Miguel Bronchud, Veteran Cancer Clinician and Researcher, shared on LinkedIn:
“New data for an old controversy? How wide should clean surgical margins’ be in DCIS (Ductal Breast Carcinoma In Situ)?
Current consensus guidelines recommend a negative margin of ‘at least 2 mm’ for patients with DCIS undergoing breast-conserving surgery with whole-breast radiotherapy; however, the investigators of a recent study noted that this recommendation was based on study-level meta-analysis rather than patient-level data, and that the optimal negative margin width remains uncertain.
Recent data suggests a new possibility of consensus?
‘In this multivariable analysis of 11,156 patients, negative margins < 2 mm were not associated with a higher local recurrence risk compared with margins ≥ 2 mm except in patients younger than 50 years at diagnosis.’
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Title: Patient-Level Evaluation of Optimal Margin Width for Lumpectomy in Ductal Carcinoma In Situ: An Analysis of Patients in the National Cancer Database Special Study
Authors: Amanda L. Nash, Yan Li, Samantha M. Thomas, Akiko Chiba, Astrid Botty van den Bruele, Jennifer K. Plichta, Laura H. Rosenberger, Maggie DiNome, Susan McDuff, Amanda Francescatti, Anne McCarthy, Ronald Weigel, Thomas Lynch, Elizabeth S. Frank, Ann H. Partridge, Alastair M. Thompson, Terry Hyslop, Marc D. Ryser, E. Shelley Hwang
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Investigators conducted a retrospective observational cohort study using data from the 2017 Commission on Cancer Special Study on DCIS. The analysis included women aged 18 years and older diagnosed with biopsy-confirmed DCIS between 2008 and 2015 who underwent lumpectomy within 6 months of diagnosis.
The final cohort was comprised of 11,156 patients from 1,231 Commission on Cancer sites.
The median age at diagnosis was 61 years, and median follow-up was 66.6 months. Overall, 72.2% of patients received breast-conserving surgery plus radiotherapy and 27.8% underwent surgery alone.
Most tumors (81.5%) were hormone receptor – positive, 38.6% were grade 3, and 62.9% measured 2 cm or less. Final surgical margin width was categorized as positive (tumor on ink), 0.01 to 0.9 mm, 1.0 to 1.9 mm, or ≥ 2 mm. The primary outcome was ipsilateral recurrence of either DCIS or invasive breast cancer.
During follow-up, 445 patients (4.2%) experienced an ipsilateral recurrence. Among the 8,059 patients who received radiotherapy, 5-year cumulative recurrence rates were 4.4% for positive margins, 2.3% for margins of 0.01 to 0.9 mm, 3.4% for margins of 1.0 to 1.9 mm, and 2.0% for margins of ≥ 2 mm.
Neither negative margin category below 2 mm differed significantly from the ≥ 2-mm group.
Among the 3,097 patients who did not receive radiotherapy, corresponding 5-year recurrence rates were 8.4%, 7.5%, 3.6%, and 4.7%, respectively.
After multivariable adjustment, positive margins were associated with increased recurrence risk compared with margins ≥ 2 mm both among patients receiving radiotherapy (hazard ratio [HR] = 2.06, 95% confidence interval [CI] = 1.52–2.79) and those not receiving radiotherapy (HR = 1.55, 95% CI = 1.07–2.24).
In contrast, narrower negative margins were not associated with a significantly increased risk of recurrence compared with wider negative margins, regardless of radiotherapy use.
But – among patients younger than 50, negative margins below 2 mm were associated with a higher recurrence risk compared with margins ≥ 2 mm (HR = 1.94, 95% CI = 1.26–2.99).”
You can also read:
Lumpectomy Margin Width and Local Recurrence in DCIS: Findings From NSABP B-35
