Background: We investigated a diverse population of newly diagnosed breast cancer patients to characterize factors associated with adherence to timely surgery. Methods: Machine learning (ML) methods were applied to electronic health record (EHR) and tumor registry data of women diagnosed with stage 0 through III breast cancer between 2014 and 2019. The ML architectures were evaluated and selected to stratify patients by risk of non-adherence to surgery. The most performant model was selected using the area under the curve (AUC) criteria. The high over low Area Deprivation Index (ADI) adherence ratio (HLAR) was plotted against time. The patients who received timely surgery that followed diagnostic confirmation indicated adherence. Results: A total of 1,004 women with breast cancer were included. The performance of the ML model at 110 days had an AUC of 0.82. The ADI was found to be the most important feature. The HLAR curve for high (most deprived) ADI shifted to the right compared to the low ADI curve, suggesting an increased delay to treatment for patients living in the most deprived zones. Conclusions: The degree of deprivation appeared to be a valid feature to help predict non-adherence, along with cancer stage and patient demographics. This important finding will guide future interventions to first predict who is at risk for non-adherence and then to study interventions to mitigate the risks. Future research needs to move from identification of non-adherence risk factors to development and implementation of interventions to mitigate the risk and improve timely adherence.

This cohort study using pooled data from 2 randomized clinical trials examines whether removing more lymph nodes with axillary lymph node dissection improved outcomes over sentinel lymph node biopsy when most patients received adjuvant radiation therapy or regional nodal irradiation.

ABSTRACT:This forum summarizes the proceedings of the joint European Surgical Association (ESA)/American Surgical Association (ASA) symposium on Quality and Outcome Assessment for Surgery that took place in Bordeaux, France, as part of the celebrations of the 30th anniversary of the ESA. Three presentations focused on a) the main messages from the Outcome4Medicine Consensus Conference, which took place in Zurich, Switzerland, in June 2022, b) the patient perspective, and c) benchmarking were hold by ESA members and discussed by ASA members in a symposium attended by members of both associations.

524 Background: Alliance A011202 is evaluating the efficacy of axillary lymph node dissection (ALND) compared to regional nodal irradiation (RNI) for patients with cN1 breast cancer who receive neoadjuvant chemotherapy (NCTX) that becomes ycN0 but remains pN+. In the absence of its publication, level I guidance does not exist regarding the optimal axillary surgery for patients receiving NCTX. We sought to evaluate outcomes across two national contemporary clinical NCTX trials based on axillary and breast response to NCTX, particularly if more aggressive surgery was associated with more favorable outcomes. Methods: With IRB approval (IRB201802781), we obtained data from NCTX trials NSABP B40 and B41. B40 enrolled women with HER2- disease, and B41 enrolled those with HER2+ disease. RNI and axillary surgery were selected at physician discretion and not protocolled. Patients received sentinel lymph node biopsy (SLNB), SLNB+ALND (S+ALND), or ALND. We examined outcomes of locoregional recurrence (LRR), distant recurrence (DR), disease free survival (DFS), and overall survival (OS). Univariable and multivariable analyses of B40 and B41 data were performed to evaluate the associations of axillary surgery with the outcomes above, adjusting for age, tumor subtype, mastectomy or not, breast pathologic complete response (pCR), axillary pCR, tumor subtype, regional nodal irradiation, and grade. Kaplan-Meier estimation was used for OS and DFS, with cumulative incidence function for LRR and DR. Results: Median follow-up for studies B40 and B41 were 4.5 and 5.1 years, respectively, including 1154 and 504 patients for analysis. A total of 786 (47%) patients were cN+, and of those, 377 had a pcR (48%). 440 (27%), 505 (31%), and 663 (41%) patients had SLNB, S+ALND, and ALND respectively. 855 (52%) and 803 (48%) patients had mastectomy and lumpectomy, respectively. 783 (51%) received RNI. For the 518 ypN+ patients on B40, 7/25 (SLNB), 69/234 (S+ALND), and 107/259 (ALND) experienced an event. DFS at 5 years was 71%, 68%, and 56% for the SLNB, S+ALND, and ALND groups respectively with ypN+ on B40. For the 112 ypN+ patients on B41, 3/6, 15/43, and 27/63 experienced an event. DFS at 5 years was 50%, 64%, and 55% for the SLNB, S+ALND, and ALND groups, respectively, with ypN+ on B41. In multivariable analyses for the combined population of B40 and B41 for LRR, DR, DFS, and OS, SLNB was never associated with a higher chance of relapse or inferior survival (HR > 1) compared to S+ALND or ALND. Conclusions: Among women prospectively treated on national trials with NCTX and axillary surgery and RNI selected at physician discretion, receipt of SLNB alone was not associated with a higher likelihood of recurrence compared to S+ALND or ALND. Anticipated results of A011202 will provide level I guidance on axillary surgery for patients with cN1 disease converting to cN0 post-NCTX.

