Breast cancer occurring during pregnancy or breastfeeding is rare. As a result, screening for breast cancer is often neglected, and malignant changes are detected at a later stage than they normally would. 

We should remember that quick diagnosis and treatment increase our chances of complete recovery. In the first part of this post we described how to diagnose breast cancer during pregnancy and lactation. In this part, we will focus on the treatment options available and the course of treatment.

How to treat breast cancer in pregnancy?

It is common knowledge that treatment of any type of cancer produces the best results when administered at an early stage. In case of pregnancy, the decision about treatment should be made jointly with the oncologist, the gynaecologist and the patient herself. It may be possible to accelerate the delivery to implement the recommended treatment, or to modify the treatment to allow the pregnancy to progress. Some breast cancer treatments carry a risk of infertility, which you should also be aware of. It is important to remember that if there is such a risk, state-of-the-art is for the ova or embryo to be extracted and cryopreserved before treatment begins so that the patient can become pregnant at a later date.

Breast cancer treatment in the first trimester

During the first trimester of pregnancy, the recommended treatment for breast cancer is surgery. A complete removal of the breast and accompanying lymph nodes is preferred. Breast-conserving surgery is not recommended because it requires subsequent treatment with X-rays, which are harmful to the baby. The baby’s internal organs are developing during this period, making chemotherapy impossible as well. Surgery is usually performed after the 12th week of pregnancy. 

Treatment of breast cancer in the second and third trimester

Again,  the method of choice is surgery with axillary lymphadenectomy, but breast conserving surgery (BCS) with subsequent chemotherapy and radiation therapy after delivery is also an option. Doctors recommend accelerated delivery followed by chemotherapy and complete breast removal for women with advanced breast cancer towards the end of their pregnancy. Information gathered by a team of scientists in 2012 (A. Keyser, Erin, et al) shows that chemotherapy used in the later stages of pregnancy is relatively safe (although not without side effects!). Before each cycle of chemotherapy, an ultrasound should be performed to monitor development of the baby.

Treating breast cancer while breastfeeding

Chemotherapy should be avoided during breastfeeding as chemotherapy drugs pass into breast milk. In the case of breast-conserving surgery, breastfeeding is possible in about 1/4 of the cases after the end of treatment. However, there are no contraindications to breastfeeding from a second breast if the woman is not receiving chemotherapy and hormone therapy at the same time. The decision regarding the choice of treatment should always be consulted with the attending physician, and in this case it is worth consulting it with a pediatrician and lactation consultant as well. If a surgery is planned, a lactating woman can be adequately prepared for the break or termination of breastfeeding. It is worth remembering that breast milk can be stored in a freezer and given to the baby at a later time, when breastfeeding is impossible as a result of l treatment.

References

• A. Keyser, Erin, et al. “Pregnancy-Associated Breast Cancer.” Rev Obstet Gynecol, vol. 5, no. 2, 2012, pp. 94–99, www.ncbi.nlm.nih.gov/pmc/articles/PMC3410508/. Accessed 7 Jan.
• 2021.Durrani, Sajid, et al. “Breast Cancer During Pregnancy.” Cureus, vol. 10, no. 7, 8 July 2018, www.ncbi.nlm.nih.gov/pmc/articles/PMC6128597/. Accessed 7 Jan. 2021.
• Marks, Julie. “Breast Cancer While Breastfeeding: Incidence and More.” Healthline, 14 June 2017, www.healthline.com/health/parenting/breast-cancer-while-breastfeeding#incidence. Accessed 7 Jan. 2021.
• Medela. Breast Cancer and Breastfeeding: Facts to Know. 16 Dec. 2019, www.medela.us/breastfeeding/articles/breast-cancer-and-breastfeeding-facts-to-know. Accessed 7 Jan. 2021.