Non-sclerosing (T-cell) and sclerosing (B-cell) lymphocytic lobulitis in diagnostic breast biopsies: Clinical, imaging, and pathologic features

Lymphocytic lobulitis (LL) is characterized by prominent lymphocytic infiltrates centered on lobules. Sclerosing lymphocytic lobulitis (SCLL) associated with diabetes mellitus (DM) or autoimmune disease (AI) was the first type to be described. Subsequently, non-sclerosing LL (NSCLL) was reported as an incidental finding in prophylactic mastectomies due to high risk germline mutations or a family history of breast cancer. The two types of LL were distinguished by stromal features and a predominant population of B-cells in the former and T-cells in the latter. In this study, 8 cases of NSCLL detected clinically or by screening were compared to 44 cases of SCLL. One case of NSCLL presented as a palpable mass, 2 as masses on screening, and 5 as MRI enhancement. In contrast, 80% of SCLL cases presented as palpable masses. Half the cases of NSCLL were associated with a BRCA1 or 2 mutation compared to 1 case of SCLL (2%). Three additional cases of NSCLL were associated with a strong family and/or personal history of breast cancer. Almost half (52%) of SCLL cases were associated with DM or AI, but only 25% of NSCLL. Immunoperoxidase studies confirmed a predominance of T-cells in NSCLL and B-cells in SCLL associated with DM or AI. It is important for pathologists to be aware of this new observation that NSCLL can be detected as a palpable mass or an imaging finding in diagnostic biopsies, as its presence can be indicative of a significant risk for breast cancer.

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.

Identifying Patterns and Barriers in OncotypeDX Recurrence Score Testing in Older Patients With Early-Stage, Estrogen Receptor-Positive Breast Cancer: Implications for Guidance and Reimbursement

PURPOSE

To evaluate the clinical patterns of utilization of OncotypeDX Recurrence Score (RS) in early-stage, hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer (BC) at an academic center with previously established internal reflex testing guidelines.

METHODS

RS testing in accordance with preexisting reflex criteria and predictors of utilization outside of reflex criteria were retrospectively analyzed for the years 2019-2021 in a quality improvement evaluation. Patients were grouped according to OncotypeDX testing within (cohort A) or outside (cohort B) of predefined criteria which included a cap at age older than 65 years.

RESULTS

Of 1,687 patients whose tumors had RS testing, 1,087 were in cohort A and 600 in cohort B. In cohort B, nearly half of patients were older than 65 years (n = 279; IQR, 67-72 years). For patients older than 65 years, those with RS testing were younger (median age: 69 v 73 years), with higher grade cancers (G2-3: 84.9% v 54.7%) and were more likely to be treated with chemotherapy (15.4% v 4.1%). Issues for implementation of RS testing in older patients were identified, including potential structural barriers related to the current policy on the reimbursements of genomic tests.

CONCLUSION

Internal guidelines may facilitate standardized utilization of the RS in early-BC. Our data suggest that clinicians preferred broader utilization of RS across the age spectrum, with therapeutically important consequences. Modifying the current policy for reimbursement of RS testing and in internal reflexive testing criteria for those older than 65 years is warranted.

Use of the Xpert Breast Cancer STRAT4 for Biomarker Evaluation in Tissue Processed in a Developing Country

Objectives

Breast cancer immunohistochemistry (IHC) biomarker testing is limited in low-resource settings, and an alternative solution is needed. A point-of-care mRNA STRAT4 breast cancer assay for ESR1, PGR, ERBB2, and MKi67, for use on the GeneXpert platform, has been recently validated on tissues from internationally accredited laboratories, showing excellent concordance with IHC.

Methods

We evaluated STRAT4/IHC ESR1/estrogen receptor (ER), ERBB2/human epidermal growth factor receptor 2 (HER2) concordance rates of 150 breast cancer tissues processed in Rwanda, with undocumented cold ischemic and fixation time.

Results

Assay fail/indeterminate rate was 2.6% for ESR1 and ERBB2. STRAT4 agreement with ER IHC was 92.5% to 93.3% and 97.8% for HER2, for standard (1x) and concentrated (4x) reagent-conserving protocols, respectively. Eleven of 12 discordant ER/ESR1 cases were ESR1- negative/IHC-positive. These had low expression of ER by IHC in mostly very small tumor areas tested (7/12; <25 mm²). In two of three discordant HER2 cases, the STRAT4-ERBB2 result correlated with the subsequent fluorescence in situ hybridization (FISH) result. STRAT4-ERBB2 results in 9 of 10 HER2-IHC equivocal cases were concordant with FISH.

Conclusions

The STRAT4 assay is an alternative for providing quality-controlled breast cancer biomarker data in laboratories unable to provide quality and/or cost-efficient IHC services.

Can pathology diagnostic services for cancer be stratified and serve global health?

BACKGROUND

Before initiating cancer therapy, a diagnostic tumor tissue sample evaluated within a pathology laboratory by a pathologist is essential to confirm the malignancy type and provide key prognostic factors that direct the treatment offered.

METHODS

Pathology evaluation includes multiple expensive reagents, complex equipment, and both laboratory and pathologist technical skills. By using breast cancer as an example, at a minimum, key tumor prognostic information required before the initiation of treatment includes subtype, tumor grade, tumor size, lymph node status when possible, and biomarker expression determined by immunohistochemistry for estrogen receptor. The additional determination of biomarker expression of progesterone receptor and human epidermal growth factor receptor (HER2) is the standard of care in high-resource settings, but assays may not be affordable in low-income and middle-income countries.

RESULTS

With positive tests, patients are eligible for either tamoxifen (for estrogen receptor-positive/progesterone receptor-positive cancers) or monoclonal antibody therapy (for HER2-positive cancers). For settings in which endocrine therapy and/or HER2-targeted therapy is unavailable, biomarker studies have no utility, and high-resource setting standards for pathology evaluation and reporting are unachievable. Resource-stratified pathology evaluation guidelines in cancer diagnosis have not been developed, in contrast to excellent comprehensive, resource-stratified clinical guidelines for use in low-income and middle-income countries, and these are long overdue.

CONCLUSIONS

The challenges of pathology evaluation in the context of global health are being met by innovative solutions, which may change the face of pathology practice.

Cross-Residency Radiologic/Pathologic Correlation Curriculum: Teaching Correlation of Surgical Specimens With Imaging

The College of American Pathologists expects pathologists to attain competency in radiologic/pathologic correlation, including correlation of histopathologic findings with imaging findings. While pathology residents appreciate the importance of radiologic/pathologic correlation, their lack of experience and confidence in interpreting imaging studies deters them from obtaining specimen radiographs and reviewing preoperative imaging studies. Formal training in this domain is lacking. A cross-residency curriculum was developed to help pathology residents build basic skills in the correlation of surgical specimens with preoperative imaging and specimen radiographs. Didactic sessions were prepared by 3 pairs of radiology and pathology residents with guidance from radiology and pathology attendings in the subspecialty areas of breast, musculoskeletal, and head and neck. The authors describe the development, implementation, and assessment of the curriculum. A total of 20 pathology residents attended the sessions, with 7 completing both the pre- and postintervention surveys. These residents gained confidence in their ability to interpret specimen radiographs and to select specimens to evaluate with radiography. They gained an appreciation of the importance of collaboration with radiologists in evaluating specimens and of viewing preoperative imaging studies to guide gross examination and dissection. They reported obtaining specimen radiographs and viewing preoperative imaging studies more frequently after attending the sessions. Innovative solutions such as this cross-residency educational initiative offer a potential solution to fulfill the radiologic/pathologic correlation competency standard for pathology residents and may be replicable by other residency programs and academic institutions.

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

21-Gene Recurrence Score Adds Significant Value for Grade 3 Breast Cancers: Results From a National Cohort

PURPOSE

The 21-gene recurrence score (RS) is used to identify patients with hormone receptor-positive early-stage breast cancer who may benefit from the addition of chemotherapy to endocrine therapy. We hypothesized that many women with poor prognostic histopathologic grade 3 disease may be offered chemotherapy irrespective of RS results, of whom a subset may not benefit from adjuvant chemotherapy.

PATIENTS AND METHODS

A total of 30,864 women in the National Cancer Database were diagnosed with pT1c to pT2, pN0 to pN1, grade 3 estrogen receptor-positive, human epidermal growth factor receptor 2-negative invasive breast carcinoma from 2010 to 2015. RS was stratified as low (less than 18), intermediate (18 to 30), and high (31 or more). Overall survival by RS was evaluated by Kaplan-Meier, log-rank, and multivariable proportional hazards, with adjustment for relevant clinical and demographic variables.

