Omission of Axillary Dissection Following Nodal Downstaging With Neoadjuvant Chemotherapy.

Importance: Data on oncological outcomes after omission of axillary lymph node dissection (ALND) in patients with breast cancer that downstages from node positive to negative with neoadjuvant chemotherapy are sparse. Additionally, the best axillary surgical staging technique in this scenario is unknown. Objective: To investigate oncological outcomes after sentinel lymph node biopsy (SLNB) with dual-tracer mapping or targeted axillary dissection (TAD), which combines SLNB with localization and retrieval of the clipped lymph node. Design, Setting, and Participants: In this multicenter retrospective cohort study that was conducted at 25 centers in 11 countries, 1144 patients with consecutive stage II to III biopsy-proven node-positive breast cancer were included between April 2013 and December 2020. The cumulative incidence rates of axillary, locoregional, and any invasive (locoregional or distant) recurrence were determined by competing risk analysis. Exposure: Omission of ALND after SLNB or TAD. Main Outcomes and Measures: The primary end points were the 3-year and 5-year rates of any axillary recurrence. Secondary end points included locoregional recurrence, any invasive (locoregional and distant) recurrence, and the number of lymph nodes removed. Results: A total of 1144 patients (median [IQR] age, 50 [41-59] years; 78 [6.8%] Asian, 105 [9.2%] Black, 102 [8.9%] Hispanic, and 816 [71.0%] White individuals; 666 SLNB [58.2%] and 478 TAD [41.8%]) were included. A total of 1060 patients (93%) had N1 disease, 619 (54%) had ERBB2 (formerly HER2)-positive illness, and 758 (66%) had a breast pathologic complete response. TAD patients were more likely to receive nodal radiation therapy (85% vs 78%; P = .01). The clipped node was successfully retrieved in 97% of TAD cases and 86% of SLNB cases (without localization). The mean (SD) number of sentinel lymph nodes retrieved was 3 (2) vs 4 (2) (P < .001), and the mean (SD) number of total lymph nodes removed was 3.95 (1.97) vs 4.44 (2.04) (P < .001) in the TAD and SLNB groups, respectively. The 5-year rates of any axillary, locoregional, and any invasive recurrence in the entire cohort were 1.0% (95% CI, 0.49%-2.0%), 2.7% (95% CI, 1.6%-4.1%), and 10% (95% CI, 8.3%-13%), respectively. The 3-year cumulative incidence of axillary recurrence did not differ between TAD and SLNB (0.5% vs 0.8%; P = .55). Conclusions and Relevance: The results of this cohort study showed that axillary recurrence was rare in this setting and was not significantly lower after TAD vs SLNB. These results support omission of ALND in this population.

Anatomy Versus Biology: What Guides Chemotherapy Decisions in Older Patients With Breast Cancer?

INTRODUCTION: With the increasing utilization of genomic assays, such as the Oncotype DX recurrence score (RS), the relevance of anatomic staging has been questioned for select older patients with breast cancer. We sought to evaluate differences in chemotherapy receipt and/or survival among older patients based on RS and sentinel lymph node biopsy (SLNB) receipt/result. METHODS: Patients aged ≥ 65 diagnosed with pT1-2/cN0/M0 hormone-receptor-positive (HR+)/HER2-breast cancer (2010-2019) were selected from the National Cancer Database. Logistic regression was used to identify factors associated with chemotherapy receipt. Cox proportional hazards models were used to estimate the association of RS/SLNB group with overall survival. A cost-benefit study was also performed. RESULTS: Of the 75,428 patients included, the majority had an intermediate RS (58.2% versus 27.9% low, 13.8% high) and were SLNB- (85.1% versus 11.6% SLNB+, 3.3% none). Chemotherapy was recommended for 13,442 patients (17.8%). After adjustment, chemotherapy receipt was more likely with higher RS and SLNB+. After adjustment, SLNB receipt/result was only associated with overall survival among those with an intermediate RS. However, returning to the OR for SLNB is not cost-effective. CONCLUSIONS: SLNB receipt/result was associated with survival for those with an intermediate RS, but not a low or high RS, suggesting that an SLNB may indeed be unnecessary for select older patients with breast cancer.

Racial/Ethnic Disparities in Pathologic Complete Response and Overall Survival in Patients With Triple-Negative Breast Cancer Treated With Neoadjuvant Chemotherapy.

