Acute Lymphocytic Leukemia - Prognosis

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Highlights	Complications	Treatment to Achieve Remission
Introduction	Diagnosis	Treatment During Remission
Symptoms	Prognosis	Treatment After Relapse
Causes	Treatment	Resources
Risk Factors	Home Management	References

The surfaces of T-cell ALL cancer cells express several antigens as well. For example, the presence of one of these, CD2, suggests a favorable prognosis.

Testing for Genetic Abnormalities

Genetic tests are useful for a number of important criteria:

Diagnosing a specific ALL subtype
Designing appropriate treatment
Deciding prognosis
Monitoring patients throughout treatment and beyond

Cytogenetics is a technique that researchers use to determine specific genetic abnormalities, which are found in nearly 65% of all leukemias. Detecting these genetic defects is helpful in making a full diagnosis of ALL and in planning the most appropriate therapy. Specific technologies called microarray chips are capable of checking up to 48,000 different genes in a single test, which holds promise for assessing prognosis and developing very targeted therapies in the future. Research on DNA microarray analysis continues to reveal different prognostic subgroups of ALL. As the precision, logistics, and cost effectiveness of DNA microarray assays improve, they may be used more commonly in the clinical setting.

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MTHFR Variants. Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in folate metabolism, and variations in the MTHRF gene may also influence response to antifolate chemotherapy. A 2004 study showed that patients with one of two specific variations of the MTHFR gene had a lower probability of survival following treatment with methotrexate.

Translocations. Genetic translocations (swapping of genes on chromosomes) may affect outlook. Examples include:

Patients with the t(12;21) genetic translocation (also referred to as TEL-AML1 fusion) have an excellent prognosis.
Patients who carry the defective gene called ETV6 often respond well to chemotherapy.
The t(4;11), sometimes referred to as MLL, is the most common translocation in children under age 1 year. Unfortunately, anyone with t(4;11) has a poor outlook. A 2001 study suggested that this genetic variant may actually be a unique leukemia and require treatments that differ from standard ALL.
The Philadelphia translocation t(9;22) also indicates a poor outlook. It represents about 20% of adult cases and about only 5% of childhood cases.
The t(1;19) location occurs in about 5% of ALL childhood cases and requires aggressive treatment.