Validation of the PREDICT Prognostication Tool in US Patients With Breast Cancer.

BACKGROUND: PREDICT is an online prognostication tool derived from breast cancer registry information on approximately 6,000 women treated in the United Kingdom that estimates the postsurgical treatment benefit of surgery alone, chemotherapy, trastuzumab, endocrine therapy, and/or adjuvant bisphosphonates in early-stage breast cancer. Our aim was to validate the PREDICT algorithm in predicting 5- and 10-year overall survival (OS) probabilities using real-world outcomes among US patients with breast cancer. METHODS: A retrospective study was performed including women diagnosed with unilateral breast cancer in 2004 through 2012. Women with primary unilateral invasive breast cancer were included. Patients with bilateral or metastatic breast cancer, no breast surgery, or missing critical clinical information were excluded. Prognostic scores from PREDICT were calculated and external validity was approached by assessing statistical discrimination through area under time-dependent receiver-operator curves (AUC) and comparing the predicted survival to the observed OS in relevant subgroups. RESULTS: We included 708,652 women, with a median age of 58 years. Most patients were White (85.4%), non-Hispanic (88.4%), and diagnosed with estrogen receptor-positive breast cancer (79.6%). Approximately 50% of patients received adjuvant chemotherapy, 67% received adjuvant endocrine therapy, 60% underwent a partial mastectomy, and 59% had 1 to 5 axillary sentinel nodes removed. Median follow-up time was 97.7 months. The population's 5- and 10-year OS were 89.7% and 78.7%, respectively. Estimated 5- and 10-year median survival with PREDICT were 88.3% and 73.8%, and an AUC of 0.77 and 0.76, respectively. PREDICT performed most poorly in patients with high Charlson-Deyo comorbidity scores (2-3), where PREDICT overestimated OS. Sensitivity analysis by year of diagnosis and HER2 status showed similar results. CONCLUSIONS: In this prognostic study utilizing the National Cancer Database, the PREDICT tool accurately predicted 5- and 10-year OS in a contemporary and diverse population of US patients with nonmetastatic breast cancer.

Estimating the overall survival benefit of adjuvant chemo-endocrine therapy in women over age 50 with pT1-2N0 early stage breast cancer and 21-gene recurrence score ≥26: A National Cancer Database analysis.

BACKGROUND: Validation studies of the 21-gene recurrence score (RS) previously demonstrated that adjuvant chemotherapy plus endocrine therapy (CET) was associated with a significant survival benefit in women with node negative breast cancer (BC) and RS >31. However, the TAILORx trial, did not quantify the benefit of adjuvant CET in older women with node negative hormone receptor positive (HR+) BC with RS ≥26. We hypothesized that CET would be associated with improved overall survival (OS) compared to endocrine therapy (ET) in women >50 with HR+/HER2-node negative BC and RS ≥26. METHODS: The National Cancer Database (NCDB) was queried to identify women >50 with RS ≥26 ER+/HER2-BC pT1-2N0M0. Chi-square and logistic regression analysis determined the difference between ET and CET. OS was analyzed using a multivariable Cox model. RESULTS: We included 16,745 women-4740 (28.3%) received ET and 12,005 (71.7%) received CET. Women who received CET had: moderately (OR = 1.853, p < 0.001) or poorly/undifferentiated tumors (OR = 3.875, p < 0.001), pT2 (OR = 1.356, p < 0.001), or lymph-vascular invasion (OR = 1.206, p = 0.001). After accounting for demographic and oncologic factors, 5-year OS rates were significantly superior in women receiving CET vs. ET alone (95.4% vs. 92.0%, Hazard Ratio = 0.680, p < 0.001). CONCLUSIONS: We observed that CET was associated with a clinically and statistically significant higher OS compared to ET alone in women >50 years of age with RS ≥26 pT1 and pT2 N0M0 HR+/HER2-breast cancer, and which suggests that cytotoxic chemotherapy has an impact on reducing mortality that is independent of induction of premature ovarian failure.

Adjuvant chemotherapy is associated with an overall survival benefit regardless of age in ER+/HER2- breast cancer pts with 1-3 positive nodes and oncotype DX recurrence score 20 to 25: an NCDB analysis.

