A mastectomy involves the surgical removal of the entire breast tissue. The impact of this procedure on future milk production depends entirely on the extent of the surgery. Successful breastfeeding relies on the preservation of the delicate network of milk-producing glands, ducts, and nerves within the breast. While treatment for breast cancer presents unique challenges to lactation, many survivors can still achieve their feeding goals.
Milk Production After Surgery
The physical capability to produce milk hinges directly on the amount of glandular tissue that remains intact after surgery. Following a unilateral mastectomy, where only one breast is removed, the remaining healthy breast often retains its full capacity for milk production. The body is typically able to compensate, and one breast can often produce a sufficient supply to support a baby’s growth and nutritional needs.
A bilateral mastectomy, which involves the removal of both breasts, eliminates the milk-producing structures entirely, making biological lactation impossible. If a remaining breast was subjected to radiation therapy, milk production can be significantly reduced. High-dose radiation damages the milk-producing lobules and ducts, often leading to a permanent decrease in supply or the complete cessation of milk flow.
Tissue damage can hamper the primary mechanism for milk production, which relies on the supply-and-demand principle. The treated breast may not undergo the normal physiological changes that occur during pregnancy, and skin elasticity may be reduced, potentially complicating latching. Any residual glandular tissue in a partially treated breast might still yield some milk, but the focus is generally placed on maximizing output from the unaffected breast.
Safety of Breast Milk After Treatment
A history of breast cancer does not inherently make breast milk unsafe for an infant. The primary safety concern revolves around the potential transfer of residual therapeutic drugs into the milk, which could harm the baby. A detailed discussion with the oncology team is imperative before attempting to breastfeed to confirm that all cancer-related medications have been fully cleared from the system.
Chemotherapy agents are generally considered unsafe during active treatment due to the risk of drug transfer into the milk. The clearance time for these drugs varies widely based on the specific drug used and its half-life, and this process must be monitored by a physician. A waiting period of several weeks or longer after the final chemotherapy dose may be required before lactation can be safely initiated.
Hormonal therapies, such as aromatase inhibitors or tamoxifen, are also contraindicated for breastfeeding because these medications can pass into the breast milk and potentially affect the infant. Since these treatments are often taken for many years, individuals must weigh the desire to breastfeed against the necessity of continuing their long-term therapy. The decision to pause any ongoing treatment must only be made in close consultation with the prescribing oncologist.
Practical Steps for Successful Feeding
For those with a remaining, unaffected breast, successful feeding focuses on maximizing the supply from that single side. Seeking the guidance of an International Board Certified Lactation Consultant (IBCLC) is a crucial first step, especially one experienced with post-surgical or low-supply feeding challenges. The IBCLC can help assess the potential milk supply and develop a personalized feeding plan before the baby is born.
Frequent and effective milk removal is the foundation for building and maintaining supply in the functioning breast. This means nursing or pumping at least eight to twelve times in a 24-hour period, using a high-quality, hospital-grade pump for maximum stimulation. Techniques like switch nursing, where the baby is moved back and forth between the functioning and non-producing breast, can help stimulate the highest possible output.
Monitoring the baby’s intake and growth is equally important to ensure adequate nutrition. Parents should track the baby’s weight gain and the number of wet and dirty diapers daily, reporting this information to their pediatrician and lactation consultant. If the milk supply is insufficient, a supplemental nursing system (SNS) can be used to deliver pasteurized donor milk or formula via a thin tube while the baby is latched at the breast.
It is wise to avoid certain herbal supplements or medications marketed to boost milk production, as some contain phytoestrogens that could potentially interfere with anti-cancer hormone therapy. Any decisions regarding supplements or medications should be reviewed by the oncology team. Utilizing resources like human milk banks offers a pathway to provide breast milk to the infant even if a full supply cannot be achieved.