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Esophageal adenocarcinoma causes 6% of cancer-related deaths worldwide. Near-infrared fluorescence molecular endoscopy (NIR-FME) uses a tracer that targets overexpressed proteins. In this study, we aimed to investigate the feasibility of an epidermal growth factor receptor (EGFR)-targeted tracer, cetuximab-800CW, to improve detection of early-stage esophageal adenocarcinoma. Methods: We validated EGFR expression in 73 esophageal tissue sections. Subsequently, we topically administered cetuximab-800CW and performed high-definition white-light endoscopy (HD-WLE), narrow-band imaging, and NIR-FME in 15 patients with Barrett esophagus (BE). Intrinsic fluorescence values were quantified using multidiameter single-fiber reflectance and single-fiber fluorescence spectroscopy. Back-table imaging, histopathologic examination, and EGFR immunohistochemistry on biopsy samples collected during NIR-FME procedures were performed and compared with in vivo imaging results. Results: Immunohistochemical preanalysis showed high EGFR expression in 67% of dysplastic tissue sections. NIR-FME visualized all 12 HD-WLE-visible lesions and 5 HD-WLE-invisible dysplastic lesions, with increased fluorescence signal in visible dysplastic BE lesions compared with nondysplastic BE as shown by multidiameter single-fiber reflectance/single-fiber fluorescence, reflecting a target-to-background ratio of 1.5. Invisible dysplastic lesions also showed increased fluorescence, with a target-to-background ratio of 1.67. Immunohistochemistry analysis showed EGFR overexpression in 16 of 17 (94%) dysplastic BE lesions, which all showed fluorescence signal. Conclusion: This study has shown that NIR-FME using cetuximab-800CW can improve detection of dysplastic lesions missed by HD-WLE and narrow-band imaging.

Background and Aims: After endoscopic resection (ER) of early esophageal adenocarcinoma (EAC), the optimal management of patients with high-risk histologic features for lymph node metastases (ie, submucosal invasion, poor differentiation grade, or lymphovascular invasion) remains unclear. We aimed to evaluate outcomes of endoscopic follow-up after ER for high-risk EAC. Methods: For this retrospective cohort study, data were collected from all Dutch patients managed with endoscopic follow-up (endoscopy, EUS) after ER for high-risk EAC between 2008 and 2019. We distinguished 3 groups: intramucosal cancers with high-risk features, submucosal cancers with low-risk features, and submucosal cancers with high-risk features. The primary outcome was the annual risk for metastases during follow-up, stratified for baseline histology. Results: One hundred twenty patients met the selection criteria. Median follow-up was 29 months (interquartile range, 15-48). Metastases were observed in 5 of 25 (annual risk, 6.9%; 95% confidence interval [CI], 3.0-15) high-risk intramucosal cancers, 1 of 55 (annual risk, .7%; 95% CI, 0-4.0) low-risk submucosal cancers, and 3 of 40 (annual risk, 3.0%; 95% CI, 0-7.0) high-risk submucosal cancers. Conclusions: Whereas the annual metastasis rate for high-risk submucosal EAC (3.0%) was somewhat lower than expected in comparison with previous reported percentages, the annual metastasis rate of 6.9% for high-risk intramucosal EAC is new and worrisome. This calls for further prospective studies and suggests that strict follow-up of this small subgroup is warranted until prospective data are available.

