Leukemia is the most common type of cancer kids get, but it is still very rare. Leukemia involves the blood and blood-forming organs, such as the bone marrow.___1___
A kid with leukemia produces lots of abnormal white blood cells in the bone marrow. Usually, white blood cells fight infection, but the white blood cells in a person with leukemia don’t work the way they’re supposed to. ___2___The abnormal white blood cells multiply out of control1, filling the bone marrow and making it hard for enough normal, infection-fighting white blood cells to form. Other blood cells — such as red blood cells (that carry oxygen in the blood to the body’s tissues) and platelets (that allow blood to clot) — are also crowded out2 by the white blood cells of leukemia. These cancer cells may also move to other parts of the body, including the bloodstream, where they continue to multiply and build up3.
Although leukemia can make kids sick, most of the time it is treatable, and kids get better. Almost all leukemia patients are treated with chemotherapy, which means using anti-cancer drugs.
___3___Chemotherapy quickly goes to work, traveling through the blood to the bone marrow. There, the drugs can attack the cancer cells. After several weeks of chemotherapy, many kids begin to feel better.
Some children with leukemia will also have to have radiation therapy, too. ___4___
If the cancer isn’t getting better from using the usual amounts of chemotherapy and radiation, then kid with leukemia will probably need more treatment —with higher doses of chemotherapy and radiation to finally kill the cancer cells. But this heavy-duty treatment will also harm the normal cells in the kid’s bone marrow too, and the bone marrow will no longer be able to produce normal blood cells. So, doctors will then give a kid — or anyone else with bone marrow that is no longer working — normal bone marrow tissue from someone else who is healthy. ___5___
leukemia 白血病 marrow 髓 innermost 最内的，最深处的
abnormal 反常的，变态的 infection 感染 multiply .增加，繁殖
platelet 血小板 clot (血等)凝结成块 bloodstream 血流
chemotherapy 化学疗法 catheter 导管 insert 插入，嵌入
invisible 看不见的，无形的 cancerous 生癌的;患癌症的
heavy-duty . 重型的;大剂量的 transplant 移植
1.out of control：失去控制;不受控制
2.are also crowded out：也被排挤出去
A. The chemotherapy drugs are given through a catheter, a narrow tube that is inserted into a blood vessel, sometimes in the kid’s upper chest.
B. Early symptoms of leukemia are often overlooked, since they may resemble symptoms of the flu or other common diseases.
C. This is a special procedure called a bone marrow transplant, and it helps the patient make new blood cells so they can recover from the leukemia.
D. Bone marrow is the innermost part of some bones where blood cells are first made.
E. They don’t protect the person from infections very well.
F. Radiation therapy uses invisible high-energy waves (similar to X-rays) to kill cancerous cells.