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Context.--Substantial variability between different antibody titration methods has been identified since the development and introduction of the uniform procedure in 2008. Objective.--To determine whether more recent methods or techniques decrease interlaboratory and intralaboratory variation measured using proficiency testing. Design.--Proficiency test data for antibody titration between 2014 and 2018 were obtained from the College of American Pathologists. Interlaboratory and intralaboratory variations were compared by analyzing the distribution of titer results by method and phase, comparing the results against the supplier's quality control titer, and by evaluating the distribution of paired titer results when each laboratory received a sample with the same titer twice. Results.--A total of 1337 laboratories participated in the antibody titer proficiency test during the study period. Only 54.1% (5874 of 10 852) of anti-D and 63.4% (3603 of 5680) of anti-A reported responses were within 1 titer of the supplier's intended result. Review of the agreement between laboratories of the same methodology found that 78.4% (3139 of 4004) for anti-A and 89.0% (9655 of 10 852) of laboratory responses for anti-D fell within 1 titer of the mode response. When provided with 2 consecutive samples of the same titer (anti-D titer: 16), 85% (367 of 434) of laboratories using the uniform procedure and 80% (458 of 576) using the other method reported a titer difference of 1 or less. Conclusions.--Despite advances, interlaboratory and intralaboratory variance for this assay remains high in comparison with the strong reliance on titer results in clinical practice. There needs to be a reevaluation of the role of this test in clinical decision-making. [ABSTRACT FROM AUTHOR]

Context.--Quantitative imaging is a promising tool that is gaining wide use across several areas of pathology. Although there has been increasing adoption of morphologic and immunohistochemical analysis, the adoption of evaluation of fluorescence in situ hybridization (FISH) on formalin-fixed, paraffin-embedded tissue has been limited because of complexity and lack of practice guidelines. Objective.--To perform human epidermal growth factor receptor 2 (HER2) FISH validation in breast carcinoma in accordance with the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2018 guideline. Design.--Clinical validation of HER2 FISH was performed using the US Food and Drug Administration- approved dual-probe HER2 IQFISH (Dako, Carpinteria, California) with digital scanning performed on a PathFusion (Applied Spectral Imaging, Carlsbad, California) system. Validation parameters evaluated included z-stacking, classifier, accuracy, precision, software, and hardware settings. Finally, we evaluated the performance of digital enumeration on clinical samples in a real-world setting. Results.--The accuracy samples showed a final concordance of 95.3% to 100% across HER2 groups 1 to 5. During clinical implementation for HER2 groups 2, 3, and 4, we achieved a final concordance of 76% (95 of 125). Of these cases, only 8% (10 of 125) had discordances with clinical impact that could be identified algorithmically and triaged for manual review. Conclusions.--Digital FISH enumeration is a useful tool to improve the efficacy of HER2 FISH enumeration and capture genetic heterogeneity across HER2 signals. Excluding cases with high background or poor image quality and manual review of cases with ASCO/CAP group discordances can further improve the efficiency of digital HER2 FISH enumeration. [ABSTRACT FROM AUTHOR]

* Context.--Next-generation sequencing-based approaches using RNA have increasingly been used by clinical laboratories for the detection of fusion genes, intragenic rearrangements, and exon-skipping events. Correspondingly, the College of American Pathologists (CAP) has advanced RNA sequencing proficiency testing (PT) to ensure optimal performance of these assays. Objective.--To report on laboratory performance and practices of RNA sequencing for the detection of fusion genes, intragenic rearrangements, and exon-skipping events using CAP PT data from 8 mailings (2018-A through 2021-B). Design.--CAP PT RNA sequencing program results from 153 laboratories across 24 proficiency test specimens, interrogating 22 distinct engineered fusion transcripts, were analyzed for correct identification of the fusion event, associated performance variables, and laboratory practices. Results.--Overall, the 4-year program detection rate (sensitivity) was 95.5% (1486 of 1556 results). False-negative rates were 3.6% (53 of 1463) and 18.3% (17 of 93) for fusion gene and intragenic rearrangement/exon-skipping events, respectively. Only 19 false-positive results were reported among the 8 PT mailings, and most were likely the result of preanalytical or postanalytical errors. There were no practice characteristics (eg, instrumentation, sequencing method) significantly associated with the fusion detection results. Conclusions.--These data reveal a high overall sensitivity and specificity for fusion gene detection by participating laboratories using clinical RNA sequencing. Performance was comparable across all laboratories, regardless of methodology. The fraction of false-negative results for intragenic rearrangement/exon-skipping events was greater than that for the chimeric fusion genes. False-negative results could not be attributed to any specific practice characteristics., Fusion oncogenes represent valuable biomarkers that aid in diagnostic classification and prognostication, as well as serving as therapeutic targets. (1-4) Examples of structural alterations/mutations that may lead to chimeric fusions [...]

Context.--Biomarker reporting has increasingly become a key component of pathology reporting, providing diagnostic, prognostic, and actionable therapeutic data for patient care. Objective.--To expand and improve the College of American Pathologists (CAP) biomarker protocols. Design.--We surveyed CAP members to better understand the limitations they experienced when reporting cancer biomarker results. A Biomarker Workgroup reviewed the survey results and developed a strategy to improve and standardize biomarker reporting. Drafts of new and revised bio-marker protocols were reviewed in both print and electronic template formats during interactive webinars presented to the CAP House of Delegates. Feedback was collected, and appropriate revisions were made to finalize the protocols. Results.--The first phase of the CAP Biomarker Workgroup saw the development of (1) a new stand-alone general Immunohistochemistry Biomarker Protocol that includes reporting for ER (estrogen receptor), PR (progesterone receptor), Ki-67, HER2 (human epidermal growth factor receptor 2), PD-L1 (programmed death ligand-1), and mismatch repair; (2) a new Head and Neck Biomarker Protocol that updates the prior 2017 paper-only version into an electronic template, adding new diagnostic and theranostic markers; (3) a major revision to the Lung Biomarker Protocol to streamline it and add in pan-cancer markers; and (4) a revision to the Colon and Rectum Biomarker Protocol to add HER2 reporting. Conclusions.--We have taken a multipronged approach to improving biomarker reporting in the CAP cancer protocols. We continue to review current biomarker reporting protocols to reduce and eliminate unnecessary methodo-logic details and update with new markers as needed. The biomarker templates will serve as standardized modular units that can be inserted into cancer-reporting protocols. [ABSTRACT FROM AUTHOR]

Barrett's esophagus (BE) is a known precursor to esophageal adenocarcinoma (EAC). Guidelines recommend BE screening in populations with multiple risk factors, for which non-endoscopic esophageal cell collection with biomarker testing is considered as an acceptable alternative to esophagogastroduodenoscopy (EGD). The aim of this study was to evaluate analytical performance characteristics of EsoGuard® (EG), a DNA methylation biomarker assay, as a laboratory-developed test (LDT) in esophageal samples collected with the swallowable EsoCheck® (EC) device. EG is a next-generation sequencing (NGS) assay that evaluates methylated vimentin (VIM) and cyclin A1 (CCNA1), clinically validated biomarkers for the detection of BE and EAC. The studies were conducted according to standards of College of American Pathology (CAP), Clinical Laboratory Improvement Amendments (CLIA), and New York (NY) state requirements for the analytical validation of molecular assays. Comparison to Sanger sequencing showed that EG was 100% accurate at all 31 CpG sites evaluated by the assay. The analytical sensitivity, specificity, and accuracy of the assay were 89%, 100%, and 96%, respectively. Intra- and inter-assay precision was 100%. The limit of detection (LOD) was 1 in 400 methylated cells, and the reference range was 84%. In summary, EsoGuard demonstrates high analytical accuracy, repeatability, and reproducibility in samples collected using the EsoCheck device. [ABSTRACT FROM AUTHOR]

