Effectiveness and toxicity of five-fraction prone accelerated partial breast irradiation.

PURPOSE: Our institution was an early adopter of 5-fraction accelerated partial breast irradiation (ABPI) to treat women with early-stage breast cancer. This study reports long-term oncologic and cosmetic outcomes. METHODS: We included patients receiving APBI 600 cGy × 5 fx delivered every other day or every day between 2010 and 2022. Logistic regression models were used to identify factors associated with development of late toxicities, clinician, and patient-rated cosmesis. Kaplan-Meier methodology was used to calculate overall survival (OS), disease-free survival (DFS), and locoregional recurrence-free survival (LR-RFS). RESULTS: 442 patients received APBI either daily (56%) or every other day (44%) in the prone position (92%). At a median follow-up of 48 months (range: 5.96-155 months), 12 (2.7%) patients developed a local recurrence (LR). Out of 258 patients with > 3-month toxicity data available, the most common late grade ≥ 2 adverse event was breast fibrosis (6.2%). On multivariate analysis, daily APBI treatment (vs every other day) did not correlate with an increased risk of any late grade ≥ 2 toxicity though it did correlate with a lower risk of any late grade ≥ 2 fibrosis. Overall, at a median follow-up of 80 months, the rates of good-excellent physician and patient-rated cosmesis were 95% and 85%, respectively, with no difference between patients treated on consecutive vs. every other day. On multivariate analysis, patients who did not receive any adjuvant therapy were at increased risk of developing a LR. Five-year OS, LRFS, and DFS were 97.2%, 97.7%, and 89.5%, respectively. CONCLUSIONS: Five-fraction APBI delivered primarily in the prone position either daily or every other day was effective with low rates of local recurrence, minimal toxicity, and excellent cosmesis at long-term follow-up.

Early effectiveness and toxicity outcomes of reirradiation after breast conserving surgery for recurrent or new primary breast cancer.

PURPOSE: Breast reirradiation (reRT) after breast conserving surgery (BCS) has emerged as a viable alternative to mastectomy for women presenting with recurrent or new primary breast cancer. There are limited data on safety of different fractionation regimens. This study reports safety and efficacy among women treated with repeat BCS and reRT. METHODS AND MATERIALS: Patients who underwent repeat BCS followed by RT from 2015 to 2021 at 2 institutions were analyzed. Univariate logistic regression models were used to identify predictors of acute and late toxicities. Kaplan-Meier estimates were used to evaluate overall survival (OS), distant metastasis-free survival (DMFS) and locoregional recurrence-free survival (LR-RFS). RESULTS: Sixty-six patients were reviewed with median follow-up of 16 months (range: 3-60 months). At time of first recurrence, 41% had invasive carcinoma with a ductal carcinoma in situ (DCIS) component, 41% had invasive carcinoma alone and 18% had DCIS alone. All were clinically node negative. For the reirradiation course, 95% received partial breast irradiation (PBI) (57.5% with 1.5 Gy BID; 27% with 1.8 Gy daily; 10.5% with hypofractionation), and 5% received whole breast irradiation (1.8-2 Gy/fx), all of whom had received PBI for initial course. One patient experienced grade 3 fibrosis, and one patient experienced grade 3 telangiectasia. None had grade 4 or higher late adverse events. We found no association between the fractionation of the second course of RT or the cumulative dose (measured as EQD2) with acute or late toxicity. At 2 years, OS was 100%, DMFS was 91.6%, and LR-RFS was 100%. CONCLUSION: In this series of patients with recurrent or new primary breast cancer, a second breast conservation surgery followed by reirradiation was effective with no local recurrences and an acceptable toxicity profile across a range of available fractionation regimens at a median follow up of 16 months. Longer follow up is required.

DNA Methylation Identifies Epigenetic Subtypes of Triple-Negative Breast Cancers With Distinct Clinicopathologic and Molecular Features.