Purpose/Objective: There is a need for innovative methods to provide high-quality care to vulnerable populations in an effort to reduce disparities. This is particularly important for women facing a new breast cancer diagnosis. The purpose of the present research was to investigate what social determinants may play a role in the existing disparities impacting adherence to care recommendations in communities with poor access to primary care and higher rates of morbidity and mortality. This study characterized adherence with breast health follow-up care in a diverse population of patients where inequalities exist that may negatively impact adherence to treatment recommendations. The objective of the study was to characterize factors associated with adherence to treatment among women with newly diagnosed breast cancer. Materials/Methods: Women diagnosed with stage I through IV breast cancer treated at the University of Florida College of Medicine-Jacksonville between 01/01/2014 and 12/31/2019 were included in the sample. Patterns of adherence were categorized using machine learning methods with data derived from the electronic medical record and the UF Health Jacksonville Tumor registry. Age, race, and Area Deprivation Index (ADI) state rank in 2019 as a disparity proxy were used to build a machine learning model and classify compliance to treatment. Included patients had a diagnostic procedure that identified breast cancer. Compliance to treatment was fulfilled if the patient received surgery following diagnostic confirmation. A machine learning model was used to stratify patients by risk of non-adherence to treatment following a diagnostic procedure. The models were evaluated using their area under the curve (AUC). Results: A total of 6,951 women were included, 629 who were adherent and 6322 non-adherent patients with breast cancer. The average age of the participants was 61.4 years, (Standard Deviation = 12.8 years). The majority of patients were Black (48%) or Caucasian (45%), 2% were Asian, and 5% were Other races. Payer type at diagnosis showed 45% had Medicare, 30% had commercial insurance, 17% were covered by Medicaid, 7% were charity, and 1% had other sources of pay. Most women were diagnosed with stage III breast cancer. Of 346 patients who received surgery that data was available, 127 (36.7%) had surgery within 30 days of diagnosis, 102 (29.5%) between 31 and 60 days, and 37 (10.7%) between 61 and 90 days. Fifteen models were compared using the PyCaret Python library. The ADI appeared as the most important factor to predict adherence in the model, followed by race and characterized by an AUC of 0.63. Conclusion: Our clinic treats predominantly more women diagnosed with biologically aggressive and advanced breast cancer especially in young African American population. The role social conditions play that precipitate and perpetuate health care disparities were investigated to determine their impact on adherence to treatment. At our safety net hospital, over one third were able to undergo surgery within 30 days of diagnosis. The ADI appeared as the most important feature to predict adherence, followed by race. This demonstrated the necessity to better understand the relation between socio-economical determinants and care received by patients. A more detailed description of the patients’ circumstances, such as access to transport, proximity of the hospital, and insurance status may further improve the model. There is a need for innovative methods of providing quality health care to vulnerable populations. Machine learning models can be used to stratify patients by risk of non-adherence to diagnostic follow-up and treatment following a diagnosis of breast cancer. Future research needs to move from identification of non-adherence risk factors to implementation of interventions to improve breast cancer outcomes. Citation Format: Guillaume Labilloy, Brian Celso, Bharti Jasra, Leigh Neumayer, Erin Mobley, Carmen Smotherman, Jennifer Brailsford. Risk factors for lack of adherence with diagnostic follow-up care in breast cancer patients [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-14-14.

