Leukemia is a class of malignant clonal diseases of hematopoietic stem cells. Clonal leukemia cells accumulate in the bone marrow and other hematopoietic tissues because of uncontrolled proliferation, impaired differentiation, impaired apoptosis, and other mechanisms, and infiltrate other nonhematopoietic tissues and organs, while inhibiting normal hematopoietic function. Clinical manifestations include varying degrees of anemia, bleeding, infectious fever, and enlargement of the liver, spleen, lymph nodes, and skeletal pain.
In China, the incidence of leukemia is reported to be the sixth most common among various tumors in all regions. Specifically:
- Acute leukemia is more common than chronic leukemia (about 5.5:1), with acute granulocytic leukemia being the most common (1.62/100,000), followed by acute leukemia (0.39/100,000), slow-onset leukemia (0.36/100,000), and slow-onset leukemia is rare;
- Male prevalence is slightly higher than female (1.81:1);
- Acute granulocytic leukemia is the most common form of acute leukemia in adults;
- Acute granulocytic leukemia is more common in children;
- slow granulocytic leukemia has a progressively higher incidence with increasing age;
- The incidence of slow-onset leukemia increases significantly after the age of 50 years;
- Significantly higher incidence in oil fields and polluted areas, and higher incidence in urban than rural areas;
- The incidence of leukemia is similar to that of Asian countries and lower than that of European and American countries.