Triple-negative breast cancers (TNBC) include diverse carcinomas with heterogeneous clinical behavior. DNA methylation is a useful tool in classifying a variety of cancers. In this study, we analyzed TNBC using DNA methylation profiling and compared the results to those of mutational analysis. DNA methylation profiling (Infinium MethylationEPIC array, Illumina) and 50-gene panel-targeted DNA sequencing were performed in 44 treatment-naïve TNBC. We identified 3 distinct DNA methylation clusters with specific clinicopathologic and molecular features. Cluster 1 (phosphoinositide 3-kinase/protein kinase B-enriched cluster; n = 9) patients were significantly older (mean age, 71 years; P = .008) with tumors that were more likely to exhibit apocrine differentiation (78%; P < .001), a lower grade (44% were grade 2), a lower proliferation index (median Ki-67, 15%; P = .002), and lower tumor-infiltrating lymphocyte fractions (median, 15%; P = .0142). Tumors carried recurrent PIK3CA and AKT1 mutations and a higher percentage of low HER-2 expression (89%; P = .033). Cluster 3 (chromosomal instability cluster; n = 28) patients were significantly younger (median age, 57 years). Tumors were of higher grade (grade 3, 93%), had a higher proliferation index (median Ki-67, 75%), and were with a high fraction of tumor-infiltrating lymphocytes (median, 30%). Ninety-one percent of the germline BRCA1/2 mutation carriers were in cluster 3, and these tumors showed the highest level of copy number alterations. Cluster 2 represented cases with intermediate clinicopathologic characteristics and no specific molecular profile (no specific molecular profile cluster; n = 7). There were no differences in relation to stage, recurrence, and survival. In conclusion, DNA methylation profiling is a promising tool to classify patients with TNBC into biologically relevant groups, which may result in better disease characterization and reveal potential targets for emerging therapies.

Results of Magnetic Resonance Imaging (MRI) Screening in Patients at High Risk for Breast Cancer.

BACKGROUND: Screening MRI as an adjunct to mammography is recommended by the ACS for patients with a lifetime risk for breast cancer > 20%. While the benefits are clear, MRI screening is associated with an increase in false-positive results. The purpose of this study was to analyze our institutional database of high-risk patients and assess the uptake of screening MRI examinations and the results of those screenings. METHODS: Our institutional review board-approved High-Risk Breast Cancer Database was queried for patients enrolled from January 2017 to January 2023 who were at high risk for breast cancer in a comparative analysis between those who were screened versus not screened with MRIs. Variables of interest included risk factor, background, MRI screening uptake, and frequency and results of image-guided breast biopsies. RESULTS: A total of 254 of 1106 high-risk patients (23%) had MRI screening. Forty-six of 852 (5.3%) patients in the non-MRI-screened cohort and nine of 254 (3.5%) patients in the MRI-screened cohort were diagnosed with a malignant lesion after image-guided biopsy (p = 0.6). There was no significant difference between MRI and non-MRI guided biopsies in detecting breast cancer. All malignant lesions were T1 or in situ disease. The 254 patients in the MRI-screened group underwent 185 biopsies. Fifty-seven percent of MRI-guided biopsies yielded benign results. CONCLUSIONS: Although the addition of MRI screening in our high-risk cohort did not produce a significant number of additional cancer diagnoses, patients monitored in our high-risk cohort who developed breast cancer were diagnosed at very early stages of disease, underscoring the benefit of participation in the program.

Outcomes of Breast Cancer Patients Treated with Chemotherapy, Biologic Therapy, Endocrine Therapy, or Active Surveillance During the COVID-19 Pandemic.