We present GeneBe, an online platform streamlining the automated application of American College of Medical Genetics and Genomics (ACMG), Association for Molecular Pathology (AMP), and the College of American Pathologists (CAP) criteria for assessment of pathogenicity of genetic variants. GeneBe utilizes automated algorithms that evaluate 17 criteria from 28, closely aligning with current guidelines and leveraging data from diverse sources, including ClinVar. The user‐friendly web interface enables manual refinement of assignments for specific criteria based on site‐collected data. Our algorithm demonstrates a high correlation (r = 0.90) of assigned pathogenicity scores compared to expert assessments from the ClinGen Evidence Repository and substantial concordance with ClinVar verdict assignments (κ = 0.69). Comparative analysis with other published tools reveals that GeneBe performs similarly to VarSome while being superior over TAPES and InterVar. In contrast to some other tools, GeneBe's web implementation is tracker‐free and third‐party request‐free, safeguarding user privacy. Additionally, GeneBe offers an Application Programming Interface (API) for enhanced flexibility and integration into existing workflows and is provided free of charge for research purposes. GeneBe is available at https://genebe.net. [ABSTRACT FROM AUTHOR]

Context.--: The American Society of Clinical Oncology/College of American Pathologists 2018 update of the human epidermal growth factor receptor 2 (HER2) testing guideline includes a fluorescence in situ hybridization (FISH) group with a HER2 to chromosome 17 centromere (CEP17) ratio less than 2.0 and HER2 copy number 6.0 or greater (group 3), which requires integrated review of HER2 immunohistochemistry (IHC). Objective.--: To assess the clinicopathologic features of group 3 patients and determine features associated with HER2-positive status after workup. Design.--: Cases submitted for HER2 FISH between January 2019 and June 2022 were identified, and relevant clinicopathologic information was obtained. Results.--: One hundred forty-two HER2 FISH cases (1.6%) were group 3. In 52 cases (36.6%) IHC was negative (0/1+), in 3 (2.8%) IHC was positive (3+), and in 86 (60.6%) IHC was 2+. Annotated IHC 2+ slides were recounted by a second reviewer in targeted areas, where 16 of 86 (18.6%) had a HER2:CEP17 ratio less than 2.0 and a HER2 copy number of 4.0 or greater to less than 6.0 (HER2 negative). After combined IHC/FISH review, 74 of 142 (52.1%) were classified as HER2 positive. HER2 copy number/cell was higher in HER2-positive compared with HER2-negative cases after the workup. The extent and intensity of staining in IHC 2+ cases did not correlate with the level of gene amplification. Twenty percent of HER2-positive patients achieved pathologic complete response. Conclusions.--: About half of group 3 cases were classified as HER2 positive after additional workup. Pathologic complete response rates in HER2-positive cases were lower than expected for group 1 (HER2:CEP17 ratio ≥2.0; HER2 copy number ≥4.0) patients. IHC-targeted FISH recounts may be redundant and may potentially lead to classification of some patients as HER2 negative, resulting in withholding of targeted therapy. [ABSTRACT FROM AUTHOR]

Context.--Two major categories of laboratories performing nonwaived testing under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) are the Certificate of Accreditation (CoA) and Certificate of Compliance (CoC) laboratories. Accreditation organizations collect more detailed laboratory personnel information than the Centers for Medicare & Medicaid Services (CMS) Quality Improvement and Evaluation System (QIES). Objective.--To estimate total numbers of testing personnel and testing volumes in CoA and CoC laboratories, by laboratory type and state. Design.--We developed a statistical inference method by using the respective correlations between testing personnel counts and test volume by laboratory type. Results.--QIES reported 33 033 active CoA and CoC laboratories in July 2021. We estimated testing personnel to be 328 000 (95% CI, 309 000-348 000), which is supported by the count of 318 780 reported by the US Bureau of Labor Statistics. There were twice as many testing personnel in hospital laboratories as in independent laboratories (158 778 versus 74 904, P < .001). Independent laboratories had the highest test volume per person, which was twice as high as physician office laboratories (62 228 versus 30102, P < .001). Hospital and independent laboratories comprised 34% of all CoA and CoC laboratories but performed the largest portion of testing (81 %). Physician office laboratories, accounting for 44% of all CoA and CoC laboratories, performed a comparatively low proportion of total tests (9%). Conclusions.--Numbers of testing personnel vary considerably by laboratory type and across states. These data can provide valuable insight when assessing laboratory workforce training needs and planning for public health emergencies. doi: 10.5858/arpa.2022-0345-0A, Clinical laboratory testing plays a critical role in health care, public health surveillance, and emergency response. A detailed study by the Lewin Group for the Centers for Disease Control and [...]

* Context.--United States' clinical practice guidelines (CPGs) are often produced by professional societies and used worldwide in daily medical practice. However, studies in various medical specialties demonstrate under-representation of women and racial and ethnic minority groups in CPGs. The representation of authors by gender, race, and ethnicity of US pathology CPGs has not been previously evaluated. Objective.--To assess if women and individuals from racial and ethnic minority groups are underrepresented as authors of pathology CPGs. Design.--The gender, race, ethnicity, and terminal degrees of authors of 18 CPGs from the College of American Pathologists were coded by using photographs and other available information online and compared to their representation in academic pathology per Association of American Medical Colleges benchmark data. Results.--Two hundred seventy-five author positions (202 physician author positions) were analyzed. Women overall (119 of 275; 43.3%) and women physicians (65 of 202; 32.2%) held fewer positions than all men and men physicians. Women physicians were significantly underrepresented in physician author positions, while White men physicians were significantly overrepresented in all, first, senior, and corresponding authorship roles when compared to the proportion of women and White men physicians among pathology faculty, respectively. Asian men and women physicians were underrepresented as compared to their representation among pathology faculty. Conclusions.--Men, particularly White men physicians, are overrepresented among pathology CPG author positions, while women physicians and some physicians from racial and ethnic minority groups are underrepresented. Further research is needed to understand the impact of these findings on the careers of underrepresented physicians and the content of guidelines. (Arch Pathol Lab Med. 2024;148:230-241; doi: 10.5858/arpa.2022-0351-OA), Clinical practice guidelines (CPGs) influence the daily practice of medicine. In the United States, guidelines are often produced by professional societies and used around the world. As such, they have [...]

* Context.--Electronic synoptic pathology reporting using xPert from mTuitive is available to all pathologists in British Columbia, Canada. Comparative feedback reports for pathologists and surgeons were created by using the synoptic reporting software. Objective.--To use data stored in a single central data repository to provide nonpunitive confidential comparative feedback reports (dashboards) to individual pathologists and surgeons for reflection on their practice and to use aggregate data for quality improvement initiatives. Design.--Integration of mTuitive middleware in 5 different laboratory information systems to have 1 software solution (xPert) sending discrete data elements to the central data repository was performed. Microsoft Office products were used to build comparative feedback reports and made the infrastructure sustainable. Two different types of reports were developed: individual confidential feedback reports (dashboards) and aggregated data reports. Results.--Pathologists have access to an individual confidential live feedback report for the 5 major cancer sites. Surgeons get an annual confidential emailed PDF report. Several quality improvement initiatives were identified from the aggregate data. Conclusions.--We present 2 novel dashboards: a live pathologist dashboard and a static surgeon dashboard. Individual confidential dashboards incentivize use of nonmandated electronic synoptic pathology reporting tools and have increased adoption rates. Use of dashboards has also led to discussions about how patient care may be improved. (Arch Pathol Lab Med. 2024;148:190-199; doi: 10.5858/arpa.2021-0542-OA), Cancer is the leading cause of death in Canada and is responsible for 30% of all deaths. (1) Lung, breast, colorectal, and prostate cancer are the most commonly diagnosed types [...]

