Leukemia: Symptoms, Types, Causes, Risk factors, Diagnose & Treatment

 

Leukemia is a type of cancer that affects the body's blood-forming tissues, such as the lymphatic and bone marrow.

 Leukemia comes in various forms.  Children are more likely to get certain types of leukemia.  Adults are primarily affected by other types of leukemia.

 White blood cells are typically affected by leukemia.  As your body requires them, your white blood cells typically divide and expand systematically, making them powerful anti-infection agents.  However, the bone marrow overproduces abnormal white blood cells that are unable to function normally in leukemia patients.

Depending on the type of leukemia and other variables, treatment can be complicated. However, some resources and strategies can help your treatment be successful.

Leukemia begins when a single bone marrow cell's DNA mutates, making it unable to grow and function normally. Leukemia cells frequently exhibit characteristics of abnormal white blood cells. The type of leukemia you have, your age, general health, and whether the disease has progressed to other organs or tissues all influence the course of treatment.

What is Leukemia?

The fast growth of abnormal blood cells is a characteristic of leukemia, a blood cancer. Your bone marrow, which produces the majority of your body's blood, is where this unchecked growth occurs. Typically, leukemia cells are immature white blood cells that are still forming. The Greek words for "white" (leukos) and "blood" (haima) are the origin of the word leukemia.

Leukemia typically doesn't develop into a mass (tumor) that appears on imaging tests like X-rays or CT scans, in contrast to other cancers.

Different forms of leukemia exist. While some are more common in adults, others are more common in children. The type of leukemia and other variables determine the course of treatment.

Also Read: Red Blood Cell Functions, Range and Treatment

What is the development of leukemia?

 The soft, spongy tissue called bone marrow, which is located inside the cavity of your bones and is where your body makes its blood cells, is where leukemia starts.  Before becoming fully developed, blood cells travel through several phases.  Normal, mature blood cells consist of:

•  Red blood cells: These are the cells that supply all of your body's tissues and organs with oxygen and other essential substances.

•  White blood cells: Anti-infection cells.

•  Platelets are cells that aid in blood coagulation.

 Hematopoietic (hemo = blood, poiesis = make) stem cells are the precursors of these blood cells.  The stem cells differentiate into either lymphoid (LIM-foyd) or myeloid (MAI-uh-loyd) cells.  The adult forms of blood cells are as follows, if normal development continues:

Red blood cells, platelets, and some forms of white blood cells (neutrophils, eosinophils, and basophils) are all produced by myeloid cells.
Certain white blood cells (lymphocytes and natural killer cells) are produced from lymphoid cells.
On the other hand, one of the growing blood cells starts to grow uncontrollably if you have leukemia. These aberrant cells, known as leukemia cells, start to occupy the interior of your bone marrow. They displace the cells that are attempting to differentiate into healthy platelets, white blood cells, and red blood cells.

What types of leukemia are there?

Leukemia comes in four primary forms and a number of subgroups. Leukemia is categorized by medical professionals according to the rate at which the illness progresses and whether leukemia cells originate from lymphoid or myeloid cells.

Leukemia classifications

Based on the type of blood cell involved and the rate of progression, medical professionals categorize leukemia.

By the rate at which the illness develops

Acute leukemia. The condition advances rapidly as the leukemia cells divide quickly. Within weeks of the leukemia cells growing, you will experience nausea if you have acute leukemia. Because acute leukemia is life-threatening, treatment must start right away. The most common type of cancer in children is acute leukemia.

Chronic leukemia. These leukemia cells frequently exhibit characteristics of both immature and adult blood cells. Though not to the same degree as their typical counterparts, some cells mature to the point where they perform as the cells they were intended to be. In contrast to acute leukemia, the disease usually progresses more slowly. It could be years before you notice any signs if you have persistent leukemia. Adults are more likely than children to develop chronic leukemia.

By cell type

Myeloid cells give rise to myelogenous (mai-uh-lOW-juh-nuhs) or myeloid leukemia. Red blood cells, white blood cells, and platelets are all produced by normal myeloid cells.
Lymphoid cells give rise to lymphocytic leukemia. Your body's immune system relies heavily on white blood cells, which are produced from normal lymphoid cells.

Types of leukemia

there are four types of leukemia

• The most common type of leukemia in children, adolescents, and young adults up to age 39 is acute lymphocytic leukemia (ALL). Adults of any age can be affected by ALL.

• The most common types of acute leukemia in adults are acute myelogenous leukemia (AML). People over 65 are more likely to have it. AML can also affect youngsters.

