Evaluating Low HER2 Status in Invasive Breast Carcinoma via HER2 Immunohistochemistry, with HER2 FISH Correlation: A Cohort of 112 Patients.

Introduction: Recent trials demonstrated clinically significant benefits in HER2-nonamplified breast cancer with HER2-low expression using novel anti-HER2 antibody-drug conjugates. Thus, HER2-low breast cancer was proposed as a separate diagnostic entity. Herein, we reclassify HER2-negative cancers according to the new HER2-low category using a modified system and further investigate HER2-very-low expression. Methods: 114 HER2 immunohistochemistry (IHC)-negative invasive breast tumors were identified from the pathology database of Mayo Clinic, Jacksonville, FL, between January 2019 and August 2022. Two blinded breast pathologists (BP) independently rescored HER2 IHC slides at 200x and 400x magnification. Discordant cases between the two BPs were rescored together. The most recent 2018 ASCO/CAP HER2 scoring criteria were used. HER2 (0) was subdivided into HER2 (absent) and HER2 (very low). HER2 FISH testing was performed in all cases. Results: The cohort comprised of 38 (33.3%) HER2 (0) and 76 (66.7%) HER2 (1+) tumors. The first round of rescoring at 200x and 400x magnification resulted in 17 (14.9%) HER2 (absent), 31 (27.2%) HER2 (very low), and 64 (56.2%) HER2 (1+) and 2 (1.8%) HER2 (2+) tumors by BP1 and 20 (17.5%) HER2 (absent), 33 (28.9%) HER2 (very low), and 61 (53.5%) HER2 (1+) tumors by BP2. The combined final rescoring by BP1 and BP2 was as follows: 15 (13.2%) HER2 (absent), 35 (30.7%) HER2 (very low), 63 (55.3%) HER2 (1+), and 1 (0.9%) HER2 (2+) cases. A comparison of the first round of rescoring between two BPs showed substantial agreement with Cohen's kappa value of 0.67. Both comparisons of first rescoring by BP1 and by BP2 to combined final rescoring showed almost perfect agreement with Cohen's kappa value of 0.83.Follow-up FISH studies showed one amplified tumor. Conclusion: Our data support the need for finer granularity, classification, and understanding of HER2-low breast cancers. We also show that reproducibility between trained BP can be obtained, albeit with scoring at high power and low threshold for showing challenging interpretations.

Comparison of endoscopic ultrasound-guided fine-needle biopsy versus fine-needle aspiration for genomic profiling and DNA yield in pancreatic cancer: a randomized crossover trial.

BACKGROUND: National guidelines recommend genomic profiling of tumor tissue to guide precision therapy. We compared the specimen adequacy for genomic profiling and yield of DNA between endoscopic ultrasound (EUS)-guided fine-needle biopsy (FNB) and EUS-guided fine-needle aspiration (FNA). METHODS: In our tandem, randomized controlled trial, consecutive patients undergoing EUS for evaluation of pancreatic masses underwent both conventional EUS-FNA with a 25-gauge needle and paired EUS-FNB (19 or 22-gauge needle), with the order randomized (EUS-FNA first followed by EUS-FNB, or vice versa). A minimum of one pass with each needle was obtained for histology. Second and third passes were performed to collect DNA. Specimens were evaluated by a cytopathologist blinded to the needle type. Specimen adequacy for genomic profiling was calculated based on FoundationOne clinical diagnostic (CDx) adequacy requirements. We compared the adequacy for genomic profiling DNA (quantity) and histology yields with both needles. RESULTS: Analysis included 50 patients (25 men; mean age 68 [standard deviation (SD) 13] years), with a mean lesion size of 38 (SD 17) mm; 37 lesions (74 %) were pancreatic ductal adenocarcinoma (PDAC). The mean DNA concentrations in PDAC by FNB and FNA needles were 5.930 (SD 0.881) µg/mL vs. 3.365 (SD 0.788) µg/mL, respectively (P = 0.01). The median standardized histology score per pass with EUS-FNB was 5 (sufficient for histology) and for EUS-FNA was 2 (enough for cytology). Specimen adequacy for genomic profiling and yield of DNA was significantly higher with FNB than with FNA needles. CONCLUSIONS: In this study, adequacy for genomic profiling, DNA, and histology yield were considerably superior using an EUS-FNB needle compared with an EUS-FNA needle.