Background Biannual instrument-correlation studies are required for nonwaived assays performed on multiple instruments. Objective To determine the feasibility of using College of American Pathologists (CAP) Quality Cross Check—Chemistry and Therapeutic Drug Monitoring (CZQ) to assess instrument correlations among multiple analyzers, analyzer models, and Clinical Laboratory Improvement Amendments (CLIA) licenses for 55 unique analytes. Methods Instrument correlation studies were performed on 9 Abbott ARCHITECT instruments (c4000 [n = 4], c8000 [n = 2], and c16000 [n = 3]) over 3 CLIA licenses using CZQ materials. The mean (SD) values, concentration difference, percent bias, and peer data for each individual level of CZQ were determined for each individual analyzer. Acceptable concentration and percentage for each analyte were set using criteria from CAP or other reputable sources such as the American Association of Bioanalysts or the Royal College of Pathologists of Australasia. Peer data were provided by CAP with the CZQ kit. Results Correlations using CZQ materials showed that 94.5% of assays studied were within the acceptability criteria by percent bias only and 98.2% were within acceptability criteria by concentration difference. Conclusions The use of CZQ provides support to standardized correlation studies among instruments within and across separate CLIA licenses. However, widespread adoption of CZQ may be limited due to concerns regarding matrix effects, analyte ranges, and ease of data analysis. [ABSTRACT FROM AUTHOR]

Context.--Rapid advancements in the understanding and manipulation of tumor-immune interactions have led to the approval of immune therapies for patients with non--small cell lung cancer. Certain immune checkpoint inhibitor therapies require the use of companion diagnostics, but methodologic variability has led to uncertainty around test selection and implementation in practice. Objective.--To develop evidence-based guideline recommendations for the testing of immunotherapy/immunomodulatory biomarkers, including programmed death ligand-1 (PD-L1) and tumor mutation burden (TMB), in patients with lung cancer. Design.--The College of American Pathologists convened a panel of experts in non--small cell lung cancer and biomarker testing to develop evidence-based recommendations in accordance with the standards for trustworthy clinical practice guidelines established by the National Academy of Medicine. A systematic literature review was conducted to address 8 key questions. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, recommendations were created from the available evidence, certainty of that evidence, and key judgments as defined in the GRADE Evidence to Decision framework. Results.--Six recommendation statements were developed. Conclusions.--This guideline summarizes the current understanding and hurdles associated with the use of PD-L1 expression and TMB testing for immune checkpoint inhibitor therapy selection in patients with advanced non--small cell lung cancer and presents evidence-based recommendations for PD-L1 and TMB testing in the clinical setting. [ABSTRACT FROM AUTHOR]

Context.--In 2014, the College of American Pathologists developed an evidence-based guideline to address analytic validation of immunohistochemical assays. Fourteen recommendations were offered. Per the National Academy of Medicine standards for developing trustworthy guidelines, guidelines should be updated when new evidence suggests modifications. Objective.--To assess evidence published since the release of the original guideline and develop updated evidence-based recommendations. Design.--The College of American Pathologists convened an expert panel to perform a systematic review of the literature and update the original guideline recommendations using the Grading of Recommendations Assessment, Development and Evaluation approach. Results.--Two strong recommendations, 1 conditional recommendation, and 12 good practice statements are offered in this updated guideline. They address analytic validation or verification of predictive and nonpredictive assays, and recommended revalidation procedures following changes in assay conditions. Conclusions.--While many of the original guideline statements remain similar, new recommendations address analytic validation of assays with distinct scoring systems, such as programmed death receptor-1 and analytic verification of US Food and Drug Administration approved/cleared assays; more specific guidance is offered for validating immunohistochemistry performed on cytology specimens. [ABSTRACT FROM AUTHOR]

Context.--Increased band neutrophils in blood smear differential counts ("bandemia") are entrenched in medicine as a flag for sepsis. However, laboratory hematology experts have long advocated for discontinuation of reporting bands separately from segmented neutrophils because of poor sensitivity and specificity, poor interobserver agreement, and availability of alternative biomarkers for sepsis. Objective.--To describe band neutrophil reporting practices and reproducibility of band classification among laboratories participating in the College of American Pathologists (CAP) proficiency testing (PT) program. Design.--A survey questionnaire was distributed to hematology PT participants. A subsequent morphologic challenge included 12 preselected cell identifications of segmented neutrophils, bands, and metamyelocytes, and a 100-cell manual differential count of a digitally scanned blood smear. Results.--Among laboratories that reported manual differentials, most respondents reported bands (4554 of 5268; 86.4%). Only 3222 of 4412 respondents (73.0%) provided band reference ranges. Though participants classified "easy" band neutrophils well (78.0%-98.3%), categorization of cell identifications for "moderate" and "difficult" bands was poor (3.1%-39.0% of laboratories), with classification instead as segmented neutrophils. This pattern was seen regardless of laboratory demographic characteristics. Marked variability in band counts was observed on the 100-cell differential count for both CAP PT participants and CAP Hematology and Clinical Microscopy Committee (HCMC) members (coefficients of variation, 55.8% and 32.9%, respectively). Variability was significantly improved when segmented and band neutrophils were grouped together (coefficients of variation, 6.2% and 5.0%, respectively). Conclusions.--Most CAP PT-participating laboratories report band counts, many without reference ranges. The survey confirms significant interlaboratory variability of band enumeration when bands are separately identified from segmented neutrophils. This study reaffirms the CAP Hematology and Clinical Microscopy Committee's strong recommendation to group segmented and band neutrophils together in manual differential counts. [ABSTRACT FROM AUTHOR]

The article describes the gaps affecting the implementation of personalized medicine in cancer care and illustrates the relative importance of each potential gap. Topics discussed include factors contributing to the challenge and the gaps in clinical practice, key strategies to address clinical practice gaps for advanced non-small cell lung cancer, and the need to develop process reforms and strategies to improve the clinical practice of precision oncology.

Introduction: CNSide is a platform that detects and characterizes tumor cells in the cerebrospinal fluid (CSF) of patients with leptomeningeal disease (LMD). The platform was validated per College of American Pathologists (CAP) and Clinical Laboratories Improvement Amendment (CLIA) guidelines and run as a commercial Laboratory Developed Test (LDT) at Biocept in San Diego, CA. The platform allows CSF tumor cell (CSF-TC) enumeration and biomarker characterization by fluorescent in situ hybridization (FISH). Methods: We performed a multicenter retrospective chart review of HER2 FISH CNSide test results that were commercially ordered on 26 patients by physicians for LMD breast cancer patients between April 2020 and October 2022. Results: We show that HER2 is amplified on CSF tumor cells in 62% (16/26) of LMD breast cancer patients. 10/26 (38%) patients had discordant HER2-positivity between the primary tumor tissue and CSF-TC; of these, 35% (9/26) of the patients displayed HER2 amplification on the CSF-TCs, however were categorized as HER2 negative on the primary tumor. Of the 27% (7/26) patients with a HER2 positive primary tumor, one patient showed a HER2 negative LMD tumor. Two patients, 8% (2/26) had a HER2 equivocal primary tumor; of these, one demonstrated a HER2 negative, and one a HER2 positive LMD tumor. Serial analysis (at least 4 longitudinal tests) of HER2 status of the CSF-TC throughout therapy was available for 14 patients and demonstrated that HER2 status of the LMD changed in 29% (4/14) during their treatment course and impacted care decisions. Conclusions: Our data suggests that CSF-TC HER2 FISH analysis in LMD breast cancer patients may be discordant to the primary tumor sample and the discovery of HER2 positivity in the CSF may open doors to anti-HER2 targeted therapy options for LMD patients. [ABSTRACT FROM AUTHOR]