BACKGROUND: Implicit bias is a key factor preventing the advancement and retention of women and under-represented minorities in academic surgery. PURPOSE: We examined the role of implicit bias in the technical component of the residency performance evaluation. The Fundamentals of Laparoscopic Surgery (FLS) score, an objective measure of technical performance, was compared to the subjective technical skills (TS) score given by attending surgeons. PROCEDURES: FLS scores and the average TS scores from chief resident evaluations at a university program were analyzed from 2015 to 2019 (n = 29 residents; female 22%, underrepresented minorities 27%). The average TS score for each resident was calculated, scores dichotomized above and below the mean for the program and analyzed across gender and racial identity. MAIN FINDINGS: There were no significant differences in FLS or TS scores between male and female trainees or racial identity. The Kappa correlation coefficient between the 2 dichotomized scores was significantly lower for female (-0.50) versus male (0.23) trainees (p < 0.01); it was not significantly different between racial groups (p = 0.34). PRINCIPAL CONCLUSIONS: There was statistically significant difference in agreement between the FLS and TS scores of individual female and male trainees, suggesting the presence of implicit bias in our pilot study. Further research with a larger sample size is warranted. OBJECTIVE: To investigate the presence of implicit bias against women and underrepresented minorities in the technical component of the residency performance evaluation. We hypothesized that women and underrepresented racial minorities would have lower subjective technical skills (TS) scores as compared to their objective FLS scores, relative to the mean for the training program. DESIGN: FLS scores and the average TS scores from chief resident performance evaluations were analyzed from 2015-2019. Both FLS and the average TS scores were dichotomized above and below the mean for the program and analyzed across gender and racial identity. Research was approved by institutional IRB. SETTING: This study was conducted at the University of Arizona General Surgery Residency Program at Banner University Medical Center in Tucson, Arizona. This is a tertiary care university training program. PARTICIPANTS: Educational records of graduated general surgery chief residents from 2015 to 2019 were accessed for the study. We analyzed 37 TS scores from attending performance evaluations and 29 FLS scores reported to the program during the study period (22% female, 27% underrepresented racial minorities). RESULTS: There were no significant differences in FLS or TS scores between male and female trainees or racial identity. The Kappa correlation coefficient between the 2 dichotomized scores was significantly lower for female (-0.50) versus male (0.23) trainees (p < 0.01); it was not significantly different between racial groups (p = 0.34). CONCLUSIONS: There was a statistically significant difference in agreement between the FLS and TS score of individual female and male trainees, suggesting the presence of implicit bias in this pilot study. Further research with a larger sample size is warranted. (C) 2021 The Author(s). Published by Elsevier Inc. on behalf of Association of Program Directors in Surgery.

From the Department of Surgery, University of Florida College of Medicine, Jacksonville, FL Disclosure Information: Nothing to disclose. Presented at the Western Surgical Association 129th Scientific Session, Indian Wells, CA, November 2021. Received December 15, 2021; Accepted December 16, 2021. Correspondence address: Leigh Neumayer, MD, MS, MBA, FACS, DABS, MAMSE, Department of Surgery, University of Florida College of Medicine-Jacksonville, 653 West 8th St, FC 3rd Floor, Jacksonville, FL 32209. email: [email protected]

OBJECTIVES: Reward and recognition of surgical educa-tion as an academic activity remains a highly variable process between institutions. The goal of this study is to provide expert consensus definition of an academic sur-gical educator, with focus on criteria for academic promotion. STUDY DESIGN AND SETTING: Following IRB approval, a Web-based modified Delphi process was used to gener-ate prioritized academic promotion criteria for surgical educators. PARTICIPANTS AND SETTING: Participants were recruited nationally from a pool of senior academic sur-geons who are members of the Society of University Sur-geons and the Society of Surgical Chairs. RESULTS: Following a three-round modified Delphi pro-cess, the top domains of educational activity for promo-tion to associate professor and professor were scholarship, teaching, and administration; mentorship was also a priority category for promotion to professor. The top three activities described for promotion to Asso-ciate Professor were active participation in conferences/ departmental educational activities for medical students and residents; educational portfolio demonstrating com-mitment to activities as an educator; and clinical teach-ing excellence at their home institution. The three activities most highly scored items for promotion to Pro-fessor were mentorship of junior surgical educators; active participation in conferences/ departmental educational activities for medical students and residents; and a record of teaching excellence at the medical stu-dent and resident levels. CONCLUSIONS: These findings demonstrate a progres-sion from teacher to scholar to leader across a surgical educator's career, with each level incorporating and building upon the prior activities. Identification of cate-gories and criteria may meaningfully inform best practi-ces to be incorporated into the career development and promotion processes for surgeons on an educator aca-demic pathway. ( J Surg Ed 79:173-178. (c) 2021 Associa-tion of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.)

