ORIGINAL ARTICLE – BREAST ONCOLOGY
The Potential Impact of AMAROS on the Management
of the Axilla in Patients with Clinical T1-2N0 Breast Cancer
Undergoing Primary Total Mastectomy
Martine Moossdorff, MD
, Faina Nakhlis, MD
, Jiani Hu, MPH
, William T. Barry, PhD
, Katya Losk, MPH
, Marjolein L. Smidt, MD, PhD
, and Tari A. King, MD
Department of Surgery, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center,
Maastricht, The Netherlands;
Department of Surgery, Brigham and Women’s Hospital, Boston, MA;
Brigham and Women’s Cancer Center, Boston, MA;
Department of Biostatistics and Computational Biology, Dana-
Farber Cancer Institute, Boston, MA;
Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
Background. Recent trials have demonstrated that axil-
lary observation or axillary radiation therapy (AxRT) is
equivalent to axillary node dissection (ALND) for patients
with one or two positive sentinel lymph nodes (SLNs).
These strategies have been widely adopted for patients
having breast conservation. This report demonstrates the
potential impact of the AMAROS trial on axillary therapy
in a retrospective cohort of mastectomy patients.
Methods. Patients undergoing primary mastectomy for
cT1-2N0 breast cancer who had one or two positive SLNs
were identiﬁed from institutional databases (2005–2015).
Locoregional management strategies were evaluated, and
variables predictive of the use of postmastectomy radiation
therapy (PMRT) were identiﬁed.
Results. Among 2594 mastectomies, 193 (7%) met the
AMAROS eligibility criteria. The median patient age was
50 years (range 22–83 years). Locoregional treatment
consisted of ALND ? PMRT for 102 patients (53%),
ALND alone for 66 patients (34%), PMRT alone for 11
patients (6%), and observation for 14 patients (7%).
Overall, 59 ALND patients (35%) had additional positive
nodes. In the multivariate analysis, age younger than
50 years (odds ratio [OR] 3.55; 95% conﬁdence interval
[CI] 1.57–8.45), lymphovascular invasion (LVI) (OR
5.78; 95% CI 2.53–4.78), macrometastases (OR 3.99;
95% CI 1.54–10.97), and extracapsular extension (OR
11.66; 95% CI 2.55–88.34) were associated with receipt
Conclusion. In this cohort of AMAROS-eligible patients,
168 (87%) underwent ALND, 102 (61%) of whom also
received PMRT, suggesting that AxRT could have been
used instead of ALND for a signiﬁcant number of patients.
Preoperative factors associated with the receipt of PMRT,
such as young age and LVI, may be useful for deﬁning a
multidisciplinary decision-making framework for axillary
management in this population.
During the last decade, a number of randomized trials
have shown that not all patients with positive axillary
lymph nodes beneﬁt from axillary node dissection
(ALND). The American College of Surgeons Oncology
Group (ACOSOG) Z0011 trial
locoregional recurrence, disease-free survival (DFS), and
overall survival (OS) with axillary observation and ALND
for patients with cT1-2N0 breast cancer undergoing breast-
conserving therapy (BCT) who were found to have one or
two positive sentinel nodes. The International Breast
Cancer Study Group (IBCSG) 23-01 trial
similar ﬁndings among cT1-2N0 patients undergoing BCT
or mastectomy who were found to have micrometastatic
disease in one or two sentinel nodes.
Electronic supplementary material The online version of this
article (https://doi.org/10.1245/s10434-018-6519-1) contains
supplementary material, which is available to authorized users.
Ó Society of Surgical Oncology 2018
First Received: 21 December 2017
T. A. King, MD
Ann Surg Oncol