Objectives A combination of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) is the current standard of care for HER2 evaluation in breast cancer. Here, we investigate the potential clinical utility of next-generation sequencing (NGS)–derived HER2/ERBB2 copy number (CN) data for predicting HER2 status as defined by American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines. Methods In total, 294 locally recurrent and metastatic breast cancers previously tested by targeted hybrid capture–based NGS and by HER2 IHC/FISH were included. Analyses focused on the ERBB2 median log2 ratios and start-end genomic coordinates from NGS, average HER2 CN and HER2/ CEP17 ratios from FISH, and the HER2 IHC scores. We also determined a more stringent log2 ratio cutoff to predict HER2-positive status with 100% specificity. Results Sixty-four (22%) cases were HER2 positive and 230 (78%) were HER2 negative by ASCO/CAP guidelines. The ERBB2 median log2 ratios from NGS strongly correlated with HER2 status by IHC/FISH (area under receiver operator characteristic curve = 0.951). ERBB2 log2 ratio more than 1.7 was 100% specific for HER2-positive results by IHC/FISH. Start and end genomic coordinates for regions of gain near ERBB2 by NGS also predicted HER2 status. Conclusions Copy number data from our NGS panel strongly correlate with HER2 status. Using a stringent cutoff, ERBB2 log2 ratio accurately predicts HER2 positivity with high specificity. The NGS CN assessment may have utility in determining HER2 status in certain clinical settings. [ABSTRACT FROM AUTHOR]

* Context.--Quantitative imaging is a promising tool that is gaining wide use across several areas of pathology. Although there has been increasing adoption of morphologic and immunohistochemical analysis, the adoption of evaluation of fluorescence in situ hybridization (FISH) on formalin-fixed, paraffin-embedded tissue has been limited because of complexity and lack of practice guidelines. Objective.--To perform human epidermal growth factor receptor 2 (HER2) FISH validation in breast carcinoma in accordance with the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2018 guideline. Design.--Clinical validation of HER2 FISH was performed using the US Food and Drug Administration-approved dual-probe HER2 IQFISH (Dako, Carpinteria, California) with digital scanning performed on a PathFusion (Applied Spectral Imaging, Carlsbad, California) system. Validation parameters evaluated included z-stacking, classifier, accuracy, precision, software, and hardware settings. Finally, we evaluated the performance of digital enumeration on clinical samples in a real-world setting. Results.--The accuracy samples showed a final concordance of 95.3% to 100% across HER2 groups 1 to 5. During clinical implementation for HER2 groups 2, 3, and 4, we achieved a final concordance of 76% (95 of 125). Of these cases, only 8% (10 of 125) had discordances with clinical impact that could be identified algorithmically and triaged for manual review. Conclusions.--Digital FISH enumeration is a useful tool to improve the efficacy of HER2 FISH enumeration and capture genetic heterogeneity across HER2 signals. Excluding cases with high background or poor image quality and manual review of cases with ASCO/CAP group discordances can further improve the efficiency of digital HER2 FISH enumeration. (Arch Pathol Lab Med. 2023;147:1402-1412; doi: 10.5858/arpa.2022-0372-OA), Determination of human epidermal growth factor receptor 2 (HER2) amplification status by fluorescence in situ hybridization (FISH) analysis is an essential part of the management of invasive breast carcinoma to [...]

Proficiency testing (PT) plays a crucial role in maintaining the quality of clinical laboratories, as mandated by the Clinical Laboratory Improvement Amendments (CLIA). (1) Central to PT is the use [...]

Increasing survivorship in kidney cancer patients has shifted treatment strategies to optimize renal function preservation. In 2010, the College of American Pathologists (CAP) updated their synoptic reporting guidelines for tumor nephrectomies to require evaluation of the nonneoplastic kidney parenchyma. We conducted this study to understand current practice behaviors regarding the evaluation of the nonneoplastic kidney parenchyma in tumor nephrectomy specimens. We emailed a 14-item multiple-choice survey to members of the Renal Pathology Society and Genitourinary Pathology Society. We also emailed a 12-item survey to program and associate program directors of American pathology residencies to assess the current state of renal pathology education. Ninety-eight genitourinary and 104 renal pathologists responded to the survey on the nonneoplastic kidney parenchyma. Ninety-five percent of respondents who examine tumor nephrectomies reported evaluating the nonneoplastic kidney parenchyma. Seventy-five percent of genitourinary pathologists and 67% of renal pathologists use synoptic reporting, and 81% use the CAP protocol. Thirty-nine percent of respondents report always contacting the clinician when they find evidence of medical renal disease. Forty-two program leaders responded to our renal pathology education survey, and 64% of them have a mandatory renal pathology rotation that on average lasts about 2 to 4 weeks. The majority of pathologists examine the nonneoplastic kidney parenchyma of tumor nephrectomies and frequently report incidences of new medical renal disease directly to clinicians, but there remains room for improvement and educational gaps during residency training. Further efforts to standardize both this evaluation and renal pathology education will improve patient care. [ABSTRACT FROM AUTHOR]

PURPOSE: Trastuzumab deruxtecan is a new treatment option for patients with advanced human epidermal growth factor receptor 2 (HER2)–low breast cancer (BC). Although HER2-low status has been characterized in early and advanced BC, it has yet to be fully characterized in brain metastases (BrM). METHODS: Patients who underwent surgery for BC BrM at Sunnybrook Health Sciences Centre and for whom HER2 status was available on resected BrM were studied. Estrogen receptor, progesterone receptor, and HER2 status were assessed on the basis of ASCO/College of American Pathologists (CAP) guidelines. HER2-zero was defined as immunohistochemistry (IHC) 0; HER2-low was defined as IHC 1+ or IHC 2+ with fluorescence in situ hybridization (FISH)–negative status. HER2-positive (HER2+) was defined as IHC 3+ or IHC 2+ with positive FISH. Clinicopathologic features were recorded. We also assessed the prognostic association between extent of HER2 expression and (1) brain-specific progression-free survival (bsPFS), as well as (2) overall survival (OS). RESULTS: In this retrospective cohort of 102 patients with resected BC BrM, 53% (n = 54) were HER2+, 29.4% (n = 30) were HER2-low, and 17.6% (n = 18) had HER2-zero status. Among BrM that were triple-negative on the basis of ASCO/CAP guidelines, 63.6% (n = 14/22) were reclassified as being HER2-low. Sixty percent (n = 15/25) of BrM that were hormone receptor–positive/HER2-negative (HR+/HER2–) were reclassified as being HER2-low. In total, 51 patients had matched primary breast and BrM tissue available; results of HER2 status when categorized as HER2-zero, HER2-low, and HER2+ were concordant in 82.3% (n = 42/51) of cases (Cohen's kappa, 0.58; P =.07). There was no significant association between HER2-zero, HER2-low, and HER2+ status in BrM and either bsPFS or OS. CONCLUSION: Among patients with surgically resected BrM, a high proportion of those with metastatic triple-negative BC and HR+/HER2– disease have HER2-low BrM with potential to benefit from HER2-targeted therapy. HER2 status of breast cancer brain metastases—a target among patients whose extracranial disease is HER2-0. [ABSTRACT FROM AUTHOR]

