Discrepant Cases Research Articles

Automated measurement of estrogen receptor in breast cancer: a comparison of fluorescent and chromogenic methods of measurement

Whereas FDA-approved methods of assessment of estrogen receptor (ER) are ‘fit for purpose', they represent a 30-year-old technology. New quantitative methods, both chromogenic and fluorescent, have been developed and studies have shown that these methods increase the accuracy of assessment of ER. Here, we compare three methods of ER detection and assessment on two retrospective tissue microarray (TMA) cohorts of breast cancer patients: estimates of percent nuclei positive by pathologists and by Aperio's nuclear algorithm (standard chromogenic immunostaining), and immunofluorescence as quantified with the automated quantitative analysis (AQUA) method of quantitative immunofluorescence (QIF). Reproducibility was excellent (R2>0.95) between users for both automated analysis methods, and the Aperio and QIF scoring results were also highly correlated, despite the different detection systems. The subjective readings show lower levels of reproducibility and a discontinuous, bimodal distribution of scores not seen by either mechanized method. Kaplan–Meier analysis of 10-year disease-free survival was significant for each method (Pathologist, P=0.0019; Aperio, P=0.0053, AQUA, P=0.0026); however, there were discrepancies in patient classification in 19 out of 233 cases analyzed. Out of these, 11 were visually positive by both chromogenic and fluorescent detection. In 10 cases, the Aperio nuclear algorithm labeled the nuclei as negative; in 1 case, the AQUA score was just under the cutoff for positivity (determined by an Index TMA). In contrast, 8 out of 19 discrepant cases had clear nuclear positivity by fluorescence that was unable to be visualized by chromogenic detection, perhaps because of low positivity masked by the hematoxylin counterstain. These results demonstrate that automated systems enable objective, precise quantification of ER. Furthermore, immunofluorescence detection offers the additional advantage of a signal that cannot be masked by a counterstaining agent. These data support the usage of automated methods for measurement of this and other biomarkers that may be used in companion diagnostic tests.

Application of array-based comparative genomic hybridization technique in genetic analysis of patients with spontaneous abortion

To investigate the value of array-based comparative genomic hybridization (array-CGH) technique for the detection of chromosomal analysis of miscarried embryo, and to provide genetic counseling for couples with spontaneous abortion. Totally 382 patients who underwent miscarriage were enrolled in this study. All aborted tissues were analyzed with conventional cytogenetic karyotyping and array-CGH, respectively. Through genetic analysis, all of the 382 specimens were successfully analyzed by array-CGH (100.0%, 382/382), and the detection rate of chromosomal aberrations was 46.6% (178/382). However, conventional karyotype analysis was successfully performed in 281 cases (73.6%, 281/382), and 113 (40.2%, 113/281) were found with chromosomal aberrations. Of these 178 samples identified by array-CGH, 163 samples (91.6%, 163/178) were aneuploidy, 15 samples (8.4%, 15/178) were segmental deletion and (or) duplication cases. Four of 10 cases with small segmental deletion and duplication were validated to be transferred from their fathers or mathers who were carriers of submicroscopic reciprocal translocation. Of these 113 abnormal karyotypes founded by conventional karyotyping, 108 cases (95.6%, 108/113) were aneuploidy and 5 cases (4.4%, 5/113) had chromosome structural aberrations. Most array-CGH results were consistent with conventional karyotyping but with 3 cases of discrepancy, which included 2 cases of triploids, 1 case of low-level mosaicism that undetcted by array-CGH. Compared with conventional karyotyping, there is an increased detection rate of chromosomal abnormalities when array-CGH is used to analyse the products of conception, primarilly because of its sucess with nonviable tissues. It could be a first-line method to determine the reason of miscarrage with higher accuracy and sensitivity.

