In the haze of joy and sleeplessness during the months after childbirth, thoughts about breast cancer are the last thing on a new mother’s mind. Her body is undergoing so many changes that, of course, she and her doctors would naturally assume any breast changes are related to breastfeeding.
Probably, they are. However, there is a small but real incidence of women who develop breast cancer during and following pregnancy. Often, they end up having delays in seeking evaluation and getting a diagnosis, because they or their doctors may not appreciate that risk!
So, what things should prompt an evaluation?
- Lumps most often will be changes in the breast tissue as it revs up milk production. A distinct lump or “dominant mass” could be a clogged duct, galactocele, cyst or a common benign tumor called a fibroadenoma, but if it doesn’t resolve within a few weeks with treatment, it needs imaging.
- Redness most often will represent infections like mastitis or an abscess, but if it doesn’t resolve within a few weeks with treatment, it will also need imaging and possibly a biopsy. At the very least, that could determine if the right antibiotics are being used. An uncommon form of breast cancer called inflammatory breast cancer can present this way.
- Bloody milk or baby refusing one breast most often will be due to nipple trauma, latch issues, or positioning; if so, seeing a board-certified lactation consultant is appropriate. But rarely, this can represent a form of breast cancer within the milk ducts.
- “Something’s not right”. You are the most knowledgeable person about your own breasts. Even if it doesn’t neatly fit one of the categories above, if something really seems wrong to you, your doctors should take that seriously.
What evaluation should be done?
- Mammogram CAN be done in a breastfeeding woman. Ideally, it should be done with an experience mammographer who knows the woman is breastfeeding, as the images will be more complex. She should empty her breasts as much as possible right before the mammogram, either by nursing or pumping.
- Ultrasound CAN be done in a breastfeeding woman. Same issues apply. Ultrasound, incidentally, can actually be somewhat useful therapeutically for breaking up a clogged duct.
- MRI CAN be done in a breastfeeding mother, though it is not recommended just for routine screening (as is done in high risk women) because the sensitivity is lowered. Gadolinium, the dye used for MRIs of the breast, barely gets into milk and is not absorbed by the baby’s gut, so it is safe – no need to pump and dump.
- Milk cytology can be done, but it’s often low-yield. It does have the advantage of being noninvasive, but needs a specialized pathologist and doesn’t usually rule out cancer.
Needle biopsies (fine needle aspiration and core biopsy) CAN be done in a breastfeeding mother. The smallest needle that will get the diagnosis should be used, but the risk of milk fistula, which is chronic milk leakage, is very rare. There is no research on the incidence of milk fistulas with biopsies, but it’s rare enough that when it happens it gets written up as case reports! Incisions around the areola should avoid the lower outer border to keep from injuring the
4th intercostal nerve, and radial incisions (or an approach similar to what is done for C-sections, where the skin incision is made to be cosmetic and the inner dissection is done in a radial fashion) are recommended. The breast should be kept well drained with nursing or pumping before and after. Use of a local anesthetic like lidocaine is safe – no need to pump and dump.
- Surgery on the breast CAN be done in a breastfeeding mother. Milk fistula is still a risk, though that risk may not be reduced much by weaning as the breast could continue to make milk for months after weaning. The surgeon should be very careful with her technique – minimizing unnecessary damage to the milk ducts and avoiding the central breast if possible. Radial incisions and avoiding the 4th intercostal nerve (see above) are recommended. The breast should be kept well drained with nursing and pumping before and after. Most types of anesthesia will be out of the milk by the time the patient is awake and alert – at most, pump and dump once.
Breastfeeding has the potential to reduce lifetime cancer risk anywhere between 5-59% but is not a risk-free window. Women who have a concern should not be dismissed just because they are breastfeeding, nor should their health care providers overreact and encourage early weaning in order to get them evaluated.
When we know how to evaluate the “working” breast properly, we can ensure that fewer women experience delays in diagnosis and more women can continue to breastfeed successfully.
Ed. note: a version of this post originally appeared here.