Importance of margins in breast conserving surgery

Importance of Margin in Breast Conserving

Surgery9th EBCC Presentation - Bodilsen et al (Aarhus University;

DBCG) – March, 2014

Sayan

• The status of the surgical margins is assessed by applying ink to the surface of the lumpectomy specimen and determining the microscopic distance between tumour cells and the inked surface. • Still no consensus on what constitutes an optimal negative margin.

“What margin width minimizes the risk of

IBTR in patients with invasive cancer

receiving WBRT after BCS?”

• 33 studies; 28162 patients; 1,506 IBTRs• A positive margin is associated with at least a 2-fold increase in IBTR.

This increased risk in IBTR is not nullified by:a) Delivery of a boost dose of radiationb) Delivery of systemic therapyc) Favourable biology• Wider negative margins are unlikely to reduce the risks of IBTR

• The overall cumulative incidence of IBTR at 10 years was 10.2% without a boost and 6.2% with a boost (P<.001). • In the small subset of 251 patients who had positive margins and received a

boost, the cumulative incidence of IBTR at 10 years was 17.5% with 10 Gy and 10.8% with 26 Gy (P>.10).• Although boost reduces IBTR when margins are microscopically positive, the

absolute benefit is not sufficient to reduce the rate of IBTR to that seen with negative margins and the use of a boost.

Jones HA et al. Impact of pathological characteristics on local relapse after breast-conserving therapy: A subgroup analysis of the EORTC boost versus no boost trial. J Clin Oncol 2009;27:4939-4947.

Patient Characteristics

Patient Characteristics

Patient Characteristics

Patient Characteristics

Patient Characteristics

Patient Characteristics

Adjuvant Therapy

No Difference in IBTR with BIGGER Margins!!!

0-1 mm : not reported

Mean Observation time – 5.6 years

Local Recurrence

Adjusted Analyses

Adjusted Analyses

Adjusted Analyses

Adjusted Analyses

Adjusted Analyses

Adjusted Analyses

Adjusted Analyses

Conclusion• In a national cohort of 12166 women, the 5 year cumulative risk of

IBTR: 2.4%• No evidence of decreased risk of IBTR with margins wider than 1mm• Predictors of IBTR include: Tumor on inked margin Young age ≥ 10 positive lymph nodes ER negativity No chemotherapy Re-excision DCIS outside invasive tumor

“The use of no ink on tumour [no cancer cells adjacent to any inked edge/surface of the specimen] as the standard for an adequate margin in invasive cancer in the era of multidisciplinary therapy is associated with low rates of IBTR and has the potential to decrease re-excision rates, improve cosmetic outcomes, and decrease healthcare costs.”

Summary of Clinical Practice Guideline Recommendations

Questions yet to be answered???• Can these findings be extrapolated to pure DCIS which has a

discontinuous growth pattern of low and intermediate grade DCIS ‐ ‐and is managed without systemic therapy?

• Are the results applicable in patients undergoing BCS following NACT especially when the tumor does not shrink concentrically but gets scattered into small masses?

• Are wider margins are required for patients treated with accelerated partial breast irradiation?