Background: The RxPONDER trial found that among breast cancer patients with estrogen receptor positive (ER+) breast cancer, 1-3 positive axillary nodes, and a recurrence score of ≤25, only pre-menopausal women benefitted from adjuvant chemoendocrine therapy; postmenopausal women with similar characteristic did not benefit from adjuvant chemotherapy. We aimed to replicate the RxPonder trial using a larger patient cohort with real world data to determine whether a RS threshold existed where adjuvant chemotherapy was beneficial regardless of age. Methods: The National Cancer Database (NCDB) was queried for women with ER+, human epidermal growth factor receptor 2 (HER2) negative breast cancer, 1-3 positive axillary nodes, and RS ≤25 who received endocrine (ET) only or chemo-endocrine therapy (CET). Cox regression interaction was explored between CET and age as a surrogate for menopausal status. Results: The final analytic cohort included 28,427 eligible women: 7,487 (26.3%) received adjuvant CET and 20,940 (73.7%) ET. In the entire cohort, RS had a normal distribution, with a median score of 14. After correcting for demographic and clinical variables, a threshold effect was observed with RS >20 being associated with a significantly inferior overall survival (OS) (P value range: < 0.001-0.019). In women with RS of 20-25, CET was associated with a significant improvement in OS compared to ET alone, regardless of age (age <=50: HR = 0.334, P=0.002; age>50: HR=0.521, P=0.019). Conclusion: Among women with ER+/HER2- breast cancer with 1-3 positive nodes, and a RS of 20-25-in contrast to the RxPONDER trial-we observed that CET was associated with an OS benefit in women regardless of age.

Allostatic load and cardiovascular outcomes in males with prostate cancer.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death in men with prostate cancer (PC). Accumulated stress plays an important role in CVD development. The cumulative burden of chronic stress and life events can be measured using allostatic load (AL). METHODS: The initial cohort included males aged 18 years and older diagnosed with PC (2005-2019). AL was modeled as an ordinal variable (0-11). Fine-Gray competing risk regressions measured the impact of precancer diagnosis AL and postdiagnosis AL in 2-year major cardiac events (MACE). The effect of AL changes over time on MACE development was calculated via piecewise Cox regression (before, and 2 months, 6 months, and 1 year after PC diagnosis). RESULTS: We included 5261 PC patients of which 6.6% had a 2-year MACE. For every 1-point increase in AL before and within 60 days after PC diagnosis, the risk of MACE increased 25% (adjusted hazard ratio [aHR] =1.25, 95% confidence interval [CI] = 1.18 to 1.33) and 27% (aHR = 1.27, 95% CI = 1.20 to 1.35), respectively. Using AL as a time-varying exposure, the risk of MACE increased 19% (aHR = 1.19, 95% CI = 1.11 to 1.27), 22% (aHR = 1.22, 95% CI = 1.14 to 1.33), 28% (aHR = 1.28, 95% CI = 1.23 to 1.33), and 31% (aHR = 1.31, 95% CI = 1.27 to 1.35) for every 1-point increase in AL before, 2 months after, 6 months after, and 1 year after PC diagnosis, respectively. CONCLUSION: AL and its changes over time are associated with MACE in PC patients, suggesting a role of a biological measure of stress as a marker of CVD risk among men with PC.

Racial disparities in breast cancer treatment patterns and treatment related adverse events.

The main objective of this work was to perform a comprehensive analysis and provide a race-stratified epidemiological report accounting for differences in treatment patterns and treatment related adverse events in Non-Hispanic women with breast cancer (BC). The cohort included women ≥ 18 years diagnosed with in-situ, early-stage, and late-stage BC (2005-2022). Treatment patterns included: surgery, breast radiation, chemotherapy, endocrine therapy, or biologic therapy. Treatment related adverse events were: chemotherapy complications, cardiovascular toxicities, immune-related adverse events, psychological affectations, or cognitive decline/dementia. The influence of race on the outcomes was measured via Cox proportional-hazards models. We included 17,454 patients (82% non-Hispanic Whites [NHW]). Most of the patients had a Charlson Comorbidity Score between 1 and 2 (68%), and TNM stage I (44.5%). Surgery was performed in 51.5% of the cases, while 30.6% received radiotherapy, 26.4% received chemotherapy, 3.1% received immunotherapy, and 41.2% received endocrine therapy. Non-Hispanic Blacks (NHB) had a lower probability of undergoing breast cancer surgery (aHR = 0.92, 95% CI 0.87-0.97) and of being prescribed endocrine therapy (aHR = 0.83, 95% CI 0.79-0.89), but a higher probability of receiving adjuvant radiotherapy (aHR = 1.40, 95% CI 1.29-1.52). Moreover, NHBs had lower risk of being diagnosed with psychological issues (aHR = 0.71, 95% CI 0.63-0.80) but a higher risk for cognitive decline/dementia (aHR = 1.30, 95% CI 1.08-1.56). In conclusion, NHB women diagnosed with BC were less likely than NHW to undergo curative intent surgery or receive endocrine therapy, and had a higher risk of cognitive decline/dementia after cancer treatment. Public policy measures are urgently needed which equalize access to quality healthcare for all patients and that promote a learning healthcare system which can improve cancer outcomes.

