Breast
Selena J. An, MD, MSPH, MA
General Surgery Resident
University of North Carolina, United States
Selena J. An, MD, MSPH, MA
General Surgery Resident
University of North Carolina, United States
Selena J. An, MD, MSPH, MA
General Surgery Resident
University of North Carolina, United States
Christine Hong Ngoc Che Thai, BS
Medical Student
University of North Carolina
Durham, North Carolina, United States
Conner Haase, MD
General Surgery Resident
University of North Carolina, United States
Julia M. Selfridge, MD
Assistant Professor of Surgical Oncology
University of North Carolina, United States
Chris Agala, PhD
Professor
UNC Hospital, United States
Kristalyn K. Gallagher, DO (she/her/hers)
Surgical Director of the Breast Care Program
UNC School of Medicine
Chapel Hill, North Carolina, United States
Philip Spanheimer, MD (he/him/his)
Attending
University of North Carolina, North Carolina, United States
In patients with clinically positive nodes, nodal clearance after neoadjuvant treatment avoids the morbidity of axillary dissection. In this study, we aimed to identify predictors of nodal pathologic complete response (npCR) among breast cancer (BC) subtypes.
Methods: Adult women with stage 1-3 BC diagnosed from 2004-2018 in the National Cancer Database who received neoadjuvant chemotherapy followed by surgery within 8 months were included. npCR, defined as cN+ to ypN0, were compared between four subtypes: triple negative breast cancer (TNBC), ER+/HER2+, ER+/HER2-, and ER-/HER2+. Predictors of npCR were modeled with multivariable logistic regression. Kaplan-Meier analyses were used to model overall survival among patients with npCR, stratified by BC subtype.
Results: 69,383 patients were included: 32,880 TNBC, 5,276 ER+/HER2+, 21,216 ER+/HER2-, and 10,011 ER-/HER2+. 51.6% in TNBC and 45.8% in ER+/HER2+ presented with cN0, while 49.1% in ER+/HER2- and 44.8% in ER-/HER2+ presented with cN1 (p< 0.001). npCR was lowest in ER+/HER2- patients at 16.6%, compared to 39.7% of TNBC, 36.6% of ER+/HER2-, and 51.2% of ER-/HER2+ patients (p< 0.001). Overall, facility region (West versus South odds ratio [OR] 1.10, 95% confidence interval [CI95] 1.02-1.20) and higher grade (2 versus 1, OR 1.70, CI95 1.40-2.06; 3, OR 3.51, CI95 2.91-4.23; 4, OR 2.48, CI95 1.53-4.04) were predictive of npCR. Older patients (OR 0.99, CI95 0.99-0.99), non-academic facilities (community programs OR 0.87, CI95 0.82-0.93; integrated networks 0.92, CI95 0.86-0.99), larger tumor size (cT3 versus cT1, OR 0.89, CI95 0.81-0.97; cT4, OR 0.78, CI95 0.71-0.86), increasing nodal burden (cN2 versus cN1, OR 0.81, CI95 0.75-0.88; cN3, OR 0.87, CI95 0.79-0.96), and lobular histology (OR 0.41, CI95 0.34-0.50) were predictive of residual disease (RD). The overall trend of npCR predictors were similar across subtypes; however, Black race was a predictor of npCR in ER+/HER2- (OR 1.26, CI95 1.09-1.46) but of RD in TNBC (OR 0.89, CI95 0.81-0.97) and ER-/HER2+ (OR 0.78, CI95 0.66-0.92) groups. Among patients achieving npCR, survival was best in the ER-/HER2+ group and worst in the ER+/HER2- group (Figure, p< 0.001).
Conclusions: Tumor characteristics, patient factors, and facility region predicted npCR. Black compared to White patients were more likely to have residual disease in TNBC and ER-/HER2+ subtypes. The mechanisms underlying these differences should be further investigated.