Background Biological treatment in inflammatory bowel disease (IBD) patients is currently hampered by high non-response rates. To enhance personalized medicine and predict response to biological therapeutics such as vedolizumab, the working mechanism should be elucidated. We aimed to visualize macroscopic and microscopic vedolizumab distribution and detect drug target cells during quantified fluorescence molecular endoscopy (QFME) to improve understanding of the mechanism of action. Methods Vedolizumab-800CW was developed and GMP produced. Forty-three QFME procedures were performed in thirty-seven IBD patients two to four days after intravenous administration of vedolizumab-800CW. Each QFME procedure consisted out of endoscopic assessment of the inflammation status per colonic segment by high-definition white light endoscopy, followed by real-time in vivo assessment of the macro-distribution of fluorescent vedolizumab-800CW signal and quantification by spectroscopy of selected segments. Dose escalation was performed using 0.0 mg, 4.5 mg and 15 mg. Subsequently, two patient cohorts were added that received a dose of 75 mg or 300 mg unlabelled vedolizumab prior to vedolizumab-800CW to assess target saturation. Tissue biopsies were obtained for histopathological assessment, for further ex vivo analysis of the fluorescent signal and for visualization of the microscopic distribution and identification of vedolizumab-800CW target cells by fluorescence microscopy (fig 1). Results Both during in vivo QFME and ex vivo analysis a clear dose- and inflammation severity-dependent increase of the fluorescent drug signal was revealed (fig 2). A significant difference was found between the dose groups for non-inflamed (p=0.0004), mild inflamed (p=0.0397) and severe inflamed (p=0.0056) tissue. In addition, the difference in intrinsic fluorescence between the severe inflamed tissue and non-inflamed tissue was significant within the 15 mg (p Conclusion QFME using vedolizumab-800CW elucidated novel detailed macroscopic and microscopic vedolizumab distribution in the inflamed target organ. In addition, its shows the potential of QFME to better understand local drug distribution, target cell identification and target engagement, which could improve understanding of targeted drugs over standard pharmacokinetic and pharmacodynamic analysis.

Simple Summary Barrett's esophagus (BE) is the only known precursor lesion of esophageal adenocarcinoma (EAC). Endoscopic surveillance plays an important role in the timely detection of neoplastic progression. However, the cost-effectiveness of current surveillance strategies is debatable. Previous studies have shown that male Barrett's patients have lower neoplastic progression risk than females. However, these studies do not provide a more practical translation of these sex disparities into different surveillance intervals. The current multicenter prospective cohort study aimed to evaluate sex differences in 868 BE patients; not only with respect to neoplastic progression risk, but also concerning the difference in time to detection of high-grade dysplasia (HGD)/EAC: time to neoplastic progression was estimated to be almost twice as low in males than in females. In contrast, the stage of neoplasia appeared to be higher in females. Our results can guide future discussions for sex-specific guidelines, supporting the implementation of neoplastic risk stratification per individual patient in BE surveillance. Recommendations in Barrett's esophagus (BE) guidelines are mainly based on male patients. We aimed to evaluate sex differences in BE patients in (1) probability of and (2) time to neoplastic progression, and (3) differences in the stage distribution of neoplasia. We conducted a multicenter prospective cohort study including 868 BE patients. Cox regression modeling and accelerated failure time modeling were used to estimate the sex differences. Neoplastic progression was defined as high-grade dysplasia (HGD) and/or esophageal adenocarcinoma (EAC). Among the 639 (74%) males and 229 females that were included (median follow-up 7.1 years), 61 (7.0%) developed HGD/EAC. Neoplastic progression risk was estimated to be twice as high among males (HR 2.26, 95% CI 1.11-4.62) than females. The risk of HGD was found to be higher in males (HR 3.76, 95% CI 1.33-10.6). Time to HGD/EAC (AR 0.52, 95% CI 0.29-0.95) and HGD (AR 0.40, 95% CI 0.19-0.86) was shorter in males. Females had proportionally more EAC than HGD and tended to have higher stages of neoplasia at diagnosis. In conclusion, both the risk of and time to neoplastic progression were higher in males. However, females were proportionally more often diagnosed with (advanced) EAC. We should strive for improved neoplastic risk stratification per individual BE patient, incorporating sex disparities into new prediction models.

