Significant variation in histopathological assessment of endoscopic resections for Barrett's neoplasia suggests need for consensus reporting: propositions for improvement.

Endoscopic resection (ER) is an important diagnostic step in management of patients with early Barrett's esophagus (BE) neoplasia. Based on ER specimens, an accurate histological diagnosis can be made, which guides further treatment. Based on depth of tumor invasion, differentiation grade, lymphovascular invasion, and margin status, the risk of lymph node metastases and local recurrence is judged to be low enough to justify endoscopic management, or high enough to warrant invasive surgical esophagectomy. Adequate assessment of these histological risk factors is therefore of the utmost importance. Aim of this study was to assess pathologist concordance on these histological features on ER specimens and evaluate causes of discrepancy. Of 62 challenging ER cases, one representative H&E slide and matching desmin and endothelial marker were digitalized and independently assessed by 13 dedicated GI pathologists from 8 Dutch BE expert centers, using an online assessment module. For each histological feature, concordance and discordance were calculated. Clinically relevant discordances were observed for all criteria. Grouping depth of invasion categories according to expanded endoscopic treatment criteria (T1a and T1sm1 vs. T1sm2/3), ≥1 pathologist was discrepant in 21% of cases, increasing to 45% when grouping diagnoses according to the traditional T1a versus T1b classification. For differentiation grade, lymphovascular invasion, and margin status, discordances were substantial with 27%, 42%, and 32% of cases having ≥1 discrepant pathologist, respectively. In conclusion, histological assessment of ER specimens of early BE cancer by dedicated GI pathologists shows significant discordances for all relevant histological features. We present propositions to improve definitions of diagnostic criteria.

Clinical value of ctDNA in upper-GI cancers: A systematic review and meta-analysis.

BACKGROUND: The recent expanding technical possibilities to detect tumor derived mutations in blood, so-called circulating tumor DNA (ctDNA), has rapidly increased the interest in liquid biopsies. This review and meta-analysis explores the clinical value of ctDNA in malignancies of the upper gastro-intestinal tract. METHODS: PubMed, Cochrane and Embase databases were searched to identify studies reporting the diagnostic, prognostic or predictive value of ctDNA in patients with esophageal, gastric and pancreatic cancer, until January 2017. The diagnostic accuracy and, using random-effect pair-wise meta-analyses, the prognostic value of ctDNA was assessed. RESULTS: A total of 34 studies met the inclusion criteria. For esophageal and gastric cancer, amplification of oncogenes in blood, such as HER2 and MYC, can be relevant for diagnostic purposes, and to predict treatment response in certain patient subpopulations. Given the limited number of studies assessing the role of ctDNA in esophageal and gastric cancer, the meta-analysis estimated the diagnostic accuracy and predictive value of ctDNA in pancreatic cancer only (n=10). The pooled sensitivity and specificity of ctDNA as a diagnostic tool in pancreatic cancer were 28% and 95%, respectively. Patients with pancreatic cancer and detectable ctDNA demonstrated a worse overall survival compared to patients with undetectable ctDNA (HR 1.92, 95% confidence interval (CI) 1.15-3.22, p=0.01). CONCLUSION: The presence of ctDNA is significantly associated with a poor prognosis in patients with pancreatic cancer. The use of ctDNA in clinical practice is promising, although standardization of sequencing techniques and further development of high-sensitive detection methods is needed.

Digital microscopy as valid alternative to conventional microscopy for histological evaluation of Barrett's esophagus biopsies.

