8 / 16
Consensus guideline on margins
for breast-conserving surgery with
whole-breast irradiation in ductal
carcinoma in situ
Comment by Lee S Schwartzberg, MD, FACP
O
ne of the topics frequently discussed at multidisciplinary breast cancer tumour boards is
how to handle patients who have DCIS with close or limited margins after lumpectomy.
Many of these patients are considered for reoperation, adding morbidity and expense. The
situation has been further complicated by recent consensus opinion that, for invasive breast cancer,
no ink on tumour is acceptable, presuming patients will receive radiation therapy.
We now have an important consensus statement on DCIS based on a thorough review of the
available literature. The panel recommends a 2-mm margin for DCIS in order to reduce the risk of
ipsilateral breast cancer recurrence to a minimum. Larger margins are not necessary.
An excellent table in the paper addresses many of the clinical questions that frequently arise
regarding benefit of radiation, endocrine therapy, and other common situations in the context of
DCIS.
This review is highly recommended for all breast surgeons and physicians who
deal with this disease.
Dr Schwartzberg is a senior partner and Medical Director of the
West Clinic, a 30-physician practice specialising in oncology,
haematology and radiology located in Memphis, Tennessee.
Rate of distant metastases in women with breast
carcinoma and an Oncotype DX recurrence score <18
Comment by Reshma L Mahtani, DO
P
atients in this analysis were considered low-risk on the basis of the traditional On-
cotype DX classification (low, <18; intermediate,
≤
31; high, >31) and overall had a
very low risk of distant metastases, although follow-up was only 46 months.
Of the 6 patients who recurred, 5 had a recurrence score (RS) between 11 and 17, and it
should be noted that these patients would have been considered eligible for randomisation
on the TAILORx study, as they would have been considered intermediate-, not low-risk
(
Clin Breast Cancer
2006;7:347-350).
We already have data for the low-risk group on TAILORx (<11); 99% of patients were
free of breast cancer recurrence after 5 years of follow-up when treated with hormonal
therapy alone. This study again highlights the need to obtain prospective data for patients
with an intermediate score (11–25 by TAILORx criteria), and, therefore, the results of
TAILORx patients in this subgroup are eagerly awaited.
Dr Mahtani is a haematologist/medical oncologist and Assistant
Professor, Division of Hematology/Oncology, Sylvester Comprehensive
Cancer Center, University of Miami Health System, Miami.
Society of Surgical Oncology – American Society for
Radiation Oncology – American Society of Clinical Oncology
consensus guideline onmargins for breast-conserving
surgery with whole-breast irradiation in ductal carcinoma
in situ
Journal of Clinical Oncology
Take-home message
•
The authors of this meta-analysis evaluated optimal margin width and ipsilateral breast
tumour recurrence (IBTR) in patients with ductal carcinoma in situ (DCIS) treated with breast-
conserving surgery and whole-breast irradiation (WBRT). Patients with negative margins
have half the risk of IBTR seen in those with positive margins. The risk is again decreased
by a 2-mm margin compared with smaller margins. Margins >2 mm are not associated
with any added benefit in reducing IBTR. Re-excision should not be planned on negative
margins <2 mm alone, and other factors should be considered.
•
A negative margin of 2 mm is the desired standard for DCIS treated with WBRT due to a
low rate of IBTR and need for further surgery. In patients with smaller margins, clinicians
need to consider each case individually when deciding on further excision.
Abstract
BACKGROUND
Controversy exists regarding the
optimal negative margin width for ductal carcino-
ma in situ (DCIS) treated with breast-conserving
surgery and whole-breast irradiation (WBRT).
METHODS
A multidisciplinary consensus panel
used a meta-analysis of margin width and ip-
silateral breast tumor recurrence (IBTR) from a
systematic review of 20 studies including 7883
patients and other published literature as the
evidence base for consensus.
RESULTS
Negative margins halve the risk of IBTR
compared with positive margins defined as ink
on DCIS. A 2 mm margin minimizes the risk of
IBTR compared with smaller negative margins.
More widely clear margins do not significantly
decrease IBTR compared with 2 mm margins.
Negative margins less than 2 mm alone are not
an indication for mastectomy, and factors known
to impact rates of IBTR should be considered in
determining the need for re-excision.
CONCLUSION
The use of a 2 mm margin as the
standard for an adequate margin in DCIS treated
with WBRT is associated with low rates of IBTR
and has the potential to decrease re-excision
rates, improve cosmetic outcome, and decrease
health care costs. Clinical judgment should be
used in determining the need for further surgery
in patients with negative margins < 2 mm.
J Clin Oncol
2016 Aug 15;[Epub ahead of print],
Morrow M, Van Zee KJ, Solin LJ, et al.
