Racial disparities in outcomes of patients with stage I-III triple-negative breast cancer after adjuvant chemotherapy: a post-hoc analysis of the E5103 randomized trial.

PURPOSE: Breast cancer mortality is higher in Black women than other racial groups. This difference has been partially attributed to a higher proportion of triple-negative breast cancer (TNBC). However, it is uncertain if survival disparities exist in racially diverse TNBC patients receiving similar treatments. Here, we examine racial differences in disease-related outcomes in TNBC patients treated on the E5103 clinical trial. METHODS: From 2007 to 2011, 4,994 patients with stage I-III HER2-negative breast cancer were randomized to adjuvant chemotherapy with or without bevacizumab. This analysis was limited to the subset of 1,742 TNBC patients with known self-reported race. Unadjusted Kaplan-Meier curves and adjusted Cox-Proportional Hazards models were used to determine breast cancer events and survival outcomes. RESULTS: Of the analysis population, 51 (2.9%) were Asian, 269 (15.4%) Black, and 1422 (81.6%) White. Median age was 51 years. Patient characteristics, treatment arm, and local therapies were similar across racial groups. White women were more commonly node-negative (56% vs. 49% and 44% in Asian and Black women, respectively; p < 0.01). At a median follow-up of 46 months, unadjusted Kaplan-Meier locoregional and distant recurrence, and disease-free and overall survival, did not differ significantly by race. In Cox models adjusted for patient and tumor characteristics and treatment arm, race was not associated with any disease event. Larger tumor size and nodal involvement were consistently associated with breast cancer events. CONCLUSION: This clinical trial population of similarly treated TNBC patients showed no racial differences in breast cancer outcomes. Disease extent, rather than race, was associated with disease events.

Real-World Implications of the SOUND Trial.

BACKGROUND: The SOUND trial demonstrated that omission of sentinel lymph node biopsy (SLNB) is noninferior to axillary staging in patients with early-stage breast cancer (BC) and negative axillary ultrasound (AxUS). We examined the generalizability of these findings in patients with hormone receptor (HR)+HER2- disease. METHODS: Patients with cT1N0M0, HR+HER2- BC and negative AxUS undergoing breast conservation with SLNB from 2016 to 2023 were identified from a prospectively maintained database. Clinicopathologic characteristics, disease burden, adjuvant treatment, and oncologic outcomes were examined and compared with the SLNB arm of the SOUND trial. In postmenopausal patients, the impact of nodal status and 21-gene recurrence score on chemotherapy recommendations were also examined. RESULTS: Of 3972 patients with cT1N0M0 HR+HER2- breast cancer, 544 underwent AxUS; 312 met SOUND eligibility criteria. Median age was 57 (interquartile range [IQR] 48-64) years, and 199 (63.8%) were postmenopausal. Median (IQR) tumor size was 1.3 (0.9-1.7) cm, and 260 (83.3%) tumors were grade 1 or 2. Sentinel lymph node biopsy was positive in 38 (12.2%) patients. Only three (0.4%) had ≥ 4 positive lymph nodes. At a median follow-up of 26.2 (IQR 10.8-38.2) months, there were no axillary recurrences and one (0.3%) distant recurrence. Among postmenopausal women with recurrence score ≤ 25, chemotherapy recommendations were not associated with nodal status. CONCLUSIONS: Examination of our real-world HR+ HER2- "SOUND-eligible" population suggests that nodal disease burden and oncologic outcomes are similar to the SOUND trial population, supporting careful implementation of trial results into multidisciplinary practice. In postmenopausal patients, omission of SLNB does not appear to impact adjuvant chemotherapy recommendations.

Defining the Biology of Estrogen Receptor-Low-Positive Breast Cancer.

BACKGROUND: We sought to better define estrogen receptor-low-positive (ER-low+) breast cancer biology and determine the utility of the Oncotype DX Breast Recurrence Score® (RS) assay in this population. METHODS: Patients with information regarding percentage ER positivity and PAM50 subtype were identified in The Cancer Genome Atlas (TCGA) and subtype distribution was determined. Next, patients with ER-low+ (ER 1-10%), HER2- breast cancer undergoing upfront surgery with known RS result were identified in the National Cancer Database (NCDB) and our institutional Dana-Farber Brigham Cancer Center (DF/BCC) database; RS distribution was examined. Finally, patients with ER-low+, HER2- breast cancer treated at DF/BCC from 2011 to 2020 without prior RS results and in whom tissue was available to perform the assay were identified. RS results, treatment, recurrence and breast cancer-specific survival (BCSS) were determined. RESULTS: Of 1033 patients in TCGA, ER percentage and PAM50 subtype were available for 342 (33.1%) patients. Forty-six (13.5%) had ER-low+/HER2- tumors, among whom 82.6% were basal and 4.3% were luminal A. Among 3423 patients with ER-low+/HER2- disease in the NCDB, RS results were available for 689 (20.1%) patients; 67% had an RS ≥26. In our institutional database, only two patients with ER-low+/HER2- disease and an RS were identified, both with RS ≥26. Among 37 patients in our institutional cohort without prior RS, 35 (97.4%) had an RS ≥26, determined with testing. After a median follow-up of 40 months (range 3-106), three patients, all treated with chemotherapy, recurred. Three-year BCSS was 97.0% (95% confidence interval 96.9-97.1%). CONCLUSIONS: Most ER-low+/HER2- breast cancers are basal-like, with RS ≥26 suggesting these tumors are similar to triple-negative disease.

