Leukemia: Causes, Types, Symptoms and More

Leukemia is a broad term for cancers of the blood cells. At a basic level, the body’s bone marrow (the soft inner part of bones) is unable to produce healthy blood cells, which hinders the body’s ability to carry oxygen to tissues, fight infections and control bleeding, among other things. Rather, the bone marrow makes abnormal white blood cells in increasingly dangerous quantities that then usually overtake the healthy cells in production and ability to counteract the abnormal blood cells. Similar to other cancers, leukemia often spreads to other parts of the body.

Developing leukemia can be the result of genetic or environmental factors, or a combination of both. There are four main types of Leukemia based on their classification are:

  • Acute myeloid leukemia (AML)
  • Chronic myeloid leukemia (CML)
  • Acute lymphocytic leukemia (ALL)
  • Chronic lymphocytic leukemia (CLL).

Leukemia is classified as myeloid or lymphocytic depends on where the cancer begins in the bone marrow cells.

Stats About Leukemia

  • Leukemia occurs most often in adults older than 55, but certain types are also increasingly common cancer in children younger than 15 (specifically, acute lymphocytic leukemia).
  • Men are more likely to develop leukemia than woman
  • Acute lymphocytic leukemia is more likely to develop in whites than in African Americans
  • More than 60,000 people are diagnosed with leukemia every year
  • There are an estimated 376,508 people living with or in remission from leukemia in the U.S. right now
  • The five-year survivability rate for people diagnosed with leukemia increased from 33 percent in 1975 to nearly 60 percent in 2005
  • Leukemia, lymphoma, and myeloma are expected to cause the deaths of an estimated 56,840 people in the U.S. in 2020, or approximately six people every hour.
The FDA has clearly determined that benzene should not be used in standard pharmaceutical production at all because of its unacceptable toxicity.
Valisure report 2021

What Causes Leukemia?

There is no single cause of leukemia. Leukemia is caused by a combination of genetic and environmental factors and some people are more susceptible to developing certain types of leukemia. This blood cancer is not transmissible—your cannot “get leukemia” from someone else but you can get it from something else. Symptoms are often vague and not specific and for most cases, it is unavoidable. Leukemia symptoms are sometimes overlooked because they may resemble symptoms of the flu and other common illnesses. For those with a slow developing chronic leukemia, they may feel no symptoms at all. For those with an acute case, they may feel a range of symptoms immediately.

Common signs and symptoms of leukemia:

  • Fever or chills
  • Persistent fatigue or weakness
  • Pale skin tone
  • Frequent severe infection
  • Losing weight without trying
  • Swollen lymph nodes in the underarms, groin, neck and stomach
  • Enlarged liver or spleen
  • Easy bleeding or bruising
  • Constant nosebleeds
  • Tiny red spots in your skin (petechiae)
  • Excessive sweating, especially at night
  • Bone pain or tenderness
  • Pain and feeling of fullness under the ribs (specifically on the left side)

Even without symptoms, leukemia can be diagnosed in a routine blood test. Additional blood and bone marrow tests can measure abnormal levels of red or white blood cells or platelets for the presence of leukemia cells and allow doctors to further diagnosis the specific type of leukemia and put together a treatment plan. Tests include: a physical exam, complete blood count test (CBC), blood cell examination, bone marrow biopsy, X-ray, CT scan, MRI and a spinal tap.