PLEKHA7, an Apical Adherens Junction Protein, Suppresses Inflammatory Breast Cancer in the Context of High E-Cadherin and p120-Catenin Expression.

Inflammatory breast cancer is a highly aggressive form of breast cancer that forms clusters of tumor emboli in dermal lymphatics and readily metastasizes. These cancers express high levels of E-cadherin, the major mediator of adherens junctions, which enhances formation of tumor emboli. Previous studies suggest that E-cadherin promotes cancer when the balance between apical and basolateral cadherin complexes is disrupted. Here, we used immunohistochemistry of inflammatory breast cancer patient samples and analysis of cell lines to determine the expression of PLEKHA7, an apical adherens junction protein. We used viral transduction to re-express PLEKHA7 in inflammatory breast cancer cells and examined their aggressiveness in 2D and 3D cultures and in vivo. We determined that PLEKHA7 was deregulated in inflammatory breast cancer, demonstrating improper localization or lost expression in most patient samples and very low expression in cell lines. Re-expressing PLEKHA7 suppressed proliferation, anchorage independent growth, spheroid viability, and tumor growth in vivo. The data indicate that PLEKHA7 is frequently deregulated and acts to suppress inflammatory breast cancer. The data also promote the need for future inquiry into the imbalance between apical and basolateral cadherin complexes as driving forces in inflammatory breast cancer.

Durable Complete Response With Immune Checkpoint Inhibitor in Breast Cancer With High Tumor Mutational Burden and APOBEC Signature.

Increasing data support the importance of preexisting host immune response and neoantigen burden for determining response to immune checkpoint inhibitors (ICIs). In lung cancer and melanoma, tumor mutational burden (TMB) has emerged as an independent biomarker for ICI response. However, the significance of TMB in breast cancer, particularly in the context of PD-L1 negativity, remains unclear. This report describes a patient with HER2-negative breast cancer with high TMB and an apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) trinucleotide signature; her disease was refractory to multiple lines of treatments but achieved durable complete response using ICIs and capecitabine. Additional analysis of the tumor revealed a low amount of stromal tumor-infiltrating lymphocytes (sTILs) and PD-L1 negativity, reflecting a poor preexisting host immune response. In collaboration with Foundation Medicine, comprehensive genomic profiling from 14,867 patients with breast cancer with the FoundationOne test was evaluated. Using the cutoff of ≥10 mutations/megabase (mut/Mb) for high TMB, PD-L1 positivity and TMB-high populations were not significantly overlapping (odds ratio, 1.02; P=.87). Up to 79% of TMB-high tumors with >20 mut/Mb were PD-L1-negative. Our study highlights that despite having low TILs and PD-L1 negativity, some patients may still experience response to ICIs.

Patient Discomfort in Relation to Thyroid Nodule Fine-Needle Aspiration (FNA) Performed with or without Parenteral and/or Topical Anesthetic.

OBJECTIVE: There is much reported variation in the impact of local anesthesia on thyroid fine-needle aspiration (FNA) related discomfort. We compare patients undergoing thyroid FNA with subcutaneous injection or topical anesthetic to no anesthetic. METHODS: We conducted a retrospective review of 585 sequential ultrasound guided thyroid FNA procedures in Mayo Clinic. Group 1 (n = 200), no anesthetic; Group 2 (n = 185), subcutaneous injection anesthetic; and Group 3 (n = 200), topical anesthetic. Patient demographics, number of FNA passes, needle gauge, and cytopathology were recorded plus a discomfort score (0 to 10) before and immediately post procedure in all 3 groups and peak discomfort during the FNA in Groups 1 and 2. RESULTS: There were no differences among the 3 groups in age, sex, FNA sufficiency rate, cytopathology, and FNA passes number. There was no significant difference between Groups 1 and 2 in peak discomfort score during the FNA: 0 (45%, 42.2%), 1 to 2 (19%, 24.9%), 3 to 5 (23.5%, 20.5%), 6 to 8 (9.5%, 10.8%), 9 to 10 (3%, 1.6%), respectively. Discomfort score post procedure: 0 (78.5%, 77.8%, 53.5%), 1 to 2 (13%, 13%, 36.5%), 3 to 5 (7%, 7%, 9%), 6 to 8 (1.5%, 2.2%, 1%), 9 to 10 (0%, 0%, 0%) for groups 1, 2, and 3, respectively. There were no significant differences among the 3 groups for a discomfort score ≥3. CONCLUSION: FNA associated patient discomfort was comparable during and after the procedure regardless of the use of anesthetic or the type utilized. Approximately 90% of patients experienced mild to moderate discomfort during the procedure. And 90% reported no more than a level 2 discomfort post procedure. ABBREVIATIONS: End = endocrinology; FNA = fine-needle aspiration; MCF = Mayo Clinic Florida; MCR = Mayo Clinic Rochester.

