Kimberly H. Allison

Recommendations for human epidermal growth factor receptor 2 testing in breast cancer: American Society of Clinical Oncology/College of American Pathologists clinical practice guideline update.

PURPOSE To update the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline recommendations for human epidermal growth factor receptor 2 (HER2) testing in breast cancer to improve the accuracy of HER2 testing and its utility as a predictive marker in invasive breast cancer. METHODS ASCO/CAP convened an Update Committee that included coauthors of the 2007 guideline to conduct a systematic literature review and update recommendations for optimal HER2 testing. RESULTS The Update Committee identified criteria and areas requiring clarification to improve the accuracy of HER2 testing by immunohistochemistry (IHC) or in situ hybridization (ISH). The guideline was reviewed and approved by both organizations. RECOMMENDATIONS The Update Committee recommends that HER2 status (HER2 negative or positive) be determined in all patients with invasive (early stage or recurrence) breast cancer on the basis of one or more HER2 test results (negative, equivocal, or positive). Testing criteria define HER2-positive status when (on observing within an area of tumor that amounts to > 10% of contiguous and homogeneous tumor cells) there is evidence of protein overexpression (IHC) or gene amplification (HER2 copy number or HER2/CEP17 ratio by ISH based on counting at least 20 cells within the area). If results are equivocal (revised criteria), reflex testing should be performed using an alternative assay (IHC or ISH). Repeat testing should be considered if results seem discordant with other histopathologic findings. Laboratories should demonstrate high concordance with a validated HER2 test on a sufficiently large and representative set of specimens. Testing must be performed in a laboratory accredited by CAP or another accrediting entity. The Update Committee urges providers and health systems to cooperate to ensure the highest quality testing. This guideline was developed through a collaboration between the American Society of Clinical Oncology and the College of American Pathologists and has been published jointly by invitation and consent in both Journal of Clinical Oncology and the Archives of Pathology & Laboratory Medicine.

Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Update

PURPOSE To update the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline recommendations for human epidermal growth factor receptor 2 (HER2) testing in breast cancer to improve the accuracy of HER2 testing and its utility as a predictive marker in invasive breast cancer. METHODS ASCO/CAP convened an Update Committee that included coauthors of the 2007 guideline to conduct a systematic literature review and update recommendations for optimal HER2 testing. RESULTS The Update Committee identified criteria and areas requiring clarification to improve the accuracy of HER2 testing by immunohistochemistry (IHC) or in situ hybridization (ISH). The guideline was reviewed and approved by both organizations. RECOMMENDATIONS The Update Committee recommends that HER2 status (HER2 negative or positive) be determined in all patients with invasive (early stage or recurrence) breast cancer on the basis of one or more HER2 test results (negative, equivocal, or positive). Testing criteria define HER2-positive status when (on observing within an area of tumor that amounts to >10% of contiguous and homogeneous tumor cells) there is evidence of protein overexpression (IHC) or gene amplification (HER2 copy number or HER2/CEP17 ratio by ISH based on counting at least 20 cells within the area). If results are equivocal (revised criteria), reflex testing should be performed using an alternative assay (IHC or ISH). Repeat testing should be considered if results seem discordant with other histopathologic findings. Laboratories should demonstrate high concordance with a validated HER2 test on a sufficiently large and representative set of specimens. Testing must be performed in a laboratory accredited by CAP or another accrediting entity. The Update Committee urges providers and health systems to cooperate to ensure the highest quality testing.

The evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer: recommendations by an International TILs Working Group 2014

BACKGROUND The morphological evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer (BC) is gaining momentum as evidence strengthens for the clinical relevance of this immunological biomarker. Accumulating evidence suggests that the extent of lymphocytic infiltration in tumor tissue can be assessed as a major parameter by evaluation of hematoxylin and eosin (H&E)-stained tumor sections. TILs have been shown to provide prognostic and potentially predictive value, particularly in triple-negative and human epidermal growth factor receptor 2-overexpressing BC. DESIGN A standardized methodology for evaluating TILs is now needed as a prerequisite for integrating this parameter in standard histopathological practice, in a research setting as well as in clinical trials. This article reviews current data on the clinical validity and utility of TILs in BC in an effort to foster better knowledge and insight in this rapidly evolving field, and to develop a standardized methodology for visual assessment on H&E sections, acknowledging the future potential of molecular/multiplexed approaches. CONCLUSIONS The methodology provided is sufficiently detailed to offer a uniformly applied, pragmatic starting point and improve consistency and reproducibility in the measurement of TILs for future studies.

Extracellular matrix stiffness and composition jointly regulate the induction of malignant phenotypes in mammary epithelium

In vitro models of normal mammary epithelium have correlated increased extracellular matrix (ECM) stiffness with malignant phenotypes. However, the role of increased stiffness in this transformation remains unclear because of difficulties in controlling ECM stiffness, composition and architecture independently. Here we demonstrate that interpenetrating networks of reconstituted basement membrane matrix and alginate can be used to modulate ECM stiffness independently of composition and architecture. We find that, in normal mammary epithelial cells, increasing ECM stiffness alone induces malignant phenotypes but that the effect is completely abrogated when accompanied by an increase in basement-membrane ligands. We also find that the combination of stiffness and composition is sensed through β4 integrin, Rac1, and the PI3K pathway, and suggest a mechanism in which an increase in ECM stiffness, without an increase in basement membrane ligands, prevents normal α6β4 integrin clustering into hemidesmosomes.

Immunosuppressive regulatory T cells are associated with aggressive breast cancer phenotypes: a potential therapeutic target.

FoxP3 is a marker for immunosuppressive CD25+CD4+ regulatory T cells. These regulatory T cells are thought to play a role in inducing immune tolerance to antigens and may be selectively recruited by carcinomas. We investigated whether breast carcinomas had significant numbers of FoxP3-positive regulatory T cells by immunohistochemistry, and if their presence was associated with other prognostic factors, such as Nottingham grade, hormone receptor immunohistochemical profile, tumor size, or lymph node metastases. Ninety-seven needle core or excisional breast biopsies with invasive breast carcinoma diagnosed at the University of Washington were stained with antibodies to FoxP3, estrogen receptor, and Her2/neu. The numbers of FoxP3-positive cells present within the neoplastic epithelium, and immediately adjacent stroma were counted manually in three high-powered fields (HPFs; × 400) by two independent pathologists. The average scores were then correlated with the parameters of interest. A threshold of ≥15 FoxP3-positive cells/HPF was used to define a FoxP3-positive case in some analyses. Higher average numbers of FoxP3-positive cells present significantly correlated with higher Nottingham grade status (P=0.000229). In addition, the presence of significant numbers (≥15/HPF) of FoxP3-positive cells in breast carcinoma was positively associated with higher Nottingham grade (P=0.00002585). Higher average numbers of FoxP3-positive cells were also significantly associated with larger tumor size (>2.0 cm; P=0.012824) and trended toward an association with estrogen receptor negativity. Interestingly, ‘triple-negative’ (estrogen and progesterone receptor negative and Her2/neu negative) Nottingham grade III cases were also significantly associated with high numbers of FoxP3 cells. These results argue that regulatory T cells may play a role in inducing immune tolerance to higher grade, more aggressive breast carcinomas, and are a potential therapeutic target for these cancers.

