The Effects of Chemotherapy on Bone Marrow

The basic function of chemotherapy is to destroy cancerous cells. An unfortunate side effect by extension is that good, healthy cells can be damaged or destroyed at the same time. This is just as true of bone marrow. Bone marrow damage is a very common side effect of chemotherapy, usually defined as bone marrow suppression or myelosuppression.

What is Chemotherapy?

• Chemotherapy is the use of chemicals to destroy cells, most commonly, to kill cancerous cells. Typically, chemotherapy is comprised of antineoplastic drugs taken in an incremental treatment regimen over time. The principal of cancer is that unhealthy cells grow and divide at a dangerous rate, and can metastasize onto important organs and impair their function. Very basically speaking, chemotherapy poisons those cells, and any around it, stunting their unchecked growth and killing the cancer.

Bone Marrow

• Bone marrow is the thick inside part of the bone that produces red blood cells (RBC's) and white blood cells (WBC's). In the normal course of life, worn out cells are replaced by new ones created in our bone marrow.

Bone Marrow and Chemotherapy

• If the bone marrow is damaged during chemotherapy, the levels of RBC's and WBC's decrease to dangerous lows, known as bone marrow suppression, or myelosuppression. It becomes harder for the new cells to replace old ones as their growth is stunted by the chemotherapy that is attacking cancerous cells.

  The cells in bone marrow are especially susceptible to the dangers of chemotherapy because they themselves grow and divide at a much quicker rate than most other types of cells in the body. In many cases, bone marrow transplants are required because too many bone marrow cells are destroyed by chemotherapy.

Testing RBCs and WBCs

• While undergoing chemotherapy, patients will have to submit to several regular blood tests to keep track of how low their cell count can get. These complete blood counts are called CBCs. Changes in RBC's and WBC's depend on the type of cancer, the type and duration of the chemotherapy regimen, and the patient.

  If CDC's are too low, doctors may administer growth factor drugs to increase cell counts so that a chemotherapy regimen can be sustained in order to combat the cancer.

Effects of CDC

• Because of the important functions of the different types of cells, it is crucial that CDC's do not remain low for too long. White blood cells help fight infections, and are especially necessary when a body fighting cancer has a lowered immune system as a result of cancer. Red blood cells carry oxygen throughout the body and deliver nutrients. A low RBC is known as anemia, and often accounts for the fatigue associated with cancer.

  If these functions are inhibited by chemotherapy, fighting cancer becomes all the more difficult. The patient can also become more susceptible to infection. This is why maintaining healthy levels of WBC's and RBC's is essential during chemotherapy.