HER2 testing across practices-Have we come to a consensus on the ideal method of testing? A systematic literature review.

Human epidermal growth factor (HER2) is an oncogene that codes for HER2 protein. The gene is amplified, and protein is overexpressed in 20% of patients and carries a poor prognosis. HER2-positive tumors tend to be more aggressive and highly proliferative. In 2006, trastuzumab, a monoclonal antibody targeting HER2, was approved for use with chemotherapy as an adjuvant treatment for women with HER2-positive breast cancer. The drug has shown improved survival rates for women with HER2-positive breast cancer. As promised for survival in HER2-positive patients continues with new research, and as novel drug approvals emerge, HER2 assessment plays a significant role in adjuvant and in metastatic setting. HER2 assays approved by the US Food and Drug administration include immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and bright field dual in situ hybridization (DISH). Accuracy of HER2 testing across laboratories has an impact on treatment as false-negative testing can deprive the patients of trastuzumab therapy. The current review will focus on the variability of HER2 testing across laboratories and the potential impact on treatment.

Hepatic Angiosarcoma: A Multi-institutional, International Experience with 44 Cases.

BACKGROUND: Hepatic angiosarcoma is a rare primary liver tumor. The aim of this current study was to evaluate the presentation and treatment outcomes in a modern cohort. METHODS: This was a retrospective, multi-institutional, observational study of patients with histopathologic diagnoses of primary hepatic angiosarcoma from four institutions. Clinicopathologic characteristics, treatments, and patient outcomes were examined. RESULTS: Forty-four patients with hepatic angiosarcoma were identified. Patients were predominantly Caucasian and presented at a median age of 63.7 years; 81.4% of patients had bilobar disease and 37.2% had metastatic disease at the time of presentation. Only 10 patients underwent surgical resection. Median overall survival for the entire cohort was 5.8 months (interquartile range 1.9-16.4), and 1-, 3-, and 5-year actual survival was 30.0%, 8.1%, and 5.6%, respectively. There were only two 5-year survivors, both of whom presented with localized disease and underwent curative resection. CONCLUSION: The prognosis for hepatic angiosarcoma remains quite poor. Surgical resection for localized disease results in the best outcomes. Unfortunately, current imaging modalities are often non- diagnostic, and most patients are unresectable at the time of presentation.

ThyroSeq®V2.0 Molecular Testing: A Cost-Effective Approach for the Evaluation of Indeterminate Thyroid Nodules.

OBJECTIVE: Approximately 15 to 30% of thyroid nodules have indeterminate cytology. Many of these nodules are treated surgically, but only 5 to 30% are malignant. Molecular testing can further narrow the risk of malignancy of these nodules. Our objective was to assess the cost effectiveness of ThyroSeq®V2.0 compared to diagnostic thyroidectomy for the evaluation of indeterminate nodules. METHODS: Cytology and histopathology slides of Bethesda category III and IV (suspicious for follicular neoplasia [SFN]) nodules obtained between January 1, 2014 and November 30, 2016 were re-reviewed by 2 endocrine cytopathologists. Costs for a diagnostic approach using ThyroSeq® were calculated and compared to those of diagnostic thyroidectomy. RESULTS: We included 8 Bethesda category III nodules that underwent ThyroSeq® and 8 that underwent diagnostic surgery. Of those submitted for ThyroSeq®, 4 were positive for mutations and underwent thyroid surgery. The average cost per nodule evaluated was $14,669 using ThyroSeq®, compared to $23,338 for diagnostic thyroid surgery. The cost per thyroid cancer case detected was $58,674 using ThyroSeq® compared to $62,233 for diagnostic thyroid surgery. We included 13 nodules Bethesda category IV that underwent ThyroSeq® and 11 that underwent diagnostic surgery. Of those submitted for ThyroSeq®, 6 were positive for mutation and underwent thyroid surgery. The average costs per nodule evaluated were $14,641 using ThyroSeq® and $24,345 using diagnostic thyroidectomy. The cost per thyroid cancer case detected was $31,721 when using ThyroSeq® compared to $53,560 for diagnostic thyroidectomy. CONCLUSION: The use of ThyroSeq® in our institution is cost effective compared to diagnostic thyroid surgery for the evaluation of Bethesda categories III and IV (SFN) nodules. ABBREVIATIONS: FNA = fine-needle aspiration; GEC = gene expression classifier; NIFTP = noninvasive follicular thyroid neoplasm with papillary-like nuclear features; PTC = papillary thyroid cancer; SFN = suspicious for follicular neoplasia.