Purpose: Somatic molecular profiling of pediatric brain tumors aids with the diagnosis and treatment of patients with a variety of high- and low-grade central nervous system neoplasms. Here, we report follow-up targeted germline evaluation for patients with possible germline variants following tumor only testing in the initial year in which somatic molecular testing was implemented at a single institution. Patients and Methods: Somatic testing was completed for all tumors of the central nervous system (CNS) undergoing diagnostic workup at Seattle Children's Hospital during the study period of November 2015 to November 2016. Sequencing was performed in a College of American Pathologists-accredited, Clinical Laboratory Improvements Amendments-certified laboratory using UWOncoPlex ™ assay (version 5), a DNA-based targeted next generation sequencing panel validated to detect genetic alterations in 262 cancer-related genes. We tracked subsequent clinical evaluation and testing on a subgroup of this cohort found to have potential germline variants of interest. Results: Molecular sequencing of 88 patients' tumors identified 31 patients with variants that warranted consideration of germline testing. To date, 19 (61%) patients have been tested. Testing confirmed germline variants for ten patients (31% of those identified for testing), one with two germline variants (NF1 and mosaic TP53). Eight (26%) patients died before germline testing was sent. One patient (13%) has not yet had testing. Conclusion: Clinically validated molecular profiling of pediatric brain tumors identifies patients who warrant further germline evaluation. Despite this, only a subset of these patients underwent the indicated confirmatory sequencing. Further work is needed to identify barriers and facilitators to this testing, including the role of genetic counseling and consideration of upfront paired somaticgermline testing. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate mesothelin (MSLN) expression and determine its clinical significance and correlation with human epidermal growth factor receptor 2 (HER2) expression in gynecological carcinosarcoma. Methods: We retrospectively evaluated patients with uterine carcinosarcoma (UCS) and ovarian carcinosarcoma (OCS) who underwent surgery between 1997 and 2019. Immunohistochemical staining of formalin-fixed, paraffin-embedded specimens for MSLN (clone SP74) and HER2 (clone 4A5) was also performed. MSLN was scored using the H-score and 4-tired scoring system (0-3+). MSLN positivity was defined as any positive cell at any intensity, while high MSLN expression was defined as an intensity of =2+ in =30% of tumor cells. HER2 expression was scored according to modified 2018 American Society of Clinical Oncology/College of American Pathologists criteria. Results: A total of 128 patients were recruited, including 119 with UCS and 9 with OCS. All cases in UCS exhibited MSLN positivity, and 33.9% showed high-MSLN expression. Clinicopathological characteristics were not significantly associated with high or low-MSLN expression. However, the high-MSLN group showed more prolonged overall survival (OS) than the low-MSLN group (not assessed vs. 36.8 months; hazard ratio=0.48, 95% confidence interval=0.26-0.89, p=0.016). HER2-high patients had higher MSLN expression than HER2- negative patients. In high-MSLN and low-MSLN expression groups, HER2 status did not affect OS. OCS showed 100% MSLN positivity, with 66.6% high-MSLN. Conclusion: MSLN expression is widely observed in gynecological carcinosarcomas. Moreover, high-MSLN expression is a favorable prognostic factor for UCS. MSLN could be a promising therapeutic target for UCS, even in the era of anti-HER2 therapy. [ABSTRACT FROM AUTHOR]

Context.-- The Sustainable Predictive Oncology Therapeutics and Diagnostics quality assurance pilot study (SPOT/Dx pilot) on molecular oncology next-generation sequencing (NGS) reportedly demonstrated performance limitations of NGS laboratory-developed tests, including discrepancies with a US Food and Drug Administration-approved companion diagnostic. The SPOT/Dx pilot methods differ from those used in proficiency testing (PT) programs. Objective.-- To reanalyze SPOT/Dx pilot data using PT program methods and compare to PT program data.Also see p. 136. Design.-- The College of American Pathologists (CAP) Molecular Oncology Committee reanalyzed SPOT/Dx pilot data applying PT program methods, adjusting for confounding conditions, and compared them to CAP NGS PT program performance (2019-2022). Results.-- Overall detection rates of KRAS and NRAS single-nucleotide variants (SNVs) and multinucleotide variants (MNVs) by SPOT/Dx pilot laboratories were 96.8% (716 of 740) and 81.1% (129 of 159), respectively. In CAP PT programs, the overall detection rates for the same SNVs and MNVs were 97.2% (2671 of 2748) and 91.8% (1853 of 2019), respectively. In 2022, the overall detection rate for 5 KRAS and NRAS MNVs in CAP PT programs was 97.3% (1161 of 1193). Conclusions.-- CAP PT program data demonstrate that laboratories consistently have high detection rates for KRAS and NRAS variants. The SPOT/Dx pilot has multiple design and analytic differences with established PT programs. Reanalyzed pilot data that adjust for confounding conditions demonstrate that laboratories proficiently detect SNVs and less successfully detect rare to never-observed MNVs. The SPOT/Dx pilot results are not generalizable to all molecular oncology testing and should not be used to market products or change policy affecting all molecular oncology testing. [ABSTRACT FROM AUTHOR]

The time has come to regulate clinical immunohistochemistry (IHC) as an assay rather than a stain. Since IHC originally evolved as an extension of special stains in anatomic pathology, (1) [...]

Perineural invasion (PNI) is defined as the dissemination of neoplastic cells within the perineural space. PNI can be a strong indicator of malignancy and is linked to poor prognosis and adverse outcomes in various malignant neoplasms; nevertheless, it can also be seen in benign pathologic conditions. In this review article, we discuss various signaling pathways and neurotrophic factors implicated in the development and progression of PNI. We also describe the methodology, benefits, and limitations of different in vitro, ex vivo, and in vivo models of PNI. The spectrum of presentation for PNI can range from diffuse spread within large nerves (“named” nerves) all the way through localized spread into unnamed microscopic nerves. Therefore, the clinical significance of PNI is related to its extent rather than its mere presence or absence. In this article, we discuss the guidelines for the identification and quantification of PNI in different malignant neoplasms based on the College of American Pathologists (CAP) and World Health Organization (WHO) recommendations. We also describe benign pathologic conditions and neoplasms demonstrating PNI and potential mimics of PNI. Finally, we explore avenues for the future development of targeted therapy options via modulation of signaling pathways involved in PNI.

Objectives: Actionable, solid tumor activating neurotrophic receptor tyrosine kinase (NTRK) fusions are best detected via nucleic acid-based assays, while Pan-TRK immunohistochemistry (IHC) serves as a reasonable screening modality. We describe a practical and cost-effective approach to validate pan-TRK and discuss challenges that may be encountered. Methods: Pan-TRK Clone EPR17341 was validated in accordance with the 2014 consensus statements set forth by the College of American Pathologists. Confirmation of IHC results were guided by the European Society of Medical Oncology recommendations for standard methods to detect NTRK fusions. Results: Within 36 samples, ETV6-NTRK3 (n = 8) and TPM4-NTRK3 (n = 1) fusions were confirmed. ETV6-NTRK3 fusion positive cases revealed cytoplasmic and nuclear staining. A TPM4-NTRK3 fusion positive high grade malignant peripheral nerve sheath tumor revealed diffuse cytoplasmic staining. A high grade ovarian serous carcinoma revealed focal punctate staining and revealed a non-actionable NTRK1 truncation at intron 2. Diffuse cytoplasmic staining was observed in a case of fusion-negative polymorphous adenocarcinoma. Wild-type expression of TRK in pulmonary meningothelial-like nodules was discovered following a false-positive IHC interpretation. Conclusion: Pan-TRK IHC shows some utility as a diagnostic and surrogate marker for NTRK screening however, physiologic or non-specific expression may lead to false-positive results. [ABSTRACT FROM AUTHOR]

