Leukemia

Abstract

If any type of human cancer is caused by a virus, it is probably leukemia. The virus may not be an infectious virus in the same sense as are those that cause polio and measles, but strong evidence is accumulating that some form of virus is involved in the etiology of leukemia. There is, however, a welter of evidence indicating that many other factors, including environmental influences and genetic predisposition, are also involved. The scenario presented by this evidence is complex, confusing, even contradictory, but this may be simply a reflection of the fact that more is known about leukemia than about any other type of cancer. The problems encountered in understanding and treating leukemia typify those found in other types of cancer and are illustrative of the general directions in which cancer research is headed.