PURPOSE: Black women have higher rates of death from triple-negative breast cancer (TNBC) than White women. We hypothesized that pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) and overall survival (OS) may vary by race/ethnicity in patients with TNBC. METHODS: We identified women 18 years and older with stage I-III TNBC who received NAC followed by surgery from the National Cancer Database (2010-2019). We excluded patients without race/ethnicity or pathology data. Primary outcomes were pCR rates and OS on the basis of race/ethnicity. RESULTS: Forty thousand eight hundred ninety women with TNBC met inclusion criteria (median age [IQR], 53 [44-61] years): 26,150 Non-Hispanic White (64%, NHW), 9,672 Non-Hispanic Black (23.7%, NHB), 3,267 Hispanic (8%), 1,368 Non-Hispanic Asian (3.3%, NHA), and 433 Non-Hispanic Other (1.1%, NHO) patients. Overall, 29.8% demonstrated pCR (NHW: 30.5%, NHB: 27%, Hispanic: 32.6%, NHA: 28.8%, NHO: 29.8%). Unadjusted OS was significantly higher for those with pCR compared with those with residual disease (5-year OS, 0.917 [95% CI, 0.911 to 0.923] v 0.667 [95% CI, 0.661 to 0.673], log-rank P < .001), and this association persisted after adjustment for demographic and tumor factors. The effect of achieving pCR on OS did not differ by race/ethnicity (interaction P = .10). However, NHB patients were less likely (odds ratio [OR], 0.89 [95% CI, 0.83 to 0.95], P = .001) and Hispanic patients were more likely (OR, 1.19 [95% CI, 1.08 to 1.31], P = .001) to achieve pCR than NHW patients. After adjustment for patient and disease factors, including achievement of pCR, Hispanic (hazard ratio [HR], 0.76 [95% CI, 0.69 to 0.85], P < .001) and NHA (HR, 0.64 [95% CI, 0.55 to 0.75], P < .001) race/ethnicity remained associated with OS. CONCLUSION: Odds of achieving pCR and OS in patients with TNBC appear to be associated with race/ethnicity. Additional research is necessary to understand how race/ethnicity is associated with rates of pCR and OS, whether related to socioeconomic factors or biologic variables, or both.

Axillary nodal disease burden is not associated with an elevated 21-gene recurrence score in post-menopausal women presenting with a clinically negative axilla.

BACKGROUND: The predictive and prognostic value of the recurrence score (RS) has emphasized the importance of tumor biology and has reduced the prognostic implications of limited nodal burden in post-menopausal women with HR+/HER2-invasive breast cancer (IBC). It is unclear whether routine axillary staging has a continued role in the management of small, clinically node negative (cN0) HR+/HER2- IBC. We sought to estimate the association of RS with pN stage. METHODS: Patients >50yo diagnosed with cN0, HR+/HER2- IBC (2015-2019) with an available RS were identified from the National Cancer Database. The clinicopathologic characteristics and rates of pN-stage (pN0, pN1, pN2/3) were compared for RS of ≤25 vs. >25. RESULTS: The median patient age was 64.1 (IQR 58-69) and the majority (75%) of tumors displayed ductal histology. Most (81.6%) were cT1 on presentation and pT1 (74.7%) on final pathology. There were 130,568 (86.2%) with a RS â€‹≤ â€‹25 and 20,879 (13.8%) with a RS â€‹> â€‹25. On final pathology, 128,995 (85.2%) were pN0 and 21,991 (14.5%) pN1. Of the pN1, 2699 (12.3%) yielded a RS â€‹> â€‹25. There were 461 (0.3%) patients with pN2-pN3 disease. Of those, 57 (12.4%) had RS â€‹> â€‹25. CONCLUSION: In our analysis, pN0 and pN1 tumors are biologically similar by gene expression assay in postmenopausal patients with similar proportions of high RS. These data support the notion that tumor biology examined via RS may have more prognostic and predictive value than metastatic dissemination to limited lymph nodes. These findings support the ongoing evaluation of routine axillary staging in postmenopausal patients with HR+/HER2- IBC.

Neoadjuvant Chemotherapy and Endocrine Therapy for Older Patients with Estrogen Receptor Positive Breast Cancer: Comparison of Approaches.

