Acute Lymphoblastic Leukemia

Definition

Definition of Acute Lymphoblastic Leukemia
Acute lymphoblastic leukemia (ALL) is a form of leukemia, or cancer of the white blood cells characterized by excess lymphoblasts.

Malignant, immature white blood cells continuously multiply and are overproduced in the bone marrow. ALL causes damage and death by crowding out normal cells in the bone marrow, and by spreading (infiltrating) to other organs. ALL is most common in childhood with a peak incidence at 2–5 years of age, and another peak in old age. The overall cure rate in children is about 80%, and about 45%-60% of adults have long-term disease-free survival.

Symptoms

Symptoms of Acute Lymphoblastic Leukemia
Initial symptoms are not specific to ALL, but worsen to the point that medical help is sought. They result from the lack of normal and healthy blood cells because they are crowded out by malignant and immature leukocytes (white blood cells). Therefore, people with ALL experience symptoms from malfunctioning of their erythrocytes (red blood cells), leukocytes, and platelets. Laboratory tests that might show abnormalities include blood count tests, renal function tests, electrolyte tests, and liver enzyme tests.

The signs and symptoms of ALL are variable but follow from bone marrow replacement and/or organ infiltration.

1. Generalized weakness and fatigue
2. Anemia
3. Frequent or unexplained fever and infection
4. Weight loss and/or loss of appetite
5. Excessive and unexplained bruising
6. Bone pain, joint pain (caused by the spread of "blast" cells to the surface of the bone or into the joint from the marrow cavity)
7. Breathlessness
8. Enlarged lymph nodes,liver and/or spleen
9. Pitting edema (swelling) in the lower limbs and/or abdomen
10. Petechia, which are tiny red spots or lines in the skin due to low platelet levels

Causes

Causes of Acute Lymphoblastic Leukemia
The cause of ALL is not known. However, certain risk factors might increase a child's chance of developing it.

Kids with an identical twin who was diagnosed with the illness before age 6 have a 20% to 25% chance of developing ALL. Fraternal twins and other siblings of children with leukemia have two to four times the average risk of developing it, too.

Children who have inherited certain genetic problems (such as Li-Fraumeni syndrome, Down syndrome, Klinefelter syndrome, neurofibromatosis, ataxia telangiectasia, or Fanconi anemia) also have a higher risk of developing leukemia, as do those who are receiving medicines to suppress their immune systems after organ transplants.

Diagnosis

Diagnosis of Acute Lymphoblastic Leukemia
Diagnosing ALL begins with a medical history, physical examination, complete blood count, and blood smears. Because the symptoms are so general, many other diseases with similar symptoms must be excluded. Typically, the higher the white blood cell count the worse the prognosis. Blast cells are seen on blood smear in majority of cases (blast cells are precursors (stem cells) to all immune cell lines). A bone marrow biopsy is conclusive proof of ALL. A lumbar puncture (also known as a spinal tap) will tell if the spinal column and brain has been invaded.

Prognosis

Prognosis of Acute Lymphoblastic Leukemia
The survival rate has improved from zero four decades ago, to 20-75 percent currently, largely due to clinical trials on new chemotherapeutic agents and improvements in stem cell transplantation (SCT) technology.

Five-year survival rates evaluate older, not current, treatments. New drugs, and matching treatment to the genetic characteristics of the blast cells, may improve those rates.

Treatment

Treatment of Acute Lymphoblastic Leukemia
The earlier acute lymphocytic leukemia is detected, the more effective the treatment. The aim is to induce a lasting remission, defined as the absence of detectable cancer cells in the body (usually less than 5% blast cells on the bone marrow).

Treatment for acute leukemia can include chemotherapy, steroids, radiation therapy, intensive combined treatments (including bone marrow or stem cell transplants), and growth factors.

Chemotherapy: Chemotherapy is the initial treatment of choice. Most ALL patients will receive a combination of different treatments. There are no surgical options, due to the body-wide distribution of the malignant cells. In general, cytotoxic chemotherapy for ALL combines multiple antileukemic drugs in various combinations. Chemotherapy for ALL consists of three phases: remission induction, intensification, and maintenance therapy.

Radiation Therapy: Radiation therapy (or radiotherapy) is used on painful bony areas, in high disease burdens, or as part of the preparations for a bone marrow transplant (total body irradiation). Radiation in the form of whole-brain radiation is also used for central nervous system prophylaxis, to prevent recurrence of leukemia in the brain. Whole-brain prophylaxis radiation used to be a common method in treatment of children’s ALL. Recent studies showed that CNS chemotherapy provided results as favorable but with less developmental side-effects. As a result, the use of whole-brain radiation has been more limited. Most specialists in adult leukemia have abandoned the use of radiation therapy for CNS prophylaxis, instead using intrathecal chemotherapy.

Prevention

Prevention of Acute Lymphoblastic Leukemia
Consult with your doctor.