Mesothelioma is a rare disease with an historically poor prognosis. Over the past decade, a grading system has been developed that is a powerful prognostic tool in epithelioid mesothelioma. Grading of epithelioid mesothelioma is now required or strongly recommended by expert consensus, the College of American Pathologists, the World Health Organization, and the International Mesothelioma Interest Group. The original nuclear grading system for epithelioid mesothelioma, developed in the United States, split epithelioid mesotheliomas into three prognostic groups with marked differences in survival. Now, this three‐tiered nuclear grading system has been combined with the presence or absence of necrosis to form the currently recommended two‐tiered grading system of low‐ and high‐grade epithelioid mesothelioma. This review will focus on the development of this grading system in mesothelioma, the grading system's shortcomings, and the application of the grading system to cytology specimens and other extra‐pleural sites. Lastly, this review will briefly discuss alternative grading systems and future considerations. [ABSTRACT FROM AUTHOR]

Nowadays, the aging human population exerts a notable influence on the treatment of thyroid diseases. The most appropriate approach for the treatment of benign and malignant thyroid diseases in older adults has not yet been determined. The aim of our study is to evaluate the effect of thyroidectomies in geriatric patients considering age, sex and histopathological parameters and to determine the importance of thyroidectomy as a treatment option in the geriatric population. A total of 910 cases from all age groups were included, for which thyroidectomies were examined and reported. In accordance with the College of American Pathologists Cancer Protocol for thyroid reporting, considering geriatric patients, the rate of Thyroid Follicular Nodular Disease was significantly higher among the tumor types in the benign tumor group (p = 0.033), while Anaplastic Thyroid Carcinoma rate was higher in the malignant tumor group. The diagnosis rate of malignant tumors was higher in males, reflecting a more advanced pT stage (p < 0.001), larger tumor size (p < 0.001) and increased lymph node involvement rate (p = 0.039). Given that increasing age is associated with a heightened incidence of thyroid disease, the safety of surgery for geriatric patients is an important issue. Thyroidectomy should be considered in the treatment of these patients, especially in males, as the rate of malignant diagnosis and worse histopathological parameters are seen with increasing age. [ABSTRACT FROM AUTHOR]

Aims: Partial response to neoadjuvant chemoradiotherapy (CRT) presents with one of two main response patterns: shrinkage or fragmentation. This study investigated the relevance of these response patterns in rectal cancer, correlation with other response indicators, and outcome. Methods and results: The study included a test (n = 197) and a validation cohort (n = 218) of post‐CRT patients with rectal adenocarcinoma not otherwise specified and a partial response. Response patterns were scored by two independent observers using a previously developed three‐step flowchart. Tumour regression grading (TRG) was established according to both the College of American Pathologists (CAP) and Dworak classifications. In both cohorts, the predominant response pattern was fragmentation (70% and 74%), and the scoring interobserver agreement was excellent (k = 0.85). Patients with a fragmented pattern presented with significantly higher pathological stage (ypTNM II‐IV, 78% versus 35%; P < 0.001), less tumour regression with Dworak (P = 0.004), and CAP TRG (P = 0.005) compared to patients with a shrinkage pattern. As a predictor of prognosis, the shrinkage pattern outperformed the TRG classification and stratified patients better in overall (fragmented pattern, hazard ratio [HR] 2.04, 95% confidence interval [CI] 1.19–3.50, P = 0.008) and disease‐free survival (DFS; fragmented pattern, HR 2.50, 95% CI 1.23–5.10, P = 0.011) in the combined cohorts. The multivariable regression analyses revealed pathological stage as the only independent predictor of DFS. Conclusions: The heterogeneous nature of tumour response following CRT is reflected in fragmentation and shrinkage. In rectal cancer there is a predominance of the fragmented pattern, which is associated with advanced stage and less tumour regression. While not independently associated with survival, these reproducible patterns give insights into the biology of tumour response. [ABSTRACT FROM AUTHOR]

Objectives: The objectives of the study were to assess the prevalence of abnormal Pap smears and their quality metrics in a tertiary health-care facility in the western region of Saudi Arabia and to share our data with other researchers in Saudi Arabia to potentially establish benchmark data based on a Saudi population. Material and Methods: A retrospective study was carried out by the Department of Pathology at King Fahd Armed Forces Hospital, Jeddah, Saudi Arabia, on Pap smear statistics for 14,376 Pap smears of both conventional and liquid-based cytology (LBC) between 2010 and 2022. Results: The prevalence of abnormal Pap smears of both conventional and LBC was 3.05% (438 Pap smears). The percentages of adenocarcinoma and squamous cell carcinoma were 0.08% and 0.02%, respectively, and the ratio of atypical squamous cells (ASCs) to squamous intraepithelial lesions (SILs) (ASC/SIL) was 2.61. Conclusion: The prevalence of abnormal Pap smears and the ASC/SIL ratio were consistent with the international benchmark data provided by the College of American Pathologists for each preparation type and within the range of the data provided by published studies, highlighting the need for greater focus on glandular abnormalities. [ABSTRACT FROM AUTHOR]

Introduction: Physicians face diagnostic dilemmas upon reports indicating disease variants of unknown significance (VUS). The most puzzling cases are patients with rare diseases, where finding another matched genotype and phenotype to associate their results is challenging. This study aims to prove the value of updating patient files with new classifications, potentially leading to better assessment and prevention. Methodology: We recruited retrospective phenotypic and genotypic data from King Saud Medical City, Riyadh, Kingdom of Saudi Arabia. Between September 2020 and December 2021, 1,080 patients' genetic profiles were tested in a College of American Pathologists accredited laboratory. We excluded all confirmed pathogenic variants, likely pathogenic variants and copy number variations. Finally, we further reclassified 194 VUS using different local and global databases, employing in silico prediction to justify the phenotype-genotype association. Results: Of the 194 VUS, 90 remained VUS, and the other 104 were reclassified as follows: 16 pathogenic, 49 likely pathogenic, nine benign, and 30 likely benign. Moreover, most of these variants had never been observed in other local or international databases. Conclusion: Reclassifying the VUS adds value to understanding the causality of the phenotype if it has been reported in another family or population. The healthcare system should establish guidelines for re-evaluating VUS, and upgrading VUS should reflect on individual/family risks and management strategies. [ABSTRACT FROM AUTHOR]

Tumor prognosis hinges on accurate cancer staging, a pivotal process influenced by the identification of lymphovascular invasion (LVI), i.e., blood vessel and lymphatic vessel invasion. Protocols by the College of American Pathologists (CAP) and the World Health Organization (WHO) have been established to assess LVI in various tumor types, including, but not limited to, breast cancer, colorectal cancer (CRC), pancreatic exocrine tumors, and thyroid carcinomas. The CAP refers to blood vessel invasion as "angioinvasion" (vascular invasion) to differentiate it from lymphatic vessel invasion (lymphatic invasion). For clarity, the latter terms will be used throughout this review. The presence of lymphatic and/or vascular invasion has emerged as a pivotal prognostic factor; therefore, its accurate identification is crucial not only for staging but also for providing the patient with an honest understanding of his/her prognosis. Given the prognostic importance of the correct identification of LVI, specific staining techniques are employed to distinguish lymphatic vessel invasion from angioinvasion and to differentiate true LVI from artifact. These encompass hematoxylin and eosin (H&E) staining, elastic staining, Factor VIII staining, Ulex europaeus I agglutinin staining, CD31, CD34, D2-40, ERG, and D2-40 (podoplanin) immunohistochemical (IHC) stains among others. Based on a review of numerous publications regarding the efficacy of various methods for LVI detection, elastin staining demonstrated superior accuracy and prognostic value, allowing for more targeted treatment strategies. The clinical significance of accurately detecting LVI cannot be overstated, as it is strongly linked to higher cancer-related mortality and an increased risk of tumor recurrence. This review aims to examine the existing literature on the use of elastin stains in the detection of vascular invasion among different types of tumors and its prognostic value. [ABSTRACT FROM AUTHOR]

