Chronic Leukemias S. Sami Kartı, MD, Prof.

What are the Leukemias?  Cancers of leukocytes or their precursors  Accumulation or proliferation of leukocytes in the bone marrow  May or may not have increased leukocyte count in the peripheral blood

Types of Leukemia Acute – no maturation beyond blast Chronic – maturation beyond blast Lymphocytic - T or B lineage ALLCLL Myeloid – (granulocytes, monocytes, erythrocytes, platelets) AMLCML

The peripheral blood white cell count in leukemia

Chronic lymphocytic leukemia

Introduction  Is characterised by the accumulation of nonproliferating mature-appearing lymphocytes in the blood, marrow, lymph nodes, and spleen  In most cases, the cells are monoclonal B lymphocytes that are CD5+  T cell CLL can occur rarely

Introduction  Is the most common form of leukemia in North America and Europe  Typically occurs in older patients, with the highest incidence being in those aged 50 to 55 years  Affects men twice as often as women

Etiology  The cause of CLL is unknown  Radiation is not a cause  Genetic factors have been postulated to play a role in high incidence of CLL in some families

Etiology  Cytogenetics clonal chromosomal abnormalities are detected in approximately 50% of CLL patients the most common clonal abnormalities are:  trisomy 12  structural abnormalities of chromosomes 13, 14 and 11  Oncogenes in most cases of CLL is overexpressed the proto-oncogene c-fgr 9a member of the src gene family of tyrosine kinases

CLL - Pathology  Genetic change in B-cell clone  Slow proliferation exceeds apoptosis  Gradual accumulation of neoplastic B- lymphocytes

CLL - pathology  Neoplastic B-lymphocyte accumulation blood lymphocytosis marrow failure lymphadenopathy (lymphocytic lymphoma) splenomegaly

lymphocytes

‘smudge’ cells

Clinical findings  Approximately 40% of CLL patients are asymptomatic at diagnosis  In symptomatic cases the most common complaint is fatigue  Less often the initial complaint are enlarged nodes or the development of an infection (bacterial)

Clinical findings  Most symptomatic patients have enlarged lymph nodes (more commonly cervical and supraclavicular) and splenomegaly  The lymph nodes are nontender  Hepatomegaly

Clinical findings  Less common manifestation are infiltration of tonsils, mesenteric or retroperitoneal lymphadenopathy, and skin infiltration  Patients rarely present with features of anemia, and bruising or bleeding

Laboratory findings  The blood lymphocyte count above 5,000/ µ L  In most patients the leukemic cells have the morphologic appearance of normal small lymphocytes  In the blood smears are commonly seen ruptured lymphocytes (“basket” or “smudge” or “smear” cells)

Laboratory findings  Careful examination of the blood smear can usually differentiate CLL, and the diagnosis can be confirmed by immunophenotyping  Clonal expansion of B (99%) or T(1%) lymphocyte In B-cell CLL clonality is confirmed by  the expression of either  or light chains on the cell surface membrane  the presence of unique idiotypic specificities on the immunoglobulins produced by CLL cells  by immunoglobulin gene rearrangements  typical B-cell CLL are unique in being CD19+ and CD5+

Laboratory findings  Hypogammaglobulinemia or agammaglobulinemia are often observed  % of patients with CLL develop autoimmune hemolytic anemia, with a positive direct Coombs’ test  The marrow aspirates shows greater than 30% of the nucleated cells as being lymphoid

The diagnostic criteria for CLL 1) A peripheral blood lymphocyte count of greater than 5000/µL 2) The cell should have the presence of B cell-specific differentiation antigens (CD19, CD20) and be CD5(+) 3) A bone marrow aspirates showing greater than 30% lymphocytes

Differential diagnosis  Infectious causes bacterial (tuberculosis) viral (mononucleosis)  Malignant causes  leukemic phase of non-Hodgkin lymphomas  Hairy-cell leukemia  Waldenstrom macroglobulinemia  large granular lymphocytic leukemia

Investigations  Pretreatment studies of patients with CLL should include examination of: complete blood count peripheral blood smear reticulocyte count Coomb’s test renal and liver function tests serum protein electrophoresis immunoglobulin levels plasma 2 microglobulin level  If available immunophenotyping should be carried out to confirm the diagnosis  Bone marrow biopsy and cytogenetic analysis is not routinely performed in CLL