BACKGROUND: Benefits of a pathologic complete response (pCR) following neoadjuvant therapy are well established, yet outcomes for older women are understudied. We sought to examine the pCR and overall survival (OS) rates of women with estrogen receptor (ER) positive breast cancer across age groups. METHODS: Women diagnosed with cT1-4, N0-3, M0, ER+/HER2- breast cancer (2010-2018) who underwent neoadjuvant chemotherapy (NACT) or neoadjuvant endocrine therapy (NET) followed by surgery were selected from the National Cancer Database and categorized by age. Differences were tested, and Cox proportional hazards models were used to estimate the association of response with OS after adjustment for covariates. RESULTS: In the 43,009-patient cohort, 84.8% received NACT and 15.2% received NET. Of those aged ≥ 70 (N = 5623), 51.0% received NACT, and 49.0% received NET. Compared with younger women receiving NACT, older women were less likely to have a breast or nodal pCR [no pCR by age: 85.1% (≥ 70 years) vs 82.2% (50-69 years) vs 77.7% (< 50 years), p < 0.001]. Rates of pCR were similarly low for all women receiving NET [no pCR by age: 95.6% (≥ 70 years) vs 95% (50-69 years) vs 96% (< 50 years), p = 0.06]. After adjustment, pCR after NACT was not associated with OS for older patients, but better survival outcomes were noted for older patients achieving pCR after NET. CONCLUSION: For women with ER+/HER2- breast cancer, pCR rates after NACT are lower in older women compared with younger women, and are equally low after NET for all women. However, pCR after NET is associated with improved OS among older women, unlike pCR after NACT.

NCCN Guidelines® Insights: Breast Cancer, Version 4.2023.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer address all aspects of management for breast cancer. The treatment landscape of metastatic breast cancer is evolving constantly. The therapeutic strategy takes into consideration tumor biology, biomarkers, and other clinical factors. Due to the growing number of treatment options, if one option fails, there is usually another line of therapy available, providing meaningful improvements in survival. This NCCN Guidelines Insights report focuses on recent updates specific to systemic therapy recommendations for patients with stage IV (M1) disease.

Racial-ethnic variations in phyllodes tumors among a multicenter United States cohort.

BACKGROUND AND OBJECTIVES: Previous studies have identified racial-ethnic differences in the diagnostic patterns and recurrence outcomes of women with phyllodes tumors (PT). However, these studies are generally limited in size and generalizability. We therefore sought to explore racial-ethnic differences in age, tumor size, subtype, and recurrence in a large US cohort of women with PT. METHODS: We performed an 11-institution retrospective review of women with PT from 2007 to 2017. Differences in age at diagnosis, tumor size and subtype, and recurrence-free survival according to race-ethnicity. RESULTS: Women of non-White race or Hispanic ethnicity were younger at the time of diagnosis with phyllodes tumor. Non-Hispanic Other women had a larger proportion of malignant PT. There were no differences in recurrence-free survival in our cohort. CONCLUSIONS: Differences in age, tumor size, and subtype were small. Therefore, the workup of young women with breast masses and the treatment of women with PT should not differ according to race-ethnicity. These conclusions are supported by our finding that there were no differences in recurrence-free survival.

The role of tumor phenotype in the surgical treatment of early-stage breast cancer.

BACKGROUND: We investigated whether tumor phenotype influences surgical decision-making, and how that may impact overall survival (OS) for early-stage breast cancer. METHODS: Women aged 18-69 with cT0-2/cN0/cM0 breast cancer in the National Cancer Database (2010-2017) were included. A generalized logistic model was used to identify factors associated with surgery type. A Kaplan-Meier curve was used to visualize unadjusted OS, and the log-rank test was used to test for differences in OS between surgery types. RESULTS: Of 597,149 patients, 58% underwent lumpectomy with radiation (BCT), 25% unilateral mastectomy (UM), and 17% bilateral mastectomy (BM). After adjustment, HER2+ and triple-negative (TN) tumors were less likely to undergo UM than BCT, versus hormone receptor-positive tumors (OR = 0.881, 95% CI = 0.860-0.903; OR = 0.485, 95% CI = 0.470-0.501). UM and BM had worse 5-year OS versus BCT (UM: 0.926, vs BM: 0.952, vs BCT: 0.960). CONCLUSIONS: BCT is increasingly used to treat HER2+ and TN tumors. More extensive surgery is not associated with better survival outcomes, regardless of tumor phenotype.

