World Breastfeeding Week - Cancer and breastfeeding

4 minute read time.

Today is the first day of World Breastfeeding Week. This blog, written by our information development nurse Teri, outlines when it may or may not be possible to breastfeed after having cancer treatment. It also looks at what breast changes to look out for while breastfeeding.

Many mothers choose to breastfeed due to the health benefits for both mum and baby. Breast milk not only protects the baby from infections and diseases, but breastfeeding also provides health benefits for the mum. However, for some women the option of breastfeeding is not straight forward.

This may be the case for women who have been diagnosed with cancer while pregnant or, soon after giving birth. Some mums in this situation will be advised by their doctor not to breastfeed. And for those who had wanted to , it can be very upsetting.

When it may not be possible to breastfeed after having cancer treatment

  • If someone is still having chemotherapy, as the drugs could be passed to the baby through the breast milk.
  • If someone is having targeted therapy drugs or hormonal drugs, as they can also be passed to your baby through breast milk.
  • If someone has had radiotherapy to treat the breast or the chest, they may not be able to produce enough milk in the treated breast.
  • If someone has had treatment for a certain types of brain tumours, it can affect a hormone produced in the brain, which controls milk production. This may mean you cannot produce enough milk to breastfeed.

When it may be possible to breastfeed, or give your baby breast milk:

  • If treatment stops some weeks before your baby is born, and further treatment is not needed, it may be possible to breast feed straight away.
  • If you have nearly finished treatment and have no further treatment planned you could think about expressing breast milk via a breast pump until treatment ends. You will not be able to use the expressed milk for the baby while you are on treatment. But expressing milk means that you will be able to continue to produce milk after treatment has finished and then you’ll be able to start breastfeeding normally.
  • If you have had radiotherapy to the breast or the chest on one side only, you should still be able to breastfeed from the non-treated side.
  • It is usually safe to continue breast feeding if you are having radiotherapy to other areas of the body, away from your chest. Check with your cancer doctor.
  • Some hospitals provide donated breast milk for babies born prematurely, if the mother does not have enough of her own breast milk. The United Kingdom Association of Milk Banking (UKAMB) is a registered charity that supports milk banking in the UK.

Many women can breastfeed after cancer treatment if they want to. Breastfeeding does not make the cancer more likely to come back. Your doctor, nurse or midwife can give you more information. We have more information about breastfeeding after cancer treatment.

Breast changes to be aware of while you are breastfeeding:
For a few years after giving birth there is slightly increased risk of developing breast cancer. However, this increased risk will go after a few years. If you notice a change in your breast while you are breastfeeding, let your GP know as soon as possible.

Changes to look for are:

  • a lump in the breast
  • a change in the size or shape of the breast
  • a change in the skin, such as dimpling (looks like orange peel)
  • the skin of your breast feeling thicker
  • a nipple that is turned in (inverted)
  • a rash (like eczema) on the nipple or breast
  • leaking (discharge) from the nipple
  • swelling or a lump in the armpit
  • discomfort or pain in the breast that does not go away.

Most breast changes are not cancer, but it’s important to find out what’s causing the change.

This quote is from Annmarie. It reads It is probably nothing but if there is that chance there's something, early detection is the best prevention of anything bad happening.

We’ve written a booklet, Cancer and pregnancy, in partnership with the charity Mummy's Star.

Mummy’s Star is the only charity in the UK and Ireland established specifically to offer support where a cancer diagnosis is received during pregnancy or within 12 months after a new birth. They offer peer support, financial help and advocacy, and work to raise awareness of cancer and pregnancy. If you would like to get support from Mummy’s Star, visit their website or email


To see what else Macmillan's cancer information team has been blogging about, please visit our blog home page! You can subscribe to receive our blogs by email or RSS too.

We're with you every step of the way

The Macmillan team is here to help. Our cancer support specialists can answer your questions, offer support, or simply listen if you need a chat. Call us free on 0808 808 00 00.

Comments? Feel free to add them below (you need to be logged in).