Most cancers are staged based on the size and spread of tumors. However, because leukemia already occurs in the developing blood cells in the bone marrow, leukemia staging is a little bit different. The stages of leukemia are often characterized by blood cell counts and the accumulation of leukemia cells in other organs, like the liver or spleen. Making an educated treatment decision begins with the stage, or progression, of the disease. The stage of leukemia is one of the most important factors in evaluating treatment options. Factors affecting leukemia staging and prognosis include:
A numbered staging system is used to describe most types of cancer and their spread throughout the body. Typically, the size of the tumor and the spread of the cancer are evaluated and a stage is assigned. For ALL, staging does not occur in this way because the disease originates in the bone marrow and usually does not form tumor masses. Because ALL will likely spread to other organs before it is detected, the staging method would take into account factors other than the spread to differentiate the stages.
Rather than using traditional staging methods, physicians often factor in the subtype of ALL and the patient"s age. This usually involves cytologic tests, flow cytometry and other lab tests to identify the subtype of ALL.B-cell ALL staging
B lymphocytes, or B cells, are produced in the bone marrow. They also mature there. B cells play a large role in humoral immune response and serve the principal functions of making antibodies against antigens and developing into memory B cells after they have been activated by antigen interaction.
T lymphocytes, or T cells, leave the bone marrow before maturation and move to the thymus, where they mature. T cells play a central role in cell-mediated immunity. There are several different subsets of T cells that have distinct functions. The different subsets of T cells include Helper, Cytotoxic, Memory, Regulatory, Natural killer and Gamma Delta T cells.
Because AML starts in the bone marrow and is usually not detected until it has spread to other organs, traditional cancer staging is not needed. Rather than using the common TNM method for evaluating the cancer, the subtype of AML is classified using a cytologic (cellular) system. Physicians are better able to predict how the cancer will respond to treatment based on the cellular classification and, in turn, more accurately assess the prognosis.AML subtypes and staging
Using a system known as French-American-British (FAB) classification, AML is classified in eight subtypes, M0 through M7, based on:
The eight AML stages are classified as follows:
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 the lymph nodes, spleen or liver are enlarged; and whether the blood disorders anemia (too few red blood cells) or thrombocytopenia (too few platelets) have developed.
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:
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.)
In order to stage CML, your doctor will examine blood and bone marrow tests to determine the number of diseased cells. There are three stages of CML are:
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