Identifying the Signs and Symptoms of AML

AML, like many different kinds of cancers, can cause many different signs and symptoms. Many of these symptoms may be subtle, or delayed.

It is common for people with AML to feel a general loss of well-being, due to the underproduction of normal bone marrow cells. These kind of symptoms may be to tire easily, or be short of breath after performing normal physical activities.

Symptoms of leukemia are generally non-specific, and include the following:

• Weight loss
• Fatigue
• Fever
• Night sweats
• Loss of appetite
• Paleness
• Signs of bleeding causes by a low platelet count, including:
• Black and blue marks or bruising occurring for no reason or because of a minor injury
• The appearance of pinhead-sized red spots on your skin, called “petechiae”
• Prolonged bleeding from minus cuts or scrapes

Unexplained bruising

Paleness of skin

Petechiae

There are also symptoms caused by high numbers of leukemia cells, which may happen in AML:

• Headache
• Weakness in one side of the body
• Slurred speech
• Confusion
• Sleepiness

If the cancer has spread to other parts of the body, symptoms of AML may include:

• Headaches
• Weakness
• Seizures
• Vomiting
• Trouble with balance
• Facial numbness
• Blurred vision

https://www.lls.org/content/nationalcontent/resourcecenter/freeeducationmaterials/leukemia/pdf/aml.pdf

http://www.cancer.org/cancer/leukemia-acutemyeloidaml/detailedguide/leukemia--acute-myeloid--myelogenous--signs-symptoms

Diagnosing AML and disease progression

According to the American Cancer Society, there is a specific list of recommended screening tests for certain kinds of cancers, but as of yet, there are no special tests recommended to find acute myeloid leukemia early – instead, they recommend that the best way to receive an early diagnosis or find leukemia early is to report any possible symptoms of leukemia to your doctor right away.

Symptoms of leukemia are generally non-specific, and include the following:

• Weight loss
• Fatigue
• Fever
• Night sweats
• Loss of appetite

More information about detailed symptoms will be discussed in a future blog.

If AML is suspected, your doctor will do a series of tests after a thorough collection of your medical history and physical assessment. 

Blood samples are generally taken from a vein in the arm. Since AML is caused by problems with abnormal blood cells, your doctor will need a sample to confirm a trends in an AML diagnosis. With a blood sample, they can run a Complete Blood Count and Peripheral Blood Smear to analyze the different kinds of blood cells and the maturity of various white blood cells.

Bone marrow samples are obtained either by obtaining a bone marrow aspiration or a bone marrow biopsy. These are generally taken from from the back of the pelvic hip bone, but can be taken from other sites as well. In an aspiration, you will lie on your side or belly and receive a local anesthetic by an injection, and after you are numbed, the provider will insert a hollow needle into your bone to withdraw liquid bone marrow. A bone marrow biopsy is done after an 
aspiration, and is done with a slightly larger needle than the one used for aspiration. This removes a small piece of bone for further inspection. The bone marrow tests are used to help diagnose leukemia.


Cytogenetics look at cell's chromosomes under a microscope. Normally, human cells have 23 sets of chromosome that are all generally a certain expected shape and size. Sometimes in AML, the chromosomes of cells have changes that are identifiable under the microscope.






Cytochemistry tests stain cells with chemical dyes that specifically react to certain kinds of leukemia cells. The different colors of the stains help the provider determine what types of cancer cells may be present, for example, AML cells will present differently from ALL cells.





Imaging tests that can help diagnose AML include x-rays, Computed Tomography (CT) scans, and magnetic resonance imaging scans (MRI's). These all create pictures from inside the body. Leukemia doesn't often form tumors, so imaging tests aren't always the most helpful. But when imaging tests are done in people with AML, it is most often to identify infections or other problems from the disease, and not specifically leukemia itself.

Etiology and pathophysiology of AML

Etiology and risk factors of AML

Like many kinds of cancers, the etiology for most cases of AML is unclear, and currently there is no known major cause of AML. However, there are multiple risk factors that are associated with AML. Generally, known risk factors account for only a small number of observed cases. These risk factors are explained and listed below.

Smoking is the only proven lifestyle-related risk factor for AML. It is known that smoking is linked to multiple types of cancer, specifically lung, mouth, throat and larynx cancers, but few people realize that smoking affects cells that don’t come into direct contact with tobacco. The tobacco that is absorbed by the lungs can spread into the bloodstream to many parts and cells of the body.

Genetic disorders and constitutional genetic defects are important risk factors associated with AML. For example, children with Down syndrome have a 10-fold to 20-fold increased likelihood of developing acute leukemia.

Certain chemical exposures increases the risk of developing AML. Long-term exposure to high levels of benzene, a solvent used in oil and gasoline-related industries, rubber industries, and chemical plants.

Certain chemotherapy drugs can also increase the risk of developing AML. Many patients are diagnosed with secondary AML, which is often developed after receiving chemotherapy for separate cancers different from AML.

Radiation exposure in high doses, such as being exposed to nuclear reactor accidents or atomic bombs increases the risk of developing cancer. Radiation treatment for cancer has also been linked to an increased risk in developing AML.

