Blood cancers are characterized by abnormal and excessive proliferation of blood cells

These diseases are clinically and biologically highly heterogeneous and are subdivided into two main groups according to whether they originate from lymphoid or myeloid tumor cells.

Among these two categories, the leukemias are classified in acute or chronic, refering to the forms of the disease and behavior of the cancer:

• Chronic :slow evolution of already differentiated mature cells,
  
  

• Acute: fairly rapid clinical evolution, associated with the proliferation of young cells blocked at an early stage of their differentiation.

Blood cancers are characterized by relative simple genetic anomalies, which analysis is facilitated by an easy access to the diseased cells, i.e. bone marrow and blood sampling.

Blood cancer diagnosis is based on:

• Marrow and blood microscopic analysis,
  
  

• Chromosomal study (cytogenetics),
  
  

• Identification of disease-specific rearranged genes (molecular diagnostics),
  
  

• Characterization of cell surface marker proteins (flow cytometry).
  
  

Available therapeutic approaches widely differ according to any given type of blood cancer:

• Chemotherapy, using chemical drugs to kill cancerous cells,
  
  

• Bone marrow grafts, following intensive chemotherapy and radiation treatment, allowing normal blood system recovery and facilitating the removal of residual cancerous cells thanks to the grafted white blood cells,
  
  

• Targeted therapies:
  
  

  • All-transretinoic acid (ATRA) derivatives, for acute promyelocytic leukemia characterized by the presence of the PML-RARa translocation,
    
    

  • Imatinib (Glivec®), dasatinib (Sprycel®) or nilotinib (Tasigna®) for the treatment of chronic myeloid leukemia.
    
    

In the last decades, leukemia and myeloma patients care significantly advanced and, in turn, helped improving prognosis of some diseases. This advance would not have been possible without the contribution of basic science efforts, new targeted drugs development and better diagnosis.

For example, the treatment of Chronic Myeloid Leukemia (CML) has been revolutionized by the discovery of tyrosine kinase inhibitors, specifically targeting leukemic cells carrying a genetic mutation: the BCR-ABL Mbcr translocation. The quantification of this translocation has progressively become indispensable for evaluating response to treatment, and then monitoring patients over time.