Perineural invasion (PNI) is defined as the dissemination of neoplastic cells within the perineural space. PNI can be a strong indicator of malignancy and is linked to poor prognosis and adverse outcomes in various malignant neoplasms; nevertheless, it can also be seen in benign pathologic conditions. In this review article, we discuss various signaling pathways and neurotrophic factors implicated in the development and progression of PNI. We also describe the methodology, benefits, and limitations of different in vitro, ex vivo, and in vivo models of PNI. The spectrum of presentation for PNI can range from diffuse spread within large nerves ("named" nerves) all the way through localized spread into unnamed microscopic nerves. Therefore, the clinical significance of PNI is related to its extent rather than its mere presence or absence. In this article, we discuss the guidelines for the identification and quantification of PNI in different malignant neoplasms based on the College of American Pathologists (CAP) and World Health Organization (WHO) recommendations. We also describe benign pathologic conditions and neoplasms demonstrating PNI and potential mimics of PNI. Finally, we explore avenues for the future development of targeted therapy options via modulation of signaling pathways involved in PNI. [ABSTRACT FROM AUTHOR]

Selected patients with early-stage melanoma have a "hidden high risk" of poor oncologic outcomes. They might benefit from clinical trials, and ultimately, if warranted by trial results, judicious everyday use of adjuvant therapy. A promising tool to identify these individuals is the immunoprint® assay. This immunohistochemical 7-biomarker prognostic test was clinically validated in three independent cohorts (N = 762) to classify early-stage patients as high-risk or low-risk regarding melanoma recurrence and mortality. Using College of American Pathologists (CAP) recommendations, we analytically validated this assay in primary melanoma specimens (N = 20 patients). We assessed assay precision by determining consistency of risk classification under repeated identical conditions (repeatability) or across varying conditions (reproducibility), involving separate assay runs, operators (laboratory scientists), and/or observers (e.g., dermatopathologists). Reference classification was followed by five analytical validation phases: intra-run/intra-operator, intra-observer, inter-run, inter-operator, and inter-observer. Concordance of classifications in each phase was assessed via Fleiss' kappa (primary endpoint) and percent agreement (secondary endpoint). Seven-marker signature classification demonstrated high consistency across validation categories (Fleiss' kappa 0.864–1.000; overall percent agreement 95–100%), in 9/10 cases, exceeding, and in 1/10 cases, closely approaching, CAP's recommended 0.9 level. The 7-marker assay has now been verified to provide excellent repeatability, reproducibility, and precision, besides having been clinically validated. [ABSTRACT FROM AUTHOR]

Context.--Therapy targeted at human epidermal growth factor receptor 2 (HER2; also known as ERBB2) was used initially for breast and gastroesophageal carcinoma and has more recently been adopted for endometrial serous carcinoma (ESC) and colorectal carcinoma (CRC). There is evidence that predictive biomarker testing algorithms for HER2 must be tumor type specific and that an algorithm validated for one tumor type cannot be applied to another. Objective.--To describe current laboratory practices for HER2 assessment in ESC and CRC. Design.--We surveyed laboratories participating in the 2021 College of American Pathologists (CAP) HER2 immunohistochemistry proficiency testing program. Results.--The survey was distributed to 1548 laboratories and returned by 1195, of which 83.5% (998) were in the United States. For ESC, 24.0% (287) of laboratories reported performing in-house testing for HER2 by immunohistochemical staining and/or in situ hybridization; of these, 44.3% (127) performed it reflexively on all cases of ESC. The most common criterion for evaluating HER2 was the American Society of Clinical Oncology/CAP 2018 guideline for breast carcinoma (69.0%; 194 of 281), whereas only 16.0% (45) of laboratories used guidelines specific to ESC. For CRC, 20.2% (239 of 1185) of laboratories performed in-house HER2 testing, and 82.0% of these (196) did the test only at the clinician's request. A plurality (49.4%; 115 of 233) used gastroesophageal cancer guidelines when scoring CRC, 30.0% (70) used the CRC scoring system from the HERACLES trial, and 16.3% (38) used the American Society of Clinical Oncology/CAP 2018 guideline for breast carcinoma. Conclusions.--Laboratories vary in their approach to HER2 testing in ESC and CRC. Most laboratories did not report using tumor type--specific recommendations for HER2 interpretation. The lack of standardization could present a challenge to evidence-based practice when considering targeted therapy for these diseases. [ABSTRACT FROM AUTHOR]

Background and purpose: Systematic treatment for breast cancer largely depends on the status of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). Discordance in ER, PR and HER2 status between primary breast cancer and distant metastases has been observed in a proportion of patients in previous studies. Liver is one of the frequent metastatic sites of breast cancer. Currently, limited data are available on the receptor conversion between primary breast cancer and matched liver metastases. This study aimed to investigate the prevalence, risk factors and prognostic impact of receptor conversion between primary breast cancer and paired liver metastases. Methods: The data of breast cancer patients who had pathologically confirmed liver metastases from January 2013 to May 2020 at Fudan University Shanghai Cancer Center were retrospectively collected. A total of 353 patients with ER, PR and HER2 status available on both primary breast cancer and matched liver metastases were finally included in this study. ER, PR and HER2 status were interpreted according to the most updated American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines. The evolution of receptor status and phenotype from primary to metastatic breast cancer was illustrated using Sankey diagrams. Kappa coefficient and McNemar's test were used to assess the agreement on receptor status between primary breast cancer and liver metastases. The Kaplan-Meier curves were plotted and survival differences across each group were assessed by log-rank test. Multivariate analyses were performed based on the COX proportional hazard regression model. Results: The total discordance rate of ER, PR and HER2 was 19.5%, 39.4% and 4.8%, respectively (Kappa coefficient: 0.569, 0.258 0.876). In de novo stage IV patients, the discordance rate of ER, PR and HER2 was 15.2%, 28.3% and 2.2%, respectively. Multivariate analysis showed that previous endocrine therapy before liver re-biopsy was an independent risk factor of PR discordance. None of the variables of interest was found to be associated with discordance in ER or HER2 status. Additionally, 37.9% of the HER2-0 tumors converted to HER2-low. A trend of increase in triple-negative and decrease in hormone receptor (HR)+/HER2- cases were observed in liver metastases. Patients with HR+/HER2- primary breast cancer who converted to triple-negative in liver metastases had a significantly shorter overall survival (OS) than those with consistent HR+/HER2- subtype. Patients with the same subtype in liver metastases shared similar OS. Conclusion: This study confirmed discordance in ER, PR and HER2 status between primary breast cancer and liver metastases. The prognosis of breast cancer patients was determined mainly by the subtype in metastases rather than that in primary disease. Our study underlined the necessity of liver re-biopsy in de novo stage IV patients with liver metastases. Over one-third of HER2-0 patients converted to HER2-low in liver metastases after reassessment, which enabled them to be treated with new antibody-drug conjugate (ADC). [ABSTRACT FROM AUTHOR]

Objectives: The advent of effective chemotherapy regimens has increased the use of neoadjuvant multiagent chemotherapy in pancreatic cancer. However, the effect of tumor downstaging with neoadjuvant treatment on survival is unclear. Methods: Retrospective study included all resected patients with pancreatic adenocarcinoma who underwent neoadjuvant chemotherapy with FOLFIRINOX or gemcitabine/Abraxane. Downstaging was quantified using (1) difference between presenting AJCC clinical and final pathologic stage and (2) College of American Pathologists (CAP) Tumor Regression Grading Schema. Results: Eighty-seven patients met inclusion criteria. FOLFIRINOX was the most common regimen, 63.2% vs 21.8%. Change in regimen occurred in 15% of patients. Downstaging based on a difference in AJCC stage group occurred in only 4.6%. In contrast, 45.2% were classified as downstaged by the CAP Tumor Regression of 0-2. Downstaging was similar for FOLFIRINOX gemcitabine/Abraxane (64.7 vs 53.6, P =.12) using the CAP criteria. On univariate analysis, treatment regimen (gemcitabine/Abraxane vs FOLFIRINOX, median survival 27 vs 29 mo; HR 1.57, P =.2) had similar survival. Downstaging by the AJCC stage was not associated with improved survival (HR 1.51, P =.4). However, there was a survival benefit for those downstaged by the CAP Tumor Regression Grading Schema, the median survival of 41 mo vs 25 mo; HR 3.05, P =.009. Improved survival 3.32 (1.35-8.16), P =.009) was maintained on multivariate analysis. Conclusion: Survival is significantly improved in those downstaged, as assessed by the CAP Tumor Regression Schema. Downstaging is an important prognostic variable that can help with joint decision making for clinicians and patients. [ABSTRACT FROM AUTHOR]