Society of Surgical Oncology Breast Disease Site Working Group Statement on Contralateral Mastectomy: Indications, Outcomes, and Risks.

Rates of contralateral mastectomy (CM) among patients with unilateral breast cancer have been increasing in the United States. In this Society of Surgical Oncology position statement, we review the literature addressing the indications, risks, and benefits of CM since the society's 2017 statement. We held a virtual meeting to outline key topics and then conducted a literature search using PubMed to identify relevant articles. We reviewed the articles and made recommendations based on group consensus. Patients consider CM for many reasons, including concerns regarding the risk of contralateral breast cancer (CBC), desire for improved cosmesis and symmetry, and preferences to avoid ongoing screening, whereas surgeons primarily consider CBC risk when making a recommendation for CM. For patients with a high risk of CBC, CM reduces the risk of new breast cancer, however it is not known to convey an overall survival benefit. Studies evaluating patient satisfaction with CM and reconstruction have yielded mixed results. Imaging with mammography within 12 months before CM is recommended, but routine preoperative breast magnetic resonance imaging is not; there is also no evidence to support routine postmastectomy imaging surveillance. Because the likelihood of identifying an occult malignancy during CM is low, routine sentinel lymph node surgery is not recommended. Data on the rates of postoperative complications are conflicting, and such complications may not be directly related to CM. Adjuvant therapy delays due to complications have not been reported. Surgeons can reduce CM rates by encouraging shared decision making and informed discussions incorporating patient preferences.

Intraoperative Pathology Assessment May Lead to Overtreatment of the Axilla in Clinically Node-Negative Breast Cancer Patients Undergoing Upfront Mastectomy.

BACKGROUND: Randomized trials have established the safety of observation or axillary radiation (AxRT) as an alternative to axillary lymph node dissection (ALND) in patients with limited nodal disease who undergo upfront surgery. Variability remains in axillary management strategies in cN0 patients undergoing mastectomy found to have one to two positive sentinel lymph nodes (SLNs). We examined the impact of intraoperative pathology assessment in axillary management in a national cohort of AMAROS-eligible mastectomy patients. METHODS: The National Cancer Database was used to identify AMAROS-eligible cT1-2N0 breast cancer patients undergoing upfront mastectomy and SLN biopsy (SLNB) and found to have one to two positive SLNs, from 2018 to 2019. We constructed a variable defining intraoperative pathology as 'not performed/not acted on' if ALND was either not performed or performed at a later date than SLNB, or 'performed/acted on' if SLNB and ALND were completed on the same day. Adjusted multivariable analysis examined predictors of treatment with both ALND and AxRT. RESULTS: Overall, 8222 patients with cT1-2N0 disease underwent upfront mastectomy and had one to two positive SLNs. Intraoperative pathology was performed/acted on in 3057 (37.2%) patients. These patients were significantly more likely to have both ALND and AxRT than those without intraoperative pathology (41.0% vs. 4.9%; p < 0.001). On multivariate analysis, the strongest predictor of receiving both ALND and AxRT was use of intraoperative pathology (odds ratio 8.99, 95% confidence interval 7.70-10.5; p < 0.001). CONCLUSIONS: We advocate that consideration should be made for omission of routine intraoperative pathology in mastectomy patients likely to be recommended postmastectomy radiation to minimize axillary overtreatment with both ALND and AxRT in appropriate patients.

Racial Disparities in Locoregional Recurrence in Postmenopausal Patients with Stage I-III, Hormone Receptor-Positive Breast Cancer Enrolled in the NSABP B-42 Clinical Trial.

