Breast-conserving therapy, including radiation therapy, could lead to a progressive reduction in breast size over time among women with early-stage breast cancer, according to a recent study published by Becker et al in Plastic and Reconstructive Surgery.
Background
Breast-conserving therapy—consisting of lumpectomy and radiation therapy—is the preferred treatment for many individuals with early-stage breast cancer because it offers survival rates similar to those of mastectomy with more favorable physical, psychologic, and quality-of-life outcomes.
However, radiation therapy can have adverse effects on breast tissue, such as breast shrinkage as a result of radiation-induced tissue atrophy and fibrosis. Although this long-term side effect is well-recognized, there are few studies examining the extent or time course of breast volume loss following breast-conserving therapy.
Study Methods and Results
Researchers analyzed changes in the breast volume of 113 patients who underwent breast-conserving therapy/radiation therapy for early-stage breast cancer between 2005 and 2023. They made measurements using mammograms obtained prior to and following breast-conserving therapy and up to 5 years later, and also assessed the impact of initial breast size and other factors on volume loss.
Reflecting the size of the tumor, breast volume decreased by an average of 9.2% following lumpectomy. The researchers noted that breast volume continued to decrease over time, even after the immediate adverse effects of treatment resolved. After a follow-up of 1 year, the average decline in breast volume was 19.3% in addition to the tissue removed at surgery.
"Additional volume change was observed yearly for 5 years," the study authors reported. By that time, the average decrease in breast size was 26.6%. Consistent with previous studies of breast shrinkage following breast-conserving therapy, there was progressive volume loss in all of the patients.
Further, the patients with larger breasts and relatively smaller tumor volumes measuring less than 10% of their breast volume had greater total breast shrinkage compared with those who had smaller breasts (29.5% vs 21.7%). Other factors associated with greater volume loss included smoking status, diabetes, and receiving cytotoxic chemotherapy in addition to radiation therapy.
The researchers indicated that expected breast shrinkage was approximately 20% within the first year, progressing to about 26% by 5 years. With the growing emphasis on patient satisfaction in evaluating the outcomes of breast cancer treatment, the study highlighted the need to discuss long-term changes in breast volume with patients undergoing breast-conserving therapy/radiation therapy.
Conclusions
“Our findings suggest that women undergoing [breast-conserving therapy/radiation therapy] may lose approximately 20% of breast volume within 1 year, with continued reductions through 5 years,” detailed senior study author Chris Reid, MD, of the University of California, San Diego. “Anticipating these changes may help guide patient expectations and assist surgical planning to restore women after breast cancer treatment.”
The greater volume loss in patients with larger breasts raised concerns regarding breast asymmetry—which is a common concern following breast-conserving therapy.
“Anticipating these changes may help guide patient expectations and assist surgeons in planning reconstructive procedures to attain symmetry post-treatment,” Dr. Reid underscored.
In future studies, the researchers hope to explore the effects of different treatment techniques on breast volume changes and identify more objective approaches to measure breast volume.
Disclosure: For full disclosures of the study authors, visit journals.lww.com.
