ORIGINAL ARTICLE – BREAST ONCOLOGY
Predictors of Residual Disease After Breast Conservation Surgery
Lisa J. Findlay-Shirras, HBSc, MBBS
, Oussama Outbih, BSc Med, MD
, Charlene N. Muzyka, MSc
Katie Galloway, MSc
, Pamela C. Hebbard, MD, FRCSC
, and Maged Nashed, MD, PhD, FRCPC
Department of General Surgery, University of Manitoba, Winnipeg, MB, Canada;
Department of Family Medicine,
University of Ottawa, Ottawa, ON, Canada;
Department of Epidemiology and Cancer Registry, CancerCare Manitoba,
Winnipeg, MB, Canada;
Section of General Surgery, Department of General Surgery, University of Manitoba, Winnipeg,
CancerCare Manitoba, Winnipeg, MB, Canada;
Radiation Oncology, Department of Radiology, University
of Manitoba, Winnipeg, MB, Canada;
Department of Radiation Oncology, CancerCare Manitoba, Winnipeg, MB, Canada
Introduction. Breast-conserving therapy is the standard of
care for early-stage breast cancer. In the era of multi-
modality therapy, the debate on the value of revision
surgery for compromised margins continues, and high re-
excision rates persist despite updated guidelines. Our study
sought to identify the local re-excision rate for compro-
mised margins after lumpectomy, and identify predictors of
residual disease at re-excision.
Methods. This population-based retrospective cohort
study included women with breast cancer who underwent a
lumpectomy between 2009 and 2012 in Manitoba, with
close (B 2 mm) or positive margins that led to re-excision.
Patient demographics and tumor characteristics were
identiﬁed through provincial cancer registries and chart re-
views. For patients with invasive cancer, the six anatomical
margins were reported for margin status, width, and
pathology type at the margin.
Results. Of the 2494 patients identiﬁed, 556 women
underwent re-excision, yielding a re-excision rate of
22.29%. Of our 311 patients with invasive cancer who
underwent re-excision, 62.7% had residual disease identi-
ﬁed on revision. On univariable analysis, the size and grade
of the invasive component, nodal stage, and the number of
positive margins were associated with residual disease on
re-excision (p \ 0.05). With the exception of nodal stage,
the same variables remained statistically signiﬁcant on
Conclusions. Our results suggest that even in the absence
of ‘no ink on tumor’, the cancer size and grade in
lumpectomy specimens are high-risk factors for residual
disease, and this subgroup of patients may beneﬁt from re-
excision. Long-term follow-up of this cohort is required to
determine their risk of recurrence after adjuvant treatment.
Breast-conserving therapy (BCT) has been the standard
of care for early-stage invasive breast cancer for many
years. It is estimated that 20–60% of women who undergo
BCT require additional breast surgery due to positive or
inadequate margins after the initial lumpectomy.
ous lack of consensus on what constitutes adequate
negative margins in BCT has led to variability in practice
between centers and surgical oncologists.
this controversy has resulted in increased rates of re-exci-
sion, as well as increased costs, risk of complications,
stress to the patient, poor cosmetic outcome, and the delay
of necessary adjuvant treatment.
Current literature has extensively examined breast can-
cer recurrence rates in relation to resection margin
A 2014 meta-analysis by Houssami et al.
speciﬁcally assessed the evidence on surgical margins for
BCT in the era of multidisciplinary therapy.
conﬁrmed that while negative margins reduced the odds of
local recurrence, increasing the width of the resection
margin was not associated with reduced recurrence rates.
Later that year, the Society of Surgical Oncology (SSO)
developed consensus guidelines for BCT, including margin
recommendations, based on the 2014 meta-analysis. The
Ó Society of Surgical Oncology 2018
First Received: 28 October 2017;
Published Online: 10 May 2018
M. Nashed, MD, PhD, FRCPC
Ann Surg Oncol (2018) 25:1936–1942