Data from preclinical studies suggest a link between increased risk of breast cancer and exposure to bisphenols at doses below what the United States Food and Drug Administration (FDA) considers as safe for consumption. Bisphenols exert estrogenic effects and are found in canned and plastic wrapped foods, food packaging, and plasticware. Mechanistically, bisphenols bind to the estrogen receptor (ER) and activate the expression of genes associated with cell proliferation and breast cancer. In this paper, we present a narrative literature review addressing bisphenol A and chemical analogs including bisphenol AF, bisphenol F, and bisphenol S selected as prototype xenoestrogens; then, we discuss biological mechanisms of action of these bisphenols in breast cells and potential impact of exposure at different stages of development (i.e., perinatal, peripubertal, and adult). Finally, we summarize studies detailing interactions, both preventative and promoting, of bisphenols with food components on breast cancer risk. We conclude the review with a discussion of current controversies in interpretation of the above research and future areas for investigation, including the impact of bisphenols and food components on breast tumor risk.

Triple negative breast cancer (TNBC) represents a highly heterogeneous group of breast cancers, lacking expression of the estrogen (ER) and progesterone (PR) receptors, and human epidermal growth factor receptor 2 (HER2). TNBC are characterized by a high level of mutation and metastasis, poor clinical outcomes and overall survival. Here, we review the epigenetic mechanisms of regulation involved in cell pathways disrupted in TNBC, with particular emphasis on dietary food components that may be exploited for the development of effective strategies for management of TNBC.

Breast cancer is the most common malignancy and cause of cancer-related mortality among women worldwide. Triple negative breast cancers (TNBC) are the most aggressive and lethal of the breast cancer molecular subtypes, due in part to a poor understanding of TNBC etiology and lack of targeted therapeutics. Despite advances in the clinical management of TNBC, optimal treatment regimens remain elusive. Thus, identifying interventional approaches that suppress the initiation and progression of TNBC, while minimizing side effects, would be of great interest. Studies have documented an inverse relationship between the incidence of hormone receptor negative breast cancer and adherence to a Mediterranean Diet, particularly higher consumption of fish and olive oil. Here, we performed a review of studies over the last 5 years investigating the effects of fish oil, olive oil and their components in model systems of TNBC. We included studies that focused on the fish oil ω-3 essential fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in addition to olive oil polyphenolic compounds and oleic acid. Both beneficial and deleterious effects on TNBC model systems are reviewed and we highlight how multiple components of these Mediterranean Diet oils target signaling pathways known to be aberrant in TNBC including PI3K/Akt/mTOR, NF-κB/COX2 and Wnt/β-catenin.

Importance:The association between exposure to hormone-modulating therapy (HMT) as breast cancer treatment and neurodegenerative disease (NDD) is unclear. Objective:To determine whether HMT exposure is associated with the risk of NDD in women with breast cancer. Design, Setting, and Participants:This retrospective cohort study used the Humana claims data set from January 1, 2007, to March 31, 2017. The Humana data set contains claims from private-payer and Medicare insurance data sets from across the United States with a population primarily residing in the Southeast. Patient claims records were surveyed for a diagnosis of NDD starting 1 year after breast cancer diagnosis for the duration of enrollment in the claims database. Participants were 57 843 women aged 45 years or older with a diagnosis of breast cancer. Patients were required to be actively enrolled in Humana claims records for 6 months prior to and at least 3 years after the diagnosis of breast cancer. The analyses were conducted between January 1 and 15, 2020. Exposure:Hormone-modulating therapy (selective estrogen receptor modulators, estrogen receptor antagonists, and aromatase inhibitors). Main Outcomes and Measures:Patients receiving HMT for breast cancer treatment were identified. Survival analysis was used to determine the association between HMT exposure and diagnosis of NDD. A propensity score approach was used to minimize measured and unmeasured selection bias. Results:Of the 326 485 women with breast cancer in the Humana data set between 2007 and 2017, 57 843 met the study criteria. Of these, 18 126 (31.3%; mean [SD] age, 76.2 [7.0] years) received HMT, whereas 39 717 (68.7%; mean [SD] age, 76.8 [7.0] years) did not receive HMT. Mean (SD) follow-up was 5.5 (1.8) years. In the propensity score-matched population, exposure to HMT was associated with a decrease in the number of women who received a diagnosis of NDD (2229 of 17 878 [12.5%] vs 2559 of 17 878 [14.3%]; relative risk, 0.89; 95% CI, 0.84-0.93; P < .001), Alzheimer disease (877 of 17 878 [4.9%] vs 1068 of 17 878 [6.0%]; relative risk, 0.82; 95% CI, 0.75-0.90; P < .001), and dementia (1862 of 17 878 [10.4%] vs 2116 of 17 878 [11.8%]; relative risk, 0.88; 95% CI, 0.83-0.93; P < .001). The number needed to treat was 62.51 for all NDDs, 93.61 for Alzheimer disease, and 69.56 for dementia. Conclusions and Relevance:Among patients with breast cancer, tamoxifen and steroidal aromatase inhibitors were associated with a decrease in the number who received a diagnosis of NDD, specifically Alzheimer disease and dementia.

