leucèmies

Leucémies, or leukemias, are a group of cancers that originate in the bone marrow or blood and are characterized by the uncontrolled growth of abnormal white blood cells. They can be acute or chronic and are commonly classified as myeloid or lymphoid, yielding four main subtypes: acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML), and chronic lymphocytic leukemia (CLL).

In most leukemias, a genetic change gives rise to a malignant clone that proliferates and disrupts normal blood cell production. The abnormal cells can accumulate in the bone marrow and spill into the bloodstream, affecting the function of other organs and tissues. The disease spectrum ranges from rapidly progressing forms that require urgent treatment to slower-growing ones that may be monitored over time.

Symptoms typically reflect reduced normal blood cell function and may include fatigue, infections, fever, easy bruising, nosebleeds, pallor, bone or joint pain, and swollen lymph nodes. Diagnosis usually begins with a complete blood count and peripheral blood smear, followed by a bone marrow biopsy. Immunophenotyping and genetic/molecular testing help determine the leukemia subtype and prognostic risk.

Treatment varies by subtype and risk, but often includes induction chemotherapy to achieve remission, followed by consolidation therapy. Targeted therapies are used in certain subtypes, such as tyrosine kinase inhibitors for CML and differentiation therapy for acute promyelocytic leukemia; monoclonal antibodies and immunotherapies, including CAR-T cell therapy, are increasingly employed. Allogeneic stem cell transplantation may be recommended for eligible patients. Prognosis depends on age, subtype, genetic features, and response to therapy, with improvements driven by targeted treatments and transplant strategies.