Comprehensive Molecular Portraits of Invasive Lobular Breast Cancer.

Invasive lobular carcinoma (ILC) is the second most prevalent histologic subtype of invasive breast cancer. Here, we comprehensively profiled 817 breast tumors, including 127 ILC, 490 ductal (IDC), and 88 mixed IDC/ILC. Besides E-cadherin loss, the best known ILC genetic hallmark, we identified mutations targeting PTEN, TBX3, and FOXA1 as ILC enriched features. PTEN loss associated with increased AKT phosphorylation, which was highest in ILC among all breast cancer subtypes. Spatially clustered FOXA1 mutations correlated with increased FOXA1 expression and activity. Conversely, GATA3 mutations and high expression characterized luminal A IDC, suggesting differential modulation of ER activity in ILC and IDC. Proliferation and immune-related signatures determined three ILC transcriptional subtypes associated with survival differences. Mixed IDC/ILC cases were molecularly classified as ILC-like and IDC-like revealing no true hybrid features. This multidimensional molecular atlas sheds new light on the genetic bases of ILC and provides potential clinical options.

Author Correction: Landscape of somatic mutations in 560 breast cancer whole-genome sequences.

In the Methods section of this Article, 'greater than' should have been 'less than' in the sentence 'Putative regions of clustered rearrangements were identified as having an average inter-rearrangement distance that was at least 10 times greater than the whole-genome average for the individual sample. '. The Article has not been corrected.

TBCRC 039: a phase II study of preoperative ruxolitinib with or without paclitaxel for triple-negative inflammatory breast cancer.

BACKGROUND: Patients with inflammatory breast cancer (IBC) have overall poor clinical outcomes, with triple-negative IBC (TN-IBC) being associated with the worst survival, warranting the investigation of novel therapies. Preclinical studies implied that ruxolitinib (RUX), a JAK1/2 inhibitor, may be an effective therapy for TN-IBC. METHODS: We conducted a randomized phase II study with nested window-of-opportunity in TN-IBC. Treatment-naïve patients received a 7-day run-in of RUX alone or RUX plus paclitaxel (PAC). After the run-in, those who received RUX alone proceeded to neoadjuvant therapy with either RUX + PAC or PAC alone for 12 weeks; those who had received RUX + PAC continued treatment for 12 weeks. All patients subsequently received 4 cycles of doxorubicin plus cyclophosphamide prior to surgery. Research tumor biopsies were performed at baseline (pre-run-in) and after run-in therapy. Tumors were evaluated for phosphorylated STAT3 (pSTAT3) by immunostaining, and a subset was also analyzed by RNA-seq. The primary endpoint was the percent of pSTAT3-positive pre-run-in tumors that became pSTAT3-negative. Secondary endpoints included pathologic complete response (pCR). RESULTS: Overall, 23 patients were enrolled, of whom 21 completed preoperative therapy. Two patients achieved pCR (8.7%). pSTAT3 and IL-6/JAK/STAT3 signaling decreased in post-run-in biopsies of RUX-treated samples, while sustained treatment with RUX + PAC upregulated IL-6/JAK/STAT3 signaling compared to RUX alone. Both treatments decreased GZMB+ T cells implying immune suppression. RUX alone effectively inhibited JAK/STAT3 signaling but its combination with PAC led to incomplete inhibition. The immune suppressive effects of RUX alone and in combination may negate its growth inhibitory effects on cancer cells. CONCLUSION: In summary, the use of RUX in TN-IBC was associated with a decrease in pSTAT3 levels despite lack of clinical benefit. Cancer cell-specific-targeting of JAK2/STAT3 or combinations with immunotherapy may be required for further evaluation of JAK2/STAT3 signaling as a cancer therapeutic target. TRIAL REGISTRATION: www. CLINICALTRIALS: gov , NCT02876302. Registered 23 August 2016.

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.

Breast Articles From 2023: Informing Practice Across the Continuum of Care.