Staging  Rai Classification for CLL 0 - lymphocytosis (>5,000/µL) I - lymphocytosis + lymphadenopathy II - lymphocytosis + splenomegaly +/- lymphadenopathy III - lymphocytosis + anemia (Hb <11g%) +/- lymphadenopathy or splenomegaly IV - lymphocytosis + thrombocytophenia (Plt <100,000/µL) +/- anemia +/-lymphadenopathy +/- splenomegaly

Staging  Binet Classification for CLL A. 10g/dL, Plt > 100,000/µL B. > 3 involved areas, Hb > 10g/dL, Plt > 100,000/µL C. - any number of involved areas, Hb < 10g/dL, Plt < 100,000/µL

Prognosis  Rai classification stagemedian survival (years) 0>10 I> 8 II 6 III 2 IV< 2  Binet classification stagemedian survival (years) A> 10 B 7 C 2

Markers of poor prognosis in CLL  Advanced Rai or Binet stage  Peripheral lymphocyte doubling time <12 months  Diffuse marrow histology  Increased number of prolymphocytes or cleaved cells  Poor response to chemotherapy  High 2- microglobulin level  Abnormal karyotyping

Treatment  Treatment is reserved for patients with low- or intermediate risk disease who are symptomatic or have progressive disease (increasing organomegaly or lymphocyte doubling time of less than 12 months) and patients with high -risk disease Alkylating agents (chlorambucil, cyclophosphamide) Nucleoside analogs (cladribine, fludarabine) Biological response modifiers Monoclonal antibodies Bone marrow transplantation Systemic complications requiring therapy  antibiotics  immunoglobulin  steroids  blood products

Chronic Myeloid Leukemia

Definition  A neoplasm of hemopoietic stem cells caused by the ‘Philadelphia’ chromosome t(9;22)  A three-phase disease chronic accelerated blastic

CML - pathology  Chronic Phase Accumulation of myeloid cells  bone marrow  peripheral blood  spleen and liver  elsewhere  Accelerated Phase Further genetic changes in the stem cell leading eventually to acute transformation (ie acute leukemia) and death

“The findings suggest a causal relationship between the chromosome abnormality observed and chronic granulocytic leukemia.” 1960 Peter Nowell

The Philadelphia Chromosome

Janet Rowley 1973

The bcr/abl fusion protein  Uncontrolled kinase activity 1.Deregulated cellular proliferation 2.Decreased adherence of leukemia cells to the bone marrow stroma 3.Leukemic cells are protected from normal programmed cell death (apoptosis)

Clinical features  30 percent of patient are asymptomatic at the time of diagnosis  Symptoms are gradual in onset  easy fatigability, malaise, anorexia, abdominal discomfort, weight loss, excessive sweating  Less frequent symptoms:  Night sweats, heat intolerance- mimicking hyperthyroidism, gouty arthitis, symptoms of leukostasis (tinnitus, stupor), splenic infarction (left upper-quadrant and left shoulder pain), urticaria (result of histamine release)

Clinical features  Physical signs:  Pallor  Splenomegaly  Sternal pain  Hepatomegaly

basophil blast neutrophils and precursors

Laboratory features  The hemoglobin decreased  Nucleated red cells in blood film  The leukocyte count above 25,000/μl (often above 100,000/μl), granulocytes at all stages of development  Hypersegmentated neutrophils  The basophiles increased  The platelet count is normal or increased  Neutrophils alkaline phosphatase activity is low or absent (90%)

Laboratory features  The marrow is hypercellular (granulocytic hyperplasia)  Reticulin fibrosis  Hyperuricemia and hyperuricosuria  Serum vitamin B12-binding proteine and serum vitamin B12 levels are increased  Pseudohyperkalemia, and spurious hypoxemia and hypoglycemia  Cytogenetic test- presence of the Ph chromosome  Molecular test – presence of the BCR-ABL fusion gene

Differential diagnosis  Polycythemia vera  Myelofibrosis  Essential thrombocytemia  Extreme reactive leukocytosis

CML - diagnosis  Blood count  Genetic analysis (RT-PCR or FISH)  Bone marrow aspiration and biopsy

CML - accelerated phase  Was inevitable – now prevented by imatinib  1/3 ALL; 2/3 AML  Clinical features sweats, weight loss, bone pain, enlarging spleen bone marrow failure, and blasts in the blood  Onset and course rapid, outcome fatal.

CML-principles of treatment  Imatinib mesylate to achieve a ‘Major Molecular Remission’ (by Q- RT-PCR)  Dasatinib  Nilotinib  Allogeneic transplantation  Hydroxyurea

O'Brien, S. G. et. al. N Engl J Med 2003;348: Kaplan-Meier Estimate of the Time to a Major Cytogenetic Response