Cellular fibroepithelial lesions of the breast: A long term follow up study.

Some fibroepithelial lesions (FEL) of the breast are difficult to classify as cellular fibroadenoma (CFA) or benign phyllodes tumor (BPT) due to overlapping histologic features. This indeterminate group is histologically characterized by prominent stromal cellularity, mild atypia, and mitotic activity. The local recurrence potential of cellular FEL (CFEL) has been insufficiently studied. The objective of this study was to evaluate the histologic features, characterize the long-term follow-up and recurrence rate of CFEL, and compare this data with the recurrence rate of definitive BPT. Ninety CFEL that were <4 cm were recovered from the benign breast disease cohort. The control group comprised of 10 randomly selected patients with BPT. Cases were classified based on a combination of mitotic activity, intracanalicular growth, stromal atypia, stromal prominence, and fat infiltration. None of the CFEL was widely excised. Of the 90 CFEL cases, there were 22 BPT-like, 35 CFA, and 33 indeterminate. The mean age of the patients was 40.1 years. The mean tumor size was 2.4 cm. All patients had at least two years of follow-up (median 27). None of the patients with BPT-like CFEL showed ipsilateral recurrence. Five of the 35 patients with CFA had recurrent ipsilateral CFA. This occurred within 1 to 11 years after the initial diagnosis. One of 33 patients with indeterminate type had a recurrent ipsilateral lesion five years after the initial diagnosis with histologic features of CFA. None of the patients in control group had any recurrence. In conclusion, as a group, CFEL have a low proclivity for recurrence, even when enucleated with close or positive margins. The presence of histologic features of BPT did not correlate with an increased potential for recurrence.

Postlactational involution biomarkers plasminogen and phospho-STAT3 are linked with active age-related lobular involution.

PURPOSE: Breast terminal duct lobular units undergo two distinctive physiological processes of involution: age-related lobular involution (LI), which is gradual and associated with decreased breast cancer risk, and postlactational involution, which is relatively precipitous, occurs with weaning, and has been associated with potentiation of tumor aggressiveness in animal models. Here we assessed whether markers of postlactational involution are associated with ongoing LI in a retrospective tissue cohort. METHODS: We selected 57 women from the Mayo Clinic Benign Breast Disease Cohort who underwent multiple biopsies and who were average age 48 at initial biopsy. Women were classified as having progressive or non-progressive LI between initial and subsequent biopsy. Serial tissue sections were immunostained for plasminogen, matrix metalloproteinase 9 (MMP-9), phospho-STAT3 (pSTAT3), tenascin C, Ki67, CD44, cytokeratin 14 (CK14), cytokeratin 19 (CK19), and c-myc. All but Ki67 were digitally quantified. Associations between maximal marker expression per sample and progressive versus non-progressive LI were assessed using logistic regression and adjusted for potential confounders. RESULTS: While no biomarker showed statistically significant association with LI progression when evaluated individually, lower expression of pSTAT3 (OR 0.35, 95% CI 0.13-0.82, p = 0.01) and higher expression of plasminogen (OR 2.89, 95% CI 1.14-8.81, p = 0.02) were associated with progressive LI in models simultaneously adjusted for all biomarkers. Sensitivity analyses indicated that the strengthening in association for pSTAT3 and plasminogen with progressive LI was due to collinearity between these two markers. CONCLUSIONS: This is the first study to identify biomarkers of active LI. Our findings that plasminogen and pSTAT3 are significantly associated with LI suggest that they may represent signaling nodes or biomarkers of pathways common to the processes of postlactational involution and LI.

