Leukemia, commonly known as “blood cancer,” is a malignant neoplastic disease of the hematopoietic system in which leukocytes and their naive cells in the blood undergo a progressive, diffuse proliferation in the bone marrow or other hematopoietic tissues without self-control, infiltrating various tissues.
Leukemia can be subdivided into acute and chronic leukemia depending on the natural course of the disease and the degree of differentiation of the primitive cells in the bone marrow.
- Acute leukemia: Acute onset, short course, untreated death within approximately 6 months, predominance of abnormal primitive and early naive cells in the bone marrow and peripheral blood, with more than 20% proto-naive cells.
- Chronic leukemia: Slow onset, natural course usually over one year, abnormal naive cells in the bone marrow stagnate at a later stage of differentiation, mostly more mature and mature cells.
In contrast to acute leukemia, the early stages of chronic leukemia do not have obvious symptoms such as hyperthermia and bleeding, but rather non-specific manifestations such as malaise, night sweats, and hypothermia.
Chronic leukemia can be divided into chronic myelogenous leukemia and chronic lymphocytic leukemia.
- Chronic granulocytic leukemia: Abdominal distention may occur, and physical examination reveals an enlarged spleen, and in some patients, even a giant spleen that reaches the pelvis.
- Chronic lymphocytic leukemia: There may be hepatosplenomegaly, but this is accompanied by enlarged lymph nodes throughout the body, a markedly elevated percentage of lymphocytes in the peripheral blood, and in some patients with chronic gonorrhea, recurrent severe infections occur.
Acute leukemia is aggressive and rapidly progressive, and the primary treatment is chemotherapy. Unlike acute leukemia, chronic leukemia is relatively mild and can be treated with oral targeted agents or relatively mild chemotherapy regimens.
- Chronic granulocytic leukemia: As depicted in the movie “I am not a druggist,” it is primarily treated orally with imatinib, a tyrosine kinase inhibitor (TKI), which has shown promising results.
- Chronic lymphocytic leukemia: Treatment is not needed immediately after the diagnosis is clear. The need for treatment can be evaluated by the physician on a case-by-case basis or by close monitoring of changes in the disease. Treatment is based on chemoimmunotherapy containing rituximab, fludarabine, etc. New small molecule targeted drugs such as the BTK inhibitor ibrutinib have also recently emerged and have shown good therapeutic efficacy.
In general, chronic leukemia has a slow onset and a better prognosis, but it takes longer to treat and has the potential to transform to acute leukemia in the course of the disease.