BACKGROUND: There are limited data examining racial disparities in locoregional recurrence (LRR) among women with access to high-quality care. We aimed to examine differences in late LRR by race in patients with stage I-IIIA, hormone receptor-positive (HR+) breast cancer enrolled in the National Surgical Adjuvant Breast and Bowel (NSABP) B-42 trial. METHODS: From 2006 to 2010, 3966 postmenopausal women with stage I-IIIA HR+ breast cancer who were disease-free after 5 years of endocrine therapy were randomized to an additional 5 years of endocrine therapy or placebo. Patients were excluded if multi-racial or if race was unknown. Kaplan-Meier curves were used to estimate 6-year LRR from the time of trial registration and according to race. Cox proportional hazards models were used for adjusted survival analyses. RESULTS: Overall, 3929 NSABP B-42 patients were included: 3688 (93.9%) White, 151 (3.8%) Black, and 90 (2.3%) Asian patients. Median follow-up was 75.2 months. Overall estimated 6-year LRR from trial registration was 1.8% and differed by race: LRR rates were 1.7% in White women, 4.9% in Black women, and 0% in Asian women (p = 0.046). Adjusted Cox proportional hazards analysis found Black race to be independently associated with LRR (hazard ratio [HzR] 2.36, 95% confidence interval [CI] 1.01-5.49; p = 0.047). Node-positivity was also associated with increased LRR (HzR 1.75, 95% CI 1.07-2.86; p = 0.025). Adjusted Cox analysis found LRR (HzR 2.32, 95% CI 1.33-4.06; p = 0.003) to be associated with increased overall mortality; however, race was not independently associated with mortality. CONCLUSION: Among postmenopausal patients with stage I-IIIA HR+ breast cancer in the NSABP B-42 trial, racial differences in late LRR were present, with the highest LRR in Black women.

Racial and Ethnic Disparities in Outcomes After Breast-Conserving Therapy and Endocrine Therapy for DCIS: A Post-Hoc Analysis of the NSABP B-35 Randomized Clinical Trial.

BACKGROUND: Racial and ethnic disparities in outcomes after treatment for ductal carcinoma in situ (DCIS) are largely unknown. The objective of this study was to examine breast cancer outcomes by race and ethnicity in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-35 clinical trial. PATIENTS AND METHODS: The NSABP B-35 trial randomized postmenopausal women with hormone receptor-positive DCIS treated with breast-conserving therapy to 5 years of tamoxifen or anastrozole. In total, 3104 women were enrolled between 2003 and 2006. For this analysis, patients without complete self-reported race and ethnicity or with immediate trial dropout were excluded. Kaplan-Meier curves and adjusted Cox-proportional hazards models were used for analyses. RESULTS: Of the 3061 women included, 2614 (85.4%) were non-Hispanic white (NHW), 255 (8.3%) were non-Hispanic Black (NHB), 95 (3.1%) were Hispanic, and 96 (3.1%) were Asian or Pacific Islander (API). Endocrine therapy assignment and duration were well balanced between racial and ethnic groups. Median follow-up was 9 years; unadjusted Kaplan-Meier curves did not show any racial differences in disease events. Adjusted Cox-proportional hazards models found API (versus NHW) race to be associated with higher local recurrence [hazard ratio (HzR) 2.45, p = 0.035] and NHB race to be associated with higher distant recurrence (HzR 5.03, p = 0.020) and breast cancer mortality (HzR 3.83, p = 0.046). CONCLUSIONS: Despite similar locoregional treatments and standard endocrine therapy in a clinical trial population, racial and ethnic disparities exist in long-term outcomes for hormone-receptor-positive DCIS. These findings suggest that factors outside of access and treatment may impact DCIS outcomes by race and ethnicity.

Nodal Positivity in Early-Stage Triple-Negative Breast Cancer: Implications for Preoperative Immunotherapy.

BACKGROUND: Adding pembrolizumab to preoperative chemotherapy improves event-free survival in patients with early-stage triple-negative breast cancer (TNBC). However, owing to potential toxicities, the risk-benefit ratio of pembrolizumab must be considered. There is consensus that the addition of immunotherapy should be recommended in node-positive patients. This study is undertaken to determine nodal positivity rates in patients with TNBC presenting with cT1-2N0 disease undergoing upfront surgery and to evaluate the utility of axillary ultrasound and biopsy in the setting of a negative clinical examination. PATIENTS AND METHODS: Patients with cT1-2N0 TNBC undergoing upfront surgery were identified from our institutional database (January 2016-February 2021; n = 343) and from the National Cancer Database (NCDB) (n = 46,015). Pathologic nodal status was determined. A second cohort of patients with cT1-T2 TNBC with a negative clinical examination was defined in our institutional database (n = 499), and utilization of axillary ultrasound was examined. RESULTS: For patients undergoing upfront surgery, pathologically positive nodes were found in 14.6% patients of our institutional cohort: 9.4% cT1a/b, 14.9% cT1c, and 20.8% cT2 tumors. In the NCDB cohort, 13.7% patients were node positive: 4.9% cT1a/b, 11.4% cT1c, and 19.7% cT2 tumors. For patients with a normal clinical examination undergoing axillary ultrasound, 7.5% of cT1c and 8.7% of cT2 had suspicious nodes biopsied and confirmed positive for metastasis. CONCLUSIONS: Pathologic node-positive disease is found in > 10 and 20% patients with cT1cN0 and cT2N0 TNBC, respectively. Axillary ultrasound can be used to identify patients presenting with a normal clinical examination for whom preoperative pembrolizumab should be considered.

