There are 2 different systems for staging CLL:
Rai system: This is used more often in the United States.
Binet system: This is used more widely in Europe.
Rai staging system divides CLL into 5 stages:
Rai stage 0: The blood lymphocyte count is high, usually defined as over 10,000 lymphocytes/mm3.
The lymph nodes, spleen, and liver are not enlarged and the red blood cell and platelet counts are near normal.
Rai stage I: Lymphocytosis plus enlarged lymph nodes. The spleen and liver are not enlarged and the red blood cell and platelet counts are near normal.
Rai stage II: Lymphocytosis plus an enlarged spleen, with or without enlarged lymph nodes. The red blood cell and platelet counts are normal.
Rai stage III: Lymphocytosis plus anemia, with or without enlarged lymph nodes, spleen, or liver. Platelet counts are near normal.
Rai stage IV: Lymphocytosis plus thrombocytopenia, with or without anemia, enlarged lymph nodes, spleen, or liver.
For practical purposes, the Rai stages are separated into low-, intermediate-, and high-risk groups when determining treatment options.
Stage 0 is considered low risk.
Stages I and II are considered intermediate risk.
Stages III and IV are considered high risk.
Binet staging system
In the Binet staging system, CLL is classified by the number of affected lymphoid groups and by whether or not the patient has anemia or thrombocytopenia.
Binet stage A: Fewer than 3 areas of lymphoid tissue are enlarged, with no anemia or thrombocytopenia.
Binet stage B: 3 or more areas of lymphoid tissue are enlarged, with no anemia or thrombocytopenia.
Binet stage C: Anemia and/or thrombocytopenia are present.