Re-excision Rate in Breast Cancer
Following the 2014 SSO/ASTRO consensus guidelines establishing "no ink on tumor" as the standard for adequate margins in invasive breast cancer, re-excision rates have decreased nationally from 16-34% before 2014 to 14-18% after guideline implementation. 1
Current Re-excision Rates by Cancer Type
Invasive Breast Cancer
- Post-guideline era (2014-2018): 9-16% at institutional level 1
- National data (2013-2015): 14-18% overall reoperation rate 1
- Pre-guideline era (before 2014): 16-34% 1
- Individual institutional studies (2011-2018): Range of 10.1-21.4% 1
The dramatic reduction in re-excision rates after 2014 directly correlates with adoption of the SSO/ASTRO "no ink on tumor" standard, which eliminated unnecessary re-excisions for close but negative margins. 1
DCIS (Ductal Carcinoma In Situ)
- Overall re-excision rate: 41.4% 2
- This substantially higher rate reflects the 2016 SSO-ASTRO-ASCO consensus requiring 2mm margins for DCIS (not just "no ink on tumor"), which is more stringent than the invasive cancer standard. 3, 4, 5
Factors Associated with Higher Re-excision Rates
Patient Factors
- Age <40-50 years: Consistently associated with increased re-excision across multiple studies 6, 2, 7, 8
- Younger patients (<35 years): Paradoxically showed lower re-excision rates in one large database study, though this may reflect selection bias 8
Tumor Characteristics
- Presence of DCIS component in invasive cancer: Significantly increases re-excision risk, particularly when DCIS extends to margins 1, 6, 2
- Multifocal disease: Independent predictor of re-excision 6, 2
- Lobular histology: Associated with higher reoperation rates 1, 2, 7
- Non-palpable lesions: Higher re-excision rates compared to palpable tumors 6
- Tumor size >2cm: Increases likelihood of positive margins requiring re-excision 2, 7
- HER2-positive subtype: Associated with increased reoperation rates 1, 2
Surgeon and System Factors
- Low surgeon volume: Strong predictor of higher re-excision rates 7, 8
- Breast surgery practice <100% of total practice: Associated with increased reoperations 1
- Non-SSO approved teaching sites: Higher reoperation rates 1
- Geographic variation: Higher rates in Northeast US and rural areas 1
Common Reasons for Re-excision
Based on the ASBrS Mastery database analysis of 6,725 lumpectomy patients: 8
- Ink-positive margins: 49.7% of all re-excisions 8
- Margins <1mm (but not positive): 34.3% 8
- Margins 1-2mm: 7.2% 8
Critical caveat: The substantial proportion of re-excisions performed for negative but close margins (41.5% combined for <1mm and 1-2mm margins) represents potentially unnecessary surgery, as the SSO/ASTRO guidelines establish that "no ink on tumor" is adequate for invasive cancer. 8
Impact of Guideline Implementation
Clinical Outcomes
- Decreased conversion to mastectomy: Fewer patients undergo mastectomy after failed lumpectomy attempts 1
- Improved breast satisfaction scores: Documented in post-guideline era 1
- Increased lumpectomy utilization: Absolute rate of lumpectomy increased while bilateral mastectomy rates declined from 34% to 18% 1
Economic Impact
- Cost savings: 17-25% reduction in costs by avoiding unnecessary reoperations 1
- National savings potential: A 3% reduction in re-excision rates would save >$116 million annually 1
Key Pitfalls to Avoid
The most common error is performing re-excision for close but negative margins (<2mm) in invasive breast cancer. The SSO/ASTRO guideline explicitly states that if tumor does not extend to the inked margin, re-excision is not necessary for invasive cancer. 1
For DCIS, the threshold is different: Margins must be ≥2mm, and margins <2mm are associated with significantly increased ipsilateral recurrence (OR 0.51 for 2mm vs 0-1mm margins, 95% CI 0.31-0.85). 3, 4, 5
Presence of DCIS at margins in invasive cancer cases: This remains a gray area where some surgeons continue to re-excise despite negative margins for invasive disease, though one study noted a trend toward fewer re-excisions for this indication post-guideline. 1