Purpose.--To update the American Society of Clinical Oncology--College of American Pathologists (ASCO-CAP) recommendations for human epidermal growth factor receptor 2 (HER2) testing in breast cancer. An Update Panel is aware that a new generation of antibody-drug conjugates targeting the HER2 protein is active against breast cancers that lack protein overexpression or gene amplification. Methods.--The Update Panel conducted a systematic literature review to identify signals for updating recommendations. Results.--The search identified 173 abstracts. Of 5 potential publications reviewed, none constituted a signal for revising existing recommendations. Recommendations.--The 2018 ASCO-CAP recommendations for HER2 testing are affirmed. Discussion.--HER2 testing guidelines have focused on identifying HER2 protein overexpression or gene amplification in breast cancer to identify patients for therapies that disrupt HER2 signaling. This update acknowledges a new indication for trastuzumab deruxtecan when HER2 is not overexpressed or amplified but is immunohistochemistry (IHC) 1þ or 2þ without amplification by in situ hybridization. Clinical trial data on tumors that tested IHC 0 are limited (excluded from DESTINY-Breast04), and evidence is lacking that these cancers behave differently or do not respond similarly to newer HER2 antibody-drug conjugates. Although current data do not support a new IHC 0 versus 1þ prognostic or predictive threshold for response to trastuzumab deruxtecan, this threshold is now relevant because of the trial entry criteria that supported its new regulatory approval. Therefore, although it is premature to create new result categories of HER2 expression (eg, HER2-Low, HER2-Ultra-Low), best practices to distinguish IHC 0 from 1þ are now clinically relevant. This update affirms prior HER2 reporting recommendations and offers a new HER2 testing reporting comment to highlight the current relevance of IHC 0 versus 1þ results and best practice recommendations to distinguish these often subtle differences. Additional information is available at www. asco.org/breast-cancer-guidelines. [ABSTRACT FROM AUTHOR]

Background: Molecular screening plays a major role in prognostic categorization and subsequent definition of treatment strategies for acute myeloid leukaemia. Aim of the work: To classify patients of AML patients and to determine the frequency of IDH 1 mutations using RQ-PCR Material and Methods: We did this prospective observational study at tertiary care center between January 2021 and June 2022. DNA was extracted from pre-treatment peripheral blood samples of 50 patients with de novo AML was used. The exon 4 of IDH1 were amplified using the previously generated mismatched primers suitable for endonuclease based detection of mutations in codon 132 of IDH1 gene by PCR. Results: The median age of IDH1 mutant AML patients is 43 years (39-48 years). The male to female ratio was 3:1. IDH1 mutations were diagnosed in 8% (p-value: 0.621) of the participants, all the mutant cases showed mutation at R132H gene (395G>A). Median PB blasts of mutant IDH patients was 85.5% (80-90%) vs. 50.68% (25-68%) for wild type (p-value: 0.001). Conclusion: IDH1 mutations are recurring genetic alterations in AML and they may have unfavourable impact on clinical outcome in adult AML. The prognostic and therapeutic implications of IDH mutations in AML led to the recent recommendation by the College of American Pathologists and the American Society of Haematology to test for IDH1 and IDH2 mutations during the diagnostic workup for AML. The RQ-PCR method allows for a fast and sensitive method for the detection of IDH1 mutations in AML. [ABSTRACT FROM AUTHOR]

Purpose: Circumferential radial margin (CRM) involvement by tumor after resection for esophageal cancer has been suggested as a significant prognostic factor. However, the prognostic value of CRM involvement after surgery with neoadjuvant concurrent chemoradiotherapy (CCRT) is unclear. This study aimed to evaluate the prognostic valueof andsurvivaloutcomes inCRMinvolvement asdefinedby theRoyal College of Pathologists (RCP) and the College of American Pathologists (CAP) for patientswith esophageal cancer undergoing neoadjuvantCCRTand esophagectomy. Methods: A total of 299 patients with esophageal cancer who underwent neoadjuvant CCRT followed by esophagectomy between 2006 and 2016 were enrolled in our study. The CRM status of the specimens obtained was determined pathologically according to both the CAP and RCP criteria. Survival analyses were performed and compared according to the two criteria. Results: Positive CRM was found in 102 (34.1%) and 40 (13.3%) patients according to RCP and CAP criteria, respectively. The overall and progression-free survival rates were significantly lower in the CRM-positive group than in the CRMnegative group according to both the RCP and CAP criteria. However, under multivariate analysis, in addition to pathological T and N staging of the tumor, only CAP-defined CRM positivity was a significant prognostic factor with adjusted hazard ratios of 2.64 (1.56-4.46) and 2.25 (1.34-3.78) for overall and progression-free survival, respectively (P < 0.001). Conclusion: In patients with esophageal cancer undergoing neoadjuvant CRT followed by esophagectomy, CAP-defined CRM positivity is an independent predictor of survival. Adjuvant therapy should be offered to patients with positive CRM. [ABSTRACT FROM AUTHOR]

Pancreatic adenocarcinoma (PDAC) is one of the most common cancers worldwide. Unfortunately, the prognosis of PDAC is rather poor, and for instance, in the USA, over 47,000 people die because of pancreatic cancer annually. Here, we demonstrate that high expression of acid sphingomyelinase in PDAC strongly correlates with long-term survival of patients, as revealed by the analysis of two independent data sources. The positive effects of acid sphingomyelinase expression on long-term survival of PDAC patients were independent of patient demographics as well as tumor grade, lymph node involvement, perineural invasion, tumor stage, lymphovascular invasion, and adjuvant therapy. We also demonstrate that genetic deficiency or pharmacological inhibition of the acid sphingomyelinase promotes tumor growth in an orthotopic mouse model of PDAC. This is mirrored by a poorer pathologic response, as defined by the College of American Pathologists (CAP) score for pancreatic cancer, to neoadjuvant therapy of patients co-treated with functional inhibitors of the acid sphingomyelinase, in particular tricyclic antidepressants and selective serotonin reuptake inhibitors, in a retrospective analysis. Our data indicate expression of the acid sphingomyelinase in PDAC as a prognostic marker for tumor progression. They further suggest that the use of functional inhibitors of the acid sphingomyelinase, at least of tricyclic antidepressants and selective serotonin reuptake inhibitors in patients with PDAC, is contra-indicated. Finally, our data also suggest a potential novel treatment of PDAC patients with recombinant acid sphingomyelinase. Key messages: Pancreatic ductal adenocarcinoma (PDAC) is a common tumor with poor prognosis. Expression of acid sphingomyelinase (ASM) determines outcome of PDAC. Genetic deficiency or pharmacologic inhibition of ASM promotes tumor growth in a mouse model. Inhibition of ASM during neoadjuvant treatment for PDAC correlates with worse pathology. ASM expression is a prognostic marker and potential target in PDAC. [ABSTRACT FROM AUTHOR]