In the past, if the fever was caused by an infection, antibiotics were ordered. When the goals of treatment were to cure the cancer, the medical staff kept a close watch on blood counts - especially the white cell count, which protects against infection. Sometimes doctors also ordered special blood counts to pinpoint the cause of infection. During the late stages of cancer, the cause of fever is not always treated and blood tests are seldom ordered. Antibiotics might be ordered but, in some cases ,the fever will be allowed to take its natural course and the cause of infection will remain unknown.
Fever has other causes besides infection.
Dehydration is one reason for a mild fever. As cancer progresses, the person usually drinks and eats less. The skin and mouth get drier, and less water and liquid circulate through the body. However, IV fluids are often not ordered for persons with advanced cancer because dehydration is a natural part of dying from an chronic illness . This does not mean that the person with advanced cancer must suffer with a high fever.