Factors that may increase the risk of developing some types of leukemia include:

  • Previous cancer treatment: People who’ve had certain types of chemotherapy and radiation therapy for other cancers have an increased risk of developing acute myeloid leukemia. Certain chemotherapy drugs are also a risk factor, including: alkylating agents, platinum agents and topoisomerase II inhibators.
  • Genetic disorders: Genetic abnormalities play a role in the development of leukemia. Certain genetic disorders, such as Down syndrome, are associated with an increased risk of leukemia. Other inherited syndromes that increase the risk of leukemia (specifically ALL and AML) include bloom syndrome, ataxia-telangiectasia and neurofibromatosis, Fanconi anemia, dyskeratosis congenita, shwachman-diamond syndrome, bloom syndrome, diamond-blackfan anemia, li-fraumeni syndrome and kostmann syndrome.
  • Chemical exposures: Exposure to certain chemicals, such as benzene is linked to an increased risk of some kinds of leukemia. Chemical exposure can take place via inhalation, ingestion or topically.
  • Cigarette smoke: Smoking cigarettes increases the risk of acute myelogenous leukemia. The cancer-causing substances contained in tobacco smoke go beyond the more commonly linked lung and throat cancers as the smoke also gets into the bloodstream and increases the chances of developing acute myeloid leukemia. While there are few things people can do to avoid leukemia, stopping smoking and avoiding second-hand smoke is one of them.
  • Family history: If members of your family have been diagnosed with leukemia, your risk of the disease may be increased. While leukemia is not considered a hereditary disease, having a first-degree family member with CLL increases your risk. In these instances, a doctor may suggest undergoing genetic testing.

Types of Leukemia

Leukemia classifications start between two divisions and then are further classified into the four types. The two divisions: acute or chronic leukemia and lymphocytic or myelogenous leukemia. Here’s what this means:

  • Acute leukemia is used to describe those types of leukemia that develops quickly almost always with a range of noticeable symptoms in the patient. Conversely, chronic leukemia develops slow but steady and many have no symptoms at all.
  • Lymphocytic leukemia refers to the type of leukemia that only affects the lymphocyte cells in the bone marrow and no other. Myelogenous leukemia only attacks the white blood cell myelocytes.

The four types of leukemia beyond these two divisions are: chronic lymphocytic leukemia (CLL), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), acute myelogenous leukemia (AML). There are sub-types of the four main leukemias.

Chronic Lymphocytic Leukemia (CLL)

Characterized by an extreme susceptibility to infections, CLL afflicts roughly 4 out of 100,000 people in the United States alone—roughly ¼ of all leukemia cases. Here are some more specifics on CLL:

  • “hairy cell” leukemia is a common sub-type of chronic lymphocytic leukemia
  • Acquired not inherited
  • Roughly 4,320 deaths from CLL every year in the United States
  • Average age of diagnosis is 70
  • Extremely rare in children

Acute Lymphocytic Leukemia (ALL)

Accounting for over 90% of childhood leukemia cases, ALL is an acute type of leukemia which means that it progresses quickly with noticeable symptoms almost immediately. Here are some more specifics on ALL:

  • Accounts for 20% of adult leukemia cases
  • Commonly caused by everyday household products such as glues, rubber and petroleum which contain benzene—a known human carcinogen
  • Usually acquired
  • There are roughly 1,500 deaths from ALL in the United States every year

Chronic Myelogenous Leukemia (CML)

The rarest of the leukemia types, CML occurs when there is a genetic change in the immature myeloid cell that then creates an abnormal gene (BCR-ABL) that ultimately multiplies in the bone marrow and enters the bloodstream. Here are some more specifics on CML:

  • Occurs mostly in adults but can occur in children as well
  • While categorized as chronic, it can become acute in some individuals
  • Often spreads from the bone marrow to the blood and spleen
  • A 2012 study found that benzene exposure can increase the risk of CML by 23%

Acute Myeloid Leukemia (AML)

One of the most common leukemia types in adults, AML can develop naturally or from external factors. For instance, exposure to the chemical benzene has been proven to cause AML.

  • Average age of an AML diagnosis is 65
  • Can occur in children
  • There are roughly 11,400 deaths from AML in the United States every year.
  • Linked to cigarette smoke

Leukemia Treatments

Leukemia treatments vary on the individual (age, sex, etc), type of cancer and more. Some of the commonly used treatment options include: surgery, chemotherapy, targeted therapy, stem cell therapy, radiation and also less invasive modalities.

