Acute lymphoblastic leukemia | causes, types, treatments, symtoms, prevention

What is it?

Acute lymphoblastic leukemia is a cancer caused by abnormal white blood cells (cells that fight infection and help protect the body against disease). Patients have too many immature white blood cells in their bone marrow these immature cells crowd out the normal white blood cells in bone marrow, preventing it from making normal blood cells that Fighting infections.

They can also spill out into the blood stream and circulate around the body. Due to their immaturity, these cells are unable to function properly to prevent or fight infection. The body gets harder time fighting infections. Acute lymphoblastic leukemia is referred to as ALL.

Medical definition: a malignant (clonal) disease of the bone marrow in which early lymphoid precursors proliferate and replace the normal hematopoietic cells of the marrow. ALL is characterised by an overproduction of immature white blood cells, called lymphoblasts or leukaemic blasts. Acute lymphoblastic leukemia aggressivly invades the blood and can spread throughout the body to other organs, such as the liver, spleen, central nervous system, lymph nodes and other organs. But it does not normally produce tumors as do many types of cancer.

ALL (Acute lymphoblastic leukemia) is an acute type of leukemia, which means it can progress quickly. Without treatment, it can be fatal within a few months. acute lymphoblastic leukemia depends on factors such as:

• Your age: Younger patients tend to have a better outlook.
• Your response to chemotherapy: The prognosis is better if you have no evidence of leukemia four to five weeks after starting treatment.
• Your lab test results: The prognosis is better if you have a lower white blood count when you're diagnosed.
• Your subtype of ALL (B-cell ALL or T-cell ALL)
• Whether you have a chromosome abnormality called the Philadelphia chromosome; having it suggests a poorer prognosis.

Signs and Symptoms of Acute lymphoblastic leukemia

Initial symptoms are not specific to Acute lymphoblastic leukemia {ALL}, but worsen to the point that medical help is sought. They result from the lack or inadequate of normal and healthy blood cells in the body system. because they are outnumbered by malignant leukocytes (immature 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. Anemia
2. Breathlessness or Shortness of breath.
3. Bruises or bleeds easily (i.e., bleeding gums, purplish patches in the skin, or petechiae [flat, pinpoint spots under the skin])
4. Bone pain and jont pain
5. Dizziness
6. Excessive and unexplained bruising
7. Enlarged lymph nodes, liver and/or spleen
8. Fever or night sweats
9. Frequent infections
10. Frequent or unexplained fever and infection
11. Generalized weakness and fatigue
12. Pitting edema (swelling) in the lower limbs and/or abdomen
13. Petechiae, which are tiny red spots or lines in the skin due to low platelet levels
14. Swollen lymph nodes, particularly lymph nodes in the neck, armpit, or groin, which are usually painless.
15. Weakness or fatigue.
16. Weight loss and/or loss of appetite

How common is acute lymphoblastic leukemia?

ALL is most common in childhood, with a peak incidence at 2–5 years of age and affects slightly more boys than girls. Treatment results in a good chance for a cure. ALL is most common in Hispanic children, followed by those of white and African-American descent. Siblings of children with leukemia have a slightly higher risk of developing ALL, but the rate is still quite low: no more than 1 in 500.

ALL occurs in both children and adults. For adults, the prognosis is not as optimistic. About 6,000 cases are reported in the United States every year. Internationally, ALL is more common in Caucasians than in Africans; it is more common in Hispanics and in Latin America. Cure is a realistic goal and is achieved in more than 80% of affected children, although only 20-40% of adults are cured.

Who gets it?

Acute lymphoblastic leukemia can occur at any age but is more common in children (0-16 years) who represent close to 60% all cases. ALL is the most common type of childhood leukaemia, and the most common childhood cancer. It is more common in Hispanic children and slightly males than in females.

What causes ALL?

The exact causes of ALL still remains unknown. So for this reason, there is no known way to prevent it. but it is thought to result from mutations in one or more of the genes that normally control blood cell development.
However, there are a few known risk factors for this type of leukemia. Research is ongoing into possible causes of this damage and certain factors have been identified that may put some people at an increased risk. But it is not yet known whether these risk factors are actual causes of the disease These include:

1. exposure to very high doses of radiation either accidentally (nuclear accident) or treatment of other cancer types.
2. exposure to industrial chemicals like benzene, a solvent used in oil refineries and other industries and present in cigarette smoke, certain cleaning products, detergents, paint strippers, pesticides and certain types of chemotherapy used to treat other cancers.
3. Infection with human T-cell lymphoma/leukemia virus-1 (HTLV-1), or Epstein-Barr virus (EBV) a related leukemia more commonly seen in Africa
4. Having an inherited genetic syndrome such as Down syndrome.