Management of Barrett's esophagus (BE) relies heavily on histopathological assessment of biopsies, associated with significant intra- and interobserver variability. Guidelines recommend biopsy review by an expert in case of dysplasia. Conventional review of biopsies, however, is impractical and does not allow for teleconferencing or annotations. An expert digital review platform might overcome these limitations. We compared diagnostic agreement of digital and conventional microscopy for diagnosing BE ± dysplasia. Sixty BE biopsy glass slides (non-dysplastic BE (NDBE); n = 25, low-grade dysplasia (LGD); n = 20; high-grade dysplasia (HGD); n = 15) were scanned at ×20 magnification. The slides were assessed four times by five expert BE pathologists, all practicing histopathologists (range: 5-30 years), in 2 alternating rounds of digital and conventional microscopy, each in randomized order and sequence of slides. Intraobserver and pairwise interobserver agreement were calculated, using custom weighted Cohen's kappa, adjusted for the maximum possible kappa scores. Split into three categories (NDBE, IND, LGD+HGD), the mean intraobserver agreement was 0.75 and 0.84 for digital and conventional assessment, respectively (p = 0.35). Mean pairwise interobserver agreement was 0.80 for digital and 0.85 for conventional microscopy (p = 0.17). In 47/60 (78%) of digital microscopy reviews a majority vote of ≥3 pathologists was reached before consensus meeting. After group discussion, a majority vote was achieved in all cases (60/60). Diagnostic agreement of digital microscopy is comparable to that of conventional microscopy. These outcomes justify the use of digital slides in a nationwide, web-based BE revision platform in the Netherlands. This will overcome the practical issues associated with conventional histologic review by multiple pathologists.

Adherence to pre-set benchmark quality criteria to qualify as expert assessor of dysplasia in Barrett's esophagus biopsies - towards digital review of Barrett's esophagus.

Background: Dysplasia assessment of Barrett's esophagus biopsies is associated with low observer agreement; guidelines advise expert review. We have developed a web-based review panel for dysplastic Barrett's esophagus biopsies. Objective: The purpose of this study was to test if 10 gastrointestinal pathologists working at Dutch Barrett's esophagus expert centres met pre-set benchmark scores for quality criteria. Methods: Ten gastrointestinal pathologists twice assessed 60 digitalized Barrett's esophagus cases, enriched for dysplasia; then randomised (7520 assessments). We tested predefined benchmark quality criteria: (a) percentage of 'indefinite for dysplasia' diagnoses, benchmark score ≤14% for all cases, ≤16% for dysplastic subset, (b) intra-observer agreement; benchmark score ≥0.66/≥0.39, (c) percentage agreement with 'gold standard diagnosis'; benchmark score ≥82%/≥73%, (d) proportion of cases with high-grade dysplasia underdiagnosed as non-dysplastic Barrett's esophagus; benchmark score ≤1/78 (≤1.28%) assessments for dysplastic subset. Results: Gastrointestinal pathologists had seven years' Barrett's esophagus-experience, handling seven Barrett's esophagus-cases weekly. Three met stringent benchmark scores; all cases and dysplastic subset, three met extended benchmark scores. Four pathologists lacked one quality criterion to meet benchmark scores. Conclusion: Predefined benchmark scores for expert assessment of Barrett's esophagus dysplasia biopsies are stringent and met by some gastrointestinal pathologists. The majority of assessors however, only showed limited deviation from benchmark scores. We expect further training with group discussions will lead to adherence of all participating gastrointestinal pathologists to quality criteria, and therefore eligible to join the review panel.

Development of benchmark quality criteria for assessing whole-endoscopy Barrett's esophagus biopsy cases.

BACKGROUND: Dysplasia in Barrett's esophagus (BE) biopsies is associated with low observer agreement among general pathologists. Therefore, expert review is advised. We are developing a web-based, national expert review panel for histological review of BE biopsies. OBJECTIVE: The aim of this study was to create benchmark quality criteria for future members. METHODS: Five expert BE pathologists, with 10-30 years of BE experience, weekly handling 5-10 cases (25% dysplastic), assessed a case set of 60 digitalized cases, enriched for dysplasia. Each case contained all slides from one endoscopy (non-dysplastic BE (NDBE), n = 21; low-grade dysplasia (LGD), n = 20; high-grade dysplasia (HGD), n = 19). All cases were randomized and assessed twice followed by group discussions to create a consensus diagnosis. Outcome measures: percentage of 'indefinite for dysplasia' (IND) diagnoses, intra-observer agreement, and agreement with the consensus 'gold standard' diagnosis. RESULTS: Mean percentage of IND diagnoses was 8% (3-14%) and mean intra-observer agreement was 0.84 (0.66-1.02). Mean agreement with the consensus diagnosis was 90% (95% prediction interval (PI) 82-98%). CONCLUSION: Expert pathology review of BE requires the scoring of a limited number of IND cases, consistency of assessment and a high agreement with a consensus gold standard diagnosis. These benchmark quality criteria will be used to assess the performance of other pathologists joining our panel.