Adjuvant Therapy in Breast Cancer Patients With Microscopic Residual Disease.

INTRODUCTION: Surgical resection is the gold standard for early-stage breast cancer. Positive surgical margins are associated with poor outcome. Endocrine therapy (ET) is recommended as primary systemic treatment for hormone receptor positive (HR+) breast cancer after surgery. We hypothesized that chemoenocrine therapy (CET) would not be associated with improved survival relative to ET for patients with positive margins. MATERIALS AND METHODS: The National Cancer Database was queried for pathologic stage I HR + HER2-breast cancer patients treated with partial mastectomy and adjuvant whole-breast irradiation between 2004 and 2017. The adjuvant treatment approaches to positive surgical margins were investigated and compared. Overall survival was compared between systemic treatment groups using multivariable cox proportional hazards regression. RESULTS: Among 228,453 patients, a positive surgical margin (microscopic residual disease, R1) was identified in 3561 (1.6%) patients. Compared with complete resections, positive margin was associated with inferior overall survival (hazard ratio [HR] = 1.276, P = 0.003). Among the R1 patients, 78.7% received ET only, 11.7% received CET, 1.2% received chemotherapy only, and 8.5% received no systemic therapy. After controlling for patient, facility, and tumor characteristics, ET provided greatest survival benefit (relative to no therapy, HR = 0.378, P < 0.001) followed by CET (HR = 0.446, P = 0.020). Compared with ET alone, CET is not associated with additional overall survival benefit (HR = 1.179, P = 0.595). CONCLUSIONS: CET appeared not to be associated with an improved overall survival in early stage HR + HER2-breast cancer with microscopic residual disease relative to ET. Positive surgical margins therefore are probably not a relevant clinical factor for adjuvant chemotherapy decision-making.

Modeling the COVID Pandemic: Do Delays in Surgery Justify Using Stereotactic Radiation to Treat Low-Risk Early Stage Non-Small Cell Lung Cancer?

INTRODUCTION: It was suggested that stereotactic radiation (SBRT) is an "alternative if no surgical capacity is available" for non-small cell lung cancer (NSCLC) care during the COVID-19 pandemic. The purpose of this study was to compare the oncologic outcomes of delayed surgical resection and early SBRT among operable patients with early stage lung cancer. METHODS: The National Cancer Database was queried for patients with cT1aN0M0 NSCLC who underwent surgery or SBRT (2010-2016) with no comorbidity. Patients with any comorbidities or age >80 were excluded. The outcome of interest was overall survival. Delays in surgical care were modeled using different times from diagnosis to surgery. A 1:1 propensity match was performed and survival was analyzed using multivariable Cox regression. RESULTS: Of 6720 healthy cT1aN0M0 NSCLC patients, 6008 (89.4%) received surgery and 712 (10.6%) received SBRT. Among surgery patients, time to surgery >30 d was associated with inferior survival (HR > 1.4, P ≤ 0.013) compared with patients receiving surgery ≤14 d. Relative to SBRT, surgery demonstrated superior survival at all time points evaluated: 0-30 d, 31-60 d, 61-90 d, and >90 d (all P < 0.001). Among a propensity-matched cohort of 256 pairs of patients, delayed surgery (>90 d) remained association with better overall survival relative to early SBRT (5-year survival 76.9% versus 32.3%, HR = 0.266, P < 0.001). CONCLUSIONS: Although longer time to surgery is associated with inferior survival among surgery patients, delayed surgery is superior to early SBRT. Surgical resection should remain the standard of care to treat operable early stage lung cancer despite delays imposed by the COVID-19 pandemic.

Trends in surgery and survival for T1-T2 male breast cancer: A study from the National Cancer Database.