Screening MRI Does Not Increase Cancer Detection or Result in an Earlier Stage at Diagnosis for Patients with High-Risk Breast Lesions: A Propensity Score Analysis.

BACKGROUND: Guidelines recommend consideration of screening MRI for patients with high-risk breast lesions (HRLs), acknowledging limited data for this moderate-risk population. METHODS: This study identified patients with atypical ductal/lobular hyperplasia (ADH/ALH), lobular carcinoma in situ, (LCIS) or both evaluated at our high-risk clinic. Patients were categorized as having received screening mammography (MMG) alone vs. MMG and breast MRI (MMG+MRI). Inverse probability weighting based on propensity scores (PS) representing likelihood of MRI use was applied to Kaplan-Meier and Cox regression analyses to determine cancer detection and biopsy rates by screening group. RESULTS: Among 908 eligible patients, 699 (77%) patients with available follow-up data were analyzed (542 with ADH/ALH and 157 with LCIS). Of the 699 patients, 540 (77%) received MMG alone, and 159 (23%) received MMG + MRI. The median follow-up period was 25 months, during which a median of two MRIs were performed. After PS-weighting, the characteristics of each screening group were well-balanced with respect to age, race, body mass index (BMI), menopausal status, breast density, family history, HRL type, and chemoprevention use. The 4 year breast cancer detection rate was 3.6% with both MMG alone and MMG+MRI (p = 0.89). The breast biopsy rates were significantly higher with MMG+MRI (30.5% vs12.6%; hazard ratio [HR], 2.67; p < 0.001). All breast cancers were clinically node-negative and pathologic stage 0 or 1. Among five cancers in the MMG+MRI group, two were MRI-detected, two were MMG-detected, and one was detected on clinical exam. CONCLUSIONS: Screening MRI did not improve cancer detection, and cancer characteristics were favorable whether screened with MMG alone or MMG + MRI. These findings question the benefit of MRI for patients with HRL, although longer-term follow-up study is needed.

The prevalence and predictors of adjuvant chemotherapy use among patients treated with neoadjuvant endocrine therapy.

PURPOSE: Neoadjuvant endocrine therapy (NET) facilitates clinical response and breast conservation in hormone receptor-positive (HR-positive) breast cancer. Patient selection for adjuvant chemotherapy (CT) post-NET is unclear and potentially evolving with use of genomic assays. We evaluated post-NET CT use in a national dataset. METHODS: Using the National Cancer DataBase, we identified patients with cT2-3N0-3M0 HR-positive/human epidermal growth factor receptor 2-negative breast cancer treated between 2010 and 2017 with 3-12 months of NET prior to breast surgery. CT use was evaluated in the overall population, in patients with a pathologic complete response (pCR) and in patients with ypT1-2N0 disease (approximating PEPI 0). Exploratory analysis included patients > 50 years with ypN0-1, and 21-gene recurrence score (RS) ≤ 25 (approximating TAILORx/RxPONDER populations not benefiting from CT). Multivariable logistic regression was used to identify factors associated with CT. RESULTS: Among 3624 eligible patients, 20.4% (740/3624) received CT. On multivariable analysis, age ≤ 50, lobular histology, grade 2, progesterone receptor negativity, ypT3, ypN + and RS ≥ 18 were associated with CT receipt. Co-morbidity, longer NET duration, ypT4, ypNx, and RS < 18 were associated with CT omission. CT was administered to 3.3% (1/30) of patients experiencing pCR and 5.5% (82/1483) with ypT1-2N0 disease. Among patients > 50 years with ypT0-3N0-1 residual disease, 13.8% (355/2569) received CT; RS was available for 24.8% (88/355) and 60% (53/88) had a score 0-25. CONCLUSION: A minority of patients receive CT post-NET. This decision appears to be driven by younger age, RS and pathological nodal status. Increased consideration of these factors prior to neoadjuvant treatment choice may be warranted.

Breast cancer knowledge and understanding treatment rationales among diverse breast cancer survivors.