• The most common type of chronic leukemia in adults is chronic lymphocytic leukemia (CLL), which primarily affects those over 65. With CLL, symptoms could not show up for years.

• Adults of any age can be affected by chronic myelogenous leukemia (CML), although it is more common in those over 65. Children hardly ever experience it. With CML, symptoms could not show up for years.

How common is leukemia?

Leukemia accounts for 3.2% of all new cancer cases in the United States, making it the tenth most frequent malignancy. Although leukemia can strike anyone, it is more common in those who are:

• 65 to 74 years old

• Male

• White or Caucasian

Though some types of leukemia occur more frequently in adults, leukemia is commonly thought of as a pediatric cancer. Leukemia is the most common form of cancer in children and teenagers, despite being uncommon in this age group.

Which symptoms of leukemia are present?

The type of leukemia has an impact on the symptoms. For example, you might not exhibit any symptoms in the early stages of a chronic form of leukemia.

Typical leukemia symptoms and indicators include:

• Fatigue, easily worn out

• Fever or sweats at night

• Recurring infections

• Shortness of breath

• Pale skin

• Inexplicable loss of weight

• Discomfort or pain in the bones or joints

• The left side of your ribcage may hurt or feel full

• Enlarged liver or spleen, as well as enlarged lymph nodes in your stomach, groin, underarms, or neck.

• Bruising and bleeding readily, such as nosebleeds, bleeding gums, or purplish/darkened skin patches or a rash that resembles tiny red spots on the skin (petechiae).

Risk factors:

Leukemia can affect anyone. However, research has indicated that several variables could raise your risk, such as:

• Previous cancer treatment. You may be more susceptible to some forms of leukemia if you have had radiation or chemotherapy for cancer in the past.

• Smoking. You are more likely to get acute myelogenous leukemia if you have a history of smoking or have been around secondhand smoke.

• Industrial chemical exposure. Benzene and formaldehyde are well-known carcinogens that can be found in home and construction products. Rubber, plastics, dyes, insecticides, medications, and detergents are all made from benzoene. Building supplies and home goods like soaps, shampoos, and cleaning supplies contain formaldehyde.

• Specific genetic disorders. Your risk may be raised by genetic disorders such as Down syndrome, Schwachman-Diamond syndrome, Klinefelter syndrome, and neurofibromatosis.

• History of leukemia in the family. Certain forms of leukemia may run in families, according to research. Generally speaking, though, having a family member with leukemia does not guarantee that you or another member of your family will get the disease. If you or a family member has a genetic issue, let your doctor know. To determine your risk, they might suggest genetic testing.

How can one diagnose leukemia?

Your doctor may be notified by the results of normal blood work that you may have acute or chronic leukemia, which calls for more testing. Or, if you have leukemia symptoms, they might suggest a workup.

Tests and diagnostic examinations could include:

• Physical examination: Your doctor will inquire about your symptoms and check for an enlarged liver or spleen as well as swollen lymph nodes. They might also check for swelling and bleeding in your gums. They might search for a red, purple, or brown skin rash linked to leukemia.

• Your doctor can determine whether you have abnormal numbers of red blood cells, white blood cells, and platelets by ordering a complete blood count (CBC). White blood cell counts are likely to be higher than normal if you have leukemia.

• Blood cell examination: To look for indicators that point to the existence of leukemia cells or a particular kind of leukemia, your doctor may draw more blood samples. Your healthcare professional may also order peripheral blood smears and flow cytometry.

• A bone marrow biopsy, also known as bone marrow aspiration, may be carried out by your doctor if your white blood cell count is abnormal. During the treatment, a large needle is introduced into your bone marrow, generally in your pelvic bone, to extract fluid. The fluid sample is examined for leukemia cells in a laboratory. A bone marrow biopsy confirms a leukemia diagnosis by estimating the proportion of aberrant cells in your bone marrow.

• Imaging and further tests: If your symptoms suggest that leukemia has impacted your bones, organs, or tissue, your doctor may prescribe a chest X-ray, CT scan, or magnetic resonance imaging (MRI). On imaging, the leukemia cells are not visible.

• Lumbar puncture (spinal tap): To determine whether leukemia has spread to the spinal fluid around your brain and spinal cord, your doctor may examine a sample of spinal fluid.

How does it treat leukemia?

The type of leukemia you have, your age, general health, and the disease has progressed to other organs or tissues all influence the course of treatment.


