Chronic Myeloid Leukemia (CML): Information on Causes, Diagnosis & Treatments
Chronic Myeloid Leukemia (CML) is a debilitating cancer that affects bone marrow and white blood cells, red blood cells, and platelets. The chronic disease is often referred to as chronic myelogenous leukemia. While most people who acquire CML are middle-aged or elderly, men and women of any age can develop the condition. Chronic myeloid leukemia often goes undiagnosed in its initial stages because it signs and symptoms mimic other illnesses.
Many individuals diagnosed with chronic myeloid leukemia have abnormal cell changes (genetic mutations) called the Philadelphia chromosome. Conclusive diagnosis of the condition requires an extensive examination of bone marrow and blood along with other tests to ensure the proper treatment is prescribed or recommended.
- Who Gets Chronic Myeloid Leukemia?
- Common Symptoms
- The Philadelphia Chromosome
- CML Phases
- Diagnosing Chronic Myeloid Leukemia
- Treating the Condition
Who Gets Chronic Myeloid Leukemia?
Certain known risk factors that can affect an individual's chance of acquiring chronic myeloid leukemia. However, having a condition, syndrome or disease associated with acquired CML is no indicator the individual will develop it the common risk factors associated with CML include:
- Exposure to Radiation – Individuals who are exposed to elevated levels of radiation from a nuclear reactor accident or atomic bomb blast have the greatest risk of acquiring chronic myeloid leukemia.
- Gender – Men seem to have a higher incident rate of acquired CML compared to females, even though scientists and researchers have yet to determine why.
- Age – The elderly and those of middle-age have an increased potential risk of developing CML compared to younger generations.
Environmental factors, including exposure to workplace chemicals, account for only a minimal number of diagnosed cases of chronic myeloid leukemia. Having a family history, or being genetically predisposed to the condition, does not appear to be a cause of developing CML.
Early detection of chronic myeloid leukemia is difficult because many of the indicators and symptoms associated with the condition mimic other types of diseases, conditions, and syndromes. However, the patient should discuss any symptom listed below with their doctor to rule out CML or accurately diagnosed the condition. The most common CML symptoms involve:
- Ongoing Excessive Tiredness
- Night sweats
- Unexpected weight loss
- Loss of appetite
- Feeling full or experiencing pain below the ribs on the left side of the body
The Philadelphia Chromosome
Many individuals with chronic myeloid leukemia are diagnosed with an abnormal cell change (genetic mutation) referred to as the Philadelphia Chromosome when genetic material (DNA) moves from one chromosome to another. When this occurs, the body produces tyrosine kinase enzymes that allow a considerable number of stem cells to become granulocytes or blasts forms of white blood cells. Fortunately, the genetic mutation is not passed down from a parent to his or her children.
The various kinds of chronic myeloid leukemia have distinct phases during the progression of the disease. The doctor can determine each phase by measuring healthy cells against disease cells in the bone marrow and blood. Higher proportion rates of diseased cells are indicators that the condition is an advanced stage. These phases include:
- Chronic – During this early stage, chronic myeloid leukemia responds much better to treatment compared to other phases.
- Accelerated – The disease is progressing and is much more aggressive during this transitional phase.
- Blastic – At this aggressive phase, the disease has become severe and life-threatening.
Diagnosing Chronic Myeloid Leukemia
The doctor in charge of diagnosing chronic myeloid leukemia will typically perform procedures and tests to verify the condition. This includes a comprehensive physical exam, gathering a family history, and testing blood and tissue.
- Physical Examination – The doctor will examine the patient and check blood pressure, pulse and other vital signs. During the examination, the doctor will feel the patient's body for abnormalities in the abdomen, spleen and lymph nodes.
- Blood Tests – Results of a blood count can provide the doctor vital information on any abnormality in the blood cell. In addition, blood chemistry tests can determine if there are abnormalities involving organ function.
- Bone Marrow Tests – The doctor may recommend bone marrow aspiration and bone marrow biopsy tests to collect samples of bone marrow to be viewed in a laboratory setting. Typically, the bone marrow is collected from the patient's hip bone.
- Philadelphia Chromosome Tests – Highly specialized tests including PCR (polymerase chain reaction) and FISH (fluorescence in situ hybridization) analysis tests can analyze blood marrow and blood samples to detect the abnormal Philadelphia Chromosome gene.
Treating the Condition
Treating chronic myeloid leukemia focuses on eliminating blood cells containing the mutating gene that is developing an overabundance of the cancer cells. Most treatments are unable to eliminate all the cells that are diseased. However, effective treatments can often result in long-term remission. The doctor will take different approaches to treating the condition including:
- Targeted Drugs – These medications are designed to attack cancer cells by focusing on those that are growing and multiplying abnormally. These include those produced by tyrosine kinase action. The drugs include:
- Gleevec (imatinib)
- Sprycel (dasatinib)
- Tasigna (nilotinib)
- Bosulif (bosutinib)
- Iclusig (ponatinib)
Doctors typically recommend targeted medications as an initial treatment after the chronic myeloid leukemia has been diagnosed. If the targeted medications are ineffective in responding to the disease, the doctor may prescribe Synribo (omacetaxine), for another treatment. The common side effects associated with these targeted medications include nausea, swelling, puffy skin, fatigue, rash, muscle cramps, skin rashes, and diarrhea.
- Blood Stem Cell Transplant – During this procedure, the doctor will transplant bone marrow. This is often considered a definitive cure for the disease. However, the treatment is typically reserved for patients who continue to suffer from chronic myeloid leukemia after all other treatments have been exhausted. The blood stem cell transplant is strictly and requires high doses of chemotherapy medications to destroy blood-forming cells in the patient's bone marrow before transplanting donor blood stem cells that are infused into the bloodstream.
- Chemotherapy – The drugs used in chemotherapy treatments for CML are often used concomitantly with other treatments to minimize many symptoms of the disease. The chemotherapy treatment is taken orally.
- Biological Therapy – Doctors often used biological therapy as an effective tool for boosting the body's immune system that can ward off or manage cancers including CML. The biological medication can mimic the body's immune system cells and reduce the growth of cancerous leukemia cells. Typically, this treatment is offered when all other medications are ineffective or can't be taken during pregnancy. However, the medication caused significant side effects including flulike symptoms, fever, fatigue, and undesirable weight loss.
- Alternative Treatments and Therapies – While no alternative drugs have been found to be effective at treating chronic myeloid leukemia, there are other treatments and therapies that might help minimize the stressful side effects associated with other treatments the patient is undergoing. These include:
- Relaxation Techniques
Some patients with chronic myeloid leukemia are ideal candidates for clinical trials that provides access to the latest treatments and medications. However, clinical trials do not guarantee the patient will be cured. Enrollment in a clinical trial is often difficult and can only be initiated by the doctor treating the patient for chronic myeloid leukemia.