Unsuspected Malignancies in Routine Femoral Head Histopathologic Examination During Primary Total Hip Arthroplasty: Cost-Effectiveness Analysis

BackgroundRoutine femoral head histopathology during primary total hip arthroplasty (THA) has been recently reported as a potentially useful screening tool for bone- and bone marrow–associated malignancies. However, cost-effectiveness of routine histopathology during THA remains unclear due to low prevalence of significant medical findings which alter patient management. The aim of this study was to evaluate the cost-effectiveness of routine histopathology in diagnosing unsuspected malignancy in patients undergoing primary THA. MethodsFrom 1993 to 2011, we retrospectively analyzed routine histopathologic findings of 3200 femoral head specimens from 2725 patients that underwent primary THA. Preoperative and postoperative diagnoses were classified into concordant (clinical diagnosis concurred with pathologic diagnosis), discrepant (differing diagnosis with no resultant impact on patient management), and discordant (differing diagnosis with subsequent change in patient management). Cost-effectiveness analysis was performed using the incremental cost-utility ratio. ResultsA total of 3055 of 3200 pathologic samples were concordant with the preoperative diagnosis (95.4%), 140 of 3200 were discrepant (4.4%), and 5 of 3200 were discordant (0.2%). Routine histopathology revealed 1 unsuspected malignancy out of 640 (5 of 3200) femoral heads. The total cost of histopathologic screening was $614,664.80. The average cost to identify a discrepant case was $4390.46, and the cost to identify a discordant case was $122,932.96. The incremental cost-utility ratio was $49,569.74 per quality-adjusted life year (QALY) gained. ConclusionOur study indicates routine femoral head histopathology may be cost-effective in diagnosing unsuspected malignancy at $49,569.74/QALY gained (less than World Health Organization recommended threshold $159,000/QALY gained), providing useful clinical information for surgeons considering the value of routine femoral head histopathology in patients undergoing THA.

P16 Immunostaining Allows for Accurate Subclassification of Vulvar Squamous Cell Carcinoma Into HPV-Associated and HPV-Independent Cases

The aim of this study was to compare morphologic assessment and p16 immunohistochemistry (IHC) in the determination of human papilloma virus (HPV) status in vulvar squamous cell carcinoma (VSCC). A total of 201 invasive VSCC cases were classified as "HPV-associated" when warty/basaloid VSCC or high-grade squamous intraepithelial lesion (vulvar intraepithelial neoplasia 2/3) was observed, or "HPV-independent" in the presence of well-differentiated keratinizing invasive SCC or differentiated vulvar intraepithelial neoplasia. For p16 IHC, strong nuclear and cytoplasmic staining of all cells in at least the lowermost third of the epithelium was scored as positive. All cases with discrepant HPV predictions by hematoxylin and eosin morphology versus p16 IHC were further analyzed by polymerase chain reaction for HPV DNA. On the basis of hematoxylin and eosin morphologic assessment, 50/201 tumors showed features suggestive of HPV-associated, and 47 of those showed p16 immunoreactivity (94% concordance). Of the 146 cases considered HPV-independent based on hematoxylin and eosin, 115 (79%) showed negative p16 immunostaining. Thus 83% (162/196) concordance between morphologic assessment and p16 IHC was observed, overall. In 34 cases, where morphologic assessment and p16 IHC did not agree, HPV polymerase chain reaction agreed with p16 IHC in 32/34 (94%). The sensitivity and specificity of p16 IHC in classification of VSCC as HPV-independent or HPV-associated was 100% and 98.4%, respectively. Morphologic assessment and p16 IHC are concordant in classifying VSCC as HPV-independent or HPV-associated in a majority of cases (83%). Most of the discrepant cases are p16-positive well-differentiated keratinizing VSCC, and HPV polymerase chain reaction supports classification of a large majority of these (94%) as HPV-associated. p16 IHC is validated as an accurate surrogate marker for determination of HPV status in VSCC.

All-Epiphyseal ACL Reconstruction in Children: Review of Safety and Early Complications

BACKGROUND All-epiphyseal anterior cruciate ligament (ACL) reconstruction is a well-described technique for skeletally immature patients. The purpose of this study was to elucidate the early complication rate and identify associated risk factors for rerupture after this procedure in children. METHODS We retrospectively reviewed patients who underwent all-epiphyseal ACL reconstructions performed at a large, tertiary care children's hospital between January 2007 and April 2013. Relevant postoperative data including the development of leg-length discrepancy, angular deformity, rerupture, infection, knee range of motion, arthrofibrosis, and other complications were recorded. Independent variables analyzed for association with rerupture included age, body mass index, graft type, graft size, and associated injuries addressed at surgery. RESULTS A total of 103 patients (average 12.1 y old; range, 6.3 to 15.7) were analyzed. The mean follow-up was 21 months. The overall complication rate was 16.5% (17/103), including 11 reruptures (10.7%), 1 case (<1.0%) of clinical leg-length discrepancy of <1 cm, and 2 cases (1.9%) of arthrofibrosis requiring manipulation under anesthesia. Two patients (1.9%) sustained contralateral ACL ruptures and 3 (2.9%) sustained subsequent ipsilateral meniscus tears during the study period. There were no associations found between age, sex, graft type, graft thickness, body mass index, or associated injuries addressed during surgery and rerupture rate. Knee flexion continued to improve by 20 degrees on an average between the 6 weeks and 6 months postoperative visits (P<0.001; paired samples Student's t test). CONCLUSIONS When taken in the context of known risk of future injury in an ACL-deficient knee, all-epiphyseal ACL reconstruction in children is safe. The rate of growth disturbance in this study is similar to previous reports in this patient demographic. The rerupture rate in this cohort is slightly higher compared with ACL reconstruction in older patients. LEVEL OF EVIDENCE Level IV-retrospective case series.

