Effects of breast-conserving therapy on lactation after pregnancy

As the incidence of breast-conserving therapy in women of childbearing years increases, patient concerns regarding subsequent pregnancies and lactation have become more prevalent. There is a paucity of data regarding lactation outcomes in women who have undergone breast-conserving therapy and then sustained full-term pregnancies. Our objective was to evaluate lactation outcomes in patients with early-stage breast cancer treated with breast-conserving therapy.

We reviewed a database of over 3,000 patients treated from 1965 to 2003 to identify our cohort of premenopausal women who underwent breast-conserving therapy and subsequently sustained full-term pregnancies. Lactation outcome parameters (breast swelling, ability to lactate, and volume of lactation in the treated and untreated breasts) were the main outcome measures.

We identified 28 pregnancies in 21 patients. The median age at diagnosis was 32 years. One patient underwent bilateral breast treatment; therefore, a total of 22 breasts were irradiated. All patients interviewed reported little or no swelling of the treated breast during pregnancy. Of the patients studied, 4 (18.2%) elected pharmacological suppression of lactation. Of the remaining 18 breasts, lactation occurred in 10 (55.6%), did not occur in 7 (38.9%) and was unknown for 1 (5.5%). The volume was reported as significantly diminished in 80% of breasts treated. Lactation in the contralateral breast occurred in all patients who did not undergo pharmacological suppression.

Patients can experience successful lactation in the contralateral, untreated breast after breast-conserving therapy. In the treated breast, functional lactation is possible but is significantly diminished in the majority of patients.