Diagnosis and Prognosis of Leukemia

June 10, 2008 - 7:30am

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Diagnosis and Prognosis of Leukemia

The diagnosis and prognosis of leukemia includes the following:

]]>Review of medical history]]>
]]>Physical exam]]>
]]>Diagnostic testing]]>
]]>Cytology and pathology]]>
]]>Classification]]>
]]>Prognosis]]>

Review of Medical History

The doctor will ask you about your symptoms and medical history. He or she will inquire about any exposures to radiation or chemicals. Some early studies showed a possible link between exposure to chemicals such as benzene and other toxins and leukemia. Further research has shown an association between radiation and leukemia. This includes a very slight increased risk of leukemia and myelodysplastic syndrome (MDS)]]> following therapeutic radiation given to treat other cancers.

Physical Exam

The doctor will perform a physical exam, checking for bruising. Bruising without known injury may be a sign of leukemia.

Diagnostic Testing

To make a diagnosis of leukemia, the following testing will be done:

Blood Tests – a sample of your blood is checked for leukemia cells. Another blood test may be done to look for specific genes or cell surface markers associated with leukemia.

Bone Marrow Aspiration – a sample of liquid bone marrow is removed and tested for malignant cells. The sample is obtained by inserting a needle into the pelvic bone. This may be done in the hospital or outpatient setting. Aspirate samples will be sent for chromosome and DNA analysis and flow cytometry to determine what type of leukemia is present.

Bone Marrow Biopsy – a sample of bone marrow and a small piece of bone are removed and tested for cancer cells. The samples are obtained by inserting a needle into the pelvic bone. This may be done in the hospital or outpatient setting.

Testing to Assess Spread of Cancer

If the bone marrow biopsy shows leukemia cells, additional tests may be done to determine if the disease has spread and what systems are affected. These tests may include the following:

Lumbar Puncture (Spinal Tap) – removal of a small amount of fluid that surrounds the brain and spinal cord to test for cancer cells. A needle is inserted between the third and fourth lumbar vertebrae in the back to extract a sample of fluid.

Chest X-rays – a series of standard x-ray images of your chest. These x-rays help to determine if infection is present at diagnosis. X-rays may occasionally demonstrate enlarged lymph nodes, but are of limited value in determining the extent of leukemia.

Cytology and Pathology

Cytology is the study of cells. The cytology of cancer cells differs significantly from normal cells, and physicians use the unique cellular features seen on biopsy samples to determine the diagnosis and assess the prognosis of a cancer.

The pathologist will examine the cells in the sample removed from your bone marrow. The number of immature cells determines if leukemia is present. The doctor will use stains to help differentiate the types of cancer cells present. Precise classification of the type of leukemia also requires immunophenotyping. Immunophenotyping is a procedure that determines what subtype of leukemia a patient has. This test identifies the surface characteristics of the cancer cells. Subtyping helps determine the appropriate treatment.

Classification

Staging is the process by which physicians determine the prognosis of a cancer that has already been diagnosed. Acute leukemia is not staged, because it involves bone marrow throughout the body and often has spread to other organs. Doctors do classify it by type and subtype in an attempt to determine prognosis and the appropriate treatment.

Doctors classify acute leukemias by type and subtype in an attempt to determine prognosis and appropriate treatment.

Classification of Acute Myelogenous Leukemia

Acute myelogenous leukemia is classified by the type of cell into the following subtypes:

M0: undifferentiated or very early, immature cells
M1-2: granulocytic
M3: promyelocytic
M4: myelomonocytic
M5: monocytic
M6: erythroblastic
M7: megakaryoblastic; poor prognosis

Classification of Acute Lymphocytic Leukemia

Acute lymphocytic leukemia is classified as follows:

L1: childhood type, cells are uniform in size
L2: adult type, cells are larger and more variable in size
L3: Burkett-type, immature cells with unique characteristics

Classification of Chronic Myelogenous Leukemia

Chronic myelogenous leukemia is grouped by phases:

Chronic: few immature cells; mild symptoms; usually requires little or no symptomatic treatment but responds to specific therapy
Accelerated phase: fewer than 30% blasts; some symptoms, such as fever, poor appetite and weight loss; not as responsive to treatment
Blast crisis: more than 30% blasts; usually very aggressive

Classification of Chronic Lymphocytic Leukemia

In the United States, chronic lymphocytic leukemia is defined with the Rai classification:

Rai Stage 0: low risk, with a high blood lymphocyte count; good prognosis
Rai Stage 1: intermediate risk, with a high blood lymphocyte count and enlarged lymph nodes; medium prognosis
Rai Stage 2: intermediate risk, with a high blood lymphocyte count and an enlarged spleen; medium prognosis
Rai Stage 3: high risk, with a high blood lymphocyte count and anemia; poor prognosis
Rai Stage 4: high risk, with a high blood lymphocyte count and low platelet count; poor prognosis

Prognosis

Prognosis is a forecast of the probable course and/or outcome of a disease or condition. Prognosis is most often expressed as the percentage of patients who are expected to survive over five or ten years. Cancer prognosis is a notoriously inexact process. This is because the predictions are based on the experience of large groups of patients suffering from cancers at various stages. Using this information to predict the future of an individual patient is always imperfect and often flawed, but it is the only method available. Prognoses provided in this monograph and elsewhere should always be interpreted with this limitation in mind. They may or may not reflect your unique situation.

Prognosis for the four main types of leukemia are as follows:

AML - Complete remission is possible in about 60% of all patients and in 80% of young adults. Between 15% and 50% of these patients will survive long-term.

ALL - Varies from poor to excellent prognosis depending on the age of the patient. Adult ALL is usually an aggressive disease, while childhood ALL is highly curable.

CML - About half of patients of CML live six to seven years after diagnosis.

CLL - The disease cannot be cured with current treatments, however, survival varies greatly depending on Rai stage at time of diagnosis.

Sources:

National Cancer Institute

American Cancer Society

The Leukemia & Lymphoma Society

Goldman L. Cecil Textbook of Medicine , 21st ed. St. Louis, MO: W.B. Saunders Company; 2000: 944-958.

Rakel, R. Conn's Current Therapy 2002, 54th ed., St. Louis, MO: W. B. Saunders Company; 2002: 413-434.

Bast R, et al. Cancer Medicine e5 . Hamilton, Ontario: B.C. Decker Inc.; 2000.

Last reviewed February 2003 by John Erban, MD]]>

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.