PURPOSE: Provide real-world data regarding the risk for SARS-CoV-2 infection and mortality in breast cancer (BC) patients on active cancer treatment. METHODS: Clinical data were abstracted from the 3778 BC patients seen at a multisite cancer center in New York between February 1, 2020 and May 1, 2020, including patient demographics, tumor histology, cancer treatment, and SARS-CoV-2 testing results. Incidence of SARS-CoV-2 infection by treatment type (chemotherapy [CT] vs endocrine and/or HER2 directed therapy [E/H]) was compared by Inverse Probability of Treatment Weighting. In those diagnosed with SARS-CoV-2 infection, Mann-Whitney test was used to a assess risk factors for severe disease and mortality. RESULTS: Three thousand sixty-two patients met study inclusion criteria with 641 patients tested for SARS-COV-2 by RT-PCR or serology. Overall, 64 patients (2.1%) were diagnosed with SARS-CoV-2 infection by either serology, RT-PCR, or documented clinical diagnosis. Comparing matched patients who received chemotherapy (n = 379) with those who received non-cytotoxic therapies (n = 2343) the incidence of SARS-CoV-2 did not differ between treatment groups (weighted risk; 3.5% CT vs 2.7% E/H, P = .523). Twenty-seven patients (0.9%) expired over follow-up, with 10 deaths attributed to SARS-CoV-2 infection. Chemotherapy was not associated with increased risk for death following SARS-CoV-2 infection (weighted risk; 0.7% CT vs 0.1% E/H, P = .246). Advanced disease (stage IV), age, BMI, and Charlson's Comorbidity Index score were associated with increased mortality following SARS-CoV-2 infection (P ≤ .05). CONCLUSION: BC treatment, including chemotherapy, can be safely administered in the context of enhanced infectious precautions, and should not be withheld particularly when given for curative intent.

Margin Assessment and Re-excision Rates for Patients Who Have Neoadjuvant Chemotherapy and Breast-Conserving Surgery.

BACKGROUND: Neoadjuvant chemotherapy (NAC) has enabled more patients to be eligible for breast-conservation surgery (BCS). Achieving negative lumpectomy margins, however, is challenging due to changes in tissue composition and potentially scattered residual carcinoma in the tumor bed. Data regarding BCS after NAC have shown variable re-excision rates. MarginProbe (Dilon Technologies, Newport News, VA, USA) has been shown to identify positive resection margins intraoperatively and to reduce the number of re-excisions in primary BCS, but has not been studied in NAC+BCS cases. This study aimed to investigate the clinicopathologic characteristics, margin status, and re-excision rates for NAC+BCS patients with and without the use of MarginProbe. METHODS: The Institutional Breast Cancer Database was queried for patients who received NAC and had BCS from 2010 to 2019. The variables of interest were demographics, tumor characteristics, pathologic complete response (pCR), MarginProbe use, and re-excision rates. RESULTS: The study population consisted of 214 patients who had NAC, 61 (28.5 %) of whom had NAC+BCS. The median age of the patients was 53.5 years. A pCR was achieved for 19 of the patients (31.1 %). Of the remaining 42 patients, 9 (21 %) had close or positive margins that required re-excision. Re-excision was associated with a larger residual tumor size (p = 0.025) and estrogen receptor (ER)-positive disease before NAC (p = 0.041). MarginProbe use was associated with a lower re-excision rate for the patients who had NAC+BCS (6 % vs. 31 %, respectively). CONCLUSION: The patients with a larger residual tumor burden and ER-positive disease had a greater risk for inadequate margins at surgery. MarginProbe use was associated with a lower re-excision rate. Techniques to reduce the need for re-excision will support the use of BCS after NAC.

Management of women at increased risk for breast cancer secondary to high-risk proliferative lesions and family history of the disease.

Women with breast biopsies showing high-risk proliferative lesions such as atypical hyperplasia (AH) and lobular carcinoma in situ (LCIS) have an increased risk of developing breast cancer. Other factors including age, family history of breast cancer, and extent of AH may play a role in increasing breast cancer risk. In addition to women with AH, there is a subset of women with a positive family history of breast cancer, without a known germline mutation, which places them also at an increased risk for breast cancer. Clinical management, screening, chemoprevention, and surgical risk-reduction are discussed in this review to inform the management of these high-risk women. Advanced imaging technology, pharmacologic research into different targets, and innovations in breast reconstruction are changing the way in which patients are counseled of their individual risk.

Pregnancy-associated breast cancer in a contemporary cohort of newly diagnosed women.

