Chronic lymphocytic leukemia stages
Due to the way this disease develops and spreads, CLL staging is different from staging for the kind of cancers that form tumors. Instead of rating the size and extent of tumors, the Rai staging system is based on blood cell counts. The Binet system (more commonly used in Europe than in the United States) summarizes the spread of the cancer throughout the lymph nodes in three stages simply labeled “A,” “B” and “C.” By identifying your stage of chronic lymphocytic leukemia, your team can choose when to begin treatment and determine which CLL treatments may be most effective for you.
Rai staging system for CLL
Chronic lymphocytic leukemia stages in the Rai system are defined by three main factors: the number of the lymphocytes in the blood; whether or not the lymph nodes, spleen or liver are enlarged; and the presence of the blood disorders anemia (too few red blood cells) or thrombocytopenia (too few platelets).
In general, CLL begins as a condition called lymphocytosis, which is having too many lymphocytes. A count of over 10,000 lymphocytes per sample is considered too high and is the benchmark for Stage 0. The five stages are labeled with Roman numerals 0-IV:
- Rai Stage 0 CLL: The levels of the lymphocytes are too high, usually more than 10,000 in one sample. There are no other symptoms at this point and other blood cell counts are normal.
- Rai Stage I CLL: In addition to the high levels of lymphocytes (lymphocytosis), the lymph nodes are swollen. The levels of red blood cells and platelets are still normal.
- Rai Stage II CLL: The number of lymphocytes remains high and now the liver or spleen might be larger than normal.
- Rai Stage III CLL: The excess amount of lymphocytes begins to crowd out the red blood cells, resulting in anemia. The lymph nodes may be swollen and the liver or spleen may be larger than normal.
- Rai Stage IV CLL: The levels of red blood cells and platelets drop below normal, causing anemia and thrombocytopenia. The lymph nodes may be swollen and the liver or spleen may be larger than normal.
The Rai system of chronic lymphocytic leukemia staging is sometimes simplified into low (Stage 0), medium (Stage I and II) and high (stage III and IV) risk categories. Doctors may use this classification to help determine when to begin treatment.
Binet staging system
Like the Rai system, advanced stages of chronic lymphocytic leukemia are characterized by the presence of blood disorders resulting from too few red blood cells and platelets. However, instead of relying on the counts from a blood test, the Binet system evaluates how many areas of lymphoid tissue are affected. (Note: The Binet stages are commonly referred to by "Clinical Stage.")
- Clinical stage A: Lymph nodes may be swollen, but the cancer is limited to fewer than three areas.
- Clinical stage B: More than three areas of lymphoid tissues are swollen.
- Clinical stage C: Either one or both of the blood disorders, anemia and thrombocytopenia, are present.
Other factors affecting CLL prognosis
Both the Rai and Binet systems provide useful information and can help patients and doctors know what to expect as the cancer develops. There are other factors, in addition to the staging, that may help doctors predict how the disease will develop and affect you. Newer lab tests can now check for the presence or absence of the proteins ZAP-70 and CD38 in the cells. Patients typically have a better prognosis (outlook) when there are lower levels of these proteins.