be replaced by transfusion. Some forms of cancer—leukemia and multiple myeloma—grow in the marrow cavity, leaving no space for the development of normal blood cells . These normal cells will then have to be provided by transfusion.
But most of the people with cancer who need blood transfusions need them because of the aggressive approaches used to treat the disease. If blood transfusions weren't available, most of the remarkably effective cancer treatments available today could never have been introduced—the chemotherapy used to kill cancer cells, for example, which may also kill developing blood cells in the marrow. Many cancers can also be cured or at least helped by surgery and that surgery may result in loss of blood by hemorrhage to the point where it has to be replaced. No other form of medical treatment can make such a difference between life and death as blood transfusions can.