Colony-stimulating factors

Colony-stimulating factors (CSFs) are not directly effective against cancer cells, so they are not used to treat cancer. They are used to lessen some of the side effects of cancer treatments. They work to stimulate the bone marrow to increase the production of blood cells. This helps reduce the risk of infection, anemia and bleeding because of low blood cell counts.

Sometimes cancer treatment needs to be stopped or the dose needs to be lowered if blood cell counts are low. CSFs allow people to continue having cancer treatment at the full dose. In some cases, having CSF treatment allows higher doses of chemotherapy or radiation therapy to be given.

CSFs are also called hematopoietic growth factors.

Granulocyte growth factors

Granulocyte growth factors increase white blood cell counts and reduce the risk of infection.

Types of granulocyte growth factors
Type of granulocyte growth factorDescriptionDrugs

granulocyte colony-stimulating factor (G-CSF)

G-CSF stimulates neutrophils, which are a type of granulocyte that help protect the body from infection.

filgrastim (Neupogen)

pegfilgrastim (Neulasta)

granulocyte-macrophage colony-stimulating factor (GM-CSF)

GM-CSF stimulates 2 types of white blood cells to develop (granulocytes and macrophages) to help protect the body from infection.

sargramostim (Leukine)

Erythrocyte growth factors

Erythrocyte growth factors tell the body to make red blood cells. They are used to treat anemia caused by chemotherapy. They are used as an alternative to red blood cell transfusions. It may take up to 6 weeks for full effects to occur.

The drugs used include:

  • epoetin (Eprex, erythropoietin)
  • darbepoetin (Aranesp)

Megakaryocyte growth factors

Megakaryocyte growth factors stimulate the production of megakaryocytes, which are the source of platelets. These growth factors increase platelet counts. They are used as an alternative to platelet transfusions and help reduce the risk of bleeding due to low platelets.

Interleukin-11 is the main megakaryocyte growth factor used to increase platelet counts during cancer treatment. It is not yet approved for use in Canada.

For more detailed information on specific drugs, go to sources of drug information.


A type of white blood cell that helps fight infection by surrounding and killing foreign cells or micro-organisms, removing dead cells and stimulating other immune system cells. 

Macrophages develop from monocytes that have moved from the blood into tissues.

Macrophages are a type of phagocyte (a white blood cell that surrounds and kills bacteria or micro-organisms, eats foreign material, removes old or damaged cells and helps to boost the immune system).


A reduction in the number of healthy red blood cells.


A type of blood cell that helps blood to clot. Platelets are made in the bone marrow.

Also called thrombocyte.