Globally, neurological disorders rank as the leading cause of disability‐adjusted life‐years, and the second‐leading cause of deaths. The high global prevalence and economic impact of Alzheimer’s disease presents a significant public health challenge while the identification of therapies to prevent Alzheimer’s disease (AD) remains a challenge. Worldwide, breast cancer is the most common non‐skin cancer in women. Approximately 1 in 8 women will be diagnosed with breast cancer during their lifetime. Currently, Alzheimer’s disease affects 1 in 9 persons in the US over the age of 65, two thirds of whom are women.

OBJECTIVES:Examine the effect of different types of firearms on readmission due to acute stress disorder (ASD) and/or post-traumatic stress disorder (PTSD) in firearm-injury victims.BACKGROUND:Survivors of firearm-related injuries suffer long-term sequelae such as disability, work loss, and deterioration in the quality of life. There is a paucity of data describing the long-term mental health outcomes in these patients.METHODS:We performed a 5-year (2011-2015) analysis of the Nationwide Readmission Database. All adult patients with firearm injuries were stratified into 3 groups by firearm type: handgun, shotgun, and semiautomatic rifle. Outcome measures were the incidence and predictors of ASD/PTSD.RESULTS:A total of 100,704 victims of firearm-related injuries were identified, of which 13.3% (n = 13,393) were readmitted within 6 months of index hospitalization, 6.7% (n = 8970) of these due to ASD/PTSD. Mean age was 34 ± 14 years, 88% were men. Of those readmitted due to ASD/PTSD, 24% (n = 2153) sustained a handgun-related injury on index hospitalization, 12% (n = 1076) shotgun, and 64% (n = 5741) semiautomatic gun (P = 0.039). On regression analysis, semiautomatic gun and shotgun victims had higher odds of developing ASD/PTSD upon readmission [odds ratio (OR): 2.05 (1.10-4.12) and OR: 1.41 (1.08-2.11)] compared to handgun. Female sex [OR: 1.79 (1.05-3.05)] and younger age representing those younger than 25 years [OR: 4.66 (1.12-6.74)] were also independently associated with higher odds of ASD/PTSD.CONCLUSIONS:Apart from the lives lost, survivors of semiautomatic rifle- and shotgun-related injuries suffer long-term mental health sequalae. These secondary and debilitating mental health outcomes are important considerations for capturing the overall burden of the disease.