Sensitive and affordable diagnostic assay for the quantitative detection of anaplastic lymphoma kinase (ALK) alterations in patients with non-small cell lung cancer.

Accurate detection of altered anaplastic lymphoma kinase (ALK) expression is critical for the selection of lung cancer patients eligible for ALK-targeted therapies. To overcome intrinsic limitations and discrepancies of currently available companion diagnostics for ALK, we developed a simple, affordable and objective PCR-based predictive model for the quantitative measurement of any ALK fusion as well as wild-type ALK upregulation. This method, optimized for low-quantity/−quality RNA from FFPE samples, combines cDNA pre-amplification with ad hoc generated calibration curves. All the models we derived yielded concordant predictions when applied to a cohort of 51 lung tumors, and correctly identified all 17 ALK FISH-positive and 33 of the 34 ALK FISH-negative samples. The one discrepant case was confirmed as positive by IHC, thus raising the accuracy of our test to 100%. Importantly, our method was accurate when using low amounts of input RNA (10 ng), also in FFPE samples with limited tumor cellularity (5–10%) and in FFPE cytology specimens. Thus, our test is an easily implementable diagnostic tool for the rapid, efficacious and cost-effective screening of ALK status in patients with lung cancer.

A nCounter CNV Assay to Detect HER2 Amplification: A Correlation Study with Immunohistochemistry and In Situ Hybridization in Advanced Gastric Cancer.

Screening amplified genes for targeted therapy with high-throughput technology is very important. The NanoString nCounter system allows multiplexed digital quantification of target molecules through the use of color-coded barcodes with the great advantage that formalin-fixed, paraffin-embedded (FFPE) tissue can be utilized. We tested nCounter custom copy number variation (CNV) panels in 220 gastric cancer samples and evaluated the utility of this method as a screening tool for the detection of CNV using HER2. For the validation of results, we compared the nCounter results with immunohistochemistry (IHC), and we further performed in situ hybridization (ISH) in discrepant cases. The average HER2 gene copy numbers (CNs) by nCounter were 17.25, 2.0 and 2.61 for the HER2 IHC positive (3+), equivocal (2+), and negative cases, respectively. Out of the 16 IHC 3+ cases, 13 (81.3%) were reported as HER2 CN gain (≥4). Gastric cancers with homogeneous HER2 overexpression or high tumor purity showed HER2 CN ≥10. Among the 192 cases with HER2 IHC negative and without HER2 gene amplification, 29 showed a HER2 CN ≥4 with the nCounter assay. The nCounter assay had a concordance rate of 83.4% (kappa value, 0.35), a sensitivity of 66.7%, a specificity of 85.2%, a negative predictive value of 96%, and a positive predictive value of 32.6% compared with HER2 IHC/ISH results. Fresh frozen (FF) samples revealed a higher concordance rate (91.5%, kappa value, 0.59) than FFPE samples (78.5%, kappa value 0.27) and showed a high specificity (97.2%). The nCounter CNV assay is a reliable and practical method to detect high CN variations. Given the intra-tumoral HER2 heterogeneity and normal cell contamination, additional IHC and/or FISH is necessary and needs caution in interpretation, especially in FFPE tissue samples.