The Influence of Body Mass Index on the Histopathology and Outcomes of Patients Diagnosed with Atypical Breast Lesions.

BACKGROUND: Multiple studies have demonstrated a link between obesity and breast cancer; however, the potential association between obesity and atypical high-risk breast lesions has not been well characterized. We sought to evaluate the characteristics and clinical outcomes of patients with breast atypia based on a woman's body mass index (BMI). METHODS: We retrospectively identified adult women diagnosed with atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), and/or lobular carcinoma in situ (LCIS) at a single institution from 2008 to 2017. BMI groups were defined as a BMI 18.5 to < 30 or BMI ≥ 30 (obese). Adjusted logistic regression was used to estimate the association of BMI group with the odds of (1) upstage to cancer after atypia on needle biopsy, and (2) subsequent diagnosis of breast cancer. RESULTS: Breast atypia was identified in 503 patients (most advanced atypia: 74.8% ADH, 4.6% ALH, 20.7% LCIS), and 41% of these patients were classified as obese. After adjustment, BMI group was not associated with upstage to breast cancer at surgical excision following needle biopsy (p = 0.16) or development of a subsequent breast cancer (p = 0.08). For those upstaged to breast cancer at the time of surgical excision, or those who developed a subsequent malignancy, tumor subtype, grade and stage were not associated with BMI group (p > 0.05). CONCLUSION: In a large cohort of patients diagnosed with atypical breast histology, the risk of upstaging and/or subsequent progression to a breast malignancy was not associated with BMI. Factors other than obesity may influence breast cancer risk.

Margin Management and Adjuvant Therapy for Phyllodes Tumors: Practice Patterns of the American Society of Breast Surgeons Members.

BACKGROUND: Phyllodes tumors (PTs) are rare breast neoplasms with variable clinical behavior by histologic type: benign, borderline, or malignant. Until recently, management guidelines recommended one approach for all subtypes. METHODS: A 21-question survey was sent to American Society of Breast Surgeon members to evaluate management patterns by subtype. Surgeon demographics, decisions regarding management of margins, re-excision, surveillance, and synoptic reporting were collected. Chi-square or analysis of variance (ANOVA) were used as appropriate, with significance set at p < 0.05. RESULTS: A total of 493 of 2969 surveys were completed for a response rate of 18.3%. Among the survey takers, 55% were fellowship trained, 72% were in practice > 10 years, and 82% performed > 100 breast cases per year. Although 25% of respondents enucleate a mass with clinical suspicion of a PT alone, this decreased to 18% if a preoperative core biopsy performed was suggestive of PT. For margin management, 47% do not re-excise positive margins for benign PTs, but 96% would for a borderline or malignant PTs (p < 0.001). Only 2% perform axillary staging for malignant PTs, and 90% refer borderline or malignant PTs for radiation. Two-year surveillance was performed by about half of respondents for benign PT. However, two-thirds of respondents would increase surveillance to 5 years for borderline or malignant PTs. Only 38% report a templated synoptic pathology report at their institution. CONCLUSION: PT management patterns are evolving but still variable when looking at initial margin intent, decision for re-excision, radiation referral, pathologic reporting, and surveillance. This suggests the need for more specific management guidelines by subtype given differences in clinical behavior.

Breast Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology.

The therapeutic options for patients with noninvasive or invasive breast cancer are complex and varied. These NCCN Clinical Practice Guidelines for Breast Cancer include recommendations for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget disease, phyllodes tumor, inflammatory breast cancer, and management of breast cancer during pregnancy. The content featured in this issue focuses on the recommendations for overall management of ductal carcinoma in situ and the workup and locoregional management of early stage invasive breast cancer. For the full version of the NCCN Guidelines for Breast Cancer, visit NCCN.org.

Does Angiosarcoma of the Breast Need Nodal Staging?