OBJECTIVE: Neoadjuvant chemoradiotherapy followed by surgery establishes a considerable pathologic complete response (pCR) in EC. The aim was to determine site of residual tumor and its prognostic impact. SUMMARY BACKGROUND DATA: High rates of residual tumor in the adventitial region even inside the radiation fields will influence current decision-making. METHODS: We evaluated resection specimens with marked target fields from 151 consecutive EC patients treated with carboplatin/paclitaxel and 41.4Gy between 2009 and 2018. RESULTS: In radically resected (R0) specimens 19.8% (27/136) had a pCR (ypT0N0) and 14% nearly no response (tumor regression grade: tumor regression grade 4-5). Residual tumor commonly extended in or restricted to the adventitia (43.1%; 47/109), whereas 7.3% was in the mucosa (ypT1a), 16.5% in the submucosa (ypT1b) and 6.4% only in lymph nodes (ypT0N+). Macroscopic residues in R0-specimens of partial responders (tumor regression grade 2-3: N = 90) were found in- and outside the gross tumor volume (GTV) in 33.3% and 8.9%, and only microscopic in- and outside the clinical target volume in 58.9% and 1.1%, respectively. Residual nodal disease was observed proximally and distally to the clinical target volume in 2 and 5 patients, respectively. Disease Free Survival decreased significantly if macroscopic tumor was outside the GTV and in ypT2-4aN+. CONCLUSIONS: After neoadjuvant chemoradiotherapy, pCR and ypT1aN0 were seen in a limited number of R0 resected specimens (19.8% and 7.3%, respectively), whereas 6.4% had only nodal disease (yT0N+). Disease Free Survival decreased significantly if macroscopic residue was outside the GTV and in responders with only nodal disease. Therefore, we should be cautious in applying wait and see strategies.

Simple Summary: Barrett's esophagus (BE) is the precursor of esophageal adenocarcinoma (EAC). Dysplastic BE (DBE), including low-grade dysplasia (LGD) and high-grade dysplasia (HGD), shows a higher progression risk to EAC compared to non-dysplastic BE (NDBE). If LGD or HGD is detected, more intensive endoscopic surveillance or endoscopic treatment is recommended. This results in a significantly improved prognosis compared to EACs treated by surgery and/or chemoradiotherapy. However, the miss rates for detecting DBE by endoscopy remain high. Fluorescence molecular endoscopy (FME) can fill this gap by targeting the tumor-specific expression of proteins. This study aimed to identify target proteins suitable for FME. We identified SPARC, SULF1, PKC iota, and DDR1 as promising imaging targets for FME to differentiate DBE from NDBE tissue. We are also the first to develop near-infrared fluorescent tracers, SULF1-800CW and SPARC-800CW, for the endoscopic imaging of DBE tissue.Abstract: Barrett's esophagus (BE) is the precursor of esophageal adenocarcinoma (EAC). Dysplastic BE (DBE) has a higher progression risk to EAC compared to non-dysplastic BE (NDBE). However, the miss rates for the endoscopic detection of DBE remain high. Fluorescence molecular endoscopy (FME) can detect DBE and mucosal EAC by highlighting the tumor-specific expression of proteins. This study aimed to identify target proteins suitable for FME. Publicly available RNA expression profiles of EAC and NDBE were corrected by functional genomic mRNA (FGmRNA) profiling. Following a class comparison between FGmRNA profiles of EAC and NDBE, predicted, significantly upregulated genes in EAC were prioritized by a literature search. Protein expression of prioritized genes was validated by immunohistochemistry (IHC) on DBE and NDBE tissues. Near-infrared fluorescent tracers targeting the proteins were developed and evaluated ex vivo on fresh human specimens. In total, 1976 overexpressed genes were identified in EAC (n = 64) compared to NDBE (n = 66) at RNA level. Prioritization and IHC validation revealed SPARC, SULF1, PKC iota, and DDR1 (all p < 0.0001) as the most attractive imaging protein targets for DBE detection. Newly developed tracers SULF1-800CW and SPARC-800CW both showed higher fluorescence intensity in DBE tissue compared to paired non-dysplastic tissue. This study identified SPARC, SULF1, PKC iota, and DDR1 as promising targets for FME to differentiate DBE from NDBE tissue, for which SULF1-800CW and SPARC-800CW were successfully ex vivo evaluated. Clinical studies should further validate these findings.