K2 ROTATION PERIODS FOR LOW-MASS HYADS AND THE IMPLICATIONS FOR GYROCHRONOLOGY

ABSTRACT As the closest open cluster to the Sun, the Hyades is an important benchmark for many stellar properties, but its members are also scattered widely over the sky. Previous studies of stellar rotation in the Hyades relied on targeted observations of single stars or data from shallower all-sky variability surveys. The re-purposed Kepler mission, K2, is the first opportunity to measure rotation periods (P rot) for many Hyads simultaneously while also being sensitive to fully convective M dwarf members. We analyze K2 data for 65 Hyads and present P rot values for 48. Thirty-seven of these are new measurements, including the first P rot measurements for fully convective Hyads. For 9 of the 11 stars with P rot in the literature and this work, the measurements are consistent; we attribute the two discrepant cases to spot evolution. Nearly all stars with masses ≲0.3 M ⊙ are rapidly rotating, indicating a change in rotation properties at the boundary to full convection. When confirmed and candidate binaries are removed from the mass–period plane, only three rapid rotators with masses ≳0.3 M ⊙ remain. This is in contrast to previous results showing that the single-valued mass–period sequence for ≈600 Myr old stars ends at ≈0.65 M ⊙ when binaries are included. We also find that models of rotational evolution predict faster rotation than is actually observed at ≈600 Myr for stars ≲0.9 M ⊙. The dearth of single rapid rotators more massive than ≈0.3 M ⊙ indicates that magnetic braking is more efficient than previously thought, and that age–rotation studies must account for multiplicity.

Mutation specific immunohistochemistry is highly specific for the presence of calreticulin mutations in myeloproliferative neoplasms

The identification of somatic calreticulin (CALR) mutations can be used to confirm the diagnosis of a myeloproliferative disorder in Philadelphia chromosome-negative, JAK2 and MPL wild type patients with thrombocytosis. All pathogenic CALR mutations result in an identical C-terminal protein and therefore may be identifiable by immunohistochemistry. We sought to test the sensitivity and specificity of mutation specific immunohistochemistry for pathogenic CALR mutations using a commercially available mouse monoclonal antibody (clone CAL2). Immunohistochemistry for mutant calreticulin was performed on the most recent bone marrow trephine from a cohort of patients enriched for CALR mutations and compared to mutation testing performed by polymerase chain reaction (PCR) amplification followed by fragment length analysis. Twenty-nine patients underwent both immunohistochemistry and molecular testing. Eleven patients had CALR mutation, and immunohistochemistry was positive in nine (82%). One discrepant case appeared to represent genuine false negative immunohistochemistry. The other may be attributable to a 12 year delay between the bone marrow trephine and the specimen which underwent molecular testing, particularly because a liver biopsy performed at the same time as molecular testing demonstrated positive staining in megakaryocytes in extramedullary haematopoiesis. All 18 cases which lacked CALR mutation demonstrated negative staining. In this population enriched for CALR mutations, the specificity was 100%; sensitivity 82-91%, positive predictive value 100% and negative predictive value 90-95%. We conclude that mutation specific immunohistochemistry is highly specific for the presence of CALR mutations. Whilst it may not identify all mutations, it may be very valuable in routine clinical care.

Clinical efficacy of the highly sensitive hepatitis C virus RNA quantitative assay in patients with relapse following interferon-based therapy with second-generation direct-acting antivirals.

For refractory chronic hepatitis C, interferon (IFN)-based triple-agent combination therapy with second-generation direct-acting antivirals (DAAs) has been established as the standard treatment method. The rate of decrease in the viral load and the negative conversion of hepatitis C virus (HCV) RNA in the early phase following treatment initiation are considered important factors for predicting the therapeutic outcome. In the present study, the Roche Cobas AmpliPrep/COBAS TaqMan (CAP/CTM) HCV v2.0 assay and the AccuGENE m-HCV RNA quantitative assay [Abbott RealTime HCV (ART) assay] were analyzed for their clinical efficacy and ability to predict therapeutic outcomes in the early phase in patients with relapse following IFN-based second-generation DAA therapy. Of the 56 patients who received IFN-based second-generation DAA therapy since December 2013, 6 achieved an end-of-treatment response (ETR), but subsequently experienced relapse. In these 6 patients, fluctuations in viral loads in the early phase detected by the CAP/CTM and ART assays were compared. At 4 weeks after treatment initiation, 4 of the 6 patients were diagnosed as negative by the CAP/CTM assay, whereas 2 of these 4 patients were not identified as negative by the ART assay. Of the 2 patients, one was signal-positive with an HCV RNA load <1.08 Log IU/ml, and the other patient had a viral load of 1.12 Log IU/ml. At 8 weeks after treatment initiation, 1 patient was found to be negative by the CAP/CTM assay, but signal-positive with a viral load <1.08 Log IU/ml by the ART assay. From 4 to 8 weeks after treatment initiation, 3 of the 6 patients appeared to be discrepant cases. In conclusion, of the 6 patients who achieved an ETR, 4 were determined to have achieved a rapid virological response (RVR) by the CAP/CTM assay, but may not have actually become negative. The ART assay is highly sensitive, has a wide measurement range, may be suitable for monitoring HCV RNA loads, and is expected to have an important role in providing a predictive marker for early therapeutic outcomes. In discrepant cases in which no RVR is proved by either assay, it was assumed important to consider continuation of treatment and to attempt to achieve a sustained virological response.