RESULTS

RS testing in grade 3 cancers increased between 2010 and 2015 (pN0, 53% to 72%; pN1, 16% to 36%). Among the 13,558 women with pN0 and the 2,840 with pN1 disease with RS testing, 27.1% and 30.0%, respectively, had low scores (less than 18). The 5-year overall survival rate for patients with a high RS, but not low RS, was significantly higher with chemotherapy (v no chemotherapy; absolute differences: high RS pN0 = 12.2% and pN1 = 25.5%, both P < .001; low RS pN0 = 2.5%, P = .07; and pN1 = 1.0%, P = .27), findings that were reinforced in multivariable analyses risk adjusted by clinicopathologic characteristics.

CONCLUSION

Increased use of RS may help to better tailor treatment recommendations by stratifying patients with grade 3 disease into those who will and will not derive survival benefit and should be considered in all patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative T1c to T2, N0 to N1 disease.

Safety-Net Hospitals, Neighborhood Disadvantage, and Readmissions Under Maryland's All-Payer Program: An Observational Study

BACKGROUND

Safety-net hospitals have higher-than-expected readmission rates. The relative roles of the mean disadvantage of neighborhoods the hospitals serve and the disadvantage of individual patients in predicting a patient's readmission are unclear.

OBJECTIVE

To examine the independent contributions of the patient's neighborhood and the hospital's service area to risk for 30-day readmission.

DESIGN

Retrospective observational study.

SETTING

Maryland.

PARTICIPANTS

All Maryland residents discharged from a Maryland hospital in 2015.

MEASUREMENTS

Predictors included the disadvantage of neighborhoods for each Maryland resident (area disadvantage index) and the mean disadvantage of each hospital's discharged patients (safety-net index). The primary outcome was unplanned 30-day hospital readmission. Generalized estimating equations and marginal modeling were used to estimate readmission rates. Results were adjusted for clinical readmission risk.

RESULTS

13.4% of discharged patients were readmitted within 30 days. Patients living in neighborhoods at the 90th percentile of disadvantage had a readmission rate of 14.1% (95% CI, 13.6% to 14.5%) compared with 12.5% (CI, 11.8% to 13.2%) for similar patients living in neighborhoods at the 10th percentile. Patients discharged from hospitals at the 90th percentile of safety-net status had a readmission rate of 14.8% (CI, 13.4% to 16.1%) compared with 11.6% (CI, 10.5% to 12.7%) for similar patients discharged from hospitals at the 10th percentile of safety-net status. The association of readmission risk with the hospital's safety-net index was approximately twice the observed association with the patient's neighborhood disadvantage status.

LIMITATIONS

Generalizability outside Maryland is unknown. Confounding may be present.

CONCLUSION

In Maryland, residing in a disadvantaged neighborhood and being discharged from a hospital serving a large proportion of disadvantaged neighborhoods are independently associated with increased risk for readmission.

PRIMARY FUNDING SOURCE

National Institute on Minority Health and Health Disparities and Maryland Health Services Cost Review Commission.

Mixed Invasive Ductal and Lobular Carcinoma of the Breast: Prognosis and the Importance of Histologic Grade

BACKGROUND

The diagnosis of mixed invasive ductal and lobular carcinoma (IDC-L) in clinical practice is often associated with uncertainty related to its prognosis and response to systemic therapies. With the increasing recognition of invasive lobular carcinoma (ILC) as a distinct disease subtype, questions surrounding IDC-L become even more relevant. In this study, we took advantage of a detailed clinical database to compare IDC-L and ILC regarding clinicopathologic and treatment characteristics, prognostic power of histologic grade, and survival outcomes.

MATERIALS AND METHODS

In this retrospective cohort study, we identified 811 patients diagnosed with early-stage breast cancer with IDC-L or ILC. Descriptive statistics were performed to compare baseline clinicopathologic characteristics and treatments. Survival rates were subsequently analyzed using the Kaplan-Meier method and compared using the Cox proportional hazards model.

RESULTS

Patients with ILC had more commonly multifocal disease, low to intermediate histologic grade, and HER2-negative disease. Histologic grade was prognostic for patients with IDC-L but had no significant discriminatory power in patients with ILC. Among postmenopausal women, those with IDC-L had significantly better outcomes when compared with those with ILC: disease-free survival (DFS) and overall survival (OS; adjusted hazard ratio [HR], 0.54; 95% confidence interval [CI] 0.31-0.95). Finally, postmenopausal women treated with an aromatase inhibitor had more favorable DFS and OS than those treated with tamoxifen only (OS adjusted HR, 0.50; 95% CI, 0.29-0.87), which was similar for both histologic types (p = .212).

CONCLUSION

IDC-L tumors have a better prognosis than ILC tumors, particularly among postmenopausal women. Histologic grade is an important prognostic factor in IDC-L but not in ILC.

IMPLICATIONS FOR PRACTICE

This study compared mixed invasive ductal and lobular carcinoma (IDC-L) with invasive lobular carcinomas (ILCs) to assess the overall prognosis, the prognostic role of histologic grade, and response to systemic therapy. It was found that patients with IDC-L tumors have a better prognosis than ILC, particularly among postmenopausal women, which may impact follow-up strategies. Moreover, although histologic grade failed to stratify the risk of ILC, it showed an important prognostic power in IDC-L, thus highlighting its clinical utility to guide treatment decisions of IDC-L. Finally, the disease-free survival advantage of adjuvant aromatase inhibitors over tamoxifen in ILC was consistent in IDC-L.

Impact of Genomic Assay Testing and Clinical Factors on Chemotherapy Use After Implementation of Standardized Testing Criteria

BACKGROUND

For clinically appropriate early-stage breast cancer patients, reflex criteria for Oncotype DX ordering ("the intervention") were implemented at our comprehensive cancer center, which reduced time-to-adjuvant chemotherapy initiation. Our objective was to evaluate Oncotype DX ordering practices and chemotherapy use before and after implementation of the intervention.

MATERIALS AND METHODS

We examined medical records for 498 patients who had definitive breast cancer surgery at our center. The post-intervention cohort consisted of 232 consecutive patients who had Oncotype DX testing after reflex criteria implementation. This group was compared to a retrospective cohort of 266 patients who were diagnosed and treated prior to reflex criteria implementation, including patients who did and did not have Oncotype DX ordered. Factors associated with Oncotype DX ordering pre- and post-intervention were examined. We used multivariate logistic regression to evaluate factors associated with chemotherapy receipt among patients with Oncotype DX testing.

RESULTS

The distribution of Oncotype DX scores, the proportion of those having Oncotype DX testing (28.9% vs. 34.1%) and those receiving chemotherapy (14.3% vs. 19.4%), did not significantly change between pre- and post-intervention groups. Age ≤65 years, stage II, grade 2, 1-3+ nodes, and tumor size >2 cm were associated with higher odds of Oncotype DX testing. Among patients having Oncotype DX testing, node status and Oncotype DX scores were significantly associated with chemotherapy receipt.

CONCLUSION

Our criteria for reflex Oncotype DX ordering appropriately targeted patients for whom Oncotype DX would typically be ordered by providers. No significant change in the rate of Oncotype DX ordering or chemotherapy use was observed after reflex testing implementation.

IMPLICATIONS FOR PRACTICE

This study demonstrates that implementing multidisciplinary consensus reflex criteria for Oncotype DX ordering maintains a stable Oncotype DX ordering rate and chemotherapy rate, mirroring what was observed in a specific clinical practice, while decreasing treatment delays due to additional testing. These reflex criteria appropriately capture patients who would likely have had Oncotype DX ordered by their providers and for whom the test results are predicted to influence management. This intervention serves as a potential model for other large integrated, multidisciplinary oncology centers to institute processes targeting patient populations most likely to benefit from genomic assay testing, while mitigating treatment delays.

Abstract 4564: The immune microenvironment in hormone receptor-positive breast cancer and treatment outcome following preoperative chemotherapy plus bevacizumab

Background: Hormone receptor-positive (HR+) breast cancers (BC) have fewer tumor-infiltrating lymphocytes (TILs) and lower response rates to immune checkpoint inhibitors in early phase studies than other breast cancer subtypes. Immune biomarkers that accurately reflect the immune microenvironment have important clinical implications in HR+ BC patients. Prior evidence suggests that macrophage-related immune pathways may be relevant to the pathophysiology of HR+ BC.