AimsThe histopathological diagnosis of low-grade dysplasia (LGD) in Barrett’s oesophagus (BO) is associated with poor interobserver agreement and guidelines dictate expert review. To facilitate nationwide expert review in the Netherlands, a web-based digital review panel has been set up, which currently consists of eight ‘core’ pathologists. The aim of this study was to evaluate if other pathologists from the Dutch BO expert centres qualify for the expert panel by assessing their performance in 80 consecutive LGD reviews submitted to the panel.MethodsPathologists independently assessed digital slides in two phases. Both phases consisted of 40 cases, with a group discussion after phase I. For all cases, a previous consensus diagnosis made by five core pathologists was available, which was used as reference. The following criteria were used: (1) percentage of ‘indefinite for dysplasia’ diagnoses, (2) percentage agreement with consensus diagnosis and (3) proportion of cases with a consensus diagnosis of dysplasia underdiagnosed as non-dysplastic. Benchmarks were based on scores of the core pathologists.ResultsAfter phase I, 1/7 pathologists met the benchmark score for all quality criteria, yet three pathologists only marginally failed the agreement with consensus diagnosis (score 68.3%, benchmark 69%). After a group discussion and phase II, 5/6 remaining aspirant panel members qualified with all scores within the benchmark range.ConclusionsThe Dutch BO review panel now consists of 14 pathologists, who—after structured assessments and group discussions—can be considered homogeneous in their review of biopsies with LGD.

The optimal treatment sequence for patients with rectal cancer and synchronous liver metastases remains unclear. The aim of this study was to evaluate the feasibility and effectiveness of short-course pelvic radiotherapy (5 × 5 Gy) followed by systemic therapy and local treatment of all tumour sites in patients with potentially curable stage IV rectal cancer in daily practice.This was a retrospective study performed in eight tertiary referral centres in the Netherlands. Patients aged 18 years or above with rectal cancer and potentially resectable liver ± extrahepatic metastases, treated between 2010 and 2015, were eligible. Main outcomes included full completion of treatment schedule, symptom control and survival.In total, 169 patients were included with a median follow-up of 49·5 (95 pr cent c.i. 43·6 to 55·6) months. The completion rate for the entire treatment schedule was 65·7 per cent. Three-year progression-free survival and overall survival (OS) rates were 24·2 (95 per cent c.i. 16·6 to 31·6) and 48·8 (40·4 to 57·2) per cent respectively. Median OS of patients who responded well and completed the treatment schedule was 51·5 months, compared with 15·1 months for patients who did not complete the treatment (P 0·001). Adequate symptom control of the primary tumour was achieved in 87·0 per cent of all patients.Multimodal treatment leads to relief of symptoms in most patients, and is associated with good survival rates in those able to complete the schedule. [Correction added on 12 February 2020, after first online publication: the Conclusion has been reworded for clarity].La secuencia óptima de tratamiento en pacientes con cáncer de recto y metástasis hepáticas sincrónicas sigue sin estar clara. El objetivo de este estudio fue evaluar en la práctica diaria la viabilidad y efectividad de la radioterapia pélvica de ciclo corto (5 x 5 Gy) seguida de tratamiento sistémico y tratamiento local de todas las localizaciones del tumor primario en pacientes con cáncer de recto estadio IV potencialmente curables. MÉTODOS: Estudio retrospectivo realizado en ocho centros terciarios de referencia en Holanda. Se consideró elegibles a los pacientes mayores de 18 años con cáncer de recto y metástasis hepáticas ± extrahepáticas potencialmente resecables, que fueron tratados entre 2010 y 2015. Los criterios de valoración principales incluyeron la finalización completa del programa de tratamiento, el control de los síntomas y la supervivencia.En total se incluyeron 169 pacientes con una mediana de seguimiento de 50 meses (rango 2-89 meses). La tasa de finalización del programa de tratamiento completo fue del 65,7%. Las tasas de supervivencia libre de progresión a 3 años y supervivencia global (overall survival, OS) fueron 24,2% (i.c. del 95% 16,6-31,6) y 48,8% (i.c. del 95% 40,4-57,2), respectivamente. La mediana de OS de los pacientes que respondieron bien y completaron el programa de tratamiento fue de 51,5 meses, en comparación con 15,1 meses en pacientes que no completaron el tratamiento (P 0,001). Se logró un control adecuado de los síntomas del tumor primario en el 87,0% de todos los pacientes. CONCLUSIÓN: El tratamiento multimodal consigue paliar los síntomas en la mayoría de los pacientes y se asocia con buenas tasas de supervivencia en aquellos pacientes que pueden completar el programa.