PURPOSE: The degree to which breast cancer survivors know about their tumors and understand treatment rationales is not well understood. We sought to identify information gaps within a diverse sample and explore whether knowledge about breast cancer and treatment may impact care. METHODS: We conducted a one-time, interviewer-administered survey of women who were diagnosed with breast cancer during 2013-2017 and received care at one of three centers in Boston, MA, and New York, NY. We examined knowledge of breast cancer and treatment rationales, information preferences, and treatment receipt. RESULTS: During 2018-2020, we interviewed 313 women (American Association for Public Opinion Research Cooperation Rates 58.4-76.5% across centers) who were 56.9% White, 23.6% Black, 14.1% Hispanic, and 5.4% other. Among the 296 included in analyses, we observed high variability in knowledge of breast cancer and treatment rationales, with a substantial number demonstrating limited knowledge despite feeling highly informed; > 25% actively avoided information. Black and Hispanic (vs. White) women consistently knew less about their cancers. Lack of understanding of treatment rationales for chemotherapy, radiation, and hormonal therapy was common but not consistently different by race and ethnicity. Understanding treatment rationale (but not cancer knowledge) was associated with treatment initiation, but small sample sizes limited in-depth examination. CONCLUSIONS: Our study highlights the need for enhanced informational support for breast cancer survivors, who are challenged with complex information during the decision-making process and beyond. More research is needed to understand how to further educate and empower diverse populations of patients with breast cancer.

Sentinel Lymph Node Biopsy Alone is Adequate for Chemotherapy Decisions in Postmenopausal Early-Stage Hormone-Receptor-Positive, HER2-Negative Breast Cancer with One to Three Positive Sentinel Lymph Nodes.

BACKGROUND: The RxPONDER trial randomized patients with cT1-3N0 hormone receptor-positive, HER2-negative (HR+HER2-) breast cancer and one to three positive nodes and Recurrence Score (RS) < 26 to endocrine therapy (ET) or chemoendocrine therapy (CET) with equivalent survival in postmenopausal women. In current practice, cN0 patients with one or two positive sentinel lymph nodes (SLN) do not undergo axillary lymph node dissection (ALND), raising concerns about applying these data in patients who may have additional nodal disease. METHODS: We identified institutional [Dana-Farber Brigham Cancer Center (DF/BCC), 2016-2020] and national [National Cancer Database (NCDB), 2012-2017] cohorts of women aged 50-75 years with cT1-3N0 HR+HER2- breast cancer and RS < 26 treated with upfront surgery with one to three positive SLN. Axillary nodal burden and outcomes were assessed on the basis of the number of positive nodes and CET use. RESULTS: A total of 197 and 13,499 HR+HER2- eligible patients with one to three positive SLN and RS < 26 were identified in the DF/BCC and NCDB databases, respectively, and 12.7% of DF/BCC and 32.4% of NCDB patients had ALND. Of these, only 12.0 and 4.9% had more than three total positive nodes, respectively. Rates of CET were 6.6% in DF/BCC and 20.9% in NCDB patients. In the NCDB, similar adjusted 4-year overall survival was seen between patients treated with CET or ET for any number of positive nodes (98.1-99.9%, all p > 0.05). CONCLUSIONS: Postmenopausal women with cT1-3N0 HR+HER2- breast cancer and RS < 26 with one to three positive SLN are unlikely to have more than three total positive nodes. CET decisions should continue to be based on SLN biopsy as ALND is unlikely to change treatment recommendations or outcomes.

Race and Site of Care Impact Treatment Delays in Older Women with Non-Metastatic Breast Cancer.

BACKGROUND: Women ≥ 65 years of age are less likely to receive guideline-concordant breast cancer care. Given existing racial/ethnic disparities, older minority breast cancer patients may be especially prone to inequalities in care. How site of care impacts older breast cancer patients is not well defined. We sought to evaluate the association between race/ethnicity and breast cancer treatment delays in older women treated at minority-serving hospitals (MSHs) versus non-MSHs. METHODS: Women ≥ 65 years of age treated for non-metastatic breast cancer were identified in the National Cancer Database (2010-2017). Treatment delay was defined as > 90 days from diagnosis to initial treatment. MSHs were defined as the top decile of hospitals serving predominantly Black or Hispanic patients. Multivariable logistic regression models adjusted for patient, tumor, and hospital characteristics were used to determine the odds of treatment delay for women at MSHs versus non-MSHs across racial/ethnic groups. RESULTS: Overall, 557,816 women were identified among 41 MSHs and 1146 non-MSHs. Average time to treatment was 33.71 days (standard deviation 26.92 days). Older women at MSHs were more likely to experience treatment delays than those at non-MSHs (odds ratio 1.28, 95% confidence interval 1.21-1.36). Regardless of where they received care, minorities were more likely to experience treatment delays than non-Hispanic White women. CONCLUSIONS: Although 97% of older women treated at Commission on Cancer-accredited hospitals received timely breast cancer care, minorities and those treated at MSHs were more likely to experience treatment delays. Interventions addressing barriers to timely breast cancer care at MSHs may be an effective approach to reducing racial/ethnic disparities.

