Chronic Myelogenous Leukemia By: Bobby Orr Danielle Heinbaugh Adam Edwards

Background: CML accounts for 20% of all leukemias affecting adults in the US. Increased incidence was reported among individuals exposed to radiation in Nagasaki and Hiroshima after the dropping of the Atomic bomb. In general, this disease occurs in the fourth and fifth decades of life.

The bio behind CML: Patients with CML have an overproduction of myeloid cells. Myeloid cells are precursors to white blood cells. These cells are produced in the bone marrow, where they mature and move into the blood stream.

Causes: Translocation between the long arms of chromosomes 22 and 9; t(9;22). The translocation results in a shortened chromosome 22. This chromosomal abnormality can be caused by radiation and/or contact with benzene.

Philadelphia Chromosome: First observed by Drs. Nowell and Hungerford (1973) and termed the Philadelphia Chromosome after the city of discovery. Found in 95% of patients with CML.

Symptoms Fatigue Weakness Irritability Headache Perspiration Chronic low grade fevers Weight loss Enlarged Spleen Loss of appetite In early stages of disease, noticeable symptoms may not be present

Three Stages of CML Stage 1: Chronic Phase Stage 2: Accelerated Phase Stage 3: Transformation/Acute Phase

Chronic Phase 3-5 years in duration. Overproduction of white blood cells can be kept in check with oral drugs (hydroxyurea), or injections (alpha-interferon). Eventually drug treatments become ineffective treatment, and disease progresses to second stage.

Accelerated Phase White blood cells and blasts (underdeveloped white blood cells) become concentrated in blood. Increased doses of hydroxyurea, or administration purinethol or cytosine arabinoside are means of temporary decrease in concentration.

Accelerated Phase In this stage the removal of the spleen may be necessary to alleviate pain of enlargement. Blood transfusions are needed to relieve fatigue (no red cells). Platelet concentrations fluctuate. Accelerated stage varies in length, and may not be distinguishable.

Transformation/Acute Phase White blood cells fail to mature (resulting in blast cells). Blast cells invade other organs and tissues and disrupt their normal functions. At this phase, CML is usually resistant to chemotherapy. This phase usually lasts no longer then 6 months before patient expires.