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.

Fluorescence molecular endoscopy (FME) is an emerging technique in the field of gastroenterology that holds potential to improve diagnosis and guide therapy, by serving as a 'red-flag' endoscopic imaging technique. Here, we investigated the safety, feasibility and optimal method of administration of EMI-137, targeting c-Met, during FME in Barrett's Esophagus (BE) and report several outcome parameters for early phase FME studies. Methods: FME was performed in 15 Barrett's neoplasia patients. EMI-137 was administered to three cohorts of five patients: 0.13 mg/kg intravenously (IV); 0.09 mg/kg IV or topically at a dose of 200 μg/cm BE (n=1) or 100 μg/cm BE (n=4). Fluorescence was visualized in vivo, quantified in vivo using multi-diameter single-fiber reflectance, single-fiber fluorescence (MDSFR/SFF) spectroscopy and correlated to histopathology and immunohistochemistry. EMI-137 localization was assessed using fluorescence microscopy. Results: FME using different IV and topical doses of EMI-137 appeared to be safe and correctly identified 16/18 lesions, although modest target-to-background ratios were observed (median range of 1.12-1.50). C-Met overexpression varied between lesions, while physiological expression in the stomach-type epithelium was observed. Microscopically, EMI-137 accumulated around the neoplastic cell membranes. We identified several outcome parameters important for the validation of EMI-137 for FME: 1) the optimal administration route; 2) optimal dose and safety; 3) in vivo FME contrast; 4) quantification of intrinsic fluorescence; 5) ex vivo correlation of fluorescence, histopathology and target expression; and 6) microscopic tracer distribution. Conclusions: C-Met targeted FME using EMI-137 may not be the ideal combination to improve BE surveillance endoscopies, however the identified outcome parameters may serve as a valuable guidance for designing and performing future early phase clinical FME studies, independent of which fluorescent tracer is investigated.

Objectives To assess the complementary value of human epidermal growth factor receptor 2 (HER2)-related biological tumor markers to clinico-radiomic models in predicting complete response to neoadjuvant chemoradiotherapy (NCRT) in esophageal cancer patients. Methods Expression of HER2 was assessed by immunohistochemistry in pre-treatment tumor biopsies of 96 patients with locally advanced esophageal cancer. Five other potentially active HER2-related biological tumor markers in esophageal cancer were examined in a sub-analysis on 43 patients. Patients received at least four of the five cycles of chemotherapy and full radiotherapy regimen followed by esophagectomy. Three reference clinico-radiomic models based on 18F-FDG PET were constructed to predict pathologic response, which was categorized into complete versus incomplete (Mandard tumor regression grade 1 vs. 2–5). The complementary value of the biological tumor markers was evaluated by internal validation through bootstrapping. Results Pathologic examination revealed 21 (22%) complete and 75 (78%) incomplete responders. HER2 and cluster of differentiation 44 (CD44), analyzed in the sub-analysis, were univariably associated with pathologic response. Incorporation of HER2 and CD44 into the reference models improved the overall performance (R2s of 0.221, 0.270, and 0.225) and discrimination AUCs of 0.759, 0.857, and 0.816. All models exhibited moderate to good calibration. The remaining studied biological tumor markers did not yield model improvement. Conclusions Incorporation of HER2 and CD44 into clinico-radiomic prediction models improved NCRT response prediction in esophageal cancer. These biological tumor markers are promising in initial response evaluation. Key Points • A multimodality approach, integrating independent genomic and radiomic information, is promising to improve prediction of γpCR in patients with esophageal cancer. • HER2 and CD44 are potential biological tumor markers in the initial work-up of patients with esophageal cancer. • Prediction models combining 18F-FDG PET radiomic features with HER2 and CD44 may be useful in the decision to omit surgery after neoadjuvant chemoradiotherapy in patients with esophageal cancer.