Optimizing Axillary Management in Clinical T1-2N0 Mastectomy Patients with Positive Sentinel Lymph Nodes.

BACKGROUND: Following publication of the AMAROS trial, we sought to optimize axillary lymph node dissection (ALND) or postmastectomy radiation therapy (PMRT) + axillary radiation (AxRT) utilization in cT1-2N0 patients with 1-2 positive sentinel lymph nodes (SLNs) after mastectomy. METHODS: In November 2015, our multidisciplinary group implemented a protocol to omit intraoperative SLN evaluation for mastectomy patients with cT1-2N0 breast cancer likely to be recommended PMRT if found to have 1-2 positive SLNs (age ≤ 60 years and/or high-risk features defined as estrogen receptor-negative and/or positive for lymphovascular invasion). We prospectively evaluated axillary management, short-term complications, and oncologic outcomes in patients with 1-2 positive SLNs. RESULTS: From November 2015 to December 2018, 479 of 560 (85%) cT1-2N0 breast cancers treated with mastectomy were potential candidates for PMRT. Intraoperative SLN evaluation was omitted in 344 (72%), thus following the protocol. Overall, 121 cases had 1-2 positive SLNs: 17 (14%) were managed with observation, 5 (4%) PMRT alone, 59 (49%) PMRT + AxRT, 16 (13%) ALND alone, and 24 (20%) ALND + PMRT. Protocol compliance resulted in less ALND (8% vs. 24%) and less ALND + PMRT (9% vs. 41%, p < 0.01). At median follow-up of 24 months, there was one regional and four distant recurrences, with no regional recurrences or differences in disease-free survival in patients treated with ALND versus PMRT + AxRT (100% vs. 98%, p = 0.67). Similarly, there were no differences in complication rates (p = 0.18). CONCLUSIONS: Omitting intraoperative SLN evaluation in cT1-2N0 mastectomy patients who would be candidates for PMRT if found to have positive nodes decreased rates of ALND and minimized use of ALND + PMRT without compromising outcomes.

Racial and Socioeconomic Disparities in Breast Cancer Outcomes within the AJCC Pathologic Prognostic Staging System.

BACKGROUND: Non-Hispanic black (NHB) women and those of lower socioeconomic status (SES) have inferior breast cancer outcomes compared with non-Hispanic white (NHW) women and those of higher SES. We examined racial and SES disparities in breast cancer survival within the AJCC 8th edition pathologic prognostic staging system. METHODS: Using the Surveillance, Epidemiology and End Results Program, we identified patients diagnosed with invasive breast cancer from 2010 to 2015, with follow-up through 2016. Census tract-level SES (cSES) data were available as a composite index and analyzed in quintiles. Cox proportional-hazards survival analyses adjusted for age, race, cSES, insurance, marital status, histology, pathologic prognostic stage, and treatment were used to estimate disease-specific survival (DSS). RESULTS: A total of 259,852 patients were included: 176,369 (67.9%) NHW; 28,510 (11.0%) NHB; 29,737 (11.4%) Hispanic; and 22,887 (8.8%) Asian. NHB race and lower cSES were associated with increased incidence of triple-negative disease compared with NHW (p < 0.01). NHB race, lower cSES, public insurance, lower education, and increased poverty were associated with lower DSS. Survival analyses adjusting for cSES, tumor, and treatment characteristics demonstrated that NHB patients had inferior DSS within each AJCC pathologic prognostic stage (hazard ratio [HR] 1.25, 95% confidence interval [CI] 1.20-1.30) compared with NHW patients. Fully adjusted models also showed patients residing in lower SES counties had inferior DSS. CONCLUSIONS: Racial and cSES disparities in breast cancer-specific mortality were evident across all stages, even within the pathologic prognostic staging system which incorporates tumor biology. Future efforts should assess the biological, behavioral, social, and environmental determinants that underlie racial and SES inequities in outcomes.

Expanding the Staging Criteria for T1-2N0 Hormone-Receptor Positive Breast Cancer Patients Enrolled in TAILORx.

