The four stages of chronic lymphocytic leukemia (CLL) are defined by the Rai and Binet staging systems. These staging systems are based on the number of lymphocytes in the blood, the size of the lymph nodes, and the degree of organ infiltration (enlargement of the spleen or liver).
Stage 0: This stage is also known as smoldering CLL. During this stage, the patient has an elevated number of lymphocytes in their blood, but there are no other symptoms of the disease present.
Stage I: During this stage, the patient has an enlarged lymph node, but no other symptoms.
Stage II: During this stage, the patient has an enlarged spleen or liver, and may have an enlarged lymph node.
Stage III: During this stage, the patient has an enlarged spleen or liver, an enlarged lymph node, and anemia.
Stage IV: During this stage, the patient has an enlarged spleen or liver, an enlarged lymph node, anemia, and symptoms of anemia.
Each stage of CLL is monitored closely, and the patient will receive different treatments depending on the stage they are in. In general, earlier stages of CLL are treated with more conservative treatments, such as watchful waiting, while later stages usually require more aggressive therapies.