With new investigations and clinical trials in breast oncology reported every year, it is critical that surgeons be aware of advances and insights into the evolving care paradigms and treatments available to their patients. This article highlights five publications found to be particularly impactful this past year. These articles report on efforts to select the minimal effective dose of tamoxifen for prevention, to challenge the existing age-based screening guidelines as they relate to race and ethnicity, to refine axillary management treatment standards, to optimize systemic therapy in multidisciplinary care settings, and to reduce the burden of breast cancer-related lymphedema after treatment. Taken together, these efforts have an impact on all facets of the continuum of care from prevention and screening through treatment and survivorship.

Trends in Locoregional Therapy in Older Women with Early-Stage Hormone Receptor-Positive Breast Cancer by Frailty and Life Expectancy.

BACKGROUND: In women ≥ 70 years of age with T1N0 hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer, breast surgery type and omission of axillary surgery or radiation therapy (RT) do not impact overall survival. Although frailty and life expectancy ideally factor into therapy decisions, their impact on therapy receipt is unclear. We sought to identify trends in and factors associated with locoregional therapy type by frailty and life expectancy. METHODS: Women ≥ 70 years of age with T1N0 HR+/HER2- breast cancer diagnosed in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database between 2010 and 2015 were stratified by validated claims-based frailty and life expectancy measures. Therapy trends over time by regimen intensity ('high intensity': lumpectomy + axillary surgery + RT, or mastectomy + axillary surgery; 'moderate intensity': lumpectomy + RT, lumpectomy + axillary surgery, or mastectomy only; or 'low intensity': lumpectomy only) were analyzed. Factors associated with therapy type were identified using generalized linear mixed models. RESULTS: Of 16,188 women, 21.8% were frail, 22.2% had a life expectancy < 5 years, and only 12.3% fulfilled both criteria. In frail women with a life expectancy < 5 years, high-intensity regimens decreased significantly (48.8-31.2%; p < 0.001) over the study period, although in 2015, 30% still received a high-intensity regimen. In adjusted analyses, frailty and life expectancy < 5 years were not associated with breast surgery type but were associated with a lower likelihood of axillary surgery (frailty: odds ratio [OR] 0.86, 95% confidence interval [CI] 0.76-0.96; life expectancy < 5 years: OR 0.22, 95% CI 0.20-0.25). Life expectancy < 5 years was also associated with a lower likelihood of RT receipt in breast-conserving surgery patients (OR 0.30, 95% CI 0.27-0.34). CONCLUSIONS: Rates of high-intensity therapy are decreasing but overtreatment persists in this population. Continued efforts aimed at appropriate de-escalation of locoregional therapy are needed.

Long-Term Patient-Reported Arm Symptoms in Breast Cancer Survivors.

BACKGROUND: Understanding long-term arm symptoms in breast cancer survivors is critical given excellent survival in the modern era. METHODS: This cross-sectional study included patients treated for stage 0-III breast cancer at our institution from 2002 to 2012. Patient-reported arm symptoms were collected from the EORTC QLQ-BR23 questionnaire. We used linear regression to evaluate adjusted associations between locoregional treatments and the continuous Arm Symptom (AS) score (0-100; higher score reflects more symptoms). RESULTS: A total of 1126 patients expressed interest in participating and 882 (78.3%) completed the questionnaire. Mean time since surgery was 10.5 years. There was a broad distribution of locoregional treatments, including axillary lymph node dissection (ALND) in 37.1% of patients, mastectomy with reconstruction in 36.5% of patients, and post-mastectomy radiation in 38.2% of patients. Overall, 64.3% (95% confidence interval [CI] 61.1-67.4%) of patients reported no arm symptoms, 17.0% (95% CI 14.7-19.6%) had one mild symptom, 9.4% (95% CI 7.7-11.5%) had two or more mild symptoms, and 9.3% (95% CI 7.6-11.4%) reported one or more severe symptoms. Adjusted AS scores were significantly higher with ALND versus sentinel node biopsy (ß 3.5, p = 0.01), and with autologous reconstruction versus all other breast/reconstructive surgery types (ß 4.5-5.5, all p < 0.05). There was a significant interaction between axillary and breast/reconstructive surgery, with the greatest effect of ALND in those with mastectomy with implant (ß 9.7) or autologous (ß 5.7) reconstruction. CONCLUSIONS: One in three patients reported arm symptoms at a mean of 10 years from treatment for breast cancer, although rates of severe symptoms were low (<10%). Attention is warranted to the arm morbidity related to both axillary and breast surgery during treatment counseling and survivorship.