BACKGROUND: The American Joint Committee on Cancer (AJCC) 8th edition pathologic prognostic staging (PPS) incorporates anatomic and biologic factors. The OncotypeDX Breast Recurrence Score (RS) was included based on the initial report of the TAILORx trial, with T1-2N0 hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer patients who had a RS < 11 staged as PPS 1A. This study examined whether the RS criteria for PPS 1A can be further expanded using patients enrolled in the TAILORx trial. METHODS: The TAILORx trial enrolled 10,273 HR+HER2- T1-2N0 patients. Those with incomplete HR-status/grade and T3 disease were excluded for analysis. The recurrence-free interval (RFI) was compared between the patients who did and those who did not fall into the current PPS 1A category using the Kaplan-Meier method. RESULTS: The study enrolled 9535 patients for analysis. The RS was < 11 in 16.1%, 11-17 in 35.9%, 18-25 in 32.4%, and > 25 in 15.6% of the patients. The majority (91.2%) of the patients (including all the T1N0 patients regardless of RS) were PPS 1A, and 8.8% were not-PPS 1A. The median follow-up time was 95 months. The PPS 1A patients had an 8-year RFI of 94.2%, which was similar to that of the patients with a RS of 11-17 who were not-PPS 1A (91.7%; p = 0.07) and better than that of the patients with a RS ≥ 18 who were not-PPS 1A (85.4% for a RS of 18-25, 76.0% for a RS > 25; both p < 0.01). Similar RFI trends were seen in patients who received endocrine therapy or chemotherapy followed by endocrine therapy. CONCLUSIONS: Patients with T1-2N0 HR+HER2- breast cancer and a RS < 18 have an RFI similar to that of patients staged as PPS 1A by the current AJCC staging system, regardless of treatment, suggesting that the criteria for PPS 1A can be expanded to include a RS < 18.

Similar rates of residual disease in patients with DCIS within 2 mm of lumpectomy margin regardless of the presence of invasive carcinoma.

PURPOSE: The 2014 Society of Surgical Oncology/American Society for Radiation Oncology (SSO/ASTRO) breast-conserving surgery (BCS) margin guidelines for invasive cancer recommended "no ink on tumor" as an adequate margin width. However, 2016 SSO/ASTRO margin guidelines for pure DCIS recommended a 2 mm margin. Thus, management of a margin with DCIS > 0 mm but < 2 mm differs based on presence or absence of invasive carcinoma. We compared rates of residual disease in patients with pure DCIS to patients with invasive cancer with DCIS. METHODS: BCS with complete shaved cavity margins (SCM) for invasive carcinoma or pure DCIS from 2004 to 2006 at our institution was reviewed. Margin width was measured on the main specimen and the presence of carcinoma in the SCM was used as a surrogate for residual disease in the cavity. Rates of residual disease were determined for varying margin widths of invasive carcinoma and DCIS. RESULTS: Of 329 BCS patients, 123 (37%) patients had pure DCIS and 206 (63%) had invasive cancer with DCIS. In the pure DCIS cohort, 61 patients had DCIS between 0 and 2 mm from the inked margin; 32 (52%) of which had residual disease in the SCM. In the invasive cancer plus DCIS cohort, 92 had DCIS between 0 and 2 mm from the inked margin; 39 (42%) of which had residual disease in the SCM (p = 0.221). CONCLUSION: Rates of residual disease are similar in patients treated with lumpectomy for pure DCIS and those with invasive carcinoma with DCIS when DCIS is found between 0 and 2 mm from the inked margin.

Oncotype DX testing in node-positive breast cancer strongly impacts chemotherapy use at a comprehensive cancer center.

PURPOSE: In 2016, we initiated standardized "reflex" Oncotype DX Recurrence Score (RS) testing for patients ≤ 65 years with pT1-2N0-1 HR+/HER2- breast cancer. Here, we examine RS testing patterns, RS distribution, and factors associated with chemotherapy use in patients with pN1 breast cancer. METHODS: Patients with stage I-III HR+/HER2- pN1 breast cancer treated with upfront surgery from February 2016 to March 2019 were identified. Clinical characteristics were compared between patients meeting reflex RS testing criteria, those with RS ordered outside of reflex criteria, and those without RS testing. RS was categorized as low (< 18), intermediate (18-30), and high (≥ 31). Multivariate logistic regression was performed to identify factors associated with adjuvant chemotherapy receipt. We examined 3-year recurrence-free survival (RFS) and overall survival (OS) stratified by chemotherapy use. RESULTS: We identified 347 HR+/HER2- pN1 patients; 272 (78.4%) received RS testing, and 194 (71.3%) met reflex criteria. RS was < 18 in 164 (61.4%) patients, 18-30 in 89 (32.7%) patients, and ≥ 31 in 16 (5.9%) patients. On multivariate analysis, RS < 18 (OR 0.47, 95% CI 0.24-0.92) was associated with lower odds of chemotherapy use, whereas presence of lymphovascular invasion (OR 1.77, 95% CI 1.03-3.07) and lobular subtype (OR 2.40, 95% CI 1.21-4.78) were associated with higher odds. No differences in 3-year RFS (p = 0.97) or OS (p = 0.19) based on chemotherapy receipt were observed. CONCLUSION: Most RS-tested HR+/HER2- pN1 patients at our center had low genomic risk. A low RS independently influenced chemotherapy omission and in RS-tested patients, short-term outcomes were excellent. Our study demonstrates increased use of RS in guiding adjuvant treatment decisions in node-positive disease.