Risk of Upgrade of Atypical Ductal Hyperplasia after Stereotactic Breast Biopsy: Effects of Number of Foci and Complete Removal of Calcifications

PURPOSE To determine if patients with fewer than three foci of atypical ductal hyperplasia (ADH) who have all of their calcifications removed after stereotactic 9- or 11-gauge vacuum-assisted breast biopsy (VABB) have a rate of upgrade to malignancy that is sufficiently low to obviate surgical excision. MATERIALS AND METHODS An institutional review board-approved, HIPAA-compliant retrospective review of 991 cases of consecutive 9- or 11-gauge stereotactic VABB performed during a 65-month period revealed 147 cases of atypia. One pathologist performed a blinded review of the results of procedures performed to assess for calcifications and confirmed ADH in 101 cases with subsequent surgical excision. Each large duct or terminal duct-lobular unit containing ADH was considered a focus and counted. Postbiopsy mammograms were reviewed to determine whether all calcifications were removed. Upgrade to malignancy was determined from excisional biopsy pathology reports. Upgrade rates as a function of both number of foci and presence or absence of residual calcifications were calculated and compared by using chi(2) tests. RESULTS Upgrade to malignancy occurred in 20 (19.8%) of the 101 cases. The upgrade rate was significantly higher in cases of three or more foci of ADH (15 [28%] of 53 cases) than in cases of fewer than three foci (five [10%] of 48 cases) (P = .02). Upgrade rates were similar, regardless of whether all mammographic calcifications were removed (seven [17%] of 41 cases) or all were not removed (nine [20%] of 45 cases) (P = .77). Upgrade occurred in two (12%) of 17 cases in which there were fewer than three ADH foci and all calcifications were removed. CONCLUSION The upgrade rate is significantly higher when ADH involves at least three foci. Surgical excision is recommended even when ADH involves fewer than three foci and all mammographic calcifications have been removed, because the upgrade rate is 12%.

The Molecular Pathogenesis of Hereditary Ovarian Carcinoma: Alterations in the Tubal Epithelium of Women with BRCA1 and BRCA2 Mutations

BRCA1 or BRCA2 (BRCA1/2)‐mutated ovarian carcinomas may originate in the fallopian tube. The authors of this report investigated alterations in BRCA1/2 tubal epithelium to define the molecular pathogenesis of these carcinomas.

Angiosarcoma Involving the Gastrointestinal Tract: A Series of Primary and Metastatic Cases

Angiosarcoma occurs very rarely in the intestinal tract as either a primary or metastatic malignancy and can present great diagnostic difficulty, especially when it displays epithelioid cytomorphology. Since only isolated case reports have been published, the purpose of this study is to more fully delineate the histopathological and clinical features from a series of 8 angiosarcomas involving the gastrointestinal tract. There were 5 male and 3 female patients whose ages ranged from 25–85 years (median 57). Presenting symptoms included intestinal bleeding, anemia and pain. Five cases involved the small bowel and 3 involved the colon/rectum. Four cases were primary to the intestinal tract, 2 patients initially presented with secondary involvement of the large bowel from occult retroperitoneal primaries, 1 patient presented with disseminated disease including small bowel involvement, and 1 case was metastatic from a breast primary. Seven cases were composed predominantly of sheets of malignant appearing epithelioid cells with subtle areas forming cleft-like spaces suggestive of vascular differentiation. Immunohistochemical studies revealed the lesional cells to be immunoreactive for CD31 (8/8), CD34 (8/8), Factor VIII (8/8), cytokeratins AE1/AE3 (7/8), cytokeratin 7 (2/8), Cam5.2/cytokeratin 8 (5/8), and cytokeratin 19 (5/8). Cytokeratin 20 was negative in all eight cases, which contrasts sharply with the characteristic positivity for cytokeratin 20 in virtually all intestinal carcinomas. One case was weakly and focally positive for EMA and all cases were negative for S-100 protein. Cytokeratin staining was variable and ranged from focal to extensive. Follow-up was available in eight cases and ranged from 1–33 months (median 12.5). Five patients died of disease, between 1 and 33 months (median 6) after diagnosis. One recently diagnosed patient is alive with disease 18 months after diagnosis, and one patient is free of disease 27 months after original diagnosis. Angiosarcomas of the gastrointestinal tract commonly display epithelioid cytomorphology, may be diffusely and strongly positive for cytokeratins and only show subtle signs of vascular differentiation, creating potential diagnostic confusion with primary or metastatic carcinoma. Given the clinically aggressive behavior of angiosarcoma, proper classification and treatment is important. Immunohistochemistry with vascular markers, CK20, and S-100 protein may be helpful in differentiating angiosarcoma from carcinoma and melanoma.

