A research finding shows a relationship between early infections in childhood and acute lymphoblastic leukemia. It provided a strong evidence to support that children who are not exposed to microbial germs, raised up in a cleaner environment and interacted less with other children in their first year, are more likely to develop acute lymphoblastic leukemia.
What is acute lymphoblastic leukemia?
Acute lymphoblastic leukemia is a malignant cancer, that affects the bone marrow. There is an abnormal and uncontrolled production of immature white blood cells (lymphoblast) in the bone marrow leading to the replacement of normal hematopoietic cells of the blood. These immature cells are pushed out into the blood circulation in large numbers and accumulate in the liver, lymph nodes, spleen and cerebrospinal fluid. Because these cells are not fully matured, they are unable to perform their normal functions.
ALL usually occurs in children between the age of 0-14years, representing about 60% of all cases.
Acute lymphoblastic leukemia can lead to deadly outcomes within a few weeks to months if not treated promptly. Patients usually die from overwhelming infections.
Who is at risk?
Certain genetic and chromosomal abnormalities increase the risks of developing acute leukemia later in life. Such conditions include Down syndrome, Klinefelter syndrome, Fanconi syndrome, Neurofibromatosis, Bloom syndrome
Cancer patients who are on chemotherapy are also at risk of developing leukemia. The patient also undergoing radiation therapy are also susceptible to developing acute leukemia.
Exposure to nuclear radiation is a well-established and known risk of developing all forms of cancer and leukemia. This was observed among survivors of Hiroshima atomic bomb and the Chernobyl nuclear disaster. Offspring of nuclear disaster survivor also carry a high risk of developing leukemia later in life.
Workers who are constantly exposed to benzene-containing compounds also have a risk of developing blood cancer. This substance is found in utilized in shoe manufacturing, crude oil refineries, rubber industries and chemical plants. Benzene is also found in a cigarette, so smokers are predisposed to leukemia.
Certain viral infections are also associated with acute leukemia. Ebstein-Bar virus (EBV) is the cause of Burkitt lymphoma. It is common among African natives. Another one is human T-cell lymphoma/Leukemia Virus (HTLV1), which gives rise to a rare form of acute leukemia.
Acute leukemia tends to be more common in Americans than in Africans.
At times, people without exposure to known risks factors still develop leukemia.
What are the signs and symptoms?
Patients with acute leukemia present initially with generalized symptoms and are not are also associated with other diseases. They include night sweats, weight loss, loss of appetite, and fever.
As the number of immature cells increases in the bone marrow and are released into the circulation, this set of symptoms becomes apparent and are indicative of acute leukemia. They are;
- Swollen lymph nodes and glands: As the cancer cells spread, they migrate to distant lymph nodes, causing them to be enlarged. They are not painful, matted together and greater than 2cm in diameter. They might be noticed as lumps under the armpit, groin or skin.
- Bone and joint pain: As the bone marrow increases the production of immature cells on the surface of the bone, they exert pressure on the bone and joint, causing severe pain.
- Skin infections that keep coming back.
- Frequent nosebleeds and bleeding gums.
- Extreme weakness and tiredness.
- Difficulty in breathing.
- Easy bruising.
- Abdominal tenderness and distension. This is because the spleen on the left side of the abdomen and liver on the right becomes enlarged and tender.
- Early satiety.
- If the cancer cells spread to the brains, it can cause various neurological symptoms ranging from headaches, seizures, problems with vision, loss of sensation.
- If the thymus is affected, it becomes enlarged and compress surrounding structures leading to difficulty in swallowing, coughing or difficulty in breathing.
Is Leukemia curable?
There are few factors that are taken into consideration when considering options for treating leukemia. These factors include the age of the patient, health status of the patient or presence of co-morbidities, the stage of cancer, and the distant spread to tissues and organs.
Treatment options include chemotherapy, radiation therapy, biologic therapy, stem cell transplant, antibody therapy, and targeted therapy.
Chemotherapy: Are drugs that are used to halt or control rapidly dividing cells. They are used alone or in combination with other drugs in the same or different groups. They administered intravenously (directly into the vein), as pills or intrathecal (into the cerebrospinal fluid). The intrathecal route is used if the cancer cells have metastasized to the brain and spinal fluid. This group of drugs has adverse side effects and they include,
- Hair loss
- nausea,
- vomiting,
- constipation, diarrhea,
- Easy bruising and nosebleed (caused by low level of platelet)
- Risk of severe infection (due to the depleted level of white blood cell),
- Abnormal sensations like numbness, burning, and prickling in the arm and legs due to damage to the sensory nerves.
- Tumor lysis syndrome. This occurs a large number of cancer cells are lysed during treatment, and their cellular contents are released into the circulation. This results in high blood pressure, hyperkalemia (high potassium in the blood), low calcium in the blood. Clinical manifestation include altered mental status, muscle weakness, papilledema and acute kidney injury
Examples of commonly used chemo drugs include Etoposide, Cyclophosphamide, Cytarabine, Methotrexate, 6-mercaptopurine
Hematopoietic stem cell transplantation
Hematopoietic stem cells play a vital role in the management and treatment of patients who are not responding well or likely to fail chemotherapy. Stem cells are harvested from bone marrows of donors with similar genetic makeup to reduce or prevent stem cell rejection. As newer and modern chemotherapeutic approaches are designed, most children and a minute portion of adults diagnosed with acute lymphoblastic leukemia will not be needing a stem cell transplant.
References
Acute lymphoblastic leukemia (ALL). (2018). Retrieved from https://www.leukaemia.org.au/disease-information/leukaemias/acute-lymphoblastic-leukaemia/
Chemotherapy for Acute Lymphocytic Leukemia. (2018). Retrieved from https://www.cancer.org/cancer/acute-lymphocytic-leukemia/treating/chemotherapy.html
Melissa Conrad Stöppler, M. (2018). Leukemia Symptoms, Causes, Treatment, Types & Survival Rate. Retrieved from https://www.medicinenet.com/leukemia/article.htm
Scientist reveals likely cause of childhood leukemia: Landmark paper sets out ‘unified theory’ for the cause of childhood leukemia — and finds it is likely to be preventable. (2018). Retrieved from https://www.sciencedaily.com/releases/2018/05/180521131746.htm
