Together is a new resource for anyone affected by pediatric cancer - patients and their parents, family members, and friends.Learn More
Most childhood cancer patients have regular complete blood count (CBC) tests during their treatment.
Cancer therapies such as chemotherapy and radiation therapy may affect the bone marrow’s ability to make blood cells. Regular complete blood count tests help the care team monitor the patient’s health and ability to fight off infections. When counts are low, the care team can provide treatment.
In patients with cancer involving the bone marrow, counting and studying blood cells provide information about the patient’s disease and how to treat it.
For a complete blood count test, a health care provider will take a sample of blood. If the patient has a central venous access device (central line, port, or peripherally inserted central catheter (PICC)), the blood may be taken from it. If the patient does not have such a device, the provider may start a peripheral IV or draw blood by inserting a needle into a vein and collecting the blood in attached vials or tubes (venipuncture).
Blood contains 3 different types of blood cells along with plasma, the liquid portion of blood. Low numbers of blood cells can lead to serious health conditions such as neutropenia, anemia, and thrombocytopenia.
Red blood cells carry oxygen to tissues and organs. A lower than normal red blood cell count results in anemia. Signs and symptoms of anemia include fatigue, shortness of breath, dizziness, headaches, a fast heartbeat, and/or pale skin. Patients with this condition may need a transfusion of red blood cells.
Platelets help the blood clot. A lower than normal platelet count results in thrombocytopenia. Signs and symptoms of thrombocytopenia may include unusual bruising, tiny spots under the skin (petechiae), urine that is pink or red, and stools that are red or black. A platelet transfusion may be needed when the platelet count is low.
White blood cells fight infection. A lower than normal white blood cell count affects the body’s ability to fight off invading bacteria, fungi, viruses, and foreign substances. A low count of a type of white blood cell called a neutrophil can result in a condition called neutropenia, which may require hospitalization.
A complete blood count test measures:
A complete blood count with differential also includes tests for the different types of white blood cells:
Normal ranges for these different types of blood cells can vary widely depending on the child’s age. The care team may review these results with families often.
Monitoring blood counts is an important part of a patient’s treatment plan.
Reviewed: June 2018