Fluorescence molecular endoscopy (FME) is an emerging technique that has the potential to improve the 22% colorectal polyp detection miss-rate. We determined the optimal dose-to-imaging interval and safety of FME using EMI-137, a c-Met-targeted fluorescent peptide, in a population at high risk for colorectal cancer. Methods: We performed in vivo FME and quantification of fluorescence by multidiameter single-fiber reflectance/single-fiber fluorescence spectroscopy in 15 patients with a dysplastic colorectal adenoma. EMI-137 was intravenously administered (0.13 mg/kg) at a 1-, 2- or 3-h dose-to-imaging interval (n = 3 patients per cohort). Two cohorts were expanded to 6 patients on the basis of target-to-background ratios. Fluorescence was correlated to histopathology and c-Met expression. EMI-137 binding specificity was assessed by fluorescence microscopy and in vitro experiments. Results: FME using EMI-137 appeared to be safe and well tolerated. All dose-to-imaging intervals showed significantly higher fluorescence in the colorectal lesions than in surrounding tissue, with a target-to-background ratio of 1.53, 1.66, and 1.74 for the 1-, 2-, and 3-h cohorts, respectively, and a mean intrinsic fluorescence of 0.035 vs. 0.023 mm-1 (P < 0.0003), 0.034 vs. 0.021 mm-1 (P < 0.0001), and 0.033 vs. 0.019 mm-1 (P < 0.0001), respectively. Fluorescence correlated with histopathology on a macroscopic and microscopic level, with significant c-Met overexpression in dysplastic mucosa. In vitro, a dose-dependent specific binding was confirmed. Conclusion: FME using EMI-137 appeared to be safe and feasible within a 1- to 3-h dose-to-imaging interval. No clinically significant differences were observed among the cohorts, although a 1-h dose-to-imaging interval was preferred from a clinical perspective. Future studies will investigate EMI-137 for improved colorectal polyp detection during screening colonoscopies.

Objective Neoadjuvant chemoradiotherapy followed by surgery establishes a considerable pathologic complete response (pCR) in EC. The aim was to determine site of residual tumor and its prognostic impact. Summary background data High rates of residual tumor in the adventitial region even inside the radiation fields will influence current decision-making. Methods We evaluated resection specimens with marked target fields from 151 consecutive EC patients treated with carboplatin/paclitaxel and 41.4Gy between 2009 and 2018. Results In radically resected (R0) specimens 19.8% (27/136) had a pCR (ypT0N0) and 14% nearly no response (tumor regression grade: tumor regression grade 4-5). Residual tumor commonly extended in or restricted to the adventitia (43.1%; 47/109), whereas 7.3% was in the mucosa (ypT1a), 16.5% in the submucosa (ypT1b) and 6.4% only in lymph nodes (ypT0N+). Macroscopic residues in R0-specimens of partial responders (tumor regression grade 2-3: N = 90) were found in- and outside the gross tumor volume (GTV) in 33.3% and 8.9%, and only microscopic in- and outside the clinical target volume in 58.9% and 1.1%, respectively. Residual nodal disease was observed proximally and distally to the clinical target volume in 2 and 5 patients, respectively. Disease Free Survival decreased significantly if macroscopic tumor was outside the GTV and in ypT2-4aN+. Conclusions After neoadjuvant chemoradiotherapy, pCR and ypT1aN0 were seen in a limited number of R0 resected specimens (19.8% and 7.3%, respectively), whereas 6.4% had only nodal disease (yT0N+). Disease Free Survival decreased significantly if macroscopic residue was outside the GTV and in responders with only nodal disease. Therefore, we should be cautious in applying wait and see strategies.