Automated Extraction of Formalin-Fixed, Paraffin-Embedded Tissue for High-Risk Human Papillomavirus Testing of Head and Neck Squamous Cell Carcinomas Using the Roche Cobas 4800 System.

-Testing for high-risk human papillomavirus (HR-HPV) in head and neck squamous cell carcinomas (HNSCCs) is important for both prognostication and clinical management. Several testing platforms are available for HR-HPV; however, effective alternative automated approaches are needed. -To assess the performance of the automated Roche cobas 4800 HPV real-time polymerase chain reaction-based system on formalin-fixed, paraffin-embedded HNSCC specimens and compare results with standard methods of in situ hybridization (ISH) and p16 immunohistochemistry. -Formalin-fixed, paraffin-embedded samples of HNSCC were collected from archival specimens in the Department of Pathology, Massachusetts General Hospital (Boston), and prepared using the automated system by deparaffinization and dehydration followed by tissue lysis. Samples were integrated into routine cervical cytology testing runs by cobas. Corresponding formalin-fixed, paraffin-embedded samples were evaluated for HR-HPV by ISH and p16 by immunohistochemistry. Discrepant cases were adjudicated by polymerase chain reaction. -Sixty-two HNSCC samples were analyzed using the automated cobas system, ISH, and immunohistochemistry. Fifty-two percent (n = 32 of 62) of formalin-fixed, paraffin-embedded tumors were positive for HR-HPV by cobas. Eighty-eight percent (n = 28 of 32) of cases were the HPV 16 subtype and 12% (n = 4 of 32) were other HR-HPV subtypes. Corresponding testing with ISH was concordant in 92% (n = 57 of 62) of cases. Compared with the adjudication polymerase chain reaction standard, there were 3 false-positive cases by cobas. -Concordance in HNSCC HR-HPV status between cobas and ISH was more than 90%. The cobas demonstrated a sensitivity of 100% and a specificity of 91% for detection of HR-HPV. Advantages favoring cobas include its automation, cost efficiency, objective results, and ease of performance.

MP73-14 WHO WATCHES THE WATCHMEN?: SYSTEMATIC UNDERESTIMATION OF THE INCIDENCE OF KIDNEY CANCER IN CANCER REGISTRY DATA

INTRODUCTION AND OBJECTIVES: Increasing numbers of small renal cell carcinomas (RCC) are being incidentally detected and followed longitudinally without surgical intervention. As additional cases of RCC’s are identified, we need to ensure that methods of detecting these individuals in regional cancer registries (CR) are timely and reflect clinical practice. The objective of this study was to identify if a gap exists in kidney cancer surveillance infrastructure which leads to a systematic underestimation of the true incidence of kidney cancer as reported by CR’s. METHODS: In Phase I of our study, data from 638 patients with a physician billing code for kidney cancer in 2008 (ICD-9: 189.0) was linked to the provincial CR. Individual patient chart review was performed to confirm diagnosis on discrepant cases. In Phase II of our study, a prospectively maintained database of 95 patients on active surveillance with presumed RCC in 2012 was linked with the CR. These years were chosen to allow for lag time of CR data capture. Data linkage statistics between these two sources and CR data are presented. RESULTS: Phase I revealed 184 patients (29%) with administratively coded kidney cancer were not captured in the CR. Ninety-five of these patients (52%) were not found for two reasons: no final cancer diagnosis was determined as per the current CR inclusion criteria or patients resided out of province. The remaining 89 patients (48%) were previously registered but with a nonkidney cancer. Phase II showed that 19 patients (20%) were identified in the CR with RCC. Of the remaining 76, 48 patients (50%) were eligible to be entered into the registry data as determined by CR rules. The remaining 28 patients (30%) did not meet current CR inclusion criteria. Thus we confirmed our hypothesized gap between CR reported and the true incidence of kidney cancer in both phases of our study. CONCLUSIONS: When utilizing administrative data, we identified a large proportion of patients with presumed kidney cancer who were not captured in the CR. When the system is challenged further by comparing it with a prospectively collected surveillance series with a lower rate of histological diagnosis, the gap is much greater. Traditionally, CR’s have relied heavily on histological confirmation for identification of patients as gold-standard cases of kidney cancer. This work demonstrates the need for CR’s to identify appropriate alternative sources of diagnostic data for non-histologically confirmed cancers. This will allow for the accurate quantification of the true incidence and burden of kidney cancer.

