Walsh & Hoyt: Leukemia: General Considerations

Leukemia constitutes 3% of all cancers in the United States but is the leading cause of death due to cancer in the United States in persons younger than 35 years of age. The annual incidence of leukemia in the United States is 13.1 for males and 7.6 for females. Leukemias are usually classified by their predominant cell type, the degree of differentiation within that cell line, and whether the process is acute or chronic. Acute leukemia occurs most commonly in the first 5 years of life, predominates in boys, and is most often lymphocytic. Chronic leukemias occur in older patients, with chronic myelocytic leukemia usually developing in men 2060 years of age and chronic lymphocytic leukemia affecting predominantly men between 45 and 60 years of age.