Methods: Patients identified from a prospective trial of preoperative bevacizumab (preop bev) followed by bev with adriamycin/cyclophosphamide/paclitaxel dose-dense chemotherapy (chemo). Tumor samples were collected at diagnosis and surgery (pre-tx and post-tx). TILs and immunohistochemical staining for PD-L1, CD8, and CD68 were scored. Whole transcriptome sequencing (RNAseq) and Nanostring PanCancer Immune Profiling Panel were performed. Pathologic response at surgery was assessed by Miller-Payne (MP) and residual cancer burden (RCB) scores. An immune score was calculated for each pre-tx specimen by integrating 10 published immune signatures. Immune cell subsets were inferred from bulk transcriptional data using CIBERSORT.

Results: 55 patients had at least 1 evaluable specimen and were included for analysis. 18% of pre-tx tumors had ‘high' (≥10%) TILs and ‘high' TILs were associated with significantly higher immune signature score (p=0.004). Immune score correlated highly with proportion of CIBERSORT anti-tumor M1 macrophage and CD8 T-cell signatures (r&gt;0.65 and p&lt;0.001) and was significantly associated with RCB. Higher pre-tx TILs, tPD-L1, sPD-L1, CD8, and CD68 were associated with favorable RCB significantly associated with more favorable RCB after adjustment for tumor size and grade. Pathologic complete response occurred in 4 pts; all 4 had high pre-tx TILs, pre-tx tPD-L1, or both. Among patients with residual disease, there were significantly fewer TILs and CD8 cells after chemotherapy (Wilcoxon signed rank p=0.037 and p=0.002, respectively), however tPD-L1 and CD68 were not significantly different. Nanostring analyses demonstrated that chemokines and complement pathway components were among most significantly enriched post-tx relative to pre-tx.

Conclusions: Most HR+/HER2- breast tumors demonstrate low levels of anti-tumor immune activity; however, those with higher levels have a more favorable response to chemo plus bev. Assessment of immune activity based on RNA signatures is consistent with histology and immune-related protein expression. T-cell- and checkpoint-related biomarkers tend to decrease following preoperative chemo plus bev in HR+/HER2- breast cancer. Following treatment with chemotherapy/bevacizumab, we observe increased expression of chemokines and complement pathway genes.

Citation Format: Adrienne G. Waks, Daniel G. Stover, William T. Barry, Deborah A. Dillon, Evisa Gjini, Scott J. Rodig, Jane E. Brock, Michele Baltay, Jennifer Savoie, Eric P. Winer, Ian E. Krop, Sara M. Tolaney. The immune microenvironment in hormone receptor-positive breast cancer and treatment outcome following preoperative chemotherapy plus bevacizumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4564.

Contemporary Evaluation of Breast Lymph Nodes in Anatomic Pathology

OBJECTIVES

Management of the axilla in breast cancer patients has evolved considerably since the introduction of the sentinel lymph node (SLN) biopsy in the 1990s. Several new clinical and technological developments in the last decade warrant special consideration due to their impact on pathology practice.

METHODS

This review covers the SLN biopsy procedure, issues in the histopathologic and molecular diagnosis of the SLN, and most importantly, evidence from recent practice-changing clinical trials.

RESULTS

ACOSOG Z0011, IBCSG 23-01, and AMAROS trials have shown that early-stage breast cancer patients who have limited metastatic involvement of the SLNs do not benefit from completion axillary dissections.

CONCLUSIONS

It is not necessary for pathologists to search for all small metastases to predict non-SLN involvement, regional recurrence, or death due to disease. Processing should be designed with the goal of detecting macrometastases. Multiple levels, routine immunohistochemistry, and molecular testing are not recommended.

Breast Cancer in Low- and Middle-Income Countries: Why We Need Pathology Capability to Solve This Challenge

Breast cancer is the leading cause of cancer mortality among women in developing countries. Timely and accurate histopathological diagnosis of breast cancer is critical to delivering high-quality breast cancer care to patients in low- and middle-income countries (LMIC). The most important prognostic factors in breast cancer along with tumor size and nodal status are tumor grade, estrogen receptor status, as well as HER2 status in countries where specific targeted therapies are available. In addition, detailed and complete cancer registry data are needed to assess a country's disease burden and guide disease prioritization and allocation of resources for breast cancer treatment. Innovations in leapfrog technology and low-cost point-of-care tests for molecular evaluations are needed to provide accurate and timely pathology, with the ultimate goal of improving survival outcomes for patients with breast cancer in LMIC.

Abstract P5-21-10: Phase 2 study and correlative analyses of ruxolitinib, a selective JAK1/2 inhibitor, in patients with metastatic, triple-negative breast cancer

Background: Preclinical data supports a role for the IL-6/JAK2/STAT3 signaling pathway in breast cancer (BC). Ruxolitinib is an orally bioavailable receptor tyrosine inhibitor targeting JAK1 and JAK2. We evaluated the safety and efficacy of ruxolitinib in patients with metastatic BC and performed correlative analyses.

Methods: This was a non-randomized, phase 2 study of patients with refractory, metastatic, triple-negative BC (TNBC). Patients with inflammatory BC (IBC) of any subtype were also enrolled. The primary endpoint was objective response by RECIST 1.1. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity. The study was designed to enroll only patients whose archival tumor tissue was pSTAT3 moderately to strongly positive in the tumor epithelial cells by central immunohistochemistry (IHC). 16 patients underwent pre-treatment biopsy, of whom 4 also had a second biopsy prior to cycle 2. Biopsy samples and paired primary tumor samples (when available) were subjected to multi-color immunofluorescence and/or immune-FISH for leukocyte markers, pSTAT3, and JAK2. RNA sequencing was performed on available on-study frozen biopsy specimens. 17 patients had plasma collected with cell-free DNA (cfDNA) extracted and subjected to low coverage whole-genome sequencing.

Results: Of 217 patients who consented to archival tumor testing, T-score for pSTAT3 was 'high' (&gt;5) in 69 patients (31.8%), demonstrating frequent activation of the JAK/STAT pathway in metastatic TNBC or IBC. 23 pSTAT3 high patients were enrolled. Ruxolitinib was generally well-tolerated. The most commonly observed adverse events (any grade) were anemia, neutropenia, thrombocytopenia, constipation, nausea, and increased AST/ALT. Grade 3 or higher toxicities were uncommon. No objective responses were seen among 21 evaluable patients, therefore the study was closed to accrual based on study design. Intensive correlative analyses revealed important insights regarding ruxolitinib effects. Pharmacodynamic analyses of baseline versus cycle 2 biopsies demonstrate downregulation of JAK2 target genes, STAT3 signatures, and JAK/STAT gene ontology gene sets, suggesting on-target activity. There was evidence of immune microenvironment modulation: gene set enrichment analysis implicated reduced macrophage/myeloid phenotypes after treatment and CIBERSORT analysis of inferred immune cell subsets demonstrated reduced monocyte/macrophage proportion after treatment (t-test p=0.013). Multi-color immunofluorescence analyses of immune microenvironment are ongoing and will be reported. 17 patients underwent cfDNA analysis with 8 patients (47%) demonstrating gain or amplification of JAK2.

Conclusions: Ruxolitinib, as a single agent, did not meet the primary efficacy endpoint in this refractory patient population. Correlative studies demonstrate evidence of on-target activity and immune microenvironment modulation. Frequent JAK/STAT pathway activation and JAK2 locus chromosomal gains in this cohort suggest that the JAK/STAT pathway remains a potential therapeutic target in BC.

Citation Format: Stover DG, Gil Del Alcazar CR, Tolaney SM, Bardia A, Guo H, Balko JM, Overmoyer BA, Gelman RS, Lloyd M, Wang V, Brock JE, Winer EP, Polyak K, Lin NU. Phase 2 study and correlative analyses of ruxolitinib, a selective JAK1/2 inhibitor, in patients with metastatic, triple-negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-10.