Pregnancy-associated breast cancer (PABC) refers to breast cancer (BC) diagnosed during pregnancy, lactation, or in the postpartum period. There is evidence that PABC is associated with a poorer prognosis, and that the development of the disease is influenced by the unique hormonal milieu of pregnancy. The purpose of this study was to investigate the clinicopathologic characteristics associated with PABC in a contemporary cohort of women with newly diagnosed BC. Our institutional Breast Cancer Database was queried for women diagnosed with BC between 2009-2018 who had at least one full-term pregnancy (FTP). Variables of interest included patient demographics and clinical and tumor characteristics. PABC was defined as breast cancer diagnosed within 24 months of delivery. Statistical analyses included Pearson's chi-square and logistic regression. Out of a total of 2202 women, 46 (2.1%) had PABC. Median follow-up in the total cohort was 5.5 years. After adjusting for age at first FTP, PABC was associated with younger age at diagnosis, older age at first FTP, non-Caucasian race, BRCA positivity, presentation with a palpable mass, higher pathologic stage, higher histologic grade, and ER-negative and triple-negative receptor status. The association of PABC with non-Caucasian race may be reflected in the increased proportion of triple-negative breast cancers in the PABC group. PABC was also associated with older age at first FTP. As more women delay childbearing, risk for PABC may increase. Our findings suggest that women who become pregnant at older ages should be followed carefully during pregnancy and the postpartum period, especially if they are BRCA mutation carriers. The optimal approach for monitoring older women during pregnancy and the postpartum period is unclear.

Sentinel lymph node positivity in patients undergoing mastectomies for ductal carcinoma in situ (DCIS).

Current guidelines recommend sentinel lymph node biopsy (SLNB) for patients undergoing mastectomy for a preoperative diagnosis of ductal carcinoma in situ (DCIS). We examined the factors associated with sentinel lymph node positivity for patients undergoing mastectomy for a diagnosis of DCIS on preoperative core biopsy (PCB). The Institutional Breast Cancer Database was queried for patients with PCB demonstrating pure DCIS followed by mastectomy and SLNB from 2010 to 2018. Patients were divided according to final pathology (DCIS or invasive cancer). Clinico-pathologic variables were analyzed using Pearson's chi-squared, Wilcoxon Rank-Sum and logistic regression. Of 3145 patients, 168(5%) had pure DCIS on PCB and underwent mastectomy with SLNB. On final mastectomy pathology, 120(71%) patients had DCIS with 0 positive sentinel lymph nodes (PSLNs) and 48(29%) patients had invasive carcinoma with 5(10%) cases of ≥1 PSLNs. Factors positively associated with upstaging to invasive cancer in univariate analysis included age (P = .0289), palpability (P < .0001), extent of disease on imaging (P = .0121), mass on preoperative imaging (P = .0003), multifocality (P = .0231) and multicentricity (P = .0395). In multivariate analysis, palpability (P = .0080), extent of disease on imaging (P = .0074) and mass on preoperative imaging (P = .0245) remained significant (Table 2). In a subset of patients undergoing mastectomy for DCIS with limited disease on preoperative evaluation, SLNB may be omitted as the risk of upstaging is low. However, patients who present with clinical findings of palpability, large extent of disease on imaging and mass on preoperative imaging have a meaningful risk of upstaging to invasive cancer, and SLNB remains important for management.

Breast Density in a Contemporary Cohort of Women With Ductal Carcinoma In Situ (DCIS).