Background: Estimated Relative Risks (RR) for breast cancer in relatives of breast cancer cases are typically not based on precise family history. Using a large resource linking deep genealogy with decades of cancer data, RRs were estimated for breast cancer based on specific and extended family history. Methods: RRs for breast cancer were estimated in females with breast cancer family histories that included number of first-(FDR), second-(SDR), and third-degree relatives (TDR), and age at earliest diagnosis in a relative. Relative risks were based on breast cancer rates estimated from 265,677 females in the resource with no FDR, SDR or TDR family history of breast cancer. Results: RRs for first-degree relatives of BC cases ranged from 2.22 (=1 FDR affected, CI: 2.14, 2.29) to 7.91 (=4 FDRs affected, CI: 5.26, 11.43). RRs for second degree relatives of probands with 0 affected FDRs ranged from 1.49 (>1 SDR affected, CI: 1.44, 1.54) to 2.60 (>4 SDRs affected, CI: 1.91, 3.46). RRs for third-degree relatives with 0 affected FDRs and 0 affected SDRs ranged from 1.22 (>1 TDR affected, CI: 1.18, 1.26) to 1.93 (>5 TDRs affected, CI: 1.62, 2.28). Increased RRs were observed for decreasing earliest age at diagnosis in a relative. Conclusions: The majority of women have a positive family history for breast cancer; any number of affected relatives significantly increases risk for breast cancer. Risk prediction derived from specific and extended family history allows identification of women at highest risk and could be a powerful, efficient tool to individualize cancer prevention and screening. Financial Support: Research was supported by the Utah Cancer Registry, which is funded by Contract No.HHSN261201000026C from the National Cancer Institute's SEER Program with additional support from the Utah State Department of Health and the University of Utah. Partial support for all data sets within the Utah Population Database (UPDB) and for LACA was provided by Huntsman Cancer Institute, Huntsman Cancer Foundation, University of Utah, and the Huntsman Cancer Institute's Cancer Center Support grant, P30 CA42014, from National Cancer Institute.

BACKGROUND:Faculty attrition has been widely acknowledged and poorly understood throughout academic medicine. To date, barriers to career advancement in academic surgery have been identified and described in a limited fashion using only survey data. The authors sought to characterize career barriers for women academic surgeons using grounded theory methodology.METHODS:Authors conducted semi-structured interviews with 15 mid-career and senior female academic surgeons in the United States. Data were drawn together using grounded theory analysis of interview transcripts to develop a conceptual model.RESULTS:Interviewees identified barriers constituting two intersecting categories: (1) obstacles within the system of academic surgery and (2) impediments based in broader culture and its power structures. Interviewees' robust description of the challenges of integrating clinical and non-clinical professional responsibilities is novel.CONCLUSIONS:Career barriers identified by women in academic surgery are complex and include cultural factors from within and outside of the profession. Identifying and dismantling barriers, particularly those that negatively impact perceptions of belonging, is imperative to creating a culture of sustained excellence in academic surgery.SUMMARY:The authors used grounded theory method to develop a conceptual model of barriers to careers in academic surgery as described by successful female academic surgeons. The authors identified intersecting cultural barriers specific to academic surgery and derived from cultural power differentials.

Table S1. contains the list of the genes used in the study, as well as indicators for which pathway they belong to in subsequent analyses. Table S2. is the list of rare variants with corresponding in silico scores. Table S3. contains the total counts that were used to create Fig. 2. (XLSX 73 kb)

Staging of breast cancer is critical for making treatment decisions as well as for prognosis. Staging systems have evolved over time, and most providers caring for patients with breast cancer use American Joint Commission on Cancer staging. This chapter also provides a review of multicentric and multifocal characteristics of breast cancer.

Context: College of American Pathologists (CAP) and the American Society of Clinical Oncology have emphasized the need to reduce preanalytic variables for evaluating predictive biomarker expression in breast cancer. Postoperative x-ray of excised breast tissue is commonplace, yet is a variable that has not been investigated previously. We asked whether such radiation affects expression of relevant biomarkers. Design: A previous study found that human breast cancers grown in mice demonstrate the same immunohistochemical and molecular profiles as the original tumors. Thirteen patient-derived xenografts were harvested fresh and divided for specimen radiography and a matched nonirradiated control, while following CAP/ASCO guidelines for cold ischemia time and fixation. Samples were processed in a tissue microarray for immunohistochemistry. Estrogen receptor (ER), progesterone receptor (PR), p53, and Ki67 staining was evaluated using an optimized scoring algorithm performed on digitally scanned slides. Samples were also scored manually by a blinded pathologist using the H-score method, and HER2 by the CAP/ASCO 2013 protocol. Histologic scores were compared by analysis of variance. Results: There was no significant difference in quantity or intensity of staining between irradiated and nonirradiated samples for estrogen receptor (P=0.28), p53 (P=0.96), and Ki67 (P=0.94). A small but statistically significant difference was observed for PR (P=0.0058). HER2 staining was similarly unchanged in the 1 tumor exhibiting 3+ staining. Conclusions: Our study demonstrates that x-ray of breast carcinomas does not significantly affect the expression of predictive biomarkers, with the exception of PR for unclear reasons. It also highlights the utility of the patient-derived xenograft model for biomarker studies.