Nipple-Invasive Primary Carcinomas: Clinical, Imaging, and Pathologic Features of Breast Carcinomas Originating in the Nipple

Context Patients choosing to retain the nipple when undergoing therapeutic or prophylactic mastectomy are at risk for cancers arising at that site. Objective To identify cases of invasive carcinoma arising within the nipple and to investigate their clinical, imaging, biologic, and staging features. Design Carcinomas were identified by prospective review of surgical and consult cases at 4 hospitals. Results The 24 patients identified presented with symptoms related to the nipple. Mammography did not detect the cancer in most cases. Ten patients (42%) had skin changes from ductal carcinoma in situ involving nipple skin (Paget disease), with small foci of invasion into the dermis, and 6 of those 10 carcinomas (60%) stained positive for human epidermal growth factor receptor 2 (HER2). The remaining 14 patients (58%) presented with a nipple mass or with skin changes. These were larger invasive carcinomas of both ductal and lobular types. Only 2 of those 14 carcinomas (14%) were HER2⁺. Three of 15 patients (20%) undergoing lymph node biopsy had a single metastasis. No patients have had recurrent disease. Conclusions Rare, invasive, primary nipple carcinomas typically present as subtle nipple thickening or an exudative crust on the skin. Imaging studies are often nonrevealing. A variety of histologic and biologic types of carcinomas occur, similar to cancers arising deeper in the breast. Although the carcinomas invaded into the dermis, some with skin ulceration, the likelihood of lymph node metastasis was no higher than carcinomas of similar sizes. Patients who choose to preserve their nipple(s) should be aware of the possibility of breast cancer arising at that site and to bring any observed changes to the attention of their health care providers.

Estimated Cost Savings: Everyone With Diabetes Counts (EDC) Program

Everyone with Diabetes Counts (EDC) is a national disparities reduction program funded by the Centers for Medicare & Medicaid Services to improve outcomes in the underserved minority, diverse, and rural populations. This analysis evaluates West Virginia's pilot program of diabetes self-management education (DSME), one component of EDC. We frequency-matched 422 DSME completers to 1688 others by demographics and enrollment from Medicare fee-for service claims. We estimated savings associated with reduced hospitalizations in multivariable negative binomial models. DSME completers had 29% fewer hospitalizations (adjusted P < .0069). We estimated savings of $35 900 per 100 DSME completers in West Virginia.

Fibromatosis of the Breast: Diagnostic Accuracy of Core Needle Biopsy

OBJECTIVES

Fibromatosis of the breast is an uncommon neoplasm with potential for local recurrence. Treatment has traditionally been surgical excision with current trends toward conservative management. Given the option of observation after diagnosis by core needle biopsy (CNB), we sought to evaluate the accuracy of CNB for diagnosing fibromatosis.

METHODS

We identified a total of 31 cases in which fibromatosis had been diagnosed or included in the differential diagnosis on a CNB, an excision, or both. Morphology and immunohistochemical results were reviewed.

RESULTS

Aberrant nuclear immunoreactivity for β-catenin and absent staining for CD34 were the most useful studies to diagnose fibromatosis, and one or both were performed in 21 (68%) cases. High molecular weight cytokeratins and p63 were helpful to exclude spindle cell carcinoma. Of 26 cases confirmed as fibromatosis on excision, 22 (85%) were diagnosed as fibromatosis or fibromatosis was favored in the differential diagnosis on CNB. More frequent use of immunohistochemistry would likely have resulted in a greater number of definitive diagnoses. Fibromatosis was rarely mistaken for other nonmalignant stromal lesions, with no cases misdiagnosed as carcinoma.

CONCLUSIONS

CNB can be an accurate method of diagnosing fibromatosis, allowing observation for a select group of patients.

Immune biomarkers and treatment (tx) outcome in hormone receptor-positive (HR+) breast cancer (BC) patients (pts) treated with preoperative chemotherapy (preop chemo) plus bevacizumab (bev)

e12134

Background: Though preliminary study of the BC immune microenvironment suggests that HR+ tumors are less immune-active than other subtypes, immune biomarkers may have important clinical implications in HR+ BC pts. Methods: 78 HR+/HER2- BC pts were enrolled on a prospective trial of preop bev followed by bev with adriamycin/cyclophosphamide/paclitaxel dose-dense chemo. Tumor samples were collected at diagnosis and surgery (pre-tx and post-tx). PD-L1 expression (by immunohistochemistry) and tumor-infiltrating lymphocytes (TILs) were scored. Whole transcriptome sequencing and Nanostring PanCancer Immune Profiling Panel were performed. Pathologic response at surgery was assessed by Miller-Payne (MP) and residual cancer burden (RCB) scores. We calculated adjusted correlations by linear/logistic regression for RCB/dichotomized MP, respectively. Results: 55 pts who received trial tx and had >1 analyzable specimen are included. Pre-tx TILs and tumor PD-L1 (tPD-L1) scores (see table) were slightly positively correlated (Spearman rho 0.23, p=0.1). Large changes (>5%) in TILs or tPD-L1 from pre-tx to post-tx were rare: 2 pts each had large changes in TIL or tPD-L1 score (N=38 and N=31 pairs, respectively). Higher pre-tx TILs or tPD-L1 were significantly associated with more favorable RCB and MP (all Spearman p<0.01) in unadjusted analyses. After adjustment for age and tumor grade, higher pre-tx TILs and tPD-L1 were associated with more favorable RCB (p<0.01 for both), and higher pre-tx tPD-L1 correlated with more favorable MP (p=0.03). Pathologic complete response occurred in 4 pts; all 4 had high pre-tx TILs, pre-tx tPD-L1, or both. Analysis of immune-related RNA signatures is ongoing. Conclusions: High levels of tumor-immune interaction were seen in only a minority of untreated HR+ breast tumors, and did not typically change after tx with chemo plus bev. Nonetheless, TILs and tPD-L1 are significantly associated with pathologic response to preop tx in HR+ disease. [Table: see text]

Abstract P2-05-07: Comparison of the Xpert breast cancer stratifier mRNA assay with central ER, PR, HER2, and Ki67 immunohistochemistry (IHC) for rapid biomarker analysis in developing countries

Breast cancer care in the developing world is limited by access to quality ER and HER2 IHC diagnostic assays needed to justify hormone and HER2 therapeutics. Shipping pathology specimens to a central testing site often out of country delays therapy and is costly. The Xpert Breast Cancer Stratifier assay makes quantitative measurements of ESR1, PGR, ERBB2, and MKi67 mRNAs from FFPE specimens in &lt;2 hours on an easy-to-use automated diagnostic platform, the GeneXpert (GX). 10,000 GX machines are currently in use in 182 countries offering the possibility of a point-of-care solution. We compared concordance in tumor samples between IHC and mRNA intending to challenge the limits of the GX mRNA assay.

83 breast tumor samples were chosen including those with low cellularity, small volume disease, unusual subtypes, ER- tumors with surrounding benign epithelium, and low level HER2+ tumors. mRNA, IHC and FISH assays were performed. Slides were tested following macrodissection of invasive carcinoma and as non-macrodissected whole sections. GX measurements for Ki67 were compared with mitotic rate as an alternative to Ki67 IHC.

Overall percent agreement following macrodissection was 95% for ER, 89% for HER2, 76% for PR, and 80% for Ki67 (&gt;20% positive cut), and using whole section, 99% for ER, 80% for PR, 92% for HER2, and 73% for Ki67. Concordance was 92% for both macrodissection and whole section using mitotic rate to assess proliferation. Ignoring HER2 2+ calls which represented low level amplified tumors by FISH, the concordance rates were 95% for macrodissection and 99% for whole section. Discordance when testing long-term stored 4μm sections was resolved in a number of cases by using a fresh cut from the FFPE block. Half the ER discrepancies were in very small volume tumors ≤25mm2 and 75% were classified as ER-ve by IHC, and positive by Stratifier. 80% of ER IHC- cases were appropriately identified as ER- by the Stratifier in the presence of benign breast epithelium. HER2+ DCIS adjacent to HER2- invasive tumor resulted in a discrepant HER2 mRNA result even with macrodissection. No ER or HER2 discrepancies occurred in low cellularity tumors (≤30% cellularity) nor in lobular and mucinous subtypes.

In a study intended to challenge an mRNA breast biomarker assay, concordance between mRNA results and IHC was high for ER and HER2, the two most important prognostic markers needed for therapeutic decision making. Use of whole sections rather than tumor macrodissection did not decrease concordance. Discrepant ER cases were more prevalent when analyzing low volumes of tumor and in this setting were seen in ER IHC- tumors surrounded by ER+ normal epithelium, or with weak IHC expression, highlighting predictable limitations of the assay. Concordance was better between Ki67 mRNA and mitotic rate than with IHC. Re-test data suggested that a fresh cut of the FFPE block yields the best results by GX, perhaps due to mRNA degradation in stored 4μm sections. The Xpert Breast Cancer Stratifier may provide a rapid, cost-effective solution to the problem of obtaining accurate diagnostic results at the point-of-care in low resource settings, and deserves further evaluation in developing countries.

