What is CML? A Lesson in Leukemia

Time to get a little technical. It's amazing how quickly you can become in expert in something you knew nothing about in so little time. Just like becoming a member of a club I never wanted to belong to, I was now an accidental student spending most of my time researching something I never thought I would know much about. So, if you are in the mood for a mini deep dive, hop into the milky-white pool with me. 

Leukemia is a cancer of the blood and bone marrow where your blood is made. The DNA of a single cell in your bone marrow mutates and can no longer function properly. This single cell then begins to replicate out of control, like a system stuck in overdrive. These replicated cells, or leukemia cells, all carry mutated DNA with the same coding error. Leukemia cells are abnormal and immature. Fully mature, healthy cells become white blood cells (fight infection), red blood cells (carry oxygen to organs/body) and platelets (clotting). 

Stem cells in the marrow turn into either myeloid cells, one of the three mentioned above, or lymphoid cells, specialized white blood cells. The rapid production of these abnormal, leukemia cells, begin to overcrowd your bone marrow, leaving less and less room for stem cells to develop into healthy cells. As the disease progresses, the abnormal cells spill over from the bone marrow into the blood. When your blood is overcrowded with abnormal white blood cells that do not function, it cannot carry the healthy cells that deliver oxygen to your body, fight infections, and clot when needed. 

​I have CML, or chronic myeloid leukemia. This is one of four types of leukemia and affects roughly 10,000 people per year and accounts for only 15% of all leukemias, making it rarer. CML is caused by a genetic mutation involving a translocation between chromosomes 9 and 22, creating the Philadelphia chromosome. This produces the BCR-ABL1 gene, which encodes a protein that drives uncontrolled cell division in my myeloid cells. 

I am fortunate to have a chronic, or slow growing form of leukemia as opposed to an acute, fast-growing form. 

CML progresses in 3 phases:
Chronic phase – slow-growing, often asymptomatic, and most responsive to treatment. I am also fortunate to still be in the chronic phase.
Accelerated phase – disease progresses, blood counts worsen, and symptoms become more noticeable.
Blast phase – aggressive, resembling acute leukemia, harder to treat, and may require intensive therapy

Common symptoms of CML include:
Fatigue
Night sweats
Weight loss
Fever
An enlarged spleen (felt as a mass under the left side of the ribcage)
Pain or a sense of "fullness" in the belly
Loss of appetite, or feeling full after eating even a small amount of food
Bone pain (caused by leukemia cells spreading from the marrow cavity to the surface of the bone or into the joint)

Leukemia can lead to other symptoms from both disease progression or treatment. There are other symptoms and side effects of modern treatments that can happen. These can either be caused by the leukemia cells crowding out other cells in the marrow and blood, or from the treatment itself:
A shortage of red blood cells (anemia) can lead to:
Feeling very tired
Weakness
Shortness of breath
This is because rbc carry oxygen to the body's and organs and tissues

A shortage of normal white blood cells (leukopenia) increases the risk of infections.
(in leukemia yes, we have too many wbc, but they do not function properly, and we are left short of the ones that actually work)

Shortage of blood platelets
A shortage of blood platelets (thrombocytopenia) can lead to:
Bruising easily
Bleeding
Frequent or severe nosebleeds
Bleeding gums

Unfortunately, 25 years ago, this diagnosis was a fatal sentence, with no treatment that would prevent the phases of this disease from becoming blastic and the abnormal wbc cells eventually taking over, losing the battle. But huge medical strides have been made, and this is the 25th anniversary of a revolutionary treatment that changed cancer treatment forever. The TKI, or Tyrosine kinase inhibitors (TKIs) are the first-line therapy, targeting the BCR-ABL1 protein to control cell growth was developed and changed the landscape of treatment.

Scientists had found a way scrub out the bugs in the system and reset the circuit. It brought people's numbers down, stopped cells from reproducing, making them 'undetectable' and in remission. Other forms of treatment for more advanced stages are chemotherapy and stem cell transplants. 

Even more exciting, now on the horizon is a further development I hope to soon be a part of. I am super fortunate to be able to be considered for a clinical trial at Karmanos Cancer Institute for the latest and greatest treatment. Scemblix is a new targeted therapy different from TKIs. While TKIs work to block proteins from developing, consider this the specialized mechanic with the magical precision tools to target my faulty cells and allow that runaway train to slow down to a halt. 

This is a medication that is typically given to patients who either relapse or have a poor molecular response to the TKIs with a new gene mutation. This drug shows significant success with a deep molecular response with the least side effects. In my trial I will be getting it first as a newly diagnosed patient as opposed to a next option after trial and failure. I spent half of my day on the day I wrote this getting close to a dozen vials of blood drawn, and getting my prescreening, including EKGs and echocardiograms, and filling out a ton of paperwork. 

I should be hearing by the end of this week if I am eligible, and if so, I start on Monday. Wish me luck, I hope to embark on a journey that can be a part of research and a new evolution in the treatment of leukemia. What do they say? Courage is being scared and doing it anyway....do I really have a choice? Yes. I choose yes.