BACKGROUND: Breast angiosarcoma is a rare malignancy classically associated with hematogenous metastases. We sought to determine the prevalence of pathologic nodal involvement in patients with nonmetastatic, resected breast angiosarcoma and its association with overall survival. STUDY DESIGN: The National Cancer Database was used to identify patients with nonmetastatic angiosarcoma of the breast who underwent surgical resection from 2004 to 2017. The prevalence of regional lymph node operation and nodal positivity was calculated. The Kaplan-Meier method was used to evaluate overall survival among node-positive and node-negative patients. Cox proportional hazard modeling was used to evaluate the adjusted association of nodal positivity with overall survival. RESULTS: We included 991 patients with angiosarcoma. The median age was 69 years (interquartile range 57 to 78), and the cohort was 99% female. A total of 298 patients (30%) had pathologic regional nodal evaluation. Of those, 15 (5.0%) had positive regional lymph nodes. Node-positive patients had significantly worse survival than patients with negative regional lymph nodes. After adjusting for patient, tumor, and treatment factors, a positive regional lymph node was associated with worse overall survival compared with patients with no nodal evaluation (hazard ratio 3.20; 95% CI 1.75 to 5.86; p < 0.001). CONCLUSIONS: Patients with nonmetastatic angiosarcoma of the breast have a 5% regional lymph node positivity rate, which is at a common threshold to consider evaluation, and identifies patients with poor survival. A prospective study to determine performance characteristics of sentinel lymph node biopsy is warranted.

Malignant phyllodes tumor and primary breast sarcoma; distinct rare tumors of the breast.

BACKGROUND: Malignant phyllodes (MP) and primary breast sarcomas (PBS) are rare neoplasms with overlapping histopathologic features. We compared overall survival (OS) and estimated the association of surgery and therapies with OS. METHODS: We utilized the National Cancer Database (2004-2016). Patients without surgery, unknown surgery, or margins, or Stage IV disease were excluded. Kaplan-Meier curves and Cox proportional hazards models were used to estimate unadjusted and adjusted OS, respectively. RESULTS: A total of 3209 (59.5%) MP, and 2185 (40.5%) PBS were identified. Despite a larger median tumor size in MP (46 vs. 40 mm PBS, p < 0.001), lumpectomy rate was higher for MP (52.9% vs. 27.0% PBS, p < 0.001). Compared to MP, PBS patients more frequently received radiation (28.9% vs. 24%), and chemotherapy (28.1% vs. 4%), both p < 0.001. Unadjusted OS was lower for PBS (57% vs. 85% MP, log-rank p < 0.001). PBS (vs. MP) had persistently worse survival (hazard ratio [HR]: 1.98, 95% confidence interval [CI]: 1.69-2.31) after adjustment. Receipt of adjuvant therapies was not associated with OS (either neoplasm); however, lumpectomy was associated with improved OS (vs. mastectomy) for both PBS (HR: 0.59, 95% CI: 0.50-0.75) and MP (HR: 0.65, 95% CI: 0.53-0.81). Positive margins had no association with OS for MP (HR: 1.09, 95% CI: 0.75-1.60), but was associated with worse survival for PBS (HR: 2.35, 95% CI: 1.82-3.02). DISCUSSION: We found significant survival differences between MP and PBS, with PBS having a consistently worse OS. Our findings support surgery as the mainstay of treatment for both tumor types and suggest that lumpectomy may be a reasonable option for select patients without compromising outcomes.

Measuring intraoperative surgical instrument use with radio-frequency identification.

OBJECTIVE: Surgical instrument oversupply drives cost, confusion, and workload in the operating room. With an estimated 78%-87% of instruments being unused, many health systems have recognized the need for supply refinement. By manually recording instrument use and tasking surgeons to review instrument trays, previous quality improvement initiatives have achieved an average 52% reduction in supply. While demonstrating the degree of instrument oversupply, previous methods for identifying required instruments are qualitative, expensive, lack scalability and sustainability, and are prone to human error. In this work, we aim to develop and evaluate an automated system for measuring surgical instrument use. MATERIALS AND METHODS: We present the first system to our knowledge that automates the collection of real-time instrument use data with radio-frequency identification (RFID). Over 15 breast surgeries, 10 carpometacarpal (CMC) arthroplasties, and 4 craniotomies, instrument use was tracked by both a trained observer manually recording instrument use and the RFID system. RESULTS: The average Cohen's Kappa agreement between the system and the observer was 0.81 (near perfect agreement), and the system enabled a supply reduction of 50.8% in breast and orthopedic surgery. Over 10 monitored breast surgeries and 1 CMC arthroplasty with reduced trays, no eliminated instruments were requested, and both trays continue to be used as the supplied standard. Setup time in breast surgery decreased from 23 min to 17 min with the reduced supply. CONCLUSION: The RFID system presented herein achieves a novel data stream that enables accurate instrument supply optimization.