BACKGROUND: Despite evidence that early-stage male breast cancer (MBC) can be treated the same as in females, we hypothesized that men undergo more extensive surgery. METHODS: Patients with clinical T1-2 breast cancer were identified in the National Cancer Database 2004-2016. Trends in surgery type and overall survival were compared between sexes. RESULTS: Of 9,782 males and 1,078,105 females, most were cN0 with AJCC stage I/II disease. Unilateral mastectomy was most common in men (67.1% vs. 24.1%, p < 0.001) and partial mastectomy in women (64.7% vs. 26.4%, p < 0.001), with no significant change over time. Over 1/3 of men received ALND in 2016. While overall survival was superior in females (HR 0.83, 95% CI 0.73-0.94, p = 0.003), partial mastectomy was associated with a 42% reduction in mortality risk for males (HR 0.58, 95% CI 0.4-0.8, p = 0.003). CONCLUSIONS: De-escalation of surgery could be considered for MBC to improve survival and align with current standards of care.

Age disparities in triple-negative breast cancer treatment and outcomes: An NCDB analysis.

BACKGROUND: Race, access to care, and molecular features result in outcome disparities in triple-negative breast cancer (TNBC). We sought to determine the role of age in TNBC disparity by hypothesizing that younger patients receive more comprehensive treatment, resulting in survival differences. METHODS: The National Cancer Database was used to identify women with unilateral TNBC treated from 2005 through 2017. Patients were stratified by age (≤40, 41-70, >70); demographics, clinical characteristics, and treatment factors were compared. Logistic regression determined factors associated with treatment received. Survival outcomes were analyzed using a stratified log-rank test. RESULTS: Of the 168,715 patients, 16,287 (9.6%) were ≤40 years. Patients ≤40 were significantly more likely to present at higher clinical stage (P < .001) and receive neoadjuvant chemotherapy (NAC, P < .001). Bilateral mastectomy was the most common surgery for patients ≤40 (37%), whereas partial mastectomy was most often used in patients 41 to 70 years old (48%) and those >70 (49%) (P < .001). Patients ≤40 years were significantly more likely to undergo both NAC and mastectomy than those >40 (odds ratio 1.5, both P < .05) despite a greater in-breast tumor response in the youngest patients. Patients treated with mastectomy and axillary lymph node dissection had inferior survival outcomes compared to those treated with partial mastectomy and sentinel lymph node biopsy across all 3 age groups (P < .001). CONCLUSION: The clinical characteristics of TNBC differ significantly at the extremes of age, likely driving treatment decisions. Although patients ≤40 present with a more advanced disease and appropriately receive NAC, they also undergo more extensive surgery that does not yield a survival benefit. Further research is needed to determine if age disparity is due to oncologic factors or patient and provider preferences.

A comparison of local therapy alone with local plus systemic therapy for stage I pT1aN0M0 HER2+ breast cancer: A National Cancer Database analysis.

BACKGROUND: Small invasive breast cancers (BCs) with tumor sizes ≤5 mm (T1a) are associated with an excellent prognosis without systemic therapy. Although HER2 overexpression (HER2+) is associated with a higher risk of recurrence and poorer clinical outcomes, in the absence of HER2 directed therapy, it remains unclear whether adjuvant systemic therapy is necessary in node-negative patients diagnosed with HER2+ invasive BCs ≤5 mm (pT1aN0M0). METHODS: The National Cancer Database was searched to identify patients diagnosed with HER2+ pT1aN0M0 BCs from 2004 to 2017. The cohort was stratified by treatment status: local therapy alone or local plus adjuvant systemic therapy. A 1:1 propensity match was performed. Overall survival (OS) was analyzed using stratified multivariable Cox proportional hazards regression analyses. RESULTS: Of the 8948 patients found, 4026 (45.0%) underwent surgery alone, and 4922 (55.0%) received surgery plus systemic therapy. Patients with either moderately differentiated (odds ratio [OR], 2.053; P < .001) or poorly/undifferentiated tumors (OR, 3.780; P < .001) or with the presence of lymphovascular invasion (OR, 3.351; P < .001) were more likely to have received systemic therapy. Propensity matching generated 1162 pairs of patients who were hormone receptor positive (HR+) and 748 pairs who were hormone receptor negative (HR-). Propensity matching effectively reduced selection bias between study groups. In the matched cohort, the addition of systemic therapy was not associated with superior OS (hazard ratio for HR+, 1.613; P = .107, and hazard ratio for HR- 1.319; P = .369) compared with patients who received local therapy alone. CONCLUSIONS: In pT1aN0M0 HER2+ BC, the addition of adjuvant systemic therapy after surgical excision was not associated with improved OS compared with local therapy alone.

Sex Differences in Lung Cancer Treatment and Outcomes at a Large Hybrid Academic-Community Practice.