Citation Format: Brock JE, Milner DA, Ho K, Natalie W, Victor C, Annaliza R, Teresa B, Kathryn G-F, Edwin LW, Jodi W, Wendy W, Michael B. Comparison of the Xpert breast cancer stratifier mRNA assay with central ER, PR, HER2, and Ki67 immunohistochemistry (IHC) for rapid biomarker analysis in developing countries [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-07.

Abstract P3-17-07: Improved long-term outcomes of breast-conserving therapy for women with ductal carcinoma in situ

Purpose: Improved mammographic and surgical techniques and pathologic evaluation, particularly greater attention to achieving negative margins, have resulted in decreased local recurrence rates for patients with ductal carcinoma in situ (DCIS). This is an updated analysis of local outcomes after breast-conserving surgery (BCS) and adjuvant radiation therapy (RT) at a single institution in the modern era.

Methods and Materials: We retrospectively reviewed the records of 245 women treated for DCIS with BCS and RT between 2001 and 2007. Competing risk analysis was used to calculate local recurrence (LR) as a first event with the development of a second non-breast malignancy, contralateral breast cancer, and death as competing first events. The median age at diagnosis was 54 (range, 32-84) and 174 (93%) women had estrogen receptor (ER) and/or progesterone receptor (PR) positive disease. Ninety-five (39%) were grade III. Specimen radiograph during surgery was obtained for 223 women (91%) and post-operative mammogram for 102 (42%). Half underwent more than one excision. The institutional goal for margins during the study period was 3 mm or greater; final margins were &gt;2 mm in 221 (90%). All received adjuvant radiation therapy to the whole breast (median whole breast dose: 4400; range, 4000 - 5220) and nearly all (99%) received a boost to the surgical cavity (median boost dose: 1600; range, 800 – 1800). Among patients with ER and/or PR+ disease, 105 (60%) received adjuvant hormonal therapy.

Results: At a median follow-up of 10.6 years, 4 patients had a LR (2 DCIS, 2 invasive ductal carcinoma) as a first event with a cumulative LR incidence of 0.0% and 1.5% at 5 and 10 years, respectively. The 5 and 10-year cumulative incidence of the competing first events is seen in the table below. Twenty women developed a contralateral breast cancer (CBC; 8 DCIS, 12 invasive carcinoma), 13 were diagnosed with a second non-breast malignancy (3 endometrial, 2 fallopian tube, 1 gallbladder, 1 leukemia and thyroid, 4 lung, 1 ovarian, and 1 uterine), and 7 died. Family history, age at diagnosis, and receipt of hormonal therapy were not significantly associated with the development of CBC on univariable analysis (all p&gt;0.05).

Incidence of local recurrence and competing eventsEvent5-year cumulative incidence10-year cumulative incidenceLocal recurrence0.0%1.5%Contralateral Breast Cancer2.5%7.9%Second non-breast malignancy2.6%4.5%Death1.2%3.5%

Conclusions: With longer follow-up, our rates of local recurrence following breast-conserving therapy for DCIS remain very low (1.5% at 10 years). The vast majority of patients had &gt;2 mm margins, specimen radiographs, and received a tumor bed boost. The majority (60%) of patients with hormone receptor positive disease received adjuvant endocrine therapy. The 10-year incidence of CBC was higher than expected. Predisposing factors for the development of CBC are worthy of investigation.

Citation Format: Warren LE, Chen Y-H, Halasz LM, Capuco A, Bellon JR, Brock JE, Punglia RS, Wong JS, Harris JR. Improved long-term outcomes of breast-conserving therapy for women with ductal carcinoma in situ [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-17-07.

Phase II and Biomarker Study of Cabozantinib in Metastatic Triple-Negative Breast Cancer Patients

Currently, no targeted therapies are available for metastatic triplenegative breast cancer (mTNBC). We evaluated the safety, efficacy, and biomarkers of response to cabozantinib, a multikinase inhibitor, in patients with mTNBC. We conducted a single arm phase II and biomarker study that enrolled patients with measurable mTNBC. Patients received cabozantinib (60 mg daily) on a 3-week cycle and were restaged after 6 weeks and then every 9 weeks. The primary endpoint was objective response rate. Predefined secondary endpoints included progression-free survival (PFS), toxicity, and tissue and blood circulating cell and protein biomarkers. Of 35 patients who initiated protocol therapy, 3 (9% [95% confidence interval (CI): 2, 26]) achieved a partial response (PR). Nine patients achieved stable disease (SD) for at least 15 weeks, and thus the clinical benefit rate (PR+SD) was 34% [95% CI: 19, 52]. Median PFS was 2.0 months [95% CI: 1.3, 3.3]. The most common toxicities were fatigue, diarrhea, mucositis, and palmar-plantar erythrodysesthesia. There were no grade 4 toxicities, but 12 patients (34%) required dose reduction. Two patients had TNBCs with MET amplification. During cabozantinib therapy, there were significant and durable increases in plasma placental growth factor, vascular endothelial growth factor (VEGF), VEGF-D, stromal cell-derived factor 1a, and carbonic anhydrase IX, and circulating CD3 + cells and CD8 + T lymphocytes, and decreases in plasma soluble VEGF receptor 2 and CD14+ monocytes (all p < .05). Higher baseline concentrations of soluble MET (sMET) associated with longer PFS (p = .03). In conclusion, cabozantinib showed encouraging safety and efficacy signals but did not meet the primary endpoint in pretreated mTNBC. Exploratory analyses of circulating biomarkers showed that cabozantinib induces systemic changes consistent with activation of the immune system and antiangiogenic activity, and that sMET should be further evaluated a potential biomarker of response.

IMPLICATIONS FOR PRACTICE

Triple-negative breast cancer (TNBC)-a disease with a dearth of effective therapies-often overexpress MET, which is associated with poor clinical outcomes. However, clinical studies of agents targeting MET and VEGF pathways-alone or in combination-have shown disappointing results. This study of cabozantinib (a dual VEGFR2/MET) in metastatic TNBC, while not meeting its prespecified endpoint, showed that treatment is associated with circulating biomarker changes, and is active in a subset of patients. Furthermore, this study demonstrates that cabozantinib therapy induces a systemic increase in cytotoxic lymphocyte populations and a decrease in immunosuppressive myeloid populations. This supports the testing of combinations of cabozantinib with immunotherapy in future studies in breast cancer patients.

Quality Assurance in Breast Pathology: Lessons Learned From a Review of Amended Reports

Context.—A review of amended pathology reports provides valuable information regarding defects in the surgical pathology process.

Objective.—To review amended breast pathology reports with emphasis placed on interpretative errors and their mechanisms of detection.

Design.—All amended pathology reports for breast surgical specimens for a 5-year period at a large academic medical center were retrospectively identified and classified based on an established taxonomy.

Results.—Of 12 228 breast pathology reports, 122 amended reports were identified. Most (88 cases; 72%) amendments were due to noninterpretative errors, including 58 report defects, 12 misidentifications, and 3 specimen defects. A few (34 cases; 27.9%) were classified as misinterpretations, including 14 major diagnostic changes (11.5% of all amendments). Among major changes, there were cases of missed microinvasion or small foci of invasion, missed micrometastasis, atypical ductal hyperplasia overcalled as ductal carcinoma in situ, ductal carcinoma in situ involving sclerosing adenosis mistaken for invasive carcinoma, lymphoma mistaken for invasive carcinoma, and amyloidosis misdiagnosed as fat necrosis. Nine major changes were detected at interpretation of receptor studies and were not associated with clinical consequences. Three cases were associated with clinical consequences, and of note, the same pathologist interpreted the corresponding receptor studies.

Conclusions.—Review of amended reports was a useful method for identifying error frequencies, types, and methods of detection. Any time that a case is revisited for ancillary studies or other reasons, it is an opportunity for the surgical pathologist to reconsider one's own or another's diagnosis.

Landscape of somatic mutations in 560 breast cancer whole-genome sequences

We analysed whole-genome sequences of 560 breast cancers to advance understanding of the driver mutations conferring clonal advantage and the mutational processes generating somatic mutations. We found that 93 protein-coding cancer genes carried probable driver mutations. Some non-coding regions exhibited high mutation frequencies, but most have distinctive structural features probably causing elevated mutation rates and do not contain driver mutations. Mutational signature analysis was extended to genome rearrangements and revealed twelve base substitution and six rearrangement signatures. Three rearrangement signatures, characterized by tandem duplications or deletions, appear associated with defective homologous-recombination-based DNA repair: one with deficient BRCA1 function, another with deficient BRCA1 or BRCA2 function, the cause of the third is unknown. This analysis of all classes of somatic mutation across exons, introns and intergenic regions highlights the repertoire of cancer genes and mutational processes operating, and progresses towards a comprehensive account of the somatic genetic basis of breast cancer.