BACKGROUND: Mammographic breast density (MBD) is an independent risk factor for breast cancer. Information regarding the relationship of MBD and breast cancer biology in women with ductal carcinoma in situ (DCIS) is currently lacking. This study aimed to examine the clinicopathologic characteristics of DCIS in women stratified by MBD. METHODS: A retrospective review was performed to identify women with pure DCIS who underwent preoperative mammography between 2010 and 2018. Clinicopathologic and demographic data were collected. For the purpose of analysis, MBD was categorized as "non-dense" (Breast Imaging-Reporting and Data System [BI-RADS] density categories A and B) or "dense" (BI-RADS C and D) according to its identification in radiology reports. RESULTS: Of 3227 patients with a breast cancer diagnosis enrolled in the institutional Breast Cancer Database during the study period, 658 (20%) had pure DCIS. Of these 658 patients, 42% had non-dense breasts, and 58% had dense breasts. Most lesions were non-palpable (92%) and detected by mammography (84%). Patients with dense breasts were more likely to be younger at the time of diagnosis (p < 0.001), premenopausal (p < 0.001), and Asian (p = 0.018), and to have higher-grade disease (p = 0.006; Table 2). Family history, BRCA status, parity, mammogram frequency, palpability, method of presentation, lesion size, hormone receptor status, comedo histology, and recurrence did not differ significantly between the two groups (Table 1). The median follow-up period was 7.1 years. CONCLUSION: Women with pure DCIS and higher MBD are more likely to be younger at the time of diagnosis, premenopausal, and Asian, and to present with higher-grade disease. Further research on the relationship of age, MBD, and tumor biology in DCIS is warranted.

A Nomogram to Predict Factors Associated with Lymph Node Metastasis in Ductal Carcinoma In Situ with Microinvasion.

INTRODUCTION: Ductal carcinoma in situ (DCIS) with foci of invasion measuring ≤ 1 mm (DCISM), represents < 1% of all invasive breast cancers. Sentinel lymph node biopsy (SLNB) has been a standard component of surgery for patients with invasive carcinoma or extensive DCIS. We hypothesize that selective performance of SLNB may be appropriate given the low incidence of sentinel node (SN) metastasis for DCISM. We investigated the clinicopathologic predictors for SN positivity in DCISM, to identify which patients might benefit from SLNB. METHODS: A retrospective review of the National Cancer Database was performed for cases from 2012 to 2015. Clinical and tumor characteristics, including SN results, were evaluated, and Pearson's Chi square tests and logistic regression were performed. RESULTS: Of 7803 patients with DCISM, 306 (4%) had at least one positive SN. Patients with positive SNs were younger, more often of Black race, had higher-grade histology and larger tumor size, and were more likely to have lymphovascular invasion (LVI; all p < 0.001). In an adjusted model, the presence of LVI was associated with the highest odds ratio (OR) for node positivity (OR 8.80, 95% confidence interval 4.56-16.96). CONCLUSIONS: Among women with DCISM, only 4% had a positive SN. Node positivity was associated with more extensive and higher-grade DCIS, and the presence of LVI was strongly correlated with node positivity. Our data suggest that LVI is the most important factor in determining which patients with DCISM will benefit from SN biopsy.

The Relationship of Breast Density and Positive Lumpectomy Margins.

BACKGROUND: A positive lumpectomy margin after breast-conserving surgery (BCS) is a significant predictor for ipsilateral cancer recurrence. The MarginProbe, a Food and Drug Administration (FDA)-approved device for intraoperative assessment of lumpectomy margins, is associated with a reduction in re-excision surgery. This study aimed to evaluate the relationship of mammographic breast density (MBD) and clinicopathologic characteristics with margin status in women undergoing BCS with the MarginProbe. METHODS: The institutional database was queried for patients with breast cancer who had BCS with the MarginProbe from 2013 to 2017. Clinicopathologic characteristics were collected. The study defined MBD as less dense (Breast Imaging Reporting and Data System [BI-RADS] A and B) and more dense (BI-RADS C and D). A positive margin was defined as smaller than 1 mm. Pearson Chi square and uni- and multivariate logistic regression were performed. RESULTS: Of 1734 patients, 341 met the study criteria. The median patient age was 63 years. The patients with higher mammographic density were younger (p < 0.0001) and had a lower body mass index (BMI) (p < 0.0001). The patients with higher MBD were more likely to present with a palpable mass (p = 0.0360). Of the 341 patients, 135 (39.6%) had one or more positive margins on the main specimen, and 101 (74.8%) were converted to final negative margins after the MarginProbe directed re-excisions. Positive final margins were associated with larger tumor size (p = 0.0242) and more advanced stage of disease at diagnosis (p = 0.0255). CONCLUSIONS: In this study of patients undergoing BCS, breast density was not correlated with the likelihood of a positive margin. The presence of positive final lumpectomy margins was associated with older age and more extensive disease.

