Why is leukemia not contagous through blood transfusion?

Leukemias are cancers of the blood. In particular, they are cancers of leukocytes. Leukemia - Mayo Clinic Basically, leukemias are an overproduction of abnormal leukocytes. read more

“Blood”, meaning red blood cell or erythrocyte, is sometimes processed to remove any white blood cells or leukocytes, of which contain the leukemia cancer cells (leukoreduction). Any residual cells in the erythrocyte preparation may get irradiating before transfusion, as happens for many different indications. read more

Not necessarily: Blood cancers, also called leukemias, result in high numbers of white blood cells. Acute leukemia can often be found on a routine blood test. However, not all blood cancers can be found this way. A diagnosis of blood cancer usually requires a history and physical exam in addition to blood tests. read more

Blood transfusions are needed when a person is low in red blood cells or other blood components, such as platelets -- tiny packages of substances that help blood to clot in the case of injury. These blood cells and blood components may be lower than normal for a variety of different reasons in cancer patients. read more