Breastfeeding During Cancer and Cancer Treatments

There is no need to wean after being diagnosed with any kind of cancer, especially not to “conserve your strength.” Lactation actually decreases the metabolism making it more efficient. Breastfeeding is also more convenient and less time-consuming than bottle-feeding. Most importantly, it provides an emotional connection and intimacy that’s nurturing to both you and your baby when you both need it most.

Maybe, depending upon the type of radiation used. 

Radiation exists in two forms: pure energy and particulate.

X-rays use pure energy, like visible light but with more energy. The effects of an X-ray are just like using a camera flash. After the X-ray is taken, the radiation is no longer there, like light from a camera flash is no longer there after the flash is over. 

Mammograms and CT scans use pure energy X-ray radiation from a special light bulb. You may be told to “pump and dump” milk for a period of time before mammographic testing  but it is not necessary.

While X-ray radiation does have the ability to mutate DNA in live cells exposed to it causing cellular dysfunction or uncontrolled replication (ie, cancer), the pure energy type of radiation used in mammogram and CT scan testing does not collect in the milk and so it’s entirely compatible with uninterrupted breastfeeding.

Radioactive agents contain particulate radiation, which has atoms with unstable nuclei that release radiation when they deteriorate, which is useful for detecting subtle tissue structures.

Ingestion or injection of a radioactive agent leaves radiation in the body until the it completely disintegrates or is excreted.

Consumption or injection of particulate radiation, such as during a ductogram, MRI, MIBI scan, or PET scan, during lactation transfers radioactive substances into the milk during milk synthesis. The radioactive toxicity and compatibility with breastfeeding depends upon the substance used. 

It’s not necessary to interrupt breastfeeding when radiopaque and radiocontrast agents are used in imaging procedures. The radiopaque and radiocontrast agents typically used in the ductogram, MRI, MIBI scan, or PET scan diagnostic tests are extremely inert and are virtually unabsorbed after being swallowed orally. These products are commonly used in pediatrics for diagnostic purposes and no harmful effects have been reported in babies who have ingested milk after radioactive agent imaging procedures.  

Radioactive isotopes accumulate in milk, which is dangerous for a baby or child to ingest. But weaning completely isn’t necessary for a procedure involving radioactive isotopes. You only need to interrupt breastfeeding temporarily, feeding your baby or child previously pumped milk or formula. Your milk can be easily tested for  radioactivity by most hospital radiology departments.  In the meantime, pumping frequently and disposing of the milk that’s collected will protect your milk production and accelerate radiation clearance from your body.

Therapy with pure energy radiation is injurious to all breast tissue, including lactation tissue, usually permanently. An irradiated breast is likely to make a lot less milk, even to the point of no milk at all. But lactation won’t affected in the breast that didn’t have radiation. So if radiation therapy happens during active lactation, breastfeeding can still continue on the other breast. 

By taking steps to increase milk production, it’s possible for the non-radiated breast to make a full milk supply. If full milk production doesn’t develop, supplementation can be given in a way that supports breastfeeding so that the breastfeeding relationship is preserved.

Not usually, although some babies refuse a breast when the milk taste changes or the milk supply decreases from a malignant mass.

No!  There’s no evidence that breastfeeding on a breast with cancer has any risk to a child. And it won’t have any effect on the cancer in the breast.

Breastfeeding during chemotherapy is not safe. The medications used to kill the cancer cells are highly toxic and transfer easily into the milk. 

If you want to resume breastfeeding after chemotherapy ends, you’ll need to pump regularly and dispose of milk that’s not safe for your baby.

Don’t wean suddenly because that can cause plugged ducts and/or mastitis (breast infection). Gradually eliminating feedings helps the breasts adjust and may minimize the emotional and physical impact. 

Once chemotherapy has ended, and depending upon the exact nature and mechanism of the chemotherapy drugs used, breastfeeding is usually safe again.

To learn how your chemotherapy drugs affect lactation, visit National Institutes of Health database listing the safety of most drugs during lactation,