Upgrade Rates and Breast Cancer Development Among Germline Pathogenic Variant Carriers with High-Risk Breast Lesions.

BACKGROUND: High-risk lesions (HRL) of the breast are risk factors for future breast cancer development and may be associated with a concurrent underlying malignancy when identified on needle biopsy; however, there are few data evaluating HRLs in carriers of germline pathogenic variants (PVs) in breast cancer predisposition genes. METHODS: We identified patients from two institutions with germline PVs in high- and moderate-penetrance breast cancer predisposition genes and an HRL in an intact breast, including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), and lobular neoplasia (LN). We calculated upgrade rates at surgical excision and used Kaplan-Meier methods to characterize 3-year breast cancer risk in patients without upgrade. RESULTS: Of 117 lesions in 105 patients, 65 (55.6%) were ADH, 48 (41.0%) were LN, and 4 (3.4%) were FEA. Most PVs (83.8%) were in the BRCA1/2, CHEK2 and ATM genes. ADH and FEA were excised in most cases (87.1%), with upgrade rates of 11.8% (95% confidence interval [CI] 5.5-23.4%) and 0%, respectively. LN was selectively excised (53.8%); upgrade rate in the excision group was 4.8% (95% CI 0.8-22.7%), and with 20 months of median follow-up, no same-site cancers developed in the observation group. Among those not upgraded, the 3-year risk of breast cancer development was 13.1% (95% CI 6.3-26.3%), mostly estrogen receptor-positive (ER +) disease (89.5%). CONCLUSIONS: Upgrade rates for HRLs in patients with PVs in breast cancer predisposition genes appear similar to non-carriers. HRLs may be associated with increased short-term ER+ breast cancer risk in PV carriers, warranting strong consideration of surgical or chemoprevention therapies in this population.

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.

The Clinical Utility of a 7-Gene Biosignature on Radiation Therapy Decision Making in Patients with Ductal Carcinoma In Situ Following Breast-Conserving Surgery: An Updated Analysis of the DCISionRT® PREDICT Study.

BACKGROUND: Breast-conserving surgery (BCS) followed by adjuvant radiotherapy (RT) is a standard treatment for ductal carcinoma in situ (DCIS). A low-risk patient subset that does not benefit from RT has not yet been clearly identified. The DCISionRT test provides a clinically validated decision score (DS), which is prognostic of 10-year in-breast recurrence rates (invasive and non-invasive) and is also predictive of RT benefit. This analysis presents final outcomes from the PREDICT prospective registry trial aiming to determine how often the DCISionRT test changes radiation treatment recommendations. METHODS: Overall, 2496 patients were enrolled from February 2018 to January 2022 at 63 academic and community practice sites and received DCISionRT as part of their care plan. Treating physicians reported their treatment recommendations pre- and post-test as well as the patient's preference. The primary endpoint was to identify the percentage of patients where testing led to a change in RT recommendation. The impact of the test on RT treatment recommendation was physician specialty, treatment settings, individual clinical/pathological features and RTOG 9804 like criteria. Multivariate logisitc regression analysis was used to estimate the odds ratio (ORs) for factors associated with the post-test RT recommendations. RESULTS: RT recommendation changed 38% of women, resulting in a 20% decrease in the overall recommendation of RT (p < 0.001). Of those women initially recommended no RT (n = 583), 31% were recommended RT post-test. The recommendation for RT post-test increased with increasing DS, from 29% to 66% to 91% for DS <2, DS 2-4, and DS >4, respectively. On multivariable analysis, DS had the strongest influence on final RT recommendation (odds ratio 22.2, 95% confidence interval 16.3-30.7), which was eightfold greater than clinicopathologic features. Furthermore, there was an overall change in the recommendation to receive RT in 42% of those patients meeting RTOG 9804-like low-risk criteria. CONCLUSIONS: The test results provided information that changes treatment recommendations both for and against RT use in large population of women with DCIS treated in a variety of clinical settings. Overall, clinicians changed their recommendations to include or omit RT for 38% of women based on the test results. Based on published clinical validations and the results from current study, DCISionRT may aid in preventing the over- and undertreatment of clinicopathological 'low-risk' and 'high-risk' DCIS patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03448926 ( https://clinicaltrials.gov/study/NCT03448926 ).