Treatments can successfully place the cancer in remission or calm leukemia symptoms in many patients but do come with various side effects. As with most cancers and other diseases, the sooner leukemia is diagnosed and treated, the better the results for most. There are also various clinical trials for every type and state of leukemia that are available for eligible patients. An oncologist and a hematologist are the two doctors leukemia patients most commonly work with. Many leukemia treatment plans are delivered in there phases:

  1. Induction therapy: with the goal of destroying as many abnormal cells as possible, induction therapy typically lasts four to six weeks.
  2. Consolidation: Once the leukemia is found to be in remission (blood cell counts normal/no detectable abnormal cells), the consolidation (or intensification) phase takes place. Given in cycles ranging from four to six months, the goal of this phase is to destroy any undetected leukemia cells.
  3. Maintenance therapy: Lasting roughly two years, maintenance therapy continues on the progress of the first two phases to avoid a relapse by providing treatments that kill any remaining bad cells. The intensity of this phase depends on the intensity of the cancer as well as the tolerance of the patient as side effects are common. In many cases, there may be additional treatment aimed at the brain and spinal cord—common sites of undetectable leukemia cells in many patients.

Benzene and Leukemia

Certain types of leukemia are unavoidable even for the healthiest individuals, but others are the result of exposures or other external factors. Benzene, an extremely common chemical that occurs naturally and synthetically causes various types of leukemia. Benzene can be found in everything from volcanoes and forest fires to gasoline and solvents. Quick and incredibly cheap to produce, benzene is one of the 20 most commonly used chemicals in the U.S. Exposure can occur topically, via inhalation and ingestion. Regulated extensively, benzene exposure causes cancer, specifically leukemia. Unfortunately even with all the regulations and warnings about the dangers of this chemical, benzene has recently been found in commonly used consumer products such as sunscreen and hand sanitizer.

Benzene contamination in a wide-range of sun-care products (sunscreens and after-sun products) is a significant health and safety concern. A list of products that have tested positive for benzene contamination can be found here. A large majority of the benzene-containing products were spray sunscreens. Individuals should review the Valisure findings and immediately stop using any products found to contain benzene. But many products tested by Valisure found no contamination and are presumably safe but continued vigilance is necessary. A list of those products can be found here.

Sunscreen is only one component of a skin-cancer prevention regimen, which also includes wearing protective clothing, sunglasses and a hat that provides shade to the whole head. Experts also advise seeking shade, when possible, during peak sunlight. Benzene is not a listed ingredient in any of the sunscreens or after-sun products that were tested; rather, something in the manufacturing process is placing it into the product that ultimately goes on your skin. For many (including children), sunscreen is applied all over the body multiple times a day. This alarming reality means that the potential for toxic levels of benzene exposure in a product encouraged for use for everyone 6 months to 100 is alarming and unacceptable.

You can also read the entire report and testing methodology here.

While most cases of leukemia are unavoidable, some are completely avoidable. When someone develops leukemia as a result of benzene exposure, the source should be traced and you may have an actionable cause via a personal injury or wrongful death civil lawsuit.

AML and Benzene

Chemicals such as benzene cause AML along with other diseases such as: non hodgkins lymphoma, myelodysplastic syndrome and multiple myeloma. Classified as a known human carcinogen by the Environmental Protection Agency, benzene causes AML in children and adults. There is no safe amount of benzene exposure for anyone. If you feel or know that you may have any level of benzene exposure in yourself or children, be sure to get in touch with your physician immediately. Doctors can use blood, breath and urine tests to detect benzene levels and if necessary also test for leukemia.

It is critical that regulatory agencies address benzene contamination in sunscreens, and all topical medications at the manufacturing and final product level, so that all individuals feel safe using sunscreen products.
Dr. Christopher Bunick, MD, PhD, Associate Professor of Dermatology at Yale University