Comparison of Breast Cancer Staging Systems After Neoadjuvant Chemotherapy.

BACKGROUND: No consensus exists for optimal staging following neoadjuvant chemotherapy (NAC). We compared the performance of the American Joint Committee on Cancer (AJCC) pathologic prognostic staging system, Residual Cancer Burden (RCB) Index, and the Neo-Bioscore in breast cancer patients after NAC. METHODS: Patients with stage I-III breast cancer who received NAC at Dana-Farber Cancer Institute from 2004 to 2014 were identified. Kaplan-Meier curves were used to estimate disease-free survival (DFS) and overall survival (OS), and model fits were compared by receiver operator characteristic (ROC) curve using the c-statistic and DeLong's test. RESULTS: Overall, 802 patients with a median age of 48 years received NAC. Most patients presented with cT2 (n = 470, 58.6%) and cN1 (n = 422, 52.6%) disease. The subtype was estrogen receptor (ER)- and/or progesterone receptor (PR)-positive/human epidermal growth factor receptor 2 (HER2)-negative in 296 (36.9%) patients, HER2-positive in 261 (32.5%) patients, and triple-negative in 245 (30.5%) patients. Median follow-up was 79.5 months. There were 174 recurrences (30 local, 25 regional, 145 distant), with 676 (76.8%) patients alive at last follow-up. AJCC pathologic prognostic staging and RCB had better discrimination for estimated 7-year DFS and OS compared with the Neo-Bioscore. The ROC c-statistics for DFS model fit were similar for AJCC pathologic prognostic stage (0.72) and RCB (0.71, p = non-significant); both had improved model fit versus the Neo-Bioscore (0.65, p < 0.01). The c-statistics for OS were 0.74, 0.71, and 0.70 for AJCC pathologic prognostic stage, RCB, and Neo-Bioscore, respectively (p = non-significant). CONCLUSIONS: These results validate the ability of these staging systems to stratify survival outcomes in NAC patients, with best discrimination achieved using AJCC pathologic prognostic stage or RCB.

Axillary Management After Neoadjuvant Endocrine Therapy for Hormone Receptor-Positive Breast Cancer.

BACKGROUND: Data to guide axillary management after neoadjuvant endocrine therapy (NET) remain limited. METHODS: We analyzed type of axillary surgery [sentinel lymph node biopsy (SLNB) vs. axillary lymph node dissection (ALND)] and residual nodal disease burden after NET in two cohorts of patients with cT1-4N0-1M0 hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer: Dana-Farber/Brigham and Women's Cancer Center (DFBWCC) cohort (2015-2018) and the National Cancer Data Base (NCDB) cohort (2012-2016). Cox proportional hazard regression was used to determine adjusted 5-year overall survival (OS) by type of axillary surgery. RESULTS: Ninety-four (4.3%) of 2191 HR+/HER2- DFBWCC patients and 4363 (1.5%) of 283,344 NCDB patients were selected for NET. Of those who underwent axillary surgery, 30 (43.5%) in the DFBWCC cohort and 1583 (40.6%) in the NCDB cohort had ALND. Over 90% of cN0 patients in both cohorts had fewer than three positive nodes on final pathology [44 (95.7%) DFBWCC and 2945 (91.3%) NCDB]. In contrast, only 7 (30.4%) DFBWCC patients and 342 (50.7%) NCDB cN1 patients had fewer than three positive nodes. In the DFBWCC patients, there were no locoregional recurrences and four distant recurrences. In the NCDB, 5-year OS did not differ by type of axillary surgery regardless of residual nodal disease burden: 96.6% SLNB versus 97.9% ALND for 0 positive nodes; 84.4% versus 84.4% for one to two positive nodes, and 75.9% versus 77.3% for three or more positive nodes (all p > 0.10). CONCLUSIONS: In cN0 patients selected for NET, > 90% have fewer than three positive nodes at surgery. The lack of a survival difference between SLNB and ALND suggests an opportunity to de-escalate treatment of the axilla in patients with limited residual nodal disease.