Chronic Lymphocytic Leukaemia (CLL) is a form of cancer that originates in the white blood cells, specifically lymphocytes. This condition is characterized by the bone marrow producing an excessive number of abnormal lymphocytes. It is generally considered a slow-growing cancer, with many individuals not experiencing symptoms for years after diagnosis. CLL primarily affects older adults, with diagnoses rare in those under 40 years of age.
What is Chronic Lymphocytic Leukaemia?
CLL is a cancer of the B lymphocytes, a type of white blood cell that plays a role in the immune system. These abnormal B cells develop in the bone marrow but do not mature properly, losing their ability to fight infection. Instead, they accumulate in the blood, bone marrow, lymph nodes, and spleen.
This accumulation of abnormal lymphocytes can eventually crowd out healthy blood cells, leading to complications. CLL is termed “chronic” because of its slow progression, often over several years. This distinguishes it from acute leukemias, which progress rapidly and require immediate treatment. CLL is one of the most common types of leukemia in adults.
Identifying CLL and How It’s Diagnosed
Many individuals with CLL do not experience symptoms at diagnosis; the condition is often discovered incidentally during routine blood tests. When symptoms emerge, they can include frequent infections due to a weakened immune system, persistent tiredness, shortness of breath, and pale skin (signs of anemia). Other indicators include easy bruising or bleeding, fever, night sweats, and swollen lymph glands in the neck, armpits, or groin.
Diagnosis typically begins with a complete blood count (CBC), which may reveal an elevated lymphocyte count. If the lymphocyte count is consistently high without another clear cause, further specific tests are performed. Flow cytometry, also known as immunophenotyping, is a definitive test that analyzes lymphocyte surface markers to confirm CLL cells and differentiate them from other blood disorders.
For prognosis and treatment planning, additional tests may be conducted. A bone marrow biopsy assesses CLL cell infiltration. Genetic tests for specific chromosomal abnormalities, and analysis of immunoglobulin heavy chain variable region (IGHV) mutation status, provide insights into the disease’s likely behavior. Staging systems classify the disease’s progression based on factors like enlarged lymph node areas, anemia, or low platelet counts.
Current Treatment Options
For many patients with early-stage, asymptomatic CLL, a “watch and wait” approach, also known as active surveillance, is adopted. This involves regular monitoring without immediate active treatment. Treatment is initiated when the disease progresses or symptoms significantly impact the patient’s quality of life.
When active treatment becomes necessary, targeted therapies are now the primary approach for CLL management, largely replacing traditional chemotherapy. BTK inhibitors, such as ibrutinib, block Bruton’s tyrosine kinase, a protein involved in CLL cell survival and proliferation. BCL-2 inhibitors, such as venetoclax, target the B-cell lymphoma 2 protein, inducing programmed cell death in CLL cells.
Immunotherapy, utilizing monoclonal antibodies such as rituximab, is also part of the treatment landscape, often in combination with other agents. These drugs bind to specific proteins on CLL cells, marking them for destruction by the immune system. While less common, stem cell transplant (SCT) remains an intensive treatment option. SCT is generally reserved for younger patients with high-risk disease or those whose CLL has not responded to other therapies, offering a potential for cure but carrying significant risks.
Life with CLL and Long-Term Outlook
Living with CLL often involves long-term management due to its chronic nature. For many individuals, the prognosis is favorable, and the disease can be managed effectively for many years, sometimes even decades. While CLL is often considered incurable in the traditional sense, advancements in treatment have made it highly treatable, allowing a significant number of patients to maintain a good quality of life.
Ongoing medical monitoring is an important aspect of living with CLL, even during periods of “watch and wait” or after treatment. This includes regular blood tests to track cell counts and disease progression. Managing potential side effects from treatments and addressing complications, such as an increased susceptibility to infections due to a weakened immune system, are ongoing considerations.
Patients with CLL may also experience an increased risk of developing other cancers, including certain skin cancers and other blood-related malignancies. Support groups and patient resources can offer valuable assistance in navigating the emotional and practical aspects of living with a chronic condition. The landscape of CLL therapies continues to evolve rapidly, with ongoing research leading to new and more effective treatment options, further improving the long-term outlook for those affected.