Adult Leukemia

Rishal Sood and Dr. Lopamudra Das Roy

Published 2021

Introduction:

Adult Leukemia is caused by an abnormal differentiation of myeloid cells resulting in a high level of immature malignant cells and fewer differentiated red blood cells, platelets and white blood cells. This disease typically occurs in people ages 60+, but can occur to anyone of any age. (1)

Causes and Risk Factors:

There are a few risk factors involved in this disease. For example, genetic abnormalities in preliminary myelodysplastic syndromes (MDS), like greater than or equal to 20% bone marrow blasts, can lead to a transformation into AML. In addition, mutation in genes or clonal evolution can cause this transformation. These risk factors can also be used to detect the cancer early on and implement the necessary care. In a study published on the PubMed database, a few more factors were listed. Data shows that both genetic factors, like the ones mentioned previously, and environmental factors, like high exposure to radiation, can cause AML. And while extensive research has not been done into parental drug/alcohol consumption, it is listed as a potential risk factor and cause. In addition, males are more likely to contract the disease. Smoking has proven to be a main contributor of the risk factors of AML. Also, exposure to chemicals, genetic syndromes, and family history are all risk factors. (2)(3)(4)

Symptoms:

AML has a numerous amount of symptoms, which can help in early detection. Some are weight loss, fatigue, fever, night sweats, and loss of appetite. These symptoms however are more likely to be caused by something other than leukemia, which is something to keep in mind. A more internal symptom is a lower level of blood cells. To talk more about cells and leukemia, when a shortage of red blood cells occurs, it can cause fatigue, weakness, coldness, dizzy/lightheadedness, headaches, pale skin, and shortness of breath. Similarly, with a shortage of white blood cells, repeated infection and fever, bruises, excessive bleeding, frequent nosebleeds, bleeding gums, and heavy menstrual bleeding in women. In terms of a higher level of leukemia cells, one can experience headache, weakness on one side of the body, slurred speech, confusion, and sleepiness. In addition to all of these symptoms, one can experience bleeding and clotting, bone/joint pain, swelling in the abdomen, seizures, vomiting, balance problems, blurred vision, enlarged lymph nodes, gum swelling, and lumps on the skin. (5)

Screening:

For AML, no screening tests have been shown to find the cancer early. AML, however, develops quickly and shows symptoms quickly, so the best way to identify if a person has AML is to report potential symptoms of the disease right away to a doctor. Once AML has been identified, you then figure out what type of AML you have. In most cancers, to determine the type/stage of cancer, you look at the size of the tumor. However, AML is spread through the bone marrow, so this cancer is not like others. To determine the exact diagnosis, doctors will look at the subtype of AML, patient’s age, and other lab results. The AML subtypes are numerous, ranging from translocations between chromosomes to mutations. (6)

Treatment:

The main treatment for most types of AML is chemotherapy, sometimes along with a targeted therapy drug. This might be followed by a stem cell transplant. Other drugs (besides standard chemotherapy drugs) may be used to treat people with acute promyelocytic leukemia (APL). Surgery and radiation therapy are not major treatments for AML, but they may be used in special circumstances. However, the most effective one to date is allogeneic hematopoietic stem cell transplantation (allo-SCT). It is a therapeutic method with the most potent anti-leukemic activity. This said activity is mediated by the graft versus leukemia effect. This effect attacks any remaining malignant cells in the body. However, despite this method being the most effective, there are many instances of relapse after the treatment has concluded. Therefore, some ways to detect a relapse have been made. Examples are minimal residual disease and chimerism status. These methods should be implemented directly after allo-SCT. (7) In addition, not smoking or quitting smoking and avoiding benzene can prevent AML. Some other methods are chemotherapy, targeted therapy drugs, and radiation therapy. These treatments all apply to different subtypes of AML. (8) A hematologist or a medical oncologist, and a variety of other specialists, will provide or assign these treatments to you and actually take care of you. In order to get treatment, you and your doctor will have to consider a few factors: age and overall health, type of AML you have, the likelihood of the treatment working, and your feelings about side effects from the treatment. You can also consider alternative or complementary methods, choose when to get help and to continue or stop treatment, and lastly partake in a clinical trial if no other options are available. (9)

Statistics:

In terms of statistics and numbers, in 2020, there were about 60,530 new cases of leukemia (all kinds) and 23,100 deaths from leukemia (all kinds), and about 19,940 new cases of acute myeloid leukemia (AML). Most of these numbers were in adults. There were about 11,180 deaths from AML, and almost all were in adults. Some predictions for the estimated leukemia cases of 2021 are reaching numbers of 61,090, whilst predicted death numbers are around 23,660. Both of these numbers are representative of just the United States. In terms of global numbers, AML was 20% of 300,000 cases of leukemia. AML itself is the most common type of leukemia in adults; however it only accounts for 1% of all cancers. The average age of diagnosis is 68 years old, but there are instances of AML in children. Statistics have also shown that when found earlier on or as early as possible, patients were able to receive proper treatment and have a greater chance of survival in all areas of the world. Socio-economic situation has also proven to be a factor when trying to treat patients, as some areas of the world aren’t as financially stable as others, thus preventing proper treatment with the most up-to-date equipment. (10)

Developed v Developing Countries:

Based on data from 2020, 31% of people who have contracted leukemia and are from a developed country survive for more than 5 years. Around half of that, or 15%, is the percent of survival for over 5 years in developing countries. (11) In terms of ethnicity, AML is much more prevalent in European countries and people of European descent. On the contrary, people of Asian descent or from an Asian country are less susceptible to contracting AML. In terms of a stigma, there are some reluctance to seek up to date medical treatment due to religious beliefs and just a fear of modern medicine. (12)

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References