Typical treatments frequently involve a mix of the following:

• Chemotherapy: The most popular treatment for leukemia is chemotherapy. Leukemia cells are either killed or prevented from proliferating by the use of drugs. You might be given the chemicals (medication) as a tablet, intravenous injection, or subcutaneous injection during treatment. You will typically be given a mix of chemotherapy drugs.

• Drugs intended to target particular leukemia cell components—such as a protein or gene—that are driving the disease to overpower healthy blood cells are used in targeted therapy.  Targeted treatments may kill leukemia cells directly, stop their blood flow, or stop them from proliferating.  Normal cells are less likely to be harmed by targeted therapy.  Tyrosine kinase inhibitors and monoclonal antibodies are two types of medications used in targeted therapy.

• Immunotherapy, also known as biologic therapy, is a treatment that uses specific medications to strengthen your body's defenses against leukemia. Your immune system can detect cancer cells and create additional immune cells to combat them with the aid of immunotherapy.

•  Radiation therapy: This treatment kills or inhibits the growth of leukemia cells using powerful radiation beams or X-rays.  During therapy, a machine either distributes radiation throughout your body or targets the precise locations of the cancer cells.  Radiation therapy may be administered to your body before a hematopoietic cell transplant.

• Hematopoietic cell transplantation, also known as a stem cell or bone marrow transplant, is a treatment that substitutes new, healthy hematopoietic cells for the malignant blood-forming cells that were destroyed by chemotherapy and/or radiation therapy. These healthy cells may originate from a donor or be extracted by your healthcare professional from your bone marrow or blood before chemotherapy and radiation. Your body needs red blood cells, white blood cells, and platelets, which form when the healthy new cells multiply and create new bone marrow and blood cells.

• With chimeric antigen receptor (CAR) T-cell therapy, your body's natural T-cells—also known as T-lymphocytes, which are immune cells—are modified to combat leukemia cells and then infused back into your body.

New cancer treatments can also be tested in clinical trials. Discuss with your healthcare practitioner the possible advantages and disadvantages of signing up for a clinical study.

Which stages are included in the treatment of leukemia?

You might undergo phased treatment or continuous, long-term leukemia treatment, depending on your treatment strategy. Phased treatment typically consists of three components. Every stage has a distinct objective.

Induction of treatment. In order to establish remission, the objective is to eliminate as many leukemia cells from your bone marrow and blood as possible. When the disease is in remission, all of its symptoms and indicators go away, blood cell counts return to normal, and there are no leukemia cells in your blood. The typical duration of induction therapy is four to six weeks.

Intensification is another name for consolidation. To prevent the cancer from returning, the objective is to eradicate any leukemia cells that may still be present. Consolidation therapy is often administered in cycles over four to six months.

Therapy for maintenance. Killing any leukemia cells that could have survived the previous two stages of treatment is the aim to stop the cancer from coming back (relapsing). About two years pass throughout treatment.
If the leukemia recurs, your doctor may decide to modify or restart your therapy.

References:

• Churpek JE. Familial myelodysplastic syndrome/acute myeloid leukemia. (https://pubmed.ncbi.nlm.nih.gov/29156196/) Best Pract Res Clin Haematol. 2017;30(4):287-289. Accessed 5/18/2022.

• Chennamadhavuni A, Lyengar V, Shimanovsky A. Leukemia. (https://pubmed.ncbi.nlm.nih.gov/32809325/#:~:text=Leukemia%252520is%252520a%252520production%252520of,based%252520on%252520the%252520originator%252520cell.) In: StatPearls. Treasure Island (FL): StatPearls Publishing; November 21, 2021. Accessed 5/18/2022.

• Leukemia. American Society of Hematology. https://www.hematology.org/education/patients/blood-cancers/leukemia. Accessed Oct. 16, 2020.

• Juliusson G, Hough R. Leukemia. (https://pubmed.ncbi.nlm.nih.gov/27595359/) Prog Tumor Res. 2016;43:87-100. Accessed 5/18/2022.

• Ma XY, Wei L, Lei Z, Chen Y, Ding Z, Chen ZS. Recent progress on targeting leukemia stem cells. Drug Discov Today. 2021;26(8):1904-1913. Accessed 5/18/2022.

• Niederhuber JE, et al., eds. Abeloff's Clinical Oncology. 6th ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed Oct. 16, 2020.

• National Cancer Institute. Surveillance, Epidemiology and End Results Program. Cancer Stat Facts: Leukemia. (https://seer.cancer.gov/statfacts/html/leuks.html) Accessed 5/18/2022.

• Medical review (expert opinion). Mayo Clinic. Dec. 2, 2020.