Benign and Malignant Breast Disease at Rwanda's First Public Cancer Referral Center

BACKGROUND

Breast cancer incidence is rising in low- and middle-income countries. Understanding the distribution of breast disease seen in clinical practice in such settings can guide early detection efforts and clinical algorithms, as well as support future monitoring of cancer detection rates and stage.

PATIENTS AND METHODS

We conducted a retrospective medical record review of 353 patients who presented to Butaro Cancer Center of Excellence in Rwanda with an undiagnosed breast concern during the first 18 months of the cancer program.

RESULTS

Eighty-two percent of patients presented with a breast mass. Of these, 55% were diagnosed with breast cancer and 36% were diagnosed with benign disease. Cancer rates were highest among women 50 years and older. Among all patients diagnosed with breast cancer, 20% had stage I or II disease at diagnosis, 46% had locally advanced (stage III) disease, and 31% had metastatic disease.

CONCLUSION

After the launch of Rwanda's first public cancer referral center and breast clinic, cancer detection rates were high among patients presenting with an undiagnosed breast concern. These findings will provide initial data to allow monitoring of changes in the distribution of benign and malignant disease and of cancer stage as cancer awareness and services expand nationally.

IMPLICATIONS FOR PRACTICE

The numbers of cases and deaths from breast cancer are rising in low-income countries. In many of these settings, health care systems to address breast problems and efficiently refer patients with symptoms concerning for cancer are rudimentary. Understanding the distribution of breast disease seen in such settings can guide early detection efforts and clinical algorithms. This study describes the characteristics of patients who came with a breast concern to Rwanda's first public cancer referral center during its first 18 months. More than half of patients with a breast mass were diagnosed with cancer; most had late-stage disease. Monitoring changes in the types of breast disease and cancer stages seen in Rwanda will be critical as breast cancer awareness and services grow.

Modern Trends in the Surgical Management of Paget's Disease

PURPOSE

We examined the incidence and modern national trends in the management of Paget's disease (PD), including the use of breast-conserving surgery (BCS), mastectomy, axillary surgery, and receipt of radiotherapy.

METHODS

Using surveillance, epidemiology and end results (SEER) data, we identified 2631 patients diagnosed with PD during 2000-2011. Of these patients, 185 (7%) had PD of the nipple only, 953 (36.2%) had PD with ductal carcinoma in situ (PD-DCIS), and 1493 (56.7%) had PD with invasive ductal carcinoma (PD-IDC). Trends in age-adjusted incidence, primary surgery, sentinel lymph node biopsy (SLNB), and axillary lymph node dissection were examined. Multivariable logistic regression was used to evaluate factors associated with receipt of BCS and radiotherapy.

RESULTS

A decrease in the age-adjusted incidence of PD occurred from 2000 to 2011 (-4.3% per year, p < 0.05). The overall rates of mastectomy in the PD only, PD-DCIS, and PD-IDC groups were 47, 69, and 88.9%, respectively. Only in the PD-IDC group did the proportion of patients undergoing BCS increase significantly, from 8.5% in 2000 to 15.7% in 2011 (p = 0.01). Of those who underwent axillary surgery, the proportion of patients undergoing SLNB increased from 2000 to 2011. In adjusted analyses, Paget's subgroup, older age, central tumor location, low/intermediate grade, tumor size <2.0 cm, SEER region, and year of diagnosis after 2006 were significantly associated with receipt of BCS.

CONCLUSIONS

The incidence of Paget's disease has decreased over time while modern trends in local therapy suggest that BCS, SLNB, and adjuvant radiotherapy remain underutilized.

Abstract P1-16-01: Effect of margin width on local recurrence in invasive lobular carcinoma treated with multimodality therapy

Background: Recent consensus guideline on margins for breast conserving surgery recommends the use of no ink on tumor as the standard for an adequate margin. Current recommendation extends to invasive lobular carcinoma (ILC), however the data in this subset is limited by small numbers. In the present analysis we sought to evaluate the influence of margin status on outcomes in ILC and mixed tumors.

Methods: We performed retrospective cohort study and reviewed 809 eligible patients diagnosed with ILC (337 with pure ILC; 472 with mixed ILC) with Stage I –III treated at Dana Farber/Brigham and Women’s Cancer Center (DFBWCC) between May 1997 and Dec 2007. Clinico-pathologic data was extracted following the Clinical Research Information Systems (CRIS) Database procedures and manually reviewed to confirm inclusion and details of margin status. Margin status was defined using the last ASCO/ASTRO/SSA consensus guidelines criteria. Analysis results were considered to be statistically significant when the two-tailed p-value was &lt;0.05.

Results: Breast conservation was performed in 399 patients (49%). Margin status at the initial attempt for breast conservation was defined as follows: 180 (45%) negative, 64 (16%) positive, 71 (18%) ≤ 1mm margin, and 84 (21%) close margins (&gt; 1 and &lt; 3 mm). Following initial lumpectomy, 102 (25%) patients underwent additional surgery (96 re-excisions and 6 mastectomies) and residual invasive disease was found in 40 patients. Whole-breast radiation therapy was performed in 376 patients (96%). In multivariate models adjusted for classic clinico-pathologic factors, tumor size (HR= 1.8 95% CI 1.0 to 3.3, p=0.05), multifocality (HR= 2.0 95% CI 1.1 to 3.6, p= 0.02) and ILC subtype (HR= 2.0 95% CI 1.0 to 3.7, p=0.04) were correlated with positive margins, while year of diagnosis, age and pre-surgical MRI findings were not statistically significant.

With 72 months median follow-up, 12 ipsilateral breast cancers (3.1%), 5 other locoregional (1.2%) and 15 distant (3.8%) recurrences were observed after definitive breast conserving therapy. The incidence of locoregional recurrence (LRR) was 4.3% and similar for ILC and mixed ILC (p=0.76). In univariate analysis positive surgical margin was associated with LRR (HR=5.1, p= 0.03) and disease-free survival (DFS) (HR=8.9, p≤ .001), but due to limited number of cases and events this could not be adjusted for other clinico-pathologic prognostic factors in a mulitvariate model. Close surgical margins, margins within 1mm and multifocality were not associated with increased LRR or worse DFS. Re-excision did not impact on DFS for patients with close margin (p= 0.57) and within 1 mm margin (p= 0.85). By contrast, significant improvement of DFS following re-excision was observed in patients with positive margin (p= 0.01).

Conclusions: Following lumpectomy, local recurrence rates for ILC patients with close surgical margin and ≤ 1mm margin are low and equivalent to those in patients with negative margins. This study supports the validity of using no ink on tumor as the standard for an adequate margin for patients diagnosed with pure or mixed ILC treated with multimodality therapy.

Citation Format: Yasuaki Sagara, William T Barry, Ines Vaz-Luis, Fatih Aydogan, Jane E Brock, Eric P Winer, Mehra Golshan, Otto Metzger-Filho. Effect of margin width on local recurrence in invasive lobular carcinoma treated with multimodality therapy [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-16-01.

Surgical Options and Locoregional Recurrence in Patients Diagnosed with Invasive Lobular Carcinoma of the Breast

PURPOSE

Recent consensus guidelines on margins for breast-conserving surgery (BCS) recommend the use of "no ink on tumor" as the standard for an adequate margin. The recommendations extend to invasive lobular carcinoma (ILC), but the data on this subset are limited. We reviewed our modern dataset on margin status with outcomes of ILC.

METHODS

We performed a retrospective cohort study on 736 patients with a diagnosis of stage I-III ILC treated at our cancer center between May 1997 and December 2007. Clinicopathologic data were extracted from the Clinical Research Information Systems Database. Margin status was defined using the latest ASCO/ASTRO/SSO consensus guideline criteria.