PD11-09 MOLECULAR TUMOR GRADING OF NON MUSCLE INVASIVE BLADDER CANCER BASED ON WHOLE TRANSCRIPTOME ANALYSIS

PD11-09 MOLECULAR TUMOR GRADING OF NON MUSCLE INVASIVE BLADDER CANCER BASED ON WHOLE TRANSCRIPTOME ANALYSIS

MP16-03 THE IMPACT OF A LEARNING CURVE IN THE PERFORMANCE OF MRI-US FUSION-TARGETED PROSTATE BIOPSY: IMPROVEMENTS IN CANCER DETECTION OVER TIME

INTRODUCTION AND OBJECTIVES: Mounting evidence suggests that MRI-ultrasound fusion-targeted prostate biopsy (MRFTB) may provide clinical benefit for men with suspicion of prostate cancer. We investigated outcomes of MRF-TB over time to evaluate how the performance characteristics vary with increasing operator experience. METHODS: Between June 2012 and April 2015, 566 men underwent MRF-TB by a single surgeon. A total of 429 men with no prior prostate cancer therapy had pre-biopsy multiparametric MRI (mpMRI) performed at our institution and reviewed by a single radiologist. During this time period, quality assurance efforts included team review of MRI interpretation, biopsy maps and outcome, and discussion of discrepant cases or unexpected pathology findings. We evaluated the cancer detection rates (CDR) among men with high mpMRI suspicion scores (mSS) as a function of operator experience. Trend was assessed using the Cochrane-Armitage test, and characteristics between groups were compared by chi-square or one-way ANOVA. RESULTS: All subjects were grouped according to the order of biopsy (1-60, 61-120, 121-180, 181-240, 241-300, 301-360, 361-429). Among groups, there was no difference in serum PSA (p 1⁄4 0.131) or mSS distribution (p 1⁄4 0.957). Cancer detection among men with mSS 4 or 5 demonstrated a significant, increasing trend as a function of biopsy experience, with CDRs of 63.0%, 69.6%, 77.8%, 68.2%, 88.0%, 84.0%, and 85.7% for groups 1-7, respectively (p 1⁄4 0.014). The CDR among men with mSS 2 or 3 did not demonstrate a trend (p 1⁄4 0.386) (Figure 1). CONCLUSIONS: Among men undergoing pre-biopsy mpMRI followed by MRF-TB, the rate of cancer detection appears to increase as a function of biopsy experience for men with high mpMRI suspicion (mSS 4-5), while little to no change is noted in men at lower suspicion (mSS 2-3). Improved outcomes over time may, in part, reflect evolution of MRI technique and interpretation, but these results additionally suggest that operator experience in the conduct of MRF-TB may play a significant role in optimizing cancer detection. Source of Funding: The Joseph and Diane Steinberg Charitable Trust

Radiologist-initiated double reading of abdominal CT: retrospective analysis of the clinical importance of changes to radiology reports

BackgroundMisinterpretation of radiological examinations is an important contributing factor to diagnostic errors. Consultant radiologists in Norwegian hospitals frequently request second reads by colleagues in real time. Our objective was to...

Any value in a specialist review of liver biopsies? Conclusions of a 4-year review.

