (hepatomegaly) or the spleen is swollen (splenomegaly).

Stage III - There are too many lymphocytes in the blood and too few red blood cells (anemia). Lymph nodes and the liver or spleen may be swollen.

Stage IV - There are too many lymphocytes in the blood and too few platelets (thrombocytopenia). The lymph nodes, liver, or spleen may be swollen, and there may be too few red blood cells (anemia).

Low-risk group - Rai Stage 0 (lymphocytosis only - blood and marrow).

Intermediate-risk group - Rai Stage I (lymphocytosis and enlarged nodes) and Stage II (enlarged spleen and/or liver) combined.

High-risk group - Rai Stage III (lymphocytosis with anemia, defined as hemoglobin of less than 11 gm%) and Stage IV (platelets of less than 100,000 per microliter of blood) combined.

Clinical stage A - Red blood cells and platelets are in the normal range and there are fewer than three areas of lymphoid involvement.

Clinical stage B - Red blood cells and platelets are in the normal range and there are three or more areas of lymphoid involvement.

Clinical stage C - Below normal numbers of red blood cells (anemia) and/or platelets (thrombocytopenia) regardless of the number of areas of lymphoid involvement.

Some consideration has been given to an integrated system utilizing both the Rai and Binet staging systems. According to the integrated system, each Binet stage is further identified by the appropriate Rai stage (e.g., A-0, A-I, AII, B-I, B-II, C-III, C-IV). The integrated system has not been widely accepted, and most physicians continue to use either the Rai or Binet system.

The Rai and Binet systems are not the only staging systems for CLL, but they are the most widely used systems.