RESULTS

The initial surgery performed was mastectomy in 352 patients (48 %) and BCS in 384 patients (52 %). In multivariate analysis, tumor size and multifocality were significantly associated with high rates of mastectomy and positive surgical margins at initial BCS. After initial BCS, additional surgery was performed in 92 patients (24 %). During a 72-month median follow-up period, 12 (3.1 %) ipsilateral breast tumor recurrences (IBTR) and 5 (1.3 %) other locoregional recurrences (LRR) were observed. Patients with margins with ink on tumor who did not receive further surgery were found to have significantly increased LRR [odds ratio (OR) 5.5; p = 0.02] and IBTR (OR 8.5; p = 0.006), whereas patients with close margins (1-3 mm) and margins within 1 mm were not.

CONCLUSIONS

Our study supports the validity of using "no ink on tumor" as the standard for a negative margin for pure and mixed ILC treated with multimodality therapy.

MRI-guided breast needle core biopsies: pathologic features of newly diagnosed malignancies

Magnetic resonance imaging (MRI) of the breast is used for select groups of patients. MRI-guided breast core needle biopsies performed over a 3-year period were retrospectively reviewed to determine the incidence and types of cancers found and to correlate the cancers with the MRI findings and the indication for the study. Patients were stratified based on indication for MRI examination including, evaluation of disease extent in patients with current ipsilateral carcinoma, surveillance for recurrence of prior ipsilateral carcinoma, as a problem-solving method and for screening high-risk patients. The high-risk screening group included those with family history (with or without germline mutations), prior chest wall radiation, and contralateral breast carcinoma (current or prior). Four-hundred and forty-five biopsies were performed on 386 patients. The majority of biopsies (79%) were benign. Biopsies demonstrating ductal carcinoma in situ (DCIS) and invasive carcinoma were more likely to present as nonmass-like and mass-forming enhancements respectively, but with only 52% specificity. The highest rate of malignancy (44%) was seen in the least frequently biopsied patient group (n = 25), those with prior ipsilateral carcinoma. Conversely, the most frequently biopsied group (n = 283), the high-risk screening group, demonstrated the lowest malignancy rate (16%). Within this group, most malignant cases were invasive carcinomas (n = 27), 67% of which were small (≤1 cm), well or moderately differentiated with a good prognostic receptor profile (estrogen receptor positive, human epidermal growth factor receptor 2 negative), and lacked nodal macrometastases. The remaining malignant cases in the high-risk screening group were DCIS with or without microinvasion (n = 18), 78% of which demonstrated high nuclear grade. Overall, enhancement pattern did not correlate with the likelihood of or type of malignancy. The most common types of carcinomas identified by screening were small estrogen receptor positive invasive tumors and high grade DCIS.

Abstract ES03-1: Clinical 101: The pathology of breast cancer

Numerous histological types of breast cancer are recognized based on their discrete architectural patterns and associated different risk factors, clinical presentations, pathological features, patterns of spread, response to therapy and outcomes. Traditional prognostic factors include tumor size, lymph node status, tumor grade, and immunohistochemical profile of Estrogen and Progesterone Receptor (ER and PR) and Her2/neu gene amplification status.

Histological tumor grade assesses degree of differentiation (tubule formation and nuclear pleomorphism) and proliferative activity (mitotic index). The three histological grades mirror aggressiveness and correlate with survival. Expression profiling reveals only two genomic grades, low and high.

The ER positive, HER2 positive and triple negative tumors have correlative molecular subtypes on transcriptome analysis; two ER positive groups, luminal A and B where B tumors have a high proliferation compared with A, a HER2 enriched group, and basal-like group corresponding to triple negative tumors. A molecular apocrine group is characterized by ER negative, Androgen Receptor positive status with paradoxical expression of ER related genes and often HER2. A subset of molecular apocrine carcinomas have a morphological correlate.

The traditional prognostic factors used to determine therapy neither capture the complexity of breast cancer nor provide tailored enough treatment options for individual patients. Gene expression profiles which predict disease recurrence pick out the proliferation related genes and a number of different prognostic signatures despite them having &lt; 25% of shared genes between the signatures (e.g. OncotypeDX, PAM50, Mammaprint) identify the Luminal A low risk subgroup, which does not benefit from chemotherapy. These prognostic signatures have no value in ER negative disease where there is a high rate of resistance to chemotherapy regimens. Predictors of sensitivity or resistance to specific regimens of chemotherapy in all tumors and predictors of resistance to hormone therapy in ER positive tumors are needed.

The low and high grade genomic signatures reflect two distinct models of tumor progression. The low grade neoplasia pathway is characterized by simple diploid karyotypes, and luminal A type invasive carcinomas in this group share genetic and transcriptomic features with precursor lesions, ADH, FEA. Special subtype tumors in this pathway include tubular, lobular, cribriform, mucinous carcinomas and some neuroendocrine carcinomas. The high grade pathway encompasses high grade DCIS, and high grade invasive ductal carcinoma and is characterized by aneuploidy and complex karyotypes.

Although tumors can be lumped broadly into low and high grade, there is enormous diversity between tumors even within the molecular subgroups. For example the basal-like/triple negative group includes tumors with distinct morphology, clinical presentation, prognosis and molecular profiles which requires tailoring of therapies. Two rare low grade clinically indolent basal-like tumors include Secretory carcinomas which harbor a characteristic recurrent balanced chromosomal translocation which leads to a fusion transcript ETV6-NTRK3 and Adenoid cystic carcinomas which have a MYB-NFIB fusion gene.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr ES03-1.

Interobserver concordance in implementing the 2010 ASCO/CAP recommendations for reporting ER in breast carcinomas: a demonstration of the difficulties of consistently reporting low levels of ER expression by manual quantification

OBJECTIVES

Endocrine therapy reduces recurrence risk by 30% to 50% in estrogen receptor (ER)-positive breast cancer. The ER-positive threshold recommended by the American Society of Clinical Oncology/College of American Pathologists is 1% based on studies using the ER-6F11 antibody. ER-SP1 antibody has a higher sensitivity and is more widely used.

METHODS

We report interobserver concordance manually measuring ER in 264 breast cancers using ER-SP1 and 1D5 and 2 scoring methods (H-score and Allred score).

RESULTS

With both antibodies, 3% to 4% of cases have a low level of ER expression (1%-10%), more than previously reported (<1%). We find a high level of paired observer concordance with both antibodies and scoring methods (κ = 0.892-0.943) with no significant difference with method of scoring. Despite excellent concordance, positive/negative discordance was almost 5% among 3 observers using either antibody, an underappreciated clinically significant rate.

CONCLUSIONS

Discordance overwhelmingly reflected differing opinions recording the proportion of tumor cells positive with low levels of expression (<10% staining; 12/13 cases).

Neoadjuvant bevacizumab: surgical complications of mastectomy with and without reconstruction

Neoadjuvant therapy (NAC) is commonly used in operable breast cancer. Previous studies have suggested a high rate of postoperative complications after NAC. We prospectively evaluated the surgical complications in a cohort of patients who underwent mastectomy following neoadjuvant adriamycin/cytoxan/taxol (AC/T) plus bevacizumab (bev) and compared the rate of complications to a matched cohort of neoadjuvant AC/T without bev. One hundred patients with HER2-negative breast cancer enrolled in a single-arm trial of neoadjuvant AC/T plus bev (cohort 1), 60 of these patients underwent mastectomy and were matched with 59 patients who received standard neoadjuvant AC/T (cohort 2) over a similar time period in the same healthcare system. All patients underwent mastectomy with or without reconstruction. Fisher's exact tests were used to compare complication rates, with p < 0.05 considered significant. Patients were matched well in terms of demographics. The overall complication rate was 32 % in cohort 1 and 31 % in cohort 2 (p value = 1, Table 1). In cohort 1, 7 of 23 (30 %) patients who underwent immediate expander/implant reconstruction had complications, including 2 patients who had explantation of their reconstructions. In cohort 2, 0 of 8 (0 %) had complications (p value = 0.15). Nearly a third of patients undergoing NAC with AC/T with or without bev developed a postoperative complication after mastectomy. The use of bev was not associated with a significant increase in surgical complications, although this is a nonrandomized data set with a small sample size. As larger data sets become available with the use of neoadjuvant bevacizumab with mastectomy, further refinement may be necessary.

