Leukemia-Chronic Lymphocytic Leukemia (CLL)

Chronic Lymphocytic Leukemia (CLL)

Chronic Lymphocytic Leukemia (CLL) is a slow-growing type of blood cancer affecting lymphocytes, a type of white blood cell (WBC) responsible for immune defense. In CLL, abnormal lymphocytes accumulate in the blood, bone marrow, lymph nodes, and other tissues. The condition is called “chronic” because it progresses gradually, and patients may remain asymptomatic for years.

Lymphocytes and their Types

Lymphocytes are a key part of the immune system, and there are three main types:

• B cells (B-lymphocytes): Produce antibodies to fight infections.

• T cells (T-lymphocytes): Destroy infected or cancerous cells and activate B cells.

• Natural Killer (NK) cells: Target viruses and some cancer cells.

These cells are primarily found in:

• Lymph nodes

• Spleen

• Thymus

• Bone marrow

About CLL

In CLL, cancerous lymphocytes accumulate in the bone marrow and interfere with the production of normal blood cells:

• Red blood cells (RBCs): Carry oxygen throughout the body.

• WBCs: Protect the body from infections.

• Platelets: Help in blood clotting.

As a result, patients may experience:

• Anemia: Fatigue due to a lack of RBCs.

• Infections: Reduced immune defense from low WBCs.

• Bleeding or bruising: Due to insufficient platelets.

Types of CLL

CLL is categorized based on which lymphocytes are affected:

1. B-cell CLL:

• Accounts for 95% of CLL cases.

• A rare subtype, B-cell prolymphocytic leukemia (PLL), occurs in 1% of cases.

2. T-cell prolymphocytic leukemia (T-PLL):

• Occurs in 1% of CLL patients.

Statistics

• In India, around 48,419 leukemia cases are reported annually, though specific data for CLL is unavailable.

• In the U.S., approximately 18,740 new cases of CLL are diagnosed each year.

• CLL primarily affects adults over the age of 50, with 90% of cases occurring in people aged 70 and above.

Survival Rate

• Adults (over 20 years): The 5-year survival rate is 88%.

Risk Factors

• Family History: A first-degree relative with CLL or related cancer increases the risk by 2-4 times.

• Age: The majority of CLL cases occur in older adults, particularly over 50 years.

• Gender: Men are more likely to develop CLL.

• Monoclonal B-cell lymphocytosis (MBL): A pre-cancerous condition that can evolve into CLL in rare cases.

Symptoms

CLL symptoms may take years to appear and include:

• Swollen lymph nodes (neck, armpits, groin)

• Feeling of fullness or discomfort in the upper left abdomen (due to an enlarged spleen)

• Persistent fever

• Chills and night sweats

• Unintended weight loss

• Fatigue and weakness

• Easy bruising or bleeding

• Frequent infections

• Difficulty breathing

• Feeling of fullness after eating small amounts

Diagnosis

1. Complete Blood Count (CBC): Detects elevated lymphocytes.

2. Flow Cytometry (Immunophenotyping): Identifies specific markers on cancer cells.

3. Genomic and Molecular Testing: Detects chromosomal abnormalities using FISH (Fluorescence In Situ Hybridization). Common mutations include del(13q), del(17p), and TP53 abnormalities.

4. Bone Marrow Biopsy: Confirms the diagnosis by analyzing bone marrow samples.

5. Imaging Tests: X-rays, CT scans, and ultrasounds help assess the extent of the disease.

Treatment Options

1. Watch and Wait/Active Surveillance:

• For early-stage CLL without symptoms, doctors may monitor the disease with regular blood tests and physical exams.

• Treatment begins only when symptoms appear or blood counts become abnormal.

2. Chemotherapy:

• Uses drugs to kill cancer cells.

• Common chemotherapy drugs for CLL include:

• Bendamustine

• Fludarabine (for younger patients)

• Cyclophosphamide

• Chlorambucil

• Cladribine

• Side effects: Fatigue, nausea, hair loss, infections, and reduced blood counts.

3. Targeted Therapy:

• Focuses on specific proteins, genes, or the tumor environment.

• Monoclonal Antibodies:

• Rituximab (Rituxan)

• Ofatumumab (Arzerra)

• Obinutuzumab (Gazyva)

• Venetoclax (Venclexta)

• Kinase Inhibitors:

• Ibrutinib (Imbruvica)

• Idelalisib (Zydelig)

4. Combination Therapy:

• Combines multiple drugs to enhance effectiveness.

• Common regimens include:

• FCR: Fludarabine, Cyclophosphamide, and Rituximab

• BR: Bendamustine and Rituximab

• Idelalisib + Rituximab: For relapsed CLL

• Obinutuzumab + Chlorambucil: For older adults

5. Bone Marrow/Stem Cell Transplantation:

• Used in high-risk or relapsed cases.

• Involves replacing damaged bone marrow with healthy stem cells from a donor (Allogeneic transplant).

• Autologous transplant (using the patient’s own cells) is rarely used for CLL.

6. Radiation Therapy:

• High-energy radiation is used to shrink swollen lymph nodes or control symptoms.

• Radiation is not a primary treatment for CLL but may be used for palliative care.

Side Effects of Treatment

• Chemotherapy: Fatigue, hair loss, nausea, and increased infection risk.

• Targeted Therapy: Nausea, diarrhea, swelling, and fatigue.

• Stem Cell Transplant: Risk of infections and graft-versus-host disease (GVHD).

• Radiation Therapy: Skin irritation, fatigue, and hair loss at the treatment site.

Follow-Up Care

• Regular Monitoring: Routine blood tests and physical exams are essential to track disease progression.

• Managing Side Effects: Patients may require treatment for infections, anemia, or other complications.

• Psychological Support: Coping with CLL may require mental health support or counseling.

While CLL is a slow-growing cancer, regular monitoring is critical to ensure timely treatment when needed. With advancements in chemotherapy, targeted therapies, and stem cell transplantation, many CLL patients can achieve long-term remission and maintain a good quality of life.

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