Certain blood disorders and myelodysplastic syndrome (MDS) are also linked to the development of AML. The blood disorders include chronic myeloproliferative disorders such as polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. Sometimes treatment of these disoders include radiation or chemotherapy, which further increases the risk of developing AML. Patients with MDS have low blood cell counts and abnormal cells in the blood and bone marrow, which can evolve overtime into AML.

Family history and having a close relative, such as a parent or sibling with AML increases your risk of developing AML. However, most cases of AML are not thought to have a strong genetic link.

Older age is considered to be more common in diagnoses of AML, although AML can even be diagnosed in childhood.

Male gender has been found to be more of a risk factor than female gender, even though the cause of this is unclear.

Disease progression and morbidity of AML

The word “acute” in acute myeloid leukemia denotes to the disease’s rapid progression. As discussed in the first blog post, myeloid leukemia involved the myeloid cells in white blood cells located in the bone marrow. When these cells are abnormal and fail to develop into proper mature white blood cells, patients’ immune systems are incredibly compromised, and regular colds or preventable illnesses become serious fast. Pneumonias can be fatal in patients with AML.

Sources

1. Deschler, B., & Lubbert, M. (2006, October 1). Acute myeloid leukemia: Epidemiology and etiology. Retrieved from http://onlinelibrary.wiley.com/doi/10.1002/cncr.22233/full

2. American Cancer Society. (2014, December 1). What are the risk factors for acute myeloid leukemia?

Epidemiology of AML in the US

Now that we have a foundational understanding of what Acute Myeloid Leukemia is, this week we will analyze the frequency and distribution of AML and learn about the specific populations that the disease effects. Many studies have been done and articles written on AML, but in the last five years, a few resources that had overlapping statistics seemed to be most reliable.

By learning about the epidemiology of the disease, we can educate more people about its prevalence and raise awareness, so that treatment options can be discussed as early as possible. Knowing which populations the disease is most prevalent in can also give certain people a good idea of who to look out for in regards to AML.

What is the distribution in the US?

The American Cancer Society’s estimates for leukemia in the US in 2014 as follows:

• About 52,380 new cases of leukemia (all kinds) and 24,090 deaths from leukemia (all kinds)
• About 18,860 new cases of acute myeloid leukemia. Most in adults

Are certain parts of the population more affected than others?

Acute myeloid leukemia is generally a disease of older people and is uncommon before the age of 45. The average age of a patient with AML is about 67 years. Around 50 children (0-14 years) are diagnosed with AML each year.

AML is slightly more common among men than women, but the average lifetime risk in both sexes is less than ½ of 1%.

An estimated 327,520 people in the US are either living with, or are in remission from, leukemia.

Total estimated number of new acute myeloid leukemia cases in the United States for 2014 is a total of 18,860; 11,530 Male cases and 7,330 Female cases

What is the mortality and morbidity from this disease?

According to the American Cancer Society estimates, the total estimated number of deaths from acute myeloid leukemia is10,460. This is made up by 6,010 Male cases and 4,450 Female cases.

When it comes to AML its mortality outlook, generally the younger you are, the more likely your treatment will go well. Of all adults diagnosed with AML, on average around 25% will live for at least 5 years. More than half of people under 45 years old will live for at least 5 years, while around 12 out of 100 people over the age of 65 years will live for more than 5 years.

There are some prognostic factors for AML listed below that has been shown to be harder to treat:

• You are older (>60 years)
• Your white blood cell count is very high when diagnosed
• Your AML developed because you had treatment for another cancer
• You have particular genetic changes (mutations) in leukemia cells
• It takes more than 2 cycles of chemotherapy to get leukemia under control

Cancer research UK. (n.d.). Statistics and outlook for acute myeloid leukaemia. Retrieved from http://www.cancerresearchuk.org/about-cancer/type/aml/treatment/statistics-and-outlook-for-acute-myeloid-leukaemia

American Cancer Society. (n.d.). What are the key statistics about acute myeloid leukemia? Retrieved from http://www.cancer.org/cancer/leukemia-acutemyeloidaml/detailedguide/leukemia-acute-myeloid-myelogenous-key-statistics

Acute myeloid leukaemia (AML). (n.d.). Retrieved from http://www.leukaemia.org.au/blood-cancers/leukaemias/acute-myeloid-leukaemia-aml

Defining Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a type of cancer that affects the blood and the bone marrow. If not treated promptly, this kind of cancer can worsen quickly.

In a healthy person, bone marrow creates blood stem cells that become mature blood cells overtime. Below is a helpful chart that shows the development of stem cells into mature blood cells. 

In individuals with AML, their myeloid cells (or myeloblasts above) become abnormal, and do not mature into healthy white blood cells. AML is characterized specifically by the rapid growth of these abnormal white blood cells. These cancer cells crowd in the bone marrow, which interfere with the production of normal red blood cells, as there is less room for healthy white blood cells, red blood cells, and platelets (as you can see in the image below).  

Because of this abnormalities in the blood cells, consequences arise in patients with AML that make them susceptible to infection, anemia, or easy bleeding occurrences. The leukemia cells can also spread outside the blood to other parts of the body, including the central nervous system, skin, and gums, causing even more complications that may be discussed in further posts.