Effects of breast-conserving therapy on lactation after pregnancy.

Background: 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.

Methods: 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.

Results: 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.

Conclusion: 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.