Chronic Lymphocytic Leukemia (CLL)

Chronic Lymphocytic Leukemia (CLL) is a blood cancer type in which the bone marrow makes too many lymphocytes (a kind of white blood cell). It mostly affects men above 55 years of age. Though the disease is rarely curable, but patients can live for many years through effective treatment measures.

Cause of CLL

As observed in most cancers, there is no certain cause of chronic lymphocytic leukemia. It is suspected to be an inherited disorder as rare instances of family history of CLL have been reported.

CLL is found to be extremely rare in Asian natives and higher among whites than blacks.

Signs and symptoms of CLL

Usually patients with CLL have no symptoms. About 25-50% of patients are asymptomatic at time of diagnosis. The disease is mostly discovered incidentally after a blood cell count is done for some other reason.

It is advisable not to ignore the below symptoms, as these may be signs of CLL:

  • Swollen lymph nodes in your neck, armpits, stomach, or groin
  • Shortness of breath, extreme fatigue
  • Loss of appetite and weight
  • Pain or fullness in stomach
  • Excessive sweating during nights longer than one month
  • Fever longer than two weeks and infections
  • Anemia or thrombocytopenia
  • Progressive or symptomatic enlargement of the spleen
  • Progressive lymphocytosis (increase in lymphocytes count in blood)

Staging of CLL

As per the Rai-Sawitsky staging system CLL patients are categorized as below:

  • Low risk (stage 0) – Lymphocytosis in the blood and marrow only
  • Intermediate risk (stages I and II) – Lymphocytosis with enlarged nodes in any site or splenomegaly (spleen enlargement) or hepatomegaly (enlarged liver)
  • High risk (stages III and IV) – Lymphocytosis with disease-related anemia (hemoglobin < 11 g/dL) or thrombocytopenia (platelets < 100 x 10 9/L)

Aggressive forms of CLL

Prolymphocytic Leukemia (PLL) and Hairy Cell Leukemia (HCL) are two types of aggressive chronic B-cell leukemia. B-cells are a type of lymphocyte that makes antibodies for the immune system.

Prolymphocytic Leukemia (PLL) involves presence of large number of immature lymphocytes in the blood. It may occur on its own, along with CLL, or CLL may transform into PLL.  PLL is more aggressive than CLL.

Hairy Cell Leukemia (HCL) is a slow-growing form of CLL. It is known as hairy cell because the abnormal lymphocytes have hair-like projections, which multiply in the bone marrow, blood, and spleen. These abnormal lymphocytes fail to fight diseases and infection. Eventually, these overgrow in number than the healthy cells.

Investigations for CLL

  • CBC with peripheral smear
  • Bone marrow aspiration and biopsy with flow cytometry (not required in all cases of CLL)
  • Ultrasound whole abdomen
  • Chromosomal test – Additional molecular testing that may help predict prognosis or clinical course
  • Lymph node biopsy – If lymph nodes enlarge rapidly, the biopsy is done to assess the possibility of change into a high-grade lymphoma.

Management of CLL

Early stages of CLL are not treated as the treatment (chemotherapy) has failed to show benefit. The treatment starts only when your doctor notices rapid progression of disease such as increase in lymphocytes count, decrease in RBCs count, or increase in lymph node swelling. The five-year survival rate of CLL is 75%.

The CLL treatment involves:

Chemotherapy: Combination regimens of chemotherapy have shown improved response rates

Bone Marrow Transplant: Allogenic bone marrow transplant, in which matching donor is required, is the only known curative therapy for CLL.