What is leukemia?
Leukemia is a blood cancer that causes an increase in the number of white blood cells in your body. Those white blood cells crowd out the red blood cells and platelets that your body needs to be healthy. Excess white blood cells are don’t work properly.
There are many large blood cells, including red blood cells (RBC), white blood cells (WBC), and platelets. In general, it refers to WBC cancers.
White blood cells are an important part of your immune system. They protect your body from attack by bacteria, viruses, and fungi, as well as abnormal cells and other foreign substances. In blood cancer, white blood cells do not function like normal white blood cells. They divide very quickly and eventually expel normal cells.
White blood cells are produced primarily in the bone marrow, but some types of white blood cells are also produced in the lymph nodes, spleen, and thymus. Once formed, white blood cells are concentrated throughout the body in the blood and lymph (the fluid that circulates through the lymphatic system), lymph nodes, and spleen.
There are many types of this disease. Other forms of blood cancer are more likely in adults. It usually affects white blood cells. White blood cells are powerful warriors against infection; they generally grow and divide according to the needs of your body. But in people with this disease, the bone marrow makes abnormal white blood cells that don’t work properly.
Treatment of blood cancer can be complex, depending on the type of this disease and other factors. But there are strategies and resources that can help make your treatment a success.
Types of leukemia
The onset of leukemia can be severe (sudden onset) or chronic (slow onset). In severe leukemia, cancer cells multiply rapidly. In chronic leukemia, the disease develops slowly and the initial symptoms can be very mild.
It can also be classified according to the type of cell. Myeloid cell leukemia is called myelogenous leukemia. Myeloid cells are immature blood cells that generally develop into granulocytes or monocytes. Blood cancer that affects lymphocytes is called lymphocytic leukemia. There are four main types of blood cancer
1. Acute myelogenous leukemia
According to the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program, 21,000 new cases of AML are diagnosed in the United States each year. It is the most common form of this disease. The five-year survival rate for AML is 26.9 per cent.
2. Acute lymphocytic leukemia
Acute lymphocytic leukemia (ALL) is more common in children. The NCI estimates that 6,000 new cases are diagnosed each year.
3. Chronic myelogenous leukemia
Chronic myelogenous leukemia (CML) mainly affects adults. About 9,000 cases of CML are diagnosed annually, the NCI said.
4. Chronic lymphocytic leukemia
Chronic lymphocytic leukemia (CLL) is more common in people over 55 years of age. It is very rare in children. According to the NCI, 20,000 new cases of CLL are diagnosed each year. Hair cell leukemia is a very rare subtype of CLL. Its name comes from the appearance of cancerous lymphocytes under a microscope.
Causes of leukemia
No one knows what causes this disease. People who have it have some abnormal chromosomes, but the chromosomes do not cause blood cancer.
You can’t prevent this disease, but some things can trigger it.
2. Excessive exposure to radiation or certain chemicals.
3. There is radiation therapy or chemotherapy to treat cancer.
4. You have a family history of blood cancer.
The exact cause of blood cancer is unknown, but it is believed to be a combination of genetic and environmental factors. Leukemia cells have mutations in their DNA that cause them to grow abnormally and lose the normal function of white blood cells. Chromosomal translocation is a type of change in the DNA of cells commonly found in this disease. In this process, a part of a chromosome breaks down and attaches to another chromosome.
The DNA translocation between chromosomes 9 and 22 is a translocation commonly found in almost all cases of CML and sometimes other types of blood cancer called the Philadelphia chromosome. It produces an oncogene (cancer-promoting gene) called BCR-ABL. This change in DNA is not inherited but occurs during some time in the life of the affected person.
Most cases of this disease are not believed to be inherited, although certain mutations and genetic conditions increase the chances of developing blood cancer along with the offspring. A condition called Li-Fraumeni syndrome is characterized by an inherited mutation in a tumor suppressor gene called TP53, and people with this condition are at increased risk for this disease and other cancers.
Symptoms & signs of leukemia
The symptoms and signs of leukemia depend on the type of blood cancer. As mentioned above, slow-growing or chronic leukemia may not cause any initial symptoms, but aggressive or rapidly progressing this disease can cause severe symptoms. Symptoms of this disease arise from the loss of normal function of blood cells or the accumulation of abnormal cells in the body.
The signs and symptoms of this disease usually include the following:
- Night sweats
- Swollen lymph nodes are usually painless
- Fatigue, feeling of fatigue
- Easy bruising or bleeding, blue or purple spots on the skin or small red spots on the skin, or recurrent runny nose
- Frequent infections
- Bone or joint pain
- Unexplained and unexpected weight loss or loss of appetite
- Enlarged spleen or liver, which can cause abdominal pain or swelling
- Red spots on the skin (petechiae)
- If leukemic cells infiltrate the brain, symptoms such as headaches, seizures, confusion, loss of muscle control, and vomiting may appear.
Factors that can increase your risk of developing certain types of this disease:
- Exposure to radiation increases the risk of developing AML, CML, or ALL.
- An increase in leukemia has been observed in people who have survived atomic bombs.
- Radiation therapy for cancer also increases the risk of this disease. Exposure to certain chemicals, including benzene (commonly used in the chemical industry), increases the risk of this disease.
- Smoking cigarettes increases the risk of developing AML.
- Blood disorders known as myelodysplastic syndromes increase the risk of developing AML.
- Some chemotherapy drugs for cancer increase the risk of AML or ALL.
Similarly, not all people who develop blood cancer have a detectable risk factor:
- Previous cancer treatment: People with certain types of chemotherapy and radiation therapy have an increased risk of developing certain types of this disease for other types of cancer.
- Genetic defects: Genetic abnormalities influence the development of this disease. Certain genetic disorders, such as Down syndrome, increase the risk of leukemia.
- Exposure to certain chemicals: Exposure to certain chemicals, such as benzene, which is found in gasoline and used by the chemical industry, increases the risk of certain types of leukemia.
- Of smoking: Smoking cigarettes increases the risk of severe myelogenous leukemia.
- Family history of leukemia: If your family members are diagnosed with leukemia, your risk of developing the disease increases.
- Be a non-smoker. Smoking does not reduce the risk of leukemia.
- Maintain a healthy body weight: Some studies have shown that being overweight and obese increase the risk of this cancer.
- Avoid inhaling benzene and formaldehyde.
Before symptoms begin, doctors can diagnose chronic leukemia with a routine blood test. If this happens, or if you have signs or symptoms that indicate leukemia, you may want to undergo the following diagnostic tests:
- Physical exam: Your doctor will look for physical signs of this disease, such as pale skin from anaemia, swollen lymph nodes, and an enlarged liver and spleen.
- Blood test: By looking at your blood sample, your doctor can determine if you have abnormal red or white blood cells or platelets; this indicates blood cancer.
- Bone marrow test: The bone marrow is removed with a long, thin needle. The sample is sent to a laboratory to detect leukemia cells. Specific tests of your leukemia cells reveal certain symptoms that can be used to determine your treatment options.
Treatment of this blood cancer depends on many factors, such as the type and subtype of the disease, the stage, the age of an individual, and general health. Since leukemia is a cancer of the blood cells, it travels throughout the body, and local therapies such as surgery and radiation therapy are rarely used.
Instead, it can be used alone or in combination with aggressive chemotherapy, bone marrow/stem cell transplantation, targeted therapy (tyrosine kinase inhibitors), monoclonal antibodies, immunotherapy, and others. In some cases, it is also advisable to wait carefully. Most people with this blood cancer have a team of medical professionals, led by blood disorders and oncologists (a haematologist/oncologist).