NanoString-based breast cancer risk prediction for women with sclerosing adenosis.

PURPOSE: Sclerosing adenosis (SA), found in » of benign breast disease (BBD) biopsies, is a histological feature characterized by lobulocentric proliferation of acini and stromal fibrosis and confers a two-fold increase in breast cancer risk compared to women in the general population. We evaluated a NanoString-based gene expression assay to model breast cancer risk using RNA derived from formalin-fixed, paraffin-embedded (FFPE) biopsies with SA. METHODS: The study group consisted of 151 women diagnosed with SA between 1967 and 2001 within the Mayo BBD cohort, of which 37 subsequently developed cancer within 10 years (cases) and 114 did not (controls). RNA was isolated from benign breast biopsies, and NanoString-based methods were used to assess expression levels of 61 genes, including 35 identified by previous array-based profiling experiments and 26 from biological insight. Diagonal linear discriminant analysis of these data was used to predict cancer within 10 years. Predictive performance was assessed with receiver operating characteristic area under the curve (ROC-AUC) values estimated from 5-fold cross-validation. RESULTS: Gene expression prediction models achieved cross-validated ROC-AUC estimates ranging from 0.66 to 0.70. Performing univariate associations within each of the five folds consistently identified genes DLK2, EXOC6, KIT, RGS12, and SORBS2 as significant; a model with only these five genes showed cross-validated ROC-AUC of 0.75, which compared favorably to risk prediction using established clinical models (Gail/BCRAT: 0.57; BBD-BC: 0.67). CONCLUSIONS: Our results demonstrate that biomarkers of breast cancer risk can be detected in benign breast tissue years prior to cancer development in women with SA. These markers can be assessed using assay methods optimized for RNA derived from FFPE biopsy tissues which are commonly available.

Flat Epithelial Atypia on Core Biopsy and Upgrade to Cancer: a Systematic Review and Meta-Analysis.

BACKGROUND: No consensus exists on whether flat epithelial atypia (FEA) diagnosed percutaneously should be surgically excised. A systematic review and meta-analysis of the frequency of upgrade to cancer or an atypical ductal hyperplasia (ADH) at surgical excision of FEA was performed. METHODS: Embase, MEDLINE, Scopus, and Web of Science databases from January 2003 to November 2015 were searched. The inclusion criteria required a manuscript in English with original data on FEA diagnosed percutaneously, data including the presence or absence of other concurrent high-risk lesions, and data including outcome of cancer at surgical excision. Studies were assessed for quality, and two reviewers extracted data. Random-effects meta-analysis was used to pool estimates. The impact of study-level characteristics was assessed by stratified meta-analysis and meta-regression. RESULTS: The inclusion criteria was met by 32 studies. A total of 1966 core needle biopsies showed pure FEA, and 1517 (77%) showed surgical excision. The proportions of patients with upgrade to cancer varied from 0 to 42%, with an overall pooled estimate of 11.1%. Heterogeneity was observed, with the greatest impact based on whether a study included cases of FEA diagnosed before 2003. With restriction of the investigation to 16 higher-quality studies, the cancer upgrade pooled estimate was 7.5% (95% confidence interval [CI], 5.4-10.4%), and the rate of invasive cancer was 3% (95% CI 1.9-4.5%). For upgrade to ADH, data from 22 studies including 937 patients were analyzed. The proportion of patients upgraded to ADH ranged from 0 to 60%, with a pooled estimate of 17.9% overall and 18.6% among high-quality studies. CONCLUSIONS: With patient management change potential for approximately 25% of patients, this analysis supports a general recommendation for surgical excision of FEA diagnosed by core biopsy.

Natural history of age-related lobular involution and impact on breast cancer risk.

