Leukemia: Understanding Blood Cancers

What is leukemia?

Leukemias are cancers of the bone marrow stem cells that produce blood cells. Leukemic cells multiply uncontrollably, invading the bone marrow and blood. Acute leukemias (rapid evolution) are distinguished from chronic leukemias (slow evolution), and lymphoid forms from myeloid forms.

The four main types

Acute lymphoblastic leukemia (ALL) is the most common in children with a 90% cure rate. Acute myeloid leukemia (AML) mainly affects adults. Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults in the West. Chronic myeloid leukemia (CML) has been revolutionized by imatinib.

Warning symptoms

Persistent fatigue, pallor, repeated infections, unexplained fever, unusual bruising and bleeding, bone pain, swollen lymph nodes. An abnormal complete blood count (CBC) guides the diagnosis.

Modern treatments

Intensive chemotherapy, bone marrow transplantation, targeted therapies (imatinib for CML, ibrutinib for CLL), and CAR-T cells (genetically modified lymphocytes) have transformed the prognosis of many leukemias. CML, once fatal, now has an almost normal life expectancy thanks to tyrosine kinase inhibitors.