Blood test results of children being treated for brain and spinal cord tumors often fluctuate wildly. WBCs can go down to zero or be above normal. RBCs may go down periodically during treatment, necessitating transfusions of packed red cells. Platelet levels may also decrease, sometimes requiring platelet transfusions. Absolute neutrophil counts (ANC) are closely watched, as they give the doctor an idea of the child’s ability to fight infections; ANCs vary from zero to in the thousands.

Neuro-oncologists consider all of the blood test results to get the total picture of a child’s reaction to illness, chemotherapy, radiation, or infection. Trends are more important than any single value. For instance, if the values were 5.0, 4.7, and 4.9, then the second result (4.7) was insignificant. If, on the other hand, the values were 5.0, 4.7, and 4.3, then the trend would indicate a decrease in the cell line.

Children with brain and spinal cord tumors who are on medications for seizures or chemotherapy can have changes in kidney and liver function, along with changes in electrolytes and mineral levels in the blood. The section below describes the most common blood tests given to children with brain or spinal cord tumors. If you have any questions about your child’s blood test results, ask the doctor for a clear explanation.