ORIGINAL ARTICLE – BREAST ONCOLOGY
Preoperative Prediction of Node-Negative Disease After
Neoadjuvant Chemotherapy in Patients Presenting with Node-
Negative or Node-Positive Breast Cancer
Brittany L. Murphy, MD, MS
, Tanya L. Hoskin, MS
, Courtney Day N. (Heins), BS
, Elizabeth B. Habermann,
, and Judy C. Boughey, MD
Department of Surgery, Mayo Clinic, Rochester, MN;
The Robert D. and Patricia E. Kern Center for the Science of
Health Care Delivery, Mayo Clinic, Rochester, MN;
Department of Health Science Research, Mayo Clinic, Rochester,
Background. Axillary node status after neoadjuvant
chemotherapy (NAC) inﬂuences the axillary surgical
staging procedure as well as recommendations regarding
reconstruction and radiation.
Objective. Our aim was to construct a clinical preopera-
tive prediction model to identify the likelihood of patients
being node negative after NAC.
Methods. Using the National Cancer Database (NCDB)
from January 2010 to December 2012, we identiﬁed cT1–
T4c, N0–N3 breast cancer patients treated with NAC. The
effects of patient and tumor factors on pathologic node
status were assessed by multivariable logistic regression
separately for clinically node negative (cN0) and clinically
node positive (cN?) disease, and two models were con-
structed. Model performance was validated in a cohort of
NAC patients treated at our institution (January 2013–July
2016), and model discrimination was assessed by estimat-
ing the area under the curve (AUC).
Results. Of 16,153 NCDB patients, 6659 (41%) were cN0
and 9494 (59%) were cN?. Factors associated with
pathologic nodal status and included in the models were
patient age, tumor grade, biologic subtype, histology,
clinical tumor category, and, in cN? patients only, clinical
nodal category. The validation dataset included 194 cN0
and 180 cN? patients. The cN0 model demonstrated good
discrimination, with an AUC of 0.73 (95% conﬁdence
interval [CI] 0.72–0.74) in the NCDB and 0.77 (95% CI
0.68–0.85) in the external validation, while the cN?
patient model AUC was 0.71 (95% CI 0.70–0.72) in the
NCDB and 0.74 (95% CI 0.67–0.82) in the external
Conclusions. We constructed two models that showed
good discrimination for predicting ypN0 status following
NAC in cN0 and cN? patients. These clinically useful
models can guide surgical planning after NAC.
The use of neoadjuvant chemotherapy (NAC) in oper-
able breast cancer continues to increase. NAC increases the
potential that a patient may undergo breast-conserving
therapy, may downstage the axilla, and allows for an
in vivo assessment of treatment response.
of nodal negativity after NAC inﬂuences the choice of
axillary staging operation, as well as the consideration of
adjuvant radiation and thus reconstructive options. There-
fore, the ability to know the likelihood of nodal negativity
preoperatively will help guide surgical decision making
both in terms of reconstruction and approach to axillary
staging. In patients who are clinically node negative (cN0)
prior to chemotherapy, sentinel lymph node (SLN) surgery
after NAC is commonly employed.
In patients with
clinically positive axillary nodes at the time of diagnosis,
Electronic supplementary material The online version of this
article (doi:10.1245/s10434-017-5872-9) contains supplementary
material, which is available to authorized users.
This work has not previously been submitted for publication but was
presented as a poster presentation at the Society of Surgical Oncology
Annual Cancer Symposium, Seattle, WA, USA, 15–18 March 2017.
Ó Society of Surgical Oncology 2017
First Received: 20 February 2017;
Published Online: 8 May 2017
J. C. Boughey, MD
Ann Surg Oncol (2017) 24:2518–2525