White Cell Growth Factor

A white cell growth factor is a medicine that signals the bone marrow to make and release more infection-fighting white blood cells.

Cancer treatment can temporarily reduce production of these cells. Growth-factor medicines, also called colony-stimulating factors, are used as supportive care when the oncology team believes help with white-cell recovery is appropriate. They do not treat the tumour itself.

These medicines act on blood-cell production rather than directly attacking cancer cells. They may be given as an injection under the skin, with timing chosen around the treatment schedule. The exact medicine, dose, and number of doses depend on your cancer treatment and blood-count plan.

White cell growth factors are used alongside selected chemotherapy plans and in other oncology situations where treatment may suppress white-cell production. They may be considered to support a planned treatment schedule or after a low count, depending on clinical judgement. They are not suitable for every person or every regimen.

The oncology team may instead use observation with blood tests, adjust the treatment schedule, or consider other supportive measures. If a low white-cell count is accompanied by fever or feeling unwell, assessment is urgent because infection can become serious while immune defences are reduced. Do not start or stop a growth factor without instructions from your cancer team.

You may notice aching in bones or muscles, tiredness, headache, or discomfort where the injection was given. These effects are not the same for everyone. Check your temperature if you feel unwell and follow the emergency contact instructions from your oncology service, especially during periods when your white-cell count may be low.

Read more about [Growth Factor Support](/treatments/supportive-and-palliative-care/growth-factor-support/).

Growth-factor support is usually planned for a specific treatment period, with decisions revisited as blood counts and treatment plans change. Report severe or persistent pain, breathing difficulty, marked swelling, allergic symptoms, or fever promptly. Keep every blood-test and treatment appointment so the team can balance support with your wider cancer-care plan.