Tumor-Infiltrating Lymphocytes in a Contemporary Cohort of Women with Ductal Carcinoma In Situ (DCIS).

BACKGROUND: Growing evidence suggests that the tumor immune microenvironment influences breast cancer development and prognosis. Density of tumor-infiltrating lymphocytes (TILs) within invasive breast cancer is correlated with response to therapy, especially in triple-negative disease. The clinical relevance and outcomes of TILs within ductal carcinoma in situ (DCIS) are less understood. METHODS: Our institutional database of 668 patients with pure DCIS from 2010 to 2018 was queried. TILs were evaluated by International TILs Working Group guidelines. Percentage of TILs was assessed from the densest focus (hotspot) in one high-power field of stroma touching the basement membrane. Statistical methods included cluster analyses (to define sparse versus dense TILs), logistic, and Cox regression models. RESULTS: Sixty-nine patients with DCIS and TILs were evaluated, of whom 54 (78%) were treated by breast-conserving surgery. Thirteen (19%) patients had ipsilateral recurrence. Each recurrence (n = 13) was matched to four controls (n = 56) based on date of surgery. Median follow-up was 6.7 years. TILs were defined as sparse (< 45%) or dense (≥ 45%). Dense TILs were associated with younger age (p = 0.045), larger tumor size (p < 0.001), high nuclear grade (p = 0.010), comedo histology (p = 0.033), necrosis (p = 0.027), estrogen receptor (ER) negativity (p = 0.037), and ipsilateral recurrence (p = 0.001). Nine patients with dense TILs had mean time to recurrence of 73.5 months compared with four patients with sparse TILs with mean time to recurrence of 97.9 months (p = 0.003). CONCLUSIONS: Dense TILs were significantly associated with age, tumor size, nuclear grade, comedo histology, necrosis, and ER status and was a significant predictor of recurrence in patients with pure DCIS.

Genomic testing in early stage invasive male breast cancer: An NCDB analysis from 2008 to 2014.

PURPOSE: Genomic assays, or tissue gene profiling tests, are widely used to predict recurrence of early stage invasive breast cancer and guide systemic therapy. The purpose of our study was to examine the current national trends of genomic testing in male breast cancer (MBC) and its association with systemic therapy. MATERIALS AND METHODS: The National Cancer Database (NCDB) includes 6227 cases of pathologic T1/T2 and N0/N1 MBC from 2008 to 2014 with known genomic testing status. Results of the tests were grouped as low, intermediate, and high risk of recurrence scores (RRS). Statistical analysis included multivariate logistic regression and Chi-square tests. A supplemental analysis in female breast cancer was provided as reference. RESULTS: Of the 6227 cases of MBC age 18-90, 1478 (23.74%) underwent genomic testing. Testing was significantly associated with age, race, tumor grade, year of diagnosis, receptor status, and nodal status. Distribution of RRS in MBC was 59.3% low, 27.4% intermediate, and 13.3% high. RRS in men were significantly associated with tumor grade and size, but not nodal status. Those with a low RRS were 7-times more likely to be treated with hormone therapy alone (AOR 7.18, CI 5.78-8.91, P < 0.001). Those with a high RRS were five times more likely to receive a combination of hormone and chemotherapy (AOR 5.16, CI 3.60-7.40, P < 0.001). CONCLUSION: Rates of testing and distribution of RRS in men and women with early stage invasive breast cancer are similar. Treatment patterns in MBC varied significantly based on genomic testing results, even when adjusted for other clinicopathologic features. Further investigation is required to determine the prognostic and predictive nature of genomic testing in male breast cancer.

Surgical treatment of young women with breast cancer: Public vs private hospitals.

