In Costa Rica, an estimated 372 new cases of leukemia are diagnosed each year. Of that number, between 15 and 20% are patients with chronic myeloid leukemia (CML), which requires specialized care due to its silent progression. It is estimated that about half of CML patients do not present symptoms until the time of diagnosis, which is usually identified during routine blood tests. In the remaining 50%, symptoms usually include abdominal discomfort due to an enlarged spleen, asthenia, and fatigue, among others.
CML is a cancer that originates when changes in bone marrow cells cause uncontrolled growth, allowing the production of too many white blood cells. (Bone marrow is the spongy tissue inside bones where blood cells are produced.)
Why are there changes in bone marrow cells?
Humans have 23 pairs of chromosomes. In people with CML, the chromosomes swap sections with each other. A section of chromosome 9 switches places with a section of chromosome 22. This creates a shorter chromosome 22 and a longer chromosome 9 than normal. The short chromosome 22 is called the Philadelphia (Ph) chromosome. It is named after the city where it was discovered. The Philadelphia chromosome is present in the blood cells of 90% of people with chronic myeloid leukemia.
In addition, genes on chromosome 9 combine with those on chromosome 22 to create a new gene called BCR-ABL. The BCR-ABL gene tells blood cells to produce an excess amount of a protein called tyrosine kinase. Tyrosine kinase promotes cancer by allowing certain blood cells to grow out of control.1 It is the chromosomes involved that give rise to the commemoration of CML Day on September 22 (September 22).
In Costa Rica, the Association of Patients with Leukemia and Myeloma (AGALEMO) represents the voice of people diagnosed with oncohematological diseases seeking answers and care for their illness.
Silvia DÃaz, its president and a patient for over 20 years, stated:
Our goal is to support patients and families throughout the process they face. We believe in patient education to empower them so they can play a more active role in their illness and the decisions surrounding it. Diagnosis often brings with it many questions, which we can support and guide them later if needed.
One of the most significant challenges of diagnosis is that this type of leukemia generally causes no symptoms and is usually detected during a routine blood test, which is recommended once a year for healthy people. In the few cases where symptoms do occur, they may include:
Bone pain
Easy bleeding
Feeling full after eating a small amount of food
Fatigue
Unintentional weight loss
Loss of appetite
Pain or pressure under the ribs on the left side
Excessive sweating during sleep
Blurred vision due to bleeding in the back of the eye
To make a definitive diagnosis, once a blood test reveals an abnormality, the hematologist performs a bone marrow study, which includes a genetic test to confirm the presence of the Ph chromosome.
Path after a diagnosis of chronic myeloid leukemia
Once the diagnosis is confirmed, it is important to discuss treatment options with your doctor. These options will depend on the stage of the disease (chronic, accelerated, or blastic) and other factors such as age and prognosis.
In recent decades, the management of CML has improved significantly, allowing CML patients to enjoy a life expectancy similar to that of the general population. A significant scientific contribution is targeted therapies that block the activity of specific proteins related to leukemia cell proliferation. These new therapies provide a new approach for patients who have an inadequate response or poor tolerability after treatment with two tyrosine kinase inhibitors (TKIs).