Age-related lobular involution (LI) is a physiological process in which the terminal duct lobular units of the breast regress as a woman ages. Analyses of breast biopsies from women with benign breast disease (BBD) have found that extent of LI is negatively associated with subsequent breast cancer development. Here we assess the natural course of LI within individual women, and the impact of progressive LI on breast cancer risk. The Mayo Clinic BBD cohort consists of 13,455 women with BBD from 1967 to 2001. The BBD cohort includes 1115 women who had multiple benign biopsies, 106 of whom had developed breast cancer. Within this multiple biopsy cohort, the progression of the LI process was examined by age at initial biopsy and time between biopsies. The relationship between LI progression and breast cancer risk was assessed using standardized incidence ratios and by Cox proportional hazards analysis. Women who had multiple biopsies were younger age and had a slightly higher family history of breast cancer as compared with the overall BBD cohort. Extent of LI at subsequent biopsy was greater with increasing time between biopsies and for women age 55 + at initial biopsy. Among women with multiple biopsies, there was a significant association of higher breast cancer risk among those with involution stasis (lack of progression, HR 1.63) as compared with those with involution progression, p = 0.036. The multiple biopsy BBD cohort allows for a longitudinal study of the natural progression of LI. The majority of women in the multiple biopsy cohort showed progression of LI status between benign biopsies, and extent of progression was highest for women who were in the perimenopausal age range at initial biopsy. Progression of LI status between initial and subsequent biopsy was associated with decreased breast cancer risk.

EUS-guided fine needle biopsy sampling using a novel fork-tip needle: a case-control study.

BACKGROUND AND AIMS: EUS-guided fine needle biopsy (FNB) sampling and FNA are important methods for obtaining core tissues and cytologic aspirates. To improve the specimen quality for pathologic evaluation, a novel EUS-FNB Shark Core (SC) needle has been designed to acquire core tissue during EUS procedures. We compared the histology yield of EUS-FNB sampling using the SC needle (EUS-FNB-SC) to EUS-FNA in patients who had solid pancreatic and nonpancreatic lesions. METHODS: This was a retrospective case-control study design. Between July 2012 and July 2015 all patients who had EUS-FNB-SC and EUS-FNA were reviewed through a hospital EUS database. Consecutive samples from EUS-FNB-SCs were matched in a 1:3 ratio by lesion site (eg, pancreatic head) and needle gauge (ie, 19 gauge, 22 gauge, 25 gauge) to recent random samples of EUS-FNA. The procedures were performed with rapid onsite evaluation. For study purposes specimen slides were evaluated by 2 cytopathologists for histologic yield using a standard scoring system (0 = no material, 1-2 = cytologic, 3-5 = histologic). The main objectives were to assess the histologic yield of the samples and compare the median number of passes required to obtain core tissue by using EUS-FNB-SC and EUS-FNA needles. RESULTS: Of the 156 patients included in study, 25% patients (n = 39) were in the EUS-FNB-SC group and 75% (n = 117) in the EUS-FNA group. According to standard scoring criteria for histology, the median histology score for EUS-FNA was 2 (sufficient for cytology but not histology) and for EUS-FNB-SC was 4 (sufficient for adequate histology). Ninety-five percent of the specimens obtained from the EUS-FNB-SC group were of sufficient size for histologic screening, compared with 59% from the EUS-FNA group (P = .01). The median number of passes required to achieve a sample was significantly lower in the EUS-FNB-SC group compared with the EUS-FNA group (2 passes vs 4 passes, P = .001). There was significant difference in the median number of passes to all lesion sites and needle gauges. CONCLUSIONS: The histology yield was significantly higher using the EUS-FNB-SC needle compared with the EUS-FNA needle. Additionally, fewer passes were required to obtain histology cores when using EUS-FNB-SC.

Flat epithelial atypia and risk of breast cancer: A Mayo cohort study.