Incidence and Mortality
Estimated new cases and deaths from ALL in the United States in 2016:

New cases: 6,590.
Deaths: 1,430.

New Cases leukemia

An estimated 60,140 new cases of leukemia are expected to be diagnosed in the US in 2016. Cases of chronic leukemia are expected to account for 2.4 percent more cases than acute leukemia.

1. Most cases of leukemia occur in older adults; the median age at diagnosis is 66 years.
2. The most common types of leukemia in adults are AML and CLL. 
3. The most common type of leukemia in children, adolescents and young adults younger than 20 years is ALL. 
4. For 2008-2012, the latest 5 years for which data are available, ALL accounted for 74.2 percent of the new leukemia cases in children, adolescents and young adults younger than 20 years.
5. Most cases of CML occur in adults. For 2008-2012, the latest 5 years for which data are available, about 3.3 percent of new cases of leukemia in children, adolescents and young adults younger than 20 years are CML. Approximately 1 percent of all cases of CML are in adolescents and young adults ages 15 to 19 years
6. In 2016, leukemia is expected to strike approximately 10 times as many adults (54,727) as children, adolescents and young adults younger than 20 years (5,413)

Anatomy

ALL presumably arises from malignant transformation of B- or T-cell progenitor cells. It is more commonly seen in children, but can occur at any age.
The disease is characterized by the accumulation of lymphoblasts in the marrow or in various extramedullary sites, frequently accompanied by suppression of normal hematopoiesis. B- and T-cell lymphoblastic leukemia cells express surface antigens that parallel their respective lineage developments.
Precursor B-cell ALL cells typically express CD10, CD19, and CD34 on their surface along, with nuclear terminal deoxynucleotide transferase (TdT), while precursor T-cell ALL cells commonly express CD2, CD3, CD7, CD34, and TdT

Anatomy of the bone

The bone is made up of compact bone, spongy bone, and bone marrow. Compact bone makes up the outer layer of the bone. Spongy bone is found mostly at the ends of bones and contains red marrow. Bone marrow is found in the center of most bones and has many blood vessels. There are two types of bone marrow: red and yellow. Red marrow contains blood stem cells that can become red blood cells, white blood cells, or platelets. Yellow marrow is made mostly of fat.

Survival for acute lymphoblastic leukaemia

Generally for 70 out of 100 people (70%) with ALL will survive their leukaemia for 5 years or more after they are diagnosed.

This is for people of all ages. Younger people tend to do much better than older people

1. In those aged 14 or younger, more than 90 out of 100 (more than 90%) will survive their leukaemia for 5 years or more after they are diagnosed.
2. In those aged between 15 and 24, almost 70 out of 100 (almost 70%) will survive their leukaemia for 5 years or more after diagnosis.
3. In those aged between 25 and 64, almost 40 out of 100 (almost 40%) will survive their leukaemia for 5 years or more after they are diagnosed.
4. In those aged 65 or older, almost 15 out of 100 (almost 15%) will survive their leukaemia for 5 years or more after diagnosis

How Is Acute Lymphoblastic Leukemia (ALL) Diagnosis

Laboratory tests and other studies used in the workup for ALL include the following:

1. Complete Blood tests to evaluate red and white blood cell count and platelet count differential
2. Coagulation studies
3. Peripheral blood smear
4. Chemistry profile, including lactic dehydrogenase, uric acid, liver function studies, and BUN/creatinine
5. Appropriate cultures (in particular, blood cultures) in patients with fever or other signs of infection
6. Chest x-ray
7. Computed tomography
8. Multiple-gated acquisition scanning
9. Electrocardiography
10. Bone marrow aspiration and biopsy (definitive for confirming leukemia)
11. Immunohistochemistry
12. Flow cytometry
13. Cytogenetics
14. Polymerase chain reaction
15. Gene expression profiling

Treatments and Management for Acute Lymphoblastic Leukemia (ALL)

Early treatment is important to ensure that your child can completely recover. Treatments that we recommend include:

• Induction chemotherapy (eg, standard 4- or 5-drug regimen, ALL-2, or hyper-CVAD)
• Consolidation chemotherapy
• Maintenance chemotherapy
• Intrathecal chemotherapy for central nervous system (CNS) prophylaxis
• Supportive care (eg, blood products, antibiotics, growth factors)

Special considerations apply to the treatment of the following:

• Mature B-cell ALL
• Ph+ ALL
• ALL in older children and younger adults
• Relapsed ALL
• ALL in patients with hyperuricemia or at high risk for tumor lysis syndrome

 Disclaimer

Based on the strength of the available evidence, treatment options may be described as either "standard" or "under clinical evaluation." These classifications should not be used as a basis for insurance reimbursement determinations.