Are Wider Surgical Margins Really Necessary for DCIS?

At the upcoming 2025 American Society of Breast Surgeons (ASBrS) Annual Meeting, groundbreaking findings challenge longstanding practices regarding surgical margins in treating hormone receptor-positive ductal carcinoma in situ (DCIS) among postmenopausal women. Recent research suggests that the routine reexcision for wider margins may not be the necessity it once seemed.

Dr. Irene L. Wapnir, the lead author and a distinguished surgical oncologist at Stanford Medicine, highlighted that the study results indicate little difference in 10-year ipsilateral breast tumor recurrence rates between patients with narrower margins and those with the recommended wider margins, questioning the need for additional surgeries.

Understanding Ductal Carcinoma In Situ (DCIS) Treatment

DCIS marks the earliest stage of breast cancer, contained within the milk ducts. Standard management typically involves a lumpectomy, followed by whole-breast radiation therapy, and often includes adjuvant endocrine therapy. The current guidelines suggest a 2 mm disease-free margin, leading many women with narrower margins back to the operating room for further excisions.

Key Findings from the NSABP B-35 Trial

The research stems from the expansive NSABP B-35 trial, which enrolled 3,104 postmenopausal women between 2003 and 2006. Participants were treated with either tamoxifen or anastrozole post-lumpectomy and irradiation. By evaluating the occurrence of local recurrences based on varying margin widths, the study revealed strikingly small differences: a mere 1.6% increase in recurrence rates for those with margins less than 1 mm compared to wider ones.

Dr. Wapnir emphasized that these differences—5.6% for margins below 1 mm and 4.0% for those above—are not significant enough to justify the anxiety and potential cosmetic damage caused by reoperations.

The Impact of Wider Margins on Patient Well-Being

Reexcision surgeries can trigger increased anxiety, subpar cosmetic results, and higher healthcare costs. Therefore, the findings open the floor for revisiting the necessity of these procedures. Dr. Wapnir insists that for the specific cohort receiving comprehensive treatment, the need for wider margins may not be as critical as previously thought.

Expert Opinions: Advocating for Change

Chandler S. Cortina, MD, a respected associate professor of surgery, echoed the study's sentiment, stressing that routine reexcision might be avoided for many patients with DCIS. With only marginal recurrence differences, he urges healthcare teams to rethink their approaches and foster shared decision-making with patients.

However, Dr. Cortina warned against generalizing these findings to all patient demographics, particularly premenopausal women and those unable to receive standard adjuvant therapies, urging caution in interpretation.

A Future of Less Invasive Treatments?

The implications of this study could revolutionize the treatment landscape for DCIS, prompting a shift toward reduced reoperations and enhanced patient experiences. As the ASBrS meeting approaches, this crucial research may pave the way for significant changes in how healthcare professionals approach surgical margins, hoping to balance effective cancer control with minimizing unnecessary interventions.