Breast carcinoma with an Oncotype Dx recurrence score <18: rate of distant metastases in a large series
with clinical follow-up
Cancer
Take-home message
•
This was a single-centre, retrospective study. The authors assessed the rate of development of
distant metastases in 1406 women with early-stage ER-positive, HER2-negative breast cancer who
had low recurrence scores on Oncotype DX testing. Overall, 1361 patients (97%) received endocrine
therapy and 170 patients (12%) received chemotherapy. Only 6 patients (0.4%) developed distant
metastases over a median follow-up of 46 months. The absolute rate of distant metastases among
patients aged <40 years was 7.1% (3 of 42 patients) versus 0.2% among patients aged ≥40 years.
•
The rate of distant metastases over 5 years in women with early-stage ER+/HER2- breast cancer and
low recurrence scores is 0.4%, although younger women have a higher rate of distant metastases.
Abstract
BACKGROUND
A 21-gene expression assay (Oncotype
DX recurrence score [RS]) that uses reverse tran-
scriptase-polymerase chain reaction is used clinically
in patients with early-stage, estrogen receptor (ER)-
positive, human epidermal growth factor receptor 2
(HER2)-negative breast carcinoma (ER+/HER2- BC) to
determine both prognosis with tamoxifen therapy and
the usefulness of adding adjuvant chemotherapy. Use
of the assay is associated with reductions in overall
chemotherapy use. The current study examined the
treatments and outcomes in patients with low RS.
METHODS
The authors reviewed the institutional data-
base to identify patients with lymph node-negative,
ER+/HER2- BC who were treated at the study institu-
tion between September 2008 and August 2013 and
their 21-gene RS results.
RESULTS
A total of 1406 consecutive patients with
lymph node-negative ER+/HER2- BC and a low RS
were identified (510 patients had an RS of 0–10 and
896 patients had an RS of 11–17). The median age at
the time of diagnosis of BC was 56 years; 63 patients
(4%) were aged <40 years. Overall, 1361 patients (97%)
received endocrine therapy and 170 patients (12%)
received chemotherapy. The median follow-up was
46 months. Six patients (0.4%) developed distant
metastases (1 patient with an RS of 5 and 5 patients
with an RS of 11–17). In the cohorts of patients with an
RS of 11 to 17, the absolute rate of distant metastasis
among patients aged <40 years was 7.1% (3 of 42
patients) versus 0.2% among patients aged ≥40 years
(2 of 854 patients).
CONCLUSIONS
The data from the current study docu-
ment a 0.4% rate of distant metastasis within 5 years
of BC diagnosis among patients with lymph node-
negative ER+/HER2- BC with an RS <18. Patients aged
<40 years at the time of BC diagnosis were observed
to have a higher rate of distant metastases. Analysis
of data from other studies is necessary to validate
this observation further.
Cancer
2016 Aug 15;[Epub ahead of print], Wen
HY, Krystel-Whittemore M, Patil S, et al.
JOURNAL SCAN
Over-irradiation
The Breast
Take-home message
•
This review discusses options for
decreasing the radiation therapy
burden for breast cancer patients.
Abstract
Decreasing the burden of radiation
therapy (RT) for breast cancer includes,
next to complete omission, several
ways to tailor the extent of RT. Possible
options for this include lowering of the
total dose, such as selective omission
of the boost, hypofractionated RT to
shorten the duration of treatment, the
selective introduction of partial breast
irradiation and anatomy based target
volume contouring to decrease the size
of the irradiated volumes.
Elective regional nodal irradiation
showed in several randomised trials and
meta-analyses to significantly impact on
local-regional control, disease-free sur-
vival, breast cancer mortality and overall
survival. The generalisability of these re-
sults remains complex in the light of the
decreasing use of axillary lymph node
dissection, the use of more effective
adjuvant systemic therapy, the increas-
ing use of primary systemic therapy and
continuously improving RT techniques.
In general, the use of RT compensates
for the decreasing extent of surgery
to the breast and the axillary lymph
nodes, eliminating residual tumour cells
while maintaining better aesthetic and
functional results. In some occasions,
however, the indications for the extent
of RT have to be based on limited path-
ological staging information. Research
is ongoing to individualise RT more on
the basis of biological factors including
gene expression profiles. When consid-
ering age, treatment decisions should
rather be based on biological instead
of formal age.
The aimof this review article is to put cur-
rent evidence into the right perspective,
and to search for an appropriate appre-
ciation of the balance between efficacy
and side effects of local-regional RT.
Breast
2016 Aug 10;[Epub ahead of
print], Poortmans PMP, Arenas M, Livi L.
BREAST
PRACTICEUPDATE HAEMATOLOGY & ONCOLOGY
8