Margin status and the risk of local recurrence in patients with early-stage breast cancer treated with breast-conserving therapy

We sought to assess whether a close surgical margin (>0 and <2 mm) after breast-conserving therapy (BCT) confers an increased risk of local recurrence (LR) compared with a widely negative margin (≥2 mm). We studied 906 women with early-stage invasive breast cancer treated with BCT between January 1998 and October 2006; 91 % received adjuvant systemic therapy. Margins were coded as: (1) widely negative (n = 729), (2) close (n = 85), or (3) close (n = 84)/positive (n = 8) but having no additional tissue to remove according to the surgeon. Cumulative incidence of LR and distant failure (DF) were calculated using the Kaplan-Meier method. Gray's competing-risk regression assessed the effect of margin status on LR and Cox proportional hazards regression assessed the effect on DF, controlling for biologic subtype, age, and number of positive lymph nodes (LNs). Three hundred seventy-seven patients (41.6 %) underwent surgical re-excision, of which 63.5 % had no residual disease. With a median follow-up of 87.5 months, the 5-year cumulative incidence of LR was 2.5 %. The 5-year cumulative incidence of LR by margin status was 2.3 % (95 % CI 1.4-3.8 %) for widely negative, 0 % for close, and 6.4 % (95 % CI 2.7-14.6 %) for no additional tissue, p = 0.3. On multivariate analysis, margin status was not associated with LR; however, triple-negative subtype (AHR 3.7; 95 % CI 1.6-8.8; p = 0.003) and increasing number of positive LNs (AHR 1.6; 95 % CI 1.1-2.3; p = 0.025) were associated. In an era of routine adjuvant systemic therapy, close surgical margins and maximally resected close/positive margins were not associated with an increased risk of LR compared to widely negative margins. Additional studies are needed to confirm this finding.

Gauging NOTCH1 Activation in Cancer Using Immunohistochemistry

Fixed, paraffin-embedded (FPE) tissues are a potentially rich resource for studying the role of NOTCH1 in cancer and other pathologies, but tests that reliably detect activated NOTCH1 (NICD1) in FPE samples have been lacking. Here, we bridge this gap by developing an immunohistochemical (IHC) stain that detects a neoepitope created by the proteolytic cleavage event that activates NOTCH1. Following validation using xenografted cancers and normal tissues with known patterns of NOTCH1 activation, we applied this test to tumors linked to dysregulated Notch signaling by mutational studies. As expected, frequent NICD1 staining was observed in T lymphoblastic leukemia/lymphoma, a tumor in which activating NOTCH1 mutations are common. However, when IHC was used to gauge NOTCH1 activation in other human cancers, several unexpected findings emerged. Among B cell tumors, NICD1 staining was much more frequent in chronic lymphocytic leukemia than would be predicted based on the frequency of NOTCH1 mutations, while mantle cell lymphoma and diffuse large B cell lymphoma showed no evidence of NOTCH1 activation. NICD1 was also detected in 38% of peripheral T cell lymphomas. Of interest, NICD1 staining in chronic lymphocytic leukemia cells and in angioimmunoblastic lymphoma was consistently more pronounced in lymph nodes than in surrounding soft tissues, implicating factors in the nodal microenvironment in NOTCH1 activation in these diseases. Among carcinomas, diffuse strong NICD1 staining was observed in 3.8% of cases of triple negative breast cancer (3 of 78 tumors), but was absent from 151 non-small cell lung carcinomas and 147 ovarian carcinomas. Frequent staining of normal endothelium was also observed; in line with this observation, strong NICD1 staining was also seen in 77% of angiosarcomas. These findings complement insights from genomic sequencing studies and suggest that IHC staining is a valuable experimental tool that may be useful in selection of patients for clinical trials.

Neoadjuvant bevacizumab: Surgical complications of mastectomy with and without reconstruction

1100

Background: Neoadjuvant therapy is commonly used in operable breast cancer. We prospectively evaluated the surgical complications in a cohort of patients who underwent mastectomy following neoadjuvant doxorubucin hydrochloride/cyclophosphamide/paclitaxel (AC/T) plus bevacizumab and compared the rate of complications to a matched cohort of neoadjuvant AC/T without bevacizumab. Methods: One hundred patients with HER2-negative breast cancer enrolled in a single-arm trial of neoadjuvant AC/T plus bevacizumab (cohort 1), 60 of these patients underwent mastectomy and were matched with 59 patients who received standard neoadjuvant AC/T (cohort 2) over a similar time period in the same healthcare system. All patients underwent mastectomy with or without reconstruction. Fisher’s exact tests were used to compare complication rates, with a p<0.05 was considered significant. Results: Patients were matched well in terms of demographics. The overall complication rate was 33% in cohort 1 and 31% in cohort 2 (P-value=0.84; Table). In cohort 1, 7 of 23 (30%) patients who underwent immediate expander/implant reconstruction had complications, including 2 patients who had explantation of their reconstructions. In cohort 2, 0 of 8 (0%) had complications (p value=0.15). Conclusions: Nearly a third of patients undergoing neoadjuvant therapy with AC/T with or without bevacizumab developed a postoperative complication after mastectomy. The use of bevacizumab was not associated with a significant increase in surgical complications, although this is a non-randomized data with a small sample size. As larger data sets become available with the use of neoadjuvant bevacizumab with mastectomy, further refinement may be necessary. [Table: see text]

Phase II study of ruxolitinib in patients with pStat3+ breast cancer

TPS1134

Background: Multiple lines of evidence implicate the IL-6/JAK2/Stat3 signaling pathway in metastatic progression and therapeutic resistance in breast cancer (Marotta et al, JCI2011; Britschgi et al, Cancer Cell 2012). Ruxolitinib, an oral inhibitor of JAK1 and JAK2, is approved for the treatment of intermediate or high-risk myelofibrosis, but has not been extensively tested in solid tumors. Methods: Pts with triple-negative breast cancer or inflammatory breast cancer of any subtype are eligible for prescreening of archival tumor tissue for pStat3 expression by immunohistochemistry. Pts with high (Cohort A; T-score >5) or low (Cohort B; T-score 3-4) pStat3 expression, measurable disease, adequate organ function, ECOG PS 0-2, and progression through > 1 line of prior therapy may proceed to receive ruxolitinib, 25 mg orally twice daily. Staging studies are performed at baseline (BL) and every 8 weeks (wk). Baseline tumor biopsy is required for pts who have accessible disease, with an optional biopsy at progression. Blood for IL-6, CRP, and circulating tumor cells are collected at BL, Wk 4, and off-treatment. Patient reported outcomes including EORTC QLQ C-30 and the M.D. Anderson Symptom Inventory are collected at BL, Wk 4, Wk 8, and off-treatment. Statistical Considerations: The primary endpoint of this open-label phase 2 trial is objective response by RECIST 1.1. The study is designed to distinguish between a response rate of 5% versus 20% in each cohort, separately. If > 2 responses out of 21 pts are observed in the first stage of Cohort A, a further 20 pts will be entered on that cohort; the agent will be deemed worthy of further study if > 5 of the total 41 pts achieve an objective response (power 0.90, type I error 0.046). Cohort B will open to accrual if Cohort A passes the first stage. If > 2 responses out of 21 pts are observed in the first stage of Cohort B, a further 20 patients will be entered into Cohort B, and the agent will be deemed worthy of further study if > 5 of the total 41 pts achieve an objective response (power 0.90, type I error 0.046). Study Status: A total of 85 patients have consented for prescreening of tumor tissue. As of January 3, 2013, 5 of a planned 41 patients with high pStat3 IHC scores have been treated with ruxolitinib, and accrual is ongoing. Clinical trial information: NCT01562873.

A comparison of equivocal immunohistochemical results with anti-HER2/neu antibodies A0485 and SP3 with corresponding FISH results in routine clinical practice

HER2/neu status in breast cancer is determined by immunohistochemical analysis and/or fluorescence in situ hybridization (FISH). Previous studies have found widely varying sensitivities and specificities for anti-HER2/neu antibodies, including recently developed rabbit monoclonal antibodies. The current prospective study compared rabbit monoclonal antibody SP3 and rabbit polyclonal antibody A0485 immunostaining on routinely processed consecutive cases of breast carcinoma. Of 1,610 cases tested, 261 (16.2%) equivocal (2+) cases were evaluated by FISH. Of 253 cases equivocal with A0485 results, 125 (49.4%) were negative with SP3. In 22 (8.7%) of 253 cases equivocal with A0485, there was amplification by FISH, and 3 of these cases were SP3- (0/1+). Of the 20 (14.8%) of 135 SP3-equivocal cases amplified by FISH, 1 case was A0485-. The reported false-negative rate with A0485 is 2.8%, and the American Society of Clinical Oncology/College of American Pathologists guidelines recommend a rate of less than 5%. Compared with A0485, the false-negative rate with SP3 is only 0.3% (3/1,156) higher, but it shows about a 50% reduction in equivocal scores, reducing the need for reflex FISH testing.