Nodal positivity and systemic therapy among patients with clinical T1-T2N0 human epidermal growth factor receptor-positive breast cancer: Results from two international cohorts.

BACKGROUND: The optimal treatment strategy for patients with small human epidermal growth factor receptor 2 (HER2)-positive tumors is based on nodal status. The authors' objective was to evaluate pathologic nodal disease (pathologic lymph node-positive [pN-positive] and pathologic lymph node-positive after preoperative systemic therapy [ypN-positive]) rates in patients who had clinical T1-T2 (cT1-cT2)N0M0, HER2-positive breast cancer treated with upfront surgery or neoadjuvant chemotherapy (NAC). METHODS: Two databases were queried for patients who had cT1-cT2N0M0, HER2-positive breast cancer: (1) the Dana-Farber Brigham Cancer Center (DF/BCC) from February 2015 to October 2020 and (2) the Hospital Clinic of Barcelona and the Hospital Clinico of Valencia (HCB/HCV) from January 2012 to September 2021. The pN-positive/ypN-positive and axillary lymph node dissection (ALND) rates were compared between patients who underwent upfront surgery versus those who received NAC. RESULTS: Among 579 patients from the DF/BCC database, 368 underwent upfront surgery, and 211 received NAC; the rates of nodal positivity were 19.8% and 12.8%, respectively (p = .021). The pN-positive rates increased by tumor size (p < .001), reaching 25% for those with cT1c tumors. The ypN-positive rates did not correlate with tumor size. NAC was associated with decreased nodal positivity (odds ratio, 0.411; 95% confidence interval, 0.202-0.838), but the ALND rates were similar (22 of 368 patients [6.0%] who underwent upfront surgery vs. 18 of 211 patients [8.5%] who received NAC; p = .173). Among 292 patients from the HCB/HCV database, 119 underwent upfront surgery, and 173 received NAC; the rates of nodal positivity were 21% and 10.4%, respectively (p = .012). The pN-positive rates increased with tumor size (p = .011). The ALND rates were equivalent by treatment strategy (23 of 119 patients [19.3%] who underwent upfront surgery vs. 24 of 173 patients [13.9%] who received NAC; p = .213). CONCLUSIONS: Among patients who had cT1-cT2N0M0, HER2-positive breast cancer, approximately 20% who underwent upfront surgery were pN-positive, and the rate reached 25% for those with cT1c tumors. Given the opportunity for tailored therapy among lymph node-positive, HER2-positive patients, these data provide rationale for future analyses investigating the utility of routine axillary imaging in patients with HER2-positive breast cancer.

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.

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.

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.

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.

Surgical Treatment After Neoadjuvant Systemic Therapy in Young Women With Breast Cancer: Results From a Prospective Cohort Study.

OBJECTIVE: We aimed to investigate eligibility for breast conserving surgery (BCS) pre- and post-neoadjuvant systemic therapy (NST), and trends in the surgical treatment of young breast cancer patients. BACKGROUND: Young women with breast cancer are more likely to present with larger tumors and aggressive phenotypes, and may benefit from NST. Little is known about how response to NST influences surgical decisions in young women. METHODS: The Young Women's Breast Cancer Study, a multicenter prospective cohort of women diagnosed with breast cancer at age ≤40, enrolled 1302 patients from 2006 to 2016. Disease characteristics, surgical recommendations, and reasons for choosing mastectomy among BCS-eligible patients were obtained through the medical record. Trends in use of NST, rate of clinical and pathologic complete response, and surgery were also assessed. RESULTS: Of 1117 women with unilateral stage I-III breast cancer, 315 (28%) received NST. Pre-NST, 26% were BCS eligible, 17% were borderline eligible, and 55% were ineligible. After NST, BCS eligibility increased from 26% to 42% (P < 0.0001). Among BCS-eligible patients after NST (n = 133), 41% chose mastectomy with reasons being patient preference (53%), BRCA or TP53 mutation (35%), and family history (5%). From 2006 to 2016, the rates of NST (P = 0.0012), clinical complete response (P < 0.0001), and bilateral mastectomy (P < 0.0001) increased, but the rate of BCS did not increase (P = 0.34). CONCLUSION: While the proportion of young women eligible for BCS increased after NST, many patients chose mastectomy, suggesting that surgical decisions are often driven by factors beyond extent of disease and treatment response.