Disparities in breast cancer treatment have been documented in young and underserved women. This study aimed to determine whether surgical disparities exist among young breast cancer patients by comparing cancer treatment at a public safety-net hospital (BH) and private cancer center (PCC) within a single institution. This was a retrospective study of young women (<45) diagnosed with invasive breast cancer (stage I-III) from 2011-2016. Patient information was abstracted from the breast cancer database at BH and PCC. Demographic variables, surgery type, method of presentation, and stage were analyzed using Pearson's chi-square tests and binary logistic regression. A total of 275 patients between ages 25-45 with invasive breast cancer (Stage I-III) were included in the study. There were 69 patients from BH and 206 patients from PCC. At PCC, the majority of patients were Caucasian (68%), followed by Asian (11%), Hispanic (10%), and African American (8.7%). At BH, patients were mostly Hispanic (47.8%), followed by Asian (27.5%), and African American (10.1%). At PCC, 82% had a college/graduate degree versus 18.6% of patients at BH (P < 0.001). All patients at PCC reported English as their primary language versus 30% of patients at BH (P < 0.001). Patients at PCC were more likely to present with lower stage cancer (P = 0.04), and less likely to present with a palpable mass (P = 0.04). Hospital type was not a predictor of receipt of mastectomy (P = 0.5), nor was race, primary language, or education level. Of patients who received a mastectomy, 87% at BH and 76% at PCC had immediate reconstruction. Surgical management of young women with breast cancer in a public hospital versus private hospital setting was equivalent, even after controlling for race, primary language, stage, and education level.

Post-mastectomy Radiation Therapy in Breast Cancer Patients with Nodal Micrometastases.

BACKGROUND: Recent data support the use of post-mastectomy radiation therapy (PMRT) in women with one to three positive lymph nodes; however, the benefit of PMRT in patients with micrometastatic nodal disease (N1mi) is unknown. We evaluated the survival impact of PMRT in patients with N1mi within the National Cancer Database. METHODS: The pattern of care and survival benefit of PMRT was examined in women with pT1-2N1mi breast cancer who underwent mastectomy without neoadjuvant chemotherapy. Univariable and multivariable Cox proportional hazard models were employed for survival analysis, and subanalyses of high-risk patients and a propensity score-matched (PSM) cohort were completed. RESULTS: From 2004 to 2014, we identified 14,019 patients who fitted the study criteria. PMRT was delivered in 18.5% of patients and its use increased over the study period. Patients treated with PMRT were younger, had better performance status and larger primaries, were estrogen receptor (ER)-negative, had higher grade, lymphovascular invasion and positive surgical margins, and more often received systemic therapy. PMRT was significantly associated with overall survival (OS) in univariable analysis (hazard ratio [HR] 0.75 [0.64-0.89]), but was not significant in multivariable analysis (adjusted HR 1.01 [0.84-1.20]). There was no survival benefit to PMRT in ER-negative, high-grade, and/or young patients. There were 2 (0.9%) death events in the sentinel lymph node biopsy (SLNB) + PMRT group versus 21 (2.9%) in the SLNB-alone group (log-rank p = 0.053), and 8 (3.9%) death events in the axillary lymph node biopsy (ALNB) + PMRT group versus 27 (3.6%) in the axillary lymph node dissection-alone group (p = 0.82). There was no significant association between PMRT and OS within the PSM subgroup. CONCLUSION: In this largest reported retrospective study, no OS differences were associated with PMRT, which suggests that PMRT may not benefit every patient with microscopic nodal disease.

Ductal carcinoma in situ on core needle biopsy only with no residual disease at surgery.

