With increasing advances in science and technology and rising living standards, the average life expectancy of humans is increasing. Some hematologic tumors have a tendency to be more frequent in the elderly and should be brought to the attention of geriatric care. For example, chronic lymphocytic leukemia, 1/3 of patients have an age of onset above 60 years old and is rare below 30 years old. The incidence of myelodysplastic syndrome, a group of hematopoietic abnormalities or hematopoietic dysfunction syndromes closely related to leukemia, is also predominant in the elderly.
Acute leukemia
Acute leukemia in the elderly is more common with acute myeloid leukemia and less common with acute lymphoblastic leukemia. It is generally accepted that older patients aged ≥65 years should be treated at a reduced intensity compared with adult acute leukemia, whereas at 60 to 65 years of age they can be treated at adult doses.
Owing to the characteristics of older patients, their ability to tolerate strong chemotherapy is reduced; prolonged post-chemotherapy dysplasia due to age-related defects in hematopoiesis; high incidence of life-threatening infections; high frequency of concurrent multimorbidity; age-related altered pharmacokinetics of antitumor agents leading to increased hematologic and extrahematologic toxicity of strong chemotherapy; age-related decline in immune function; allogeneic and autologous stem cell transplantation procedures are less appropriate and feasible; social family, awareness issues impede the implementation of strong chemotherapy regimens, and many other factors that make therapeutic use different from that of adults.
It is these characteristics that determine that older patients with leukemia are often primary drug resistant or have a short maintenance of remission after treatment, are prone to relapse, and become refractory or relapsed leukemias.
Chemotherapy in leukemia is very important, but because of the characteristics of the elderly patient’s own pathogenesis that make the treatment of leukemia more difficult, treatment should take into account the functional status of each organ of the patient, focus on the protection of organ function, and give strong supportive therapy to allow chemotherapy to proceed smoothly.
For example, human immunoglobulin and colony-stimulating factor are given to prevent infection and reduce complications when white blood cells are declining; glucose monitoring and adjustment of glucose-lowering drugs to avoid large fluctuations in blood glucose when glucocorticoids are used in diabetic patients; and myocardial protection before and after anthracyclines are given, all of which can effectively reduce treatment-related complications.
Chronic lymphocytic leukemia
This disease is most common in the elderly, with onset at 40 to 75 years of age and a long natural course, with an average survival of 4 to 6 years. The disease has an insidious onset, and the symptoms are mostly asymptomatic, accounting for 25% of the cases. The enlarged lymph nodes are not painful or adherent, and skin damage is more common. The white blood cell count is increased, usually (50-100×10^9/L), with mature lymphocytes being the majority. Mature lymphocytes are also predominant in the bone marrow.
The principles of treatment are the same as in adults, and in older patients, aggressive supportive therapy is important. The dose and duration of dosing can be adjusted according to individual status, e.g. fludarabine can be used once to three times a week; monoclonal antibodies (anti-CD20 antibodies, melphalan) can be applied at doses starting from 100 mg/d in elderly patients with refractory progressive slow gonorrhea or complicated by autoimmune hemolytic anemia or thrombocytopenic purpura.
Chronic granulocytic leukemia
In addition to the usual manifestations of chronic granulocytic leukemia, chronic granulocytic leukemia in the elderly has the following features:
- More often combined with other diseases (cardiopulmonary disease, tumors, etc.).
- No hepatomegaly or splenomegaly or only mildly enlarged.
- Moderate or mildly increased white blood cell count.
- Normal or markedly increased platelets.
- There is a tendency to cause myelosuppression in anti-leukemia drug therapy, so the amount of medication should be reduced as appropriate.