Accuracy of the Breast Cancer Surveillance Consortium Model Among Women with LCIS.

PURPOSE: The Breast Cancer Surveillance Consortium (BCSC) model predicts risk of invasive breast cancer risk based on age, race, family history, breast density, and history of benign breast disease, including lobular carcinoma in situ (LCIS). However, validation studies for this model included few women with LCIS. We sought to evaluate the accuracy of the BCSC model among this cohort. METHODS: Women with LCIS diagnosed between 1983 and 2017 were identified from a prospectively maintained database. The BCSC score was calculated; those with prior breast cancer, unknown breast density, age < 35 years or > 74 years, or with history of chemoprevention use were excluded. The Kaplan-Meier method was used to estimate incidence rates. Time-dependent receiver operating characteristic (ROC) analysis was used to analyze the discriminative capacity of the model. RESULTS: 1302 women with LCIS were included. At a median follow-up of 7 years, 152 women (12%) developed invasive cancer (6 with bilateral disease). Cumulative incidences of invasive breast cancer were 7.1% (95% CI 5.6-8.7) and 13.3% (95% CI 10.9-15.6), respectively, and the median BCSC risk scores were 4.9 and 10.4, respectively, at 5 and 10 years. The median 10-year BCSC score was significantly lower than the 10-year Tyrer-Cuzick score (10.4 vs 20.8, p < 0.001). The ROC curve scores (AUC) for BCSC at 5 and 10 years were 0.59 (95% CI 0.52-0.66) and 0.58 (95% CI 0.52-0.64), respectively. CONCLUSION: The BCSC model has moderate accuracy in predicting invasive breast cancer risk among women with LCIS with fair discrimination for risk prediction between individuals.

Synchronous and metachronous bilateral breast cancer among women with a history of lobular carcinoma in situ.

PURPOSE: Lobular carcinoma in situ (LCIS) confers increased cancer risk in either breast, but it remains unclear if this population is at increased risk for bilateral breast cancer (BC) development. Here we report bilateral BC incidence among women with a history of LCIS. METHODS: Women with classic-type LCIS diagnosed from 1980 to 2017 who developed unilateral BC (UBC) or bilateral BC were identified. Bilateral BC was categorized as synchronous (bilateral BC diagnosed < 6 months apart; SBBC) or metachronous (bilateral BC diagnosed ≥ 6 months apart; MBBC). Five-year incidence rates of bilateral BC among this population were evaluated. Comparisons were made to identify factors associated with bilateral BC. RESULTS: At 7 years' median follow-up, 249/1651 (15%) women with LCIS developed BC; 34 with bilateral BC (2%). There were no clinicopathologic feature differences between those with UBC and bilateral BC. SBBC occurred in 18 without significant differences versus UBC. Among 211 with UBC and a contralateral breast at risk, 16 developed MBBC at a median follow-up of 3 years. MBBC patients were less likely to receive endocrine therapy and more likely to receive chemotherapy versus UBC. Tumor histology was not associated with MBBC. Estimated 5-year MBBC risk was 6.4%. Index estrogen/progesterone receptor positivity and endocrine therapy were the only factors associated with MBBC risk. CONCLUSION: Bilateral BC occurred in 2% of women with LCIS history at median follow-up of 7 years. Similar to the general BC population, a decrease in MBBC is seen among women with a history of LCIS who develop hormone receptor-positive disease and those who receive endocrine therapy, highlighting the protective effects of this treatment.