BACKGROUND: The treatment of ductal carcinoma in situ (DCIS) remains controversial and may be particularly difficult for patients with minimal disease. There is a dearth of information regarding patients who have been diagnosed with DCIS on core needle biopsy (CNB), who have no residual disease in the lumpectomy specimen. The purpose of this study was to explore the frequency of this presentation and short-term outcomes in these patients. METHODS: Our institutional Breast Cancer Database was queried for all women who were diagnosed with pure DCIS from 2010 to 2016 and treated with lumpectomy. Variables included patient and tumor characteristics, adjuvant treatment, and ipsilateral breast tumor recurrence (IBTR). Statistical analyses included Pearson's chi-square, Fisher's exact tests, and Kaplan-Meier analysis. RESULTS: Of 547 patients with pure DCIS, 50 (14%) had DCIS on CNB only. Of the patients with DCIS on CNB only, 15 were treated with lumpectomy and radiation therapy (RT), while 35 underwent lumpectomy without RT. At a median follow-up of 4 years, there were 3 (6%) IBTR all within the same quadrant as the original lumpectomy site. None of the patients who recurred received adjuvant RT or hormonal therapy. CONCLUSIONS: Despite the minimal extent of disease exhibited in these cases, 6% of patients with DCIS on CNB only had IBTR at a median follow-up of 4 years. These data suggest that even minimal DCIS represents a significant risk of recurrence to the patient. Size and margins are not sufficient criteria to stratify risk and guide decisions for adjuvant therapies.

The Relationship of Race, Oncotype DX, and Ki67 in a Population Highly Screened For Breast Cancer.

Oncotype DX recurrence score (ODX) can predict risk of invasive breast cancer recurrence and benefit of chemotherapy. Literature is limited on the relationship of ODX and race in women with hormone receptor positive and node negative/positive disease. Our study examines the relationship between race and clinical characteristics within a population of highly screened women with newly diagnosed breast cancer. The institutional Breast Cancer Database was queried for patients with newly diagnosed breast cancer between January2010 and March2015. We analyzed clinical and tumor characteristics including ODX. Statistical analyses included Pearson's Chi-Square and Fisher's Exact Tests. There were 2,092 women in our study cohort. The majority had college-level education (84%), regular screening (78%), and clinical breast exams (88%). The majority had invasive ductal carcinoma (IDC) (62%), early stage (0, I, II) tumors (93%), ER+ (84%), PR+ (71%), Her2 negative (86%), and node negative disease (83%). There was a significantly higher proportion of later stage disease among African-Americans (p = 0.001) and Asians (p = 0.006) and more triple negative breast cancers among African-Americans (p < 0.0001). A majority of patients had a low ODX (56%). While ODX was not different among the race categories (p = 0.97), there were significant racial differences in Ki-67 (p < 0.0001). In a population of highly screened women, differences were found between races regarding tumor histology. No statistical difference between race and ODX was noted, but there were racial differences in Ki67. Therefore we recommend that further research be focused on refining management algorithms by ethnicity.

A Prospective, Single Arm, Multi-site, Clinical Evaluation of a Nonradioactive Surgical Guidance Technology for the Location of Nonpalpable Breast Lesions during Excision.

OBJECTIVES: This study was a multicenter evaluation of the SAVI SCOUT(®) breast localization and surgical guidance system using micro-impulse radar technology for the removal of nonpalpable breast lesions. The study was designed to validate the results of a recent 50-patient pilot study in a larger multi-institution trial. The primary endpoints were the rates of successful reflector placement, localization, and removal. METHODS: This multicenter, prospective trial enrolled patients scheduled to have excisional biopsy or breast-conserving surgery of a nonpalpable breast lesion. From March to November 2015, 154 patients were consented and evaluated by 20 radiologists and 16 surgeons at 11 participating centers. Patients had SCOUT(®) reflectors placed up to 7 days before surgery, and placement was confirmed by mammography or ultrasonography. Implanted reflectors were detected by the SCOUT(®) handpiece and console. Presence of the reflector in the excised surgical specimen was confirmed radiographically, and specimens were sent for routine pathology. RESULTS: SCOUT(®) reflectors were successfully placed in 153 of 154 patients. In one case, the reflector was placed at a distance from the target that required a wire to be placed. All 154 lesions and reflectors were successfully removed during surgery. For 101 patients with a preoperative diagnosis of cancer, 86 (85.1 %) had clear margins, and 17 (16.8 %) patients required margin reexcision. CONCLUSIONS: SCOUT(®) provides a reliable and effective alternative method for the localization and surgical excision of nonpalpable breast lesions using no wires or radioactive materials, with excellent patient, radiologist, and surgeon acceptance.