Liver pathology is a challenging subspeciality, with histopathologists frequently seeking specialist opinions. This study aims to determine the impact of specialist reviews on the final diagnosis and patient management. Agreement with the initial reporting centre in the histopathological diagnosis of 1265 liver biopsies was determined. The nature of differences was explored in more depth for 103 discrepant cases. Differences in the histopathological interpretation were present in 749 of 1265 (59%) biopsies, of which 505 of 749 (67%) were predicted at the time of reporting to impact upon patient management. Agreement was good in cases with chronic viral hepatitis, fatty liver disease, malignancy and minimal pathological changes, while diagnostic differences occurred in more than 70% with biliary disease, autoimmune hepatitis or vascular/architectural changes. A clinical review of a subset of reports with histopathological differences predicted changes in patient management in 63 of 103 (61%). Clinically significant differences in liver biopsy interpretation between local pathologists and subspecialists are common. Diagnoses with frequent discrepancies, such as biliary disease, may benefit from a specialist review as standard when diagnosed initially, while cases requiring specialist advice from disease subgroups where discrepancies are less common, such as chronic viral hepatitis, could be selected during the clinicopathological conference process.

Integrated Taxonomy and DNA Barcoding of Alpine Midges (Diptera: Chironomidae).

Rapid and efficient DNA-based tools are recommended for the evaluation of the insect biodiversity of high-altitude streams. In the present study, focused principally on larvae of the genus Diamesa Meigen 1835 (Diptera: Chironomidae), the congruence between morphological/molecular delimitation of species as well as performances in taxonomic assignments were evaluated. A fragment of the mitochondrial cox1 gene was obtained from 112 larvae, pupae and adults (Diamesinae, Orthocladiinae and Tanypodinae) that were collected in different mountain regions of the Alps and Apennines. On the basis of morphological characters 102 specimens were attributed to 16 species, and the remaining ten specimens were identified to the genus level. Molecular species delimitation was performed using: i) distance-based Automatic Barcode Gap Discovery (ABGD), with no a priori assumptions on species identification; and ii) coalescent tree-based approaches as the Generalized Mixed Yule Coalescent model, its Bayesian implementation and Bayesian Poisson Tree Processes. The ABGD analysis, estimating an optimal intra/interspecific nucleotide distance threshold of 0.7%-1.4%, identified 23 putative species; the tree-based approaches, identified between 25–26 entities, provided nearly identical results. All species belonging to zernyi, steinboecki, latitarsis, bertrami, dampfi and incallida groups, as well as outgroup species, are recovered as separate entities, perfectly matching the identified morphospecies. In contrast, within the cinerella group, cases of discrepancy arose: i) the two morphologically separate species D. cinerella and D. tonsa are neither monophyletic nor diagnosable exhibiting low values of between-taxa nucleotide mean divergence (0.94%); ii) few cases of larvae morphological misidentification were observed. Head capsule color is confirmed to be a valid character able to discriminate larvae of D. zernyi, D. tonsa and D. cinerella, but it is here better defined as a color gradient between the setae submenti and genal setae. DNA barcodes performances were high: average accuracy was ~89% and precision of ~99%. On the basis of the present data, we can thus conclude that molecular identification represents a promising tool that could be effectively adopted in evaluating biodiversity of high-altitude streams.

The value of secondary pathology review.

6 Background: Improving the value of cancer care is a major focus for the Alliance of Dedicated Cancer Centers (ADCC). Looking to align with the Institute of Medicine’s (IOM) initiative to “Develop and deploy approaches to identify, learn from, and reduce diagnostic errors and near misses in clinical practice,” the ADCC implemented a study to examine the clinical impact of expert secondary pathology review. The goal of this project was to: 1) demonstrate the value of secondary review of outside pathological specimens by ADCC subspecialty pathologists in identifying significant errors that can potentially impact treatment; and 2) create an opportunity to improve patient cancer care. Methods: All consult slides from patients referred to each ADCC center were reviewed by designated pathologists. Patient-level data for original and revised diagnoses were collected for two months in 2014. Discrepancies were classified as: 1) major - diagnosis changes treatment or surveillance; or, 2) minor - diagnosis does not change affect treatment or surveillance. To verify these assessments, disease-specific, multi-center teams of clinical experts reviewed each discrepant case and provided treatment recommendations for the original and revised diagnoses. Results: A total of 13,109 cases were collected across all ADCC centers and the discrepancy rate was 11% (1,488/1309); 3% (359/13,109) were major and 9% (1,129/13,109) were minor. The most common discrepancy was reclassification of the neoplasm cell type. The highest discrepancy rate was shown in the neuro-oncology and head and neck cases, with a 7% and 4% major discrepancy rate respectively. Conclusions: We identified an overall discrepancy rate of 11%, with 3% of cases leading to a change in treatment or surveillance. This demonstrates the importance of expert pathology review and that secondary pathology review can significantly improve clinical outcomes through precise and accurate pathological diagnoses. As indicated in the recent IOM report, this project further demonstrates that “diagnostic errors may cause harm to patients by preventing or delaying appropriate treatment, providing unnecessary or harmful treatment, or resulting in psychological or financial repercussions.”