BACKGROUND: Based on its cytologic features, and its co-occurrence with atypical hyperplasia and breast cancer, flat epithelial atypia (FEA) has been proposed as a precursor lesion on the pathway to the development of breast cancer. It is often referred to as an "atypical" or high-risk lesion. However, to the authors' knowledge, the long-term risk of breast cancer in women with FEA is undefined. METHODS: Specimens with FEA were identified among excisional breast biopsies in the Mayo Clinic Benign Breast Disease Cohort, which includes 11,591 women who had benign biopsy findings at the Mayo Clinic in Rochester, Minnesota between 1967 and 2001. Breast cancer risk among subsets of patients with FEA and nonproliferative, proliferative, and atypical hyperplasia (AH) was assessed using standardized incidence ratios (SIRs) compared with the Iowa Surveillance, Epidemiology, and End Results registry. RESULTS: FEA was identified in 282 women (2.4%); 130 had associated AH (46%) and 152 (54%) were classified as having proliferative disease without atypia (PDWA). With median follow-up of 16.8 years, the SIR for breast cancer in patients with AH plus FEA was 4.74 (95% confidence interval [95% CI], 3.17-6.81) versus 4.23 (95% CI, 3.44-5.13) for those with AH without FEA (P = .59). The SIR for patients with PDWA plus FEA was 2.04 (95% CI, 1.23-3.19) versus 1.90 (95% CI, 1.72-2.09) for patients with PDWA without FEA (P = .76). CONCLUSIONS: FEA is an uncommon finding in women with benign breast disease. FEA does not appear to convey an independent risk of breast cancer beyond that of the associated PDWA or AH.

Complex fibroadenoma and breast cancer risk: a Mayo Clinic Benign Breast Disease Cohort Study.

The purpose of this study is to examine the breast cancer risk overall among women with simple fibroadenoma or complex fibroadenoma and to examine the association of complex fibroadenoma with breast cancer through stratification of other breast cancer risks. The study included women aged 18-85 years from the Mayo Clinic Benign Breast Disease Cohort who underwent excisional breast biopsy from 1967 through 1991. Within this cohort, women who had fibroadenoma were compared to women who did not have fibroadenoma. Breast cancer risk (observed versus expected) across fibroadenoma levels was assessed through standardized incidence ratios (SIRs) by using age- and calendar-stratified incidence rates from the Iowa Surveillance, Epidemiology, and End Results registry. Analyses were performed overall, within subgroups of involution status, with other demographic characteristics (age, year of biopsy, indication for biopsy, and family history), and with histologic characteristics, including overall impression [nonproliferative disease, proliferative disease without atypia (PDWA), or atypical hyperplasia]. Fibroadenoma was identified in 2136 women [noncomplex, 1835 (85.9%); complex, 301 (14.1%)]. SIR for noncomplex fibroadenoma was 1.49 (95% CI 1.26-1.74); for complex fibroadenoma, it was 2.27 (95% CI 1.63-3.10) (test for heterogeneity in SIR, P = .02). However, women with complex fibroadenoma were more likely to have other, concomitant high-risk histologic characteristics (e.g., incomplete involution and PDWA). In analyses stratified by involution status and PDWA, complex fibroadenoma was not an independent risk marker for breast cancer. Complex fibroadenoma does not confer increased breast cancer risk beyond other established histologic characteristics.

Ki-67 expression in sclerosing adenosis and adjacent normal breast terminal ductal lobular units: a nested case-control study from the Mayo Benign Breast Disease Cohort.

Sclerosing adenosis (SA) increases risk for invasive breast cancer (BC) 2.1 times relative to that in the general population. Here, we sought to evaluate whether the proliferation marker Ki-67 stratifies risk among women with SA. A nested case-control sample of patients with SA was obtained from the Mayo Clinic Benign Breast Disease Cohort. Ki-67 expression was evaluated in SA lesions and in the adjacent normal terminal duct lobular units (TDLU) in women who did (cases, n = 133) or did not (controls, n = 239) develop BC. Ki-67 was scored by intensity and number of positively stained cells per one high-power field (magnification, ×40) (40× HPF) for both SA and normal TDLU. Associations of Ki-67 expression with case-control status were assessed using conditional logistic regression. Higher Ki-67 expression was significantly associated with case-control status in both SA (P = 0.03) and normal background TDLU (P = 0.006). For the SA lesion, >2 average positively stained cells/40× HPF showed an adjusted odds ratio (OR) of 1.9 (95 % CI, 1.1-3.4) compared to samples with an average of ≤2 positively stained cells. For background TDLU, lobules with >2 but ≤6 average positively stained cells showed an adjusted OR of 1.3-1.5, whereas those with an average of >6 positively stained cells had an OR of 2.4 (95 % CI, 1.1-5.3) compared to those with an average of <2 positively stained cells. Among women with SA, increased Ki-67 expression in either the SA lesion or the normal background TDLU carried an approximately twofold increased odds of subsequent BC as compared to lower Ki-67 expression.

Gene signature model for breast cancer risk prediction for women with sclerosing adenosis.