Negative circumferential resection margins (CRM) are the cornerstone for the curative treatment of locally advanced rectal cancer (LARC). However, in up to 18.6% of patients, tumor-positive resection margins are detected on histopathology. In this proof-of-concept study, we investigated the feasibility of optical molecular imaging as a tool for evaluating the CRM directly after surgical resection to improve tumor-negative CRM rates. Methods: LARC patients treated with neoadjuvant chemoradiotherapy received an intravenous bolus injection of 4.5 mg of bevacizumab-800CW, a fluorescent tracer targeting vascular endothelial growth factor A, 2-3 d before surgery (ClinicalTrials.gov identifier: NCT01972373). First, for evaluation of the CRM status, back-table fluorescence guided imaging (FGI) of the fresh surgical resection specimens (n = 8) was performed. These results were correlated with histopathology results. Second, for determination of the sensitivity and specificity of bevacizumab-800CW for tumor detection, a mean fluorescence intensity cutoff value was determined from the formalin-fixed tissue slices (n = 42; 17 patients). Local bevacizumab-800CW accumulation was evaluated by fluorescence microscopy. Results: Back-table FGI correctly identified a tumor-positive CRM by high fluorescence intensities in 1 of 2 patients (50%) with a tumor-positive CRM. For the other patient, low fluorescence intensities were shown, although (sub)millimeter tumor deposits were present less than 1 mm from the CRM. FGI correctly identified 5 of 6 tumor-negative CRM (83%). The 1 patient with false-positive findings had a marginal negative CRM of only 1.4 mm. Receiver operating characteristic curve analysis of the fluorescence intensities of formalin-fixed tissue slices yielded an optimal mean fluorescence intensity cutoff value for tumor detection of 5,775 (sensitivity of 96.19% and specificity of 80.39%). Bevacizumab-800CW enabled a clear differentiation between tumor and normal tissue up to a microscopic level, with a tumor-to-background ratio of 4.7 +/- 2.5 (mean SD). Conclusion: In this proof-of-concept study, we showed the potential of back-table FGI for evaluating the CRM status in LARC patients. Optimization of this technique with adaptation of standard operating procedures could change perioperative decision making with regard to extending resections or applying intraoperative radiation therapy in the case of positive CRM.

Clinical significance of the pT4 category in colon cancer is increasing with several therapeutic implications. The aim of this study was to evaluate variability in diagnosing pT4a colon cancer. Twelve pathologists classified 66 preselected scanned Hematoxylin/Eosin-stained slides with tumor cells at a distance of 25–1500 μm (n = 22), 0–25 μm (n = 22), or on (n = 22) the peritoneal surface. Inter- and intraobserver variability were calculated using Kappa statistics. For interlaboratory variability, pathology reports of pT3 and pT4a colon cancer were extracted from the Dutch Pathology Registry between 2012 and 2015. The proportion of pT4a (pT4a/(pT3+pT4a)) was compared between 33 laboratories. Potential risk of understaging was assessed by determining the average number of blocks taken from pT3 and pT4a N0-2M0 tumors with metachronous peritoneal metastasis. Interobserver variability among 12 pathologists was 0.50 (95%CI 0.41–0.60; moderate agreement). Intraobserver variability (8 pathologists) was 0.71 (substantial agreement). A total of 7745 reports with pT3 or pT4aN0-2M0 colon cancer from 33 laboratories were included for interlaboratory analysis. Median percentage of pT4a was 15.5% (range 3.2–24.6%). After adjustment for case mix, 8 labs diagnosed pT4a significantly less or more frequently than the median lab. Metachronous peritoneal metastases were histologically verified in 170 of 6629 pT3 and in 129 of 1116 pT4a tumors, with a mean number of blocks of 4.03(SD 1.51) and 4.78 (SD 1.76) taken from the primary tumors, respectively (p

Background: Diagnostic screening of premalignant esophageal lesions is hampered by the absence of biomarkers indicative of metaplastic and/or malignant transformation. The aim of this exploratory study was to investigate the potential use of miRNAs as biomarkers capable of identifying patients with (pre)malignant lesions: Barrett’s esophagus (BE) metaplasia, high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC). Methods: A total of 69 patients were included in the study. Six serum samples from each of four study groups, i.e., patients with normal squamous epithelium (SE), BE, HGD and EAC, were profiled using the Nanostring miRNA analysis platform. Differential miRNA expression patterns then were validated in 69 patient samples using qRT-PCR. Results: miRNA expression profiling revealed seven miRNAs with a 2-fold change in expression level. Validation by qRT-PCR confