What Makes AML Different? Decoding the Leukemia Alphabet Soup
Leukemia has many different forms. Understanding the acronyms is the first step to understanding the unique challenges of AML.
Understanding the Differences
Lifeblood. It’s not a medical term. But it may come to mind when facing the complex challenges of leukemia, a disease that freshly and starkly reminds us how essential [healthy] blood is to life.
The various kinds of leukemia are made up of a basket of acronyms that are impersonal, but their differences are significant. The letters that makeup these acronyms are a guide to making sense of the many forms of leukemia, a cancer of the blood that causes immature blood cells to malfunction, crowding out healthy cells in bone marrow and keeping them from doing important jobs like carrying oxygen through the body, fighting infections and clotting to stop bleeding.
The experiences, treatments and outcomes associated with leukemia vary greatly depending on the type. Decoding and understanding the differences can help you navigate what comes next. For example, chronic leukemia grows slowly and gets worse over time, while acute leukemia is more aggressive and progresses quickly in the body, especially if left untreated.
The four main types of leukemia, often referred to by their initials, are:
Acute Myeloid Leukemia (AML): The Pervasive Aggressor
This type of leukemia is caused by abnormality in an early stage of myeloid cells in the bone marrow. Normal bone marrow makes red blood cells, platelets and different kinds of white blood cells. Generally a disease impacting older people, the average age of an AML patient is 68 at the time of diagnosis. Because it’s so aggressive, treatment for AML is considered harder on the body, especially for older patients with other health challenges.
Chronic Myeloid Leukemia (CML): The Persistent Enemy
Similar to AML, this type of leukemia originates in the early stage of myeloid cells in the bone marrow. However, it’s slow growing and can take a long time before causing noticeable problems. It can also mutate into a hard-to-treat, fast-growing acute leukemia, making the monitoring of this blood cancer very important. The risk of getting CML increases with age.
Acute Lymphocytic Leukemia (ALL): The Early Attacker
The risk of developing ALL is highest in children younger than 5 years old. It starts in the early form of white blood cells called lymphocytes in the bone marrow. While most cases of ALL occur in children (six out of 10), most deaths from ALL occur in adults.
Chronic Lymphocytic Leukemia (CLL): The Slow, Creeping Invader
This form of leukemia also originates in the lymphocytes (early white blood cells) in the bone marrow. The chronic nature of CLL means it’s less aggressive, but it still requires treatment to stop the progress and correct the malfunctioning lymphocytes. CLL is also most common in older adults.
Why the Letters Matter
When asked about acute myeloid leukemia (AML), doctors, researchers and patient advocates almost always answer with the same word: devastating.
“Acute myeloid leukemia progresses rapidly with high intensity, and because it is a disease of the bone marrow, it interferes with the production of normal blood cells that are essential for various normal functions,” explains Jalaja Potluri, M.D., medical director, oncology development, AbbVie. Potluri has dedicated her career to pursuing a better understanding of AML and how it overtakes the body. She is working on advancing treatment options available for patients, especially those whose bodies or immune systems may not be able to bounce back from the significant side effects of the standard of care regimen.
“Based on their age, some [AML] patients have difficulty tolerating the regular treatment, which includes intensive chemotherapy and later a bone marrow transplant," Potluri says. “This cancer causes problems throughout the body, resulting in organ impairment, and because the biology of AML is so aggressive, these problems mount quickly affecting all aspects of living a normal life.”
For younger, healthier patients, the chances of getting better through the current standard of care rise significantly. “Earlier in my career when I was a practicing hematologist, I treated a patient who was diagnosed with AML just two months away from his 21st birthday. He had a number of complications as a result of the AML and his particular cancer was very difficult to treat. But he pulled through given his young age, and not only did he celebrate his 21st birthday, he remained my patient for the next 10 years.”
But for the majority of patients diagnosed with AML, the standard of care treatment – strong chemotherapy and a bone marrow transplant – is not an option. This is what makes AML so devastating compared to other forms of leukemia. It is an arduous challenge for scientists who have made progress in dosing chemotherapy and found ways to make bone marrow transplants safer for patients. Still, the treatment for AML has not changed significantly in the past two decades, and health care professionals have few answers for patients who can’t tolerate current treatment options. But they aren’t giving up.
Paving the Way for New Answers
Given the difficulty of treating AML, clinical research plays a crucial role for patients in need of alternative options. Potluri leads design, development and analysis for AML clinical trials at AbbVie. She’s hopeful about the work, especially for older patients who have the largest need for new medicines, and she encourages doctors to consider clinical trials for their patients. “We now have a deeper understanding of the complex biology of this cancer, and we’re testing more targeted agents that could potentially be combined with existing treatments for maximizing the results.”
What keeps Potluri and her team going as they explore these possibilities? “We know we’re getting closer to the day when doctors can say, ‘I have something different for you.’”