A protein complex of SCRIB, NOS1AP and VANGL1 regulates cell polarity and migration, and is associated with breast cancer progression

By analyzing public data sets of gene expression in human breast cancers we observed that increased levels of transcripts encoding the planar cell polarity (PCP) proteins SCRIB and VANGL1 correlate with increased risk of patient relapse. Experimentally, we found that reducing expression of SCRIB by short-hairpin RNAs (shRNAs) reduces the growth of human breast cancer cells in xenograft assays. To investigate SCRIB-associated proteins that might participate in the responses of breast cancer cells to altered levels of SCRIB, we used mass spectrometry and confocal microscopy. These studies reveal that SCRIB is present in at least two unique protein complexes: (1) a complex of SCRIB, ARHGEF, GIT and PAK (p21-activated kinase), and (2) a complex of SCRIB, NOS1AP and VANGL. Focusing on NOS1AP, we observed that NOS1AP colocalizes with both SCRIB and VANGL1 along cellular protrusions in metastatic breast cancer cells, but does not colocalize with either SCRIB or VANGL1 at cell junctions in normal breast cells. We investigated the effects of shRNA-mediated knockdown of NOS1AP and SCRIB in vitro, and found that reducing NOS1AP and SCRIB slows breast cancer cell migration and prevents the establishment of leading–trailing polarity. We also find that reduction of NOS1AP enhances anchorage-independent growth. Collectively these data point to the relevance of NOS1AP and SCRIB protein complexes in breast cancer.

Frequency and Upgrade Rates of Atypical Ductal Hyperplasia Diagnosed at Stereotactic Vacuum-Assisted Breast Biopsy: 9-Versus 11-Gauge

OBJECTIVE Our goals were to determine the frequency and upgrade rate for atypical ductal hyperplasia (ADH) diagnosed with stereotactic 9-gauge vacuum-assisted breast biopsy and to compare the frequencies and upgrade rates of ADH between 9- and 11-gauge vacuum-assisted breast biopsy. MATERIALS AND METHODS We retrospectively reviewed the pathology results of 991 consecutive 9- or 11-gauge stereotactic vacuum-assisted breast biopsy procedures from February 2001 through June 2006 and identified lesions diagnosed as ADH. The final diagnosis after surgical excision was determined from medical records. The frequencies and upgrade rates to carcinoma were calculated for all ADH lesions and compared between 9- and 11-gauge procedures. The number of core samples was recorded and compared. RESULTS One hundred forty-one of 991 (14.2%) lesions yielded a diagnosis of ADH at 9- or 11-gauge stereotactic vacuum-assisted breast biopsy. Upgrade to ductal carcinoma in situ or invasive carcinoma occurred in 26 of 123 (21.1%) patients. The frequency of ADH was 83 of 600 (13.8%) lesions for 9-gauge and 58 of 391 (14.8%) lesions for 11-gauge vacuum-assisted breast biopsy. The 9-gauge upgrade rate was 16 of 74 (21.6%) lesions compared with 10 of 49 (20.4%) lesions for 11-gauge vacuum-assisted breast biopsy. There was no significant difference between the number of core samples obtained with each device (p=0.40). Neither the frequency of ADH (p=0.66) nor the upgrade rates (p=0.87) were significantly different between 9- and 11-gauge vacuum-assisted breast biopsy. CONCLUSION Compared with an 11-gauge vacuum-assisted breast biopsy device, the use of a larger 9-gauge vacuum-assisted breast biopsy needle does not decrease the upgrade rate of ADH. Our frequency of ADH at vacuum-assisted breast biopsy is higher than any previously reported and may reflect regional differences in the incidence of breast cancer or practice patterns of the pathologist.