Benign breast disease (BBD) is diagnosed in 1-2 million women/year in the US, and while these patients are known to be at substantially increased risk for subsequent development of breast cancer, existing models for risk assessment perform poorly at the individual level. Here, we describe a DNA-microarray-based transcriptional model for breast cancer risk prediction for patients with sclerosing adenosis (SA), which represent » of all BBD patients. A training set was developed from 86 patients diagnosed with SA, of which 27 subsequently developed cancer within 10 years (cases) and 59 remained cancer-free at 10 years (controls). An diagonal linear discriminate analysis-prediction model for prediction of cancer within 10 years (SA TTC10) was generated from transcriptional profiles of FFPE biopsy-derived RNA. This model was tested on a separate validation case-control set composed of 65 SA patients. The SA TTC10 gene signature model, composed of 35 gene features, achieved a clear and significant separation between case and control with receiver operating characteristic area under the curve of 0.913 in the training set and 0.836 in the validation set. Our results provide the first demonstration that benign breast tissue contains transcriptional alterations that indicate risk of breast cancer development, demonstrating that essential precursor biomarkers of malignancy are present many years prior to cancer development. Furthermore, the SA TTC10 gene signature model, which can be assessed on FFPE biopsies, constitutes a novel prognostic biomarker for patients with SA.

Clinical outcome in pleomorphic lobular carcinoma: a case-control study with comparison to classic invasive lobular carcinoma.

Pleomorphic lobular carcinoma (PLC), a variant of invasive lobular carcinoma (ILC) is described as an aggressive tumor with poor prognosis. Multiple studies show lower overall survival for patients with PLC than for patients with classic ILC (cILC). We compared the clinicopathologic characteristics of PLC with those of cILC. All cases with a diagnosis of ILC, Nottingham grades 2 or 3 that were diagnosed between January 1, 1990, and December 31, 2010, were retrieved from pathology files in the institutional anatomic pathology database. The cases (N = 52) were reviewed to identify those meeting the criteria for PLC. An E-cadherin immunostain was used to confirm the lobular immunophenotype. Clinicopathologic data were assessed and analyzed. A control group (N = 103) of cILC, Nottingham grade 1, was selected, with 2 controls for each case, matched by age and year of diagnosis. PLC was associated more closely with in situ carcinoma (P = .03), and had lower progesterone receptor expression (P = .03) than cILC. Both disease-free survival and overall survival were similar between patients with PLC and matched cILC controls, and both depended on disease stage, tumor size, and lymph node status. PLC is similar to cILC in terms of patient survival and outcomes.

Radial scar/complex sclerosing lesions: a clinicopathologic correlation study from a single institution.

Radial scars (RSs) or complex sclerosing lesions (CSLs) of the breast are benign radiologic and histologic entities. With the introduction of population-based screening programs, their incidence has increased to 0.03% to 0.09% of all core needle biopsies (CNBs). They can pose diagnostic difficulty because their radiologic and histologic appearances mimic carcinoma. We retrospectively searched for and reviewed all cases of RS/CSL diagnosed on image-guided CNB from January 1, 1994, to August 31, 2013, at a single institution. We also assessed the pathologic reports from excisional biopsies to identify cases upstaged to atypia or neoplasm. After exclusions, 100 CNBs were identified from 97 women, which showed RS/CSL without concomitant atypia. Mean age of the women was 52.9 years. Thirty-five women (38/100 CNBs, 38%) had follow-up excision. The median size of the excised RS/CSLs was 1.2 cm; 69% were larger than 1.0 cm. Almost all excised cases (92%) showed radiologic and pathologic concordance, and 79% were designated as suspicious for malignancy (Breast Imaging Reporting and Data System level 4). The most common findings of 38 follow-up excisional biopsies were residual RS (22 [58%]), atypical lobular hyperplasia (5 [13%]), and no residual lesion (5 [13%]). Eleven excisional biopsies (29%) were upstaged to invasive or in situ carcinoma or to atypical hyperplasia. Follow-up excisional biopsy is warranted for RS/CSLs, specifically those larger than 1.0 cm with worrisome radiographic findings or with radiologic and pathologic discordance. Approximately 29% of cases were upstaged to in situ or invasive carcinomas or other high-risk lesions in our study.