NCCN Guidelines for Patients® | Chronic Myeloid Leukemia

10 NCCN Guidelines for Patients ® : Chronic Myeloid Leukemia, 2018 A disease of cells Your body is made of trillions of cells. Cancer is a disease of cells. Each type of cancer is named after the cell from which it is derived. Cell of origin MPNs ( m yelo p roliferative n eoplasms) are a group of rare blood cancers. They are cancers that derive from blood-forming stem cells within the myeloid branch. “Myelo” means marrow. “Proliferative” means growing and refers to making too many cells. A neoplasm is any abnormal growth. MPNs have too many blood-forming cells in the marrow. In turn, there are also too many blood cells. CML is a type of MPN. The cell that is affected is a stem cell that makes granulocytes. Thus, there is an excess of white blood cells, in particular neutrophils. Other cell counts that can be high include basophils and eosinophils. “Chronic” means this cancer worsens slowly. The cause of CML Cells have a control center called the nucleus. The nucleus contains chromosomes, which are long strands of DNA ( d eoxyribo n ucleic a cid) tightly wrapped around proteins. See Figure 3 . Within DNA are coded instructions for building new cells and controlling how cells behave. These instructions are called genes. There are often abnormal changes in genes within cancer cells. These abnormal changes are called mutations. Mutations cause cancer cells to not behave like normal cells. Also, mutations sometimes cause cancer cells to look very different from normal cells. The mutation that causes CML is the BCR-ABL1 gene. It is explained next. Philadelphia chromosome A cell must make a copy of its chromosomes before dividing into 2 cells. Sometimes, there are mistakes in the copies. One type of mistake is when parts of two chromosomes switch with each other. This is called a translocation. It can result in a fusion gene. 1 CML basics A disease of cells Figure 3 Genetic material in cells Most human cells contain the “blueprint of life”—the plan by which our bodies are made and work. The plan is found inside of chromosomes, which are long strands of DNA that are tightly wrapped around proteins. Genes are small pieces of DNA that contain instructions for building new cells and controlling how cells behave. Humans have an estimated 20,000 to 25,000 genes. Illustration Copyright © 2017 Nucleus Medical Media, All rights reserved.