Introduction: Lung cancer is the leading cause of cancer-related death and the second most often diagnosed malignancy worldwide. Males have higher incidence of lung cancer and higher mortality. It is hypothesized that the sex differences in survival are primarily driven by a better response of females to treatment. The primary objective of this work is to analyze and describe outcome differences between males and females diagnosed with having lung cancer. Methods: Data were obtained from a large hybrid academic-community practice institution and validated with Surveillance, Epidemiology, and End Results (SEER). The initial cohort included patients aged more than or equal to 18 years diagnosed with having primary malignant lung cancer. Patients were excluded from the analysis if they had an unknown diagnosis date, were missing sex, or had prior history of cancer. Chi-square, t test, and Kruskal-Wallis tests were used to compare characteristics of males and females. Risks were estimated by logistic and Cox regressions. Results: A total of 8909 patients from our institution and 725,018 in SEER were analyzed. Male-to-female ratio was 1.0. Females were more likely to undergo surgery and less likely to be treated with immunotherapy. Females had higher rates of documented psychological affections, depression, anxiety, urinary tract infection, hypothyroidism, and hyperthyroidism, while displaying lower rates of acute kidney injury, myocardial infarction, and myocarditis. Paired multivariable models revealed a lower risk of death for females in SEER (hazard ratio for females = 0.84, confidence interval: 0.69-1.02, p = 0.08) and equal risks in our institution (hazard ratio for females = 0.84, confidence interval: 0.69-1.02, p = 0.08). Conclusions: Female sex was associated with higher surgical rates, lower immunotherapy use rates, higher rates of endocrinologic complications after immunotherapy use, and higher rates of psychological disorders.

Minimally Invasive Mastectomy Could Achieve Non-inferior Oncological Outcome in Appropriately Selected Patients: Propensity Matched Analysis of the National Cancer Database.

BACKGROUND: Minimally invasive mastectomy (MIM) was emerged as an approach to decrease morbidity and increase patient satisfaction through improved cosmetic results; however, there is a paucity of data regarding the long-term oncologic outcomes of these minimally invasive approaches. METHODS: Patients who underwent mastectomy procedures were identified in the National Cancer Database (2010-2016). Patients were categorized as MIM or open mastectomy. A 1:1 propensity match was performed to balance the bias on reconstruction, nipple sparing, lymph node procedures, and other confounding factors between the cohorts. Short- and long-term outcomes were compared. RESULTS: A total of 328 811 patients met the criteria: 327 643 (99.6%) received open mastectomy and 1168 (.4%) received MIM. Propensity match identified 384 "pairs" of MIM and open mastectomy patients. Among them, MIM was associated with shorter length of stay (LOS) (mean 1.3 vs. 1.06 days, P = .003). No differences were observed in the rates of positive margins, unplanned readmissions, or 90-day mortality between the 2 operative approaches. Overall survival (OS) was equivalent between MIM and open mastectomy patients. Cox proportional hazard regression showed no effect of the procedure performed on OS. DISCUSSION: MIM is associated with shorter LOS, and it is non-inferior to open mastectomy in terms of other short-term outcomes and long-term oncologic survival outcomes. These data suggest that MIM may be considered in appropriately selected breast cancer patients as an additional approach to the community.

Adjuvant trastuzumab with or without chemotherapy in stage 1 pT1N0 HER2+ breast cancer: a National Cancer Database analysis.

PURPOSE: Approximately 20% of all breast cancers (BC) are HER2 amplified. In the APT trial, weekly paclitaxel/trastuzumab in node negative HER2+ BC with tumors < 3 cm was associated with a 7-year invasive disease-free survival of 93%. However, this was in the context of a non-randomized trial, and for pT1N0 HER2+ BC it remains unclear whether HER2 monotherapy would provide similar clinical outcomes to chemo-HER2 therapy. We hypothesized that adjuvant chemo-HER2 therapy would be associated with a modestly improved overall survival compared to HER2 monotherapy in patients with tumors < 2 cm. METHODS: In the National Cancer Database (2004-2017), patients with a primary diagnosis of pT1N0M0 HER2+ BC, were separated into two groups: (i) HER2 monotherapy, i.e., trastuzumab, and (ii) chemo-HER2 therapy. A 3:1 propensity match was performed to balance patient selection bias between the two different cohorts. Long-term overall survival (OS) was compared between both groups. RESULTS: A total of 23,281 patients met the criteria. 22,268 (96.7%) received chemo-HER2 therapy and 1013 (4.4%) received HER2 monotherapy. Propensity match identified 1995 patients who received chemo-HER2 therapy, and 666 who received HER2 monotherapy. After matching, adjuvant chemo-HER2 therapy was associated with a modest survival advantage over HER2 monotherapy (5-year OS 94.1% vs. 90.6%, P = 0.041). CONCLUSIONS: Even though there is a modest OS advantage favoring adjuvant chemo-HER2 therapy in patients with pT1N0 HER2+ BC, HER2 monotherapy was associated with 5-year OS > 90%. Therefore, in select patients who have contraindications for cytotoxic chemotherapy, or decline adjuvant chemotherapy altogether, adjuvant trastuzumab monotherapy appears to be a reasonable alternative.