Implementation of a virtual learning from discrepancy meeting: a method to improve attendance and facilitate shared learning from radiological error

To assess the effect on radiologist participation in learning from discrepancy meetings (LDMs) in a multisite radiology department by establishing virtual LDMs using OsiriX (Pixmeo). Sets of anonymised discrepancy cases were added to an OsiriX database available for viewing on iMacs in all radiology reporting rooms. Radiologists were given a 3-week period to review the cases and send their feedback to the LDM convenor. Group learning points and consensus feedback were added to each case before it was moved to a permanent digital LDM library. Participation was recorded and compared with that from the previous 4 years of conventional LDMs. Radiologist feedback comparing the two types of LDM was collected using an anonymous online questionnaire. Numbers of radiologists attending increased significantly from a mean of 12±2.9 for the conventional LDM to 32.7±7 for the virtual LDM (p<0.0001) and the percentage of radiologists achieving the UK standard of participation in at least 50% of LDMs annually rose from an average of 18% to 68%. The number of cases submitted per meeting rose significantly from an average of 11.1±3 for conventional LDMs to 15.9±5.9 for virtual LDMs (p<0.0097). Analysis of 35 returned questionnaires showed that radiologists welcomed being able to review cases at a time and place of their choosing and at their own pace. Introduction of virtual LDMs in a multisite radiology department improved radiologist participation in shared learning from radiological discrepancy and increased the number of submitted cases.

Abstract P1-01-17: Integrative pathology: Analysis of cellular multiplex technology to detect proteomic, genomic and DNA data from fine needle aspiration biopsy specimens

Abstract Background: An integrative system capable of detecting proteomic, genomic and DNA content from cell isolates obtained by fine needle aspiration (FNA) biopsy may offer distinct advantages in diagnosing breast cancer and monitoring response to therapy. Cellular Multiplex™ is such a system. An initial pilot study evaluating this technology established a series of variables that could separate normal from cancerous elements using cells obtained from an FNA performed on excised tumors and reduction mammoplasty specimens. In order for the technology to be clinically relevant, it must perform robustly on intact tumors. The current study was therefore undertaken to validate Cellular Multiplex™ on cells obtained by FNA performed on intact tumor at the time of diagnosis. Methods: Patients undergoing lumpectomy requiring either needle or 125I seed localization were identified. FNA was performed on intact tumor (A samples) at the time of radiographic localization prior to lumpectomy and repeated on the excised tumor (B samples). Cells obtained by FNA were placed in a proprietary fixative then hybridized and stained to detect multiple mRNA and protein targets along with DNA content. Estrogen receptor, progesterone receptor and HER2 were included in the panel of targets and compared to the routine clinical pathology report. Cell morphology was assessed by mean corpuscular volume. Samples were analyzed using an EC800 (Sony Biotechnology, San Jose, CA) and the results from matched A and B samples were compared using the Mann-Whitney Wilcoxson Rank Sum test. The study is designed to enroll 50 patients. Here we report an analysis of the first 9 cases. Results: The cell number obtained from the excised tumors were 3-4 times greater (median to median) than obtained from the intact tumor. There was no statistical difference in the expression of the 2 mRNA targets, 8 protein targets, DNA content and cell morphology between the A and B samples. The parameters derived from Cellular Multiplex matched the standard pathologic features reported on the clinical pathology report in 8 of 9 cases. In the one discrepant case, Cellular Multiplexing detected ER positive cells in a case where standard pathologic evaluation with immunohistochemistry reported the tumor to be estrogen receptor negative. Conclusions: This interim analysis demonstrates that the Cellular Multiplex technology is working well using cells obtained by FNA performed on intact tumors with readouts matching those obtained from excised specimens. If confirmed in the remaining patients, these data suggest that this technology will be applicable for the evaluation of intact tumors thereby making it relevant for multiple clinical indications including diagnosis and monitoring response to neoadjuvant therapy. Citation Format: Mittendorf EA, Dogan B, Morgan R, Chargin A, Wu Y, Cornett-Risher S, Shults K. Integrative pathology: Analysis of cellular multiplex technology to detect proteomic, genomic and DNA data from fine needle aspiration biopsy specimens. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-01-17.