Utilization of neoadjuvant chemotherapy in high-risk, node-negative early breast cancer.

BACKGROUND: Controversy exists regarding the optimal sequence of chemotherapy among women with operable node-negative breast cancers with high-risk tumor biology. We evaluated national patterns of neoadjuvant chemotherapy (NACT) use among women with early-stage HER2+, triple-negative (TNBC), and high-risk hormone receptor-positive (HR+) invasive breast cancers. METHODS: Women ≥18 years with cT1-2/cN0 HER2+, TNBC, or high recurrence risk score (≥31) HR+ invasive breast cancers who received chemotherapy were identified in the National Cancer Database (2010-2016). Cochran-Armitage and logistic regression examined temporal trends and likelihood of undergoing NACT versus adjuvant chemotherapy based on patient age and molecular subtype. RESULTS: Overall, 96,622 patients met study criteria; 25% received NACT and 75% underwent surgery first, with comparable 5-year estimates of overall survival (0.90, 95% CI 0.892-0.905 vs 0.91, 95% CI 0.907-0.913). During the study period, utilization of NACT increased from 14% to 36% and varied according to molecular subtype (year*molecular subtype p < 0.001, p-corrected < 0.001). Women with HER2+ (OR 4.17, 95% CI 3.70-4.60, p < 0.001, p-corrected < 0.001) and TNBC (OR 3.81, 95% CI 3.38-4.31, p < 0.001, p-corrected < 0.001) were more likely to receive NACT over time, without a change in use among those with HR+ disease (OR 1.58, 95% CI 0.88-2.87, p = 0.13, p-corrected = 0.17). CONCLUSION: Among women with early-stage triple-negative and HER2+ breast cancers, utilization of NACT increased over time, a trend that correlates with previously reported improved rates of pCR and options post-neoadjuvant treatment with residual disease. Future research is needed to better understand multidisciplinary decisions for NACT and implications for breast cancer patients.

Disparities at the Intersection of Race and Ethnicity: Examining Trends and Outcomes in Hispanic Women With Breast Cancer.

PURPOSE: We sought to examine tumor subtype, stage at diagnosis, time to surgery (TTS), and overall survival (OS) among Hispanic patients of different races and among Hispanic and non-Hispanic (NH) women of the same race. METHODS: Women 18 years of age or older who had been diagnosed with stage 0-IV breast cancer and who had undergone lumpectomy or mastectomy were identified in the National Cancer Database (2004-2014). Tumor subtype and stage at diagnosis were compared by race/ethnicity. Multivariable linear regression and Cox proportional hazards modeling were used to estimate associations between race/ethnicity and adjusted TTS and OS, respectively. RESULTS: A total of 44,374 Hispanic (American Indian [AI]: 79 [0.2%]; Black: 1,011 [2.3%]; White: 41,126 [92.7%]; Other: 2,158 [4.9%]) and 858,634 NH women (AI: 2,319 [0.3%]; Black: 97,206 [11.3%]; White: 727,270 [84.7%]; Other: 31,839 [3.7%]) were included. Hispanic Black women had lower rates of triple-negative disease (16.2%) than did NH Black women (23.5%) but higher rates than did Hispanic White women (13.9%; P < .001). Hispanic White women had higher rates of node-positive disease (23.2%) versus NH White women (14.4%) but slightly lower rates than Hispanic (24.6%) and NH Black women (24.5%; P < .001). Hispanic White women had longer TTS versus NH White women regardless of treatment sequence (adjusted means: adjuvant chemotherapy, 42.71 v 38.60 days; neoadjuvant chemotherapy, 208.55 v 201.14 days; both P < .001), but there were no significant racial differences in TTS among Hispanic patients. After adjustment, Hispanic White women (hazard ratio, 0.77 [95% CI, 0.74 to 0.81]) and Black women (hazard ratio, 0.75 [95% CI, 0.58 to 0.96]) had improved OS versus NH White women (reference) and Black women (hazard ratio, 1.15 [95% CI, 1.12 to 1.18]; all P < .05). CONCLUSION: Hispanic women had improved OS versus NH women, but racial differences in tumor subtype and nodal stage among Hispanic women highlight the importance of disaggregating racial/ethnic data in breast cancer research.