Neoadjuvant Endocrine Therapy as an Alternative to Neoadjuvant Chemotherapy Among Hormone Receptor-Positive Breast Cancer Patients: Pathologic and Surgical Outcomes.

BACKGROUND: Neoadjuvant chemotherapy (NCT) is considered more effective in downstaging hormone receptor-positive (HR+) breast cancer than neoadjuvant endocrine therapy (NET), particularly in node-positive disease. This study compared breast and axillary response and survival after NCT and NET in HR+ breast cancer. METHODS: Based on American College of Surgeons Oncology Group (ACOSOG) Z1031 criteria, women age 50 years or older with cT2-4 HR+ breast cancer who underwent NET or NCT and surgery were identified in the National Cancer Database 2010-2016. Chi-square and logistic regression analysis determined differences between the NCT and NET groups and therapy response, including downstaging and pathologic complete response (pCR, ypT0/is and ypN0). RESULTS: Of 19,829 patients, 14,025 (70.7%) received NCT and 5804 (29.3%) received NET. The NET patients were older (mean age, 68.9 vs. 60.3; P < 0.001) and had greater comorbidity (1+ Charlson-Deyo score, 21% vs. 16%; P < 0.001). Therapy achieved T downstaging (any) for 58% of the patients with NCT versus 40.5% of the patients with NET, and in-breast pCR was achieved for 9.3% of the NCT versus 1.3% of the NET patients (P < 0.001). Approximately half of the mastectomy procedures could have been potentially avoided for the patients with in-breast pCR (53.6% of the NCT and 43.8% of the NET patients). For the cN+ patients, N downstaging (any) was 29% for the NCT patients versus 18.3% for the NET patients (P < 0.001), and nodal pCR was achieved for 20.3% of the NCT versus 13.5% of the NET patients (P < 0.001). Among those with nodal pCR, axillary lymph node dissection (ALND) still was performed for 56% of the patients after NCT and 45% of the patients after NET. CONCLUSIONS: Although the response rates after NCT were higher, NET achieved both T and N downstaging and pCR. Neoadjuvant endocrine therapy can be used to de-escalate surgery for patients who cannot tolerate NCT or when chemotherapy may not be effective based on genomic testing.

Despite Equivalent Outcomes, Men Receive Neoadjuvant Chemotherapy Less Often Than Women for Lymph Node-Positive Breast Cancer.

BACKGROUND: Neoadjuvant chemotherapy (NAC) downstages breast cancer and provides prognostic information. Males with breast cancer are known to receive less treatment overall and have poorer outcomes relative to females. We hypothesized that males would be less likely to receive NAC. PATIENTS AND METHODS: Patients with a primary diagnosis of cN1-3 breast cancer were identified in the National Cancer Database (2004-2016). Multivariable logistic regression determined the association between NAC utilization and sex, and the relationship between sex and NAC response, controlling for demographic and tumor factors. Overall survival was analyzed using a multivariable Cox model. RESULTS: In total, 196,027 patients (194,010 females, 2017 males) met inclusion criteria. A significantly greater proportion of males underwent mastectomy (80% vs. 60%, P < 0.001), and axillary lymph node dissection (76% vs. 74%, P = 0.022). Overall fewer men received chemotherapy than women (73% vs. 84%, P < 0.001); men also received NAC at a significantly lower rate (26% men vs. 45% women, P < 0.001). After accounting for demographic and oncologic factors including hormone receptor (HR) subtype, females remained more likely to undergo NAC (OR 1.84, P < 0.001). On multivariable analysis, sex was not associated with pathologic response or overall survival after NAC. CONCLUSIONS: Although oncologic outcomes after NAC were similar, males with node-positive breast cancer received less NAC and more aggressive surgery than females. These data suggest men achieve outcomes comparable to women with cN1-3 disease, and NAC should be used in appropriate male patients to downstage the breast and axilla.