Chronic Myeloid Leukemia: Recognizing Early Symptoms and Key Indicators

Chronic Myeloid Leukemia (CML) often begins with subtle, nonspecific symptoms that can easily be mistaken for common fatigue or stress. One of the most frequently reported early signs is persistent fatigue, which occurs due to the bone marrow's reduced ability to produce healthy blood cells. As abnormal white blood cells accumulate, normal red blood cell production declines, leading to anemia and a general sense of weakness and exhaustion.

Abdominal Discomfort and Enlarged Spleen

A hallmark feature of CML is splenomegaly, or an enlarged spleen, which typically causes discomfort or a feeling of fullness in the upper left abdomen. Because the spleen sits near the stomach, its enlargement can physically compress the stomach, reducing its capacity. This leads to early satiety—feeling full after eating only small amounts of food—a symptom many patients report before diagnosis.

Digestive Changes and Appetite Loss

Loss of appetite (anorexia) is another common complaint among individuals with CML. The pressure from the swollen spleen not only affects gastric volume but may also interfere with normal digestive function. Combined with fatigue, this can result in unintended weight loss and a noticeable decline in overall energy levels.

Systemic Symptoms Resembling Infection

In addition to abdominal and digestive issues, CML can trigger systemic symptoms such as night sweats, low-grade fever, and unexplained weight loss. These are often referred to as "B symptoms" in oncology and suggest increased metabolic activity due to rapid cancer cell proliferation. Patients may wake up drenched in sweat or feel constantly run down, even without physical exertion.

Why Early Detection Matters

Because these symptoms mimic those of more common conditions—like viral infections, chronic stress, or gastrointestinal disorders—CML can go undiagnosed for months. However, when fatigue is accompanied by left-sided abdominal discomfort and confirmed splenomegaly on physical exam, healthcare providers should consider CML as a potential cause.

Differential Diagnosis and Confirmatory Testing

It's important to note that an enlarged spleen and abnormal blood counts aren't exclusive to CML. Conditions such as liver cirrhosis, portal hypertension, and hypersplenism can present similarly. Therefore, a thorough evaluation—including a complete blood count (CBC), peripheral blood smear, and bone marrow biopsy—is essential for accurate diagnosis.

The presence of the Philadelphia chromosome or the BCR-ABL1 fusion gene, detectable through molecular testing, confirms the diagnosis of CML. Early identification allows for timely initiation of targeted therapies like tyrosine kinase inhibitors (TKIs), significantly improving long-term outcomes.