- Surgical Management of DCIS (2024 to 2025 Update):
- Re-excision vs Mastectomy:
- Re-excision is indicated for positive (ink-on-tumor) margins after lumpectomy;
- Unless specific skin-only or fascia-only circumstances justify margin acceptance:
- Always document clearly
- Unless specific skin-only or fascia-only circumstances justify margin acceptance:
- Total mastectomy is appropriate when negative margins cannot be achieved, or if disease is diffuse or multifocal:
- Most mastectomy patients do not require radiotherapy after DCIS resection
- Re-excision is indicated for positive (ink-on-tumor) margins after lumpectomy;
- Reference:
- American Cancer Society. Treatment of ductal carcinoma in situ (DCIS). accessed June 2025.
- Reference:
- American Society of Breast Surgeons. “Margins in Breast Conservation Surgery: Resource Guide.” 2024.
- Axillary Management:
- Avoid ALND (axillary lymph node dissection):
- In pure DCIS without clinical / radiologic evidence of invasion or nodal disease
- SLNB (sentinel lymph node biopsy):
- Omit for pure DCIS treated with BCS when there’s no clinical / radiological suspicion of invasion:
- Nodal involvement is very low
- Perform or strongly consider if:
- Mastectomy is planned (because SLNB is not feasible afterward if invasion is unexpectedly found)
- There’s high suspicion of invasion (e.g., palpable mass, abnormal imaging / biopsy)
- Excision location could compromise future SLN (upper-outer quadrant /axillary tail)
- Omit for pure DCIS treated with BCS when there’s no clinical / radiological suspicion of invasion:
- References:
- American Society of Breast Surgeons, “Management of the Axilla: Position Statement.” 2024.
- American Cancer Society. Treatment of ductal carcinoma in situ (DCIS). accessed June 2025.
- NCCN-derived peer-reviewed statement, “Strong consideration for SLNB with mastectomy or mapping-compromising locations,” published in Annals of Surgical Oncology (exact citation not available; institutional statement)
- Emerging data:
- Older patients ≥ 50 with radiologically normal axilla undergoing mastectomy:
- Suggest SLNB may be omitted, but this is not yet in guidelines and must be individualized
- Reference:
- Madak-Erdogan et al., Annals of Surgical Oncology, 2023
- Older patients ≥ 50 with radiologically normal axilla undergoing mastectomy:
- Avoid ALND (axillary lymph node dissection):
- De-escalation and Active Surveillance:
- Early results from COMET (Comparison of Operative versus Monitoring and Endocrine Therapy) randomized trial in low-risk DCIS:
- At 2 years active surveillance ± endocrine therapy yielded non-inferior rates of invasive progression compared to surgery /RT:
- Patient-reported outcomes are pending
- Long-term outcomes:
- Not yet available
- Active surveillance:
- Should only be considered within clinical trials or carefully selected settings
- At 2 years active surveillance ± endocrine therapy yielded non-inferior rates of invasive progression compared to surgery /RT:
- Reference:
- Narod et al., Journal of Clinical Oncology, 2025; and associated JAMA Oncology report 2025.
- Early results from COMET (Comparison of Operative versus Monitoring and Endocrine Therapy) randomized trial in low-risk DCIS:
- Re-excision vs Mastectomy:
- Margins in DCIS:
- Standard Adequate Margin:
- For pure DCIS (and DCIS with microinvasion) treated with BCS plus whole-breast radiotherapy:
- A negative margin of ≥ 2 mm is recommended:
- Wider margins do not further reduce ipsilateral breast tumor recurrence (IBTR)
- A negative margin of ≥ 2 mm is recommended:
- Reference:
- Morrow M, Van Zee KJ, Solin LJ, et al. “Society of Surgical Oncology–American Society for Radiation Oncology–American College of Surgeons consensus guideline on margins for breast-conserving surgery with whole-breast irradiation in ductal carcinoma in situ.” Journal of Clinical Oncology. 2016;34(33):4040–4046.
- American Society of Breast Surgeons. “Margins in Breast Conservation Surgery: Resource Guide.” 2024.
- For pure DCIS (and DCIS with microinvasion) treated with BCS plus whole-breast radiotherapy:
- Margin-Width Decision Chart:
- Ink-positive margins:
- Re-excision required
- Reference: American Society of Breast Surgeons. 2024.
- Re-excision required
- < 2 mm but still negative:
- With WBRT planned, re-excision generally not required, unless there are complicating features:
- Multifocality, specimen fragmentation, APBI plans
- Reference: American Society of Breast Surgeons. 2024.
- With WBRT planned, re-excision generally not required, unless there are complicating features:
- ≥ 2 mm:
- Adequate:
- No evidence to support further wider excision
- Reference: American Society of Breast Surgeons. 2024.
- Adequate:
- If RT is omitted (e.g., in select older or low-risk patients):
- Retrospective data suggest wider margins correlate with lower local events:
- But no definitive guideline threshold exists
- Document discussions clearly
- Reference: American Society of Breast Surgeons. 2024.
- Retrospective data suggest wider margins correlate with lower local events:
- Mixed Invasive + DCIS:
- Treat according to invasive cancer standards:
- “No ink on tumor” is adequate, even if DCIS is near the edge
- Reference: American Society of Breast Surgeons. 2024.
- Treat according to invasive cancer standards:
- DCIS with Microinvasion (≤ 1 mm):
- Manage margins like pure DCIS:
- Aim for ≥ 2 mm margin with whole-breast RT
- Reference: American Society of Breast Surgeons. 2024.
- Manage margins like pure DCIS:
- Margin Exceptions:
- Skin-only or fascia-only positive margins after full-thickness excision may be acceptable without re-excision if no residual breast parenchyma remains:
- Document rationale
- Reference: American Society of Breast Surgeons. 2024.
- Skin-only or fascia-only positive margins after full-thickness excision may be acceptable without re-excision if no residual breast parenchyma remains:
- Atypical ductal hyperplasia (ADH), ALH, or classic LCIS at / near the margin:
- Should not prompt re-excision:
- Re-excise based solely on DCIS or invasive cancer margins
- Reference: American Society of Breast Surgeons. 2024.
- Should not prompt re-excision:
- New Evidence (PRECISION Cohort):
- PRECISION pooled international cohort (≈ 47,000 DCIS cases) demonstrated that:
- Margins < 2 mm are associated with higher 10-year ipsilateral events compared to ≥ 2 mm, although absolute differences are modest, supporting the 2 mm standard with RT
- Reference:
- PRECISION Collaboration. “Margin width and local recurrence in DCIS: pooled analysis of international cohorts.” BMJ. 2023;383:e076022.
- PRECISION Collaboration. PubMed; PMID 37903527.
- PRECISION pooled international cohort (≈ 47,000 DCIS cases) demonstrated that:
- Ink-positive margins:
- Standard Adequate Margin:
- References:
- Morrow M, Van Zee KJ, Solin LJ, et al. Society of Surgical Oncology–American Society for Radiation Oncology–American College of Surgeons consensus guideline on margins for breast-conserving surgery with whole-breast irradiation in ductal carcinoma in situ. Journal of Clinical Oncology. 2016;34(33):4040–4046.
- American Society of Breast Surgeons. Margins in Breast Conservation Surgery: Resource Guide. 2024. Available from: https://www.breastsurgeons.org/docs/statements/asbrs-rg-margins.pdf
- American Society of Breast Surgeons. Management of the Axilla: Position Statement. 2024. Available from: https://www.breastsurgeons.org/docs/statements/management-of-the-axilla.pdf
- American Cancer Society. Treatment of ductal carcinoma in situ (DCIS). Accessible via: https://www.cancer.org/cancer/types/breast-cancer/treatment/…dcis.html (Accessed June 2025).
- Narod SA, et al. COMET trial early outcomes — active surveillance versus surgery/radiation in low-risk DCIS. Journal of Clinical Oncology. 2025.
- PRECISION Collaboration. Margin width and local recurrence in DCIS: pooled analysis of international cohorts. BMJ. 2023;383:e076022.
- PRECISION Collaboration. PMID: 37903527.
Madak-Erdogan Z, et al. Considerations regarding omission of SLNB in selected DCIS mastectomy patients. Annals of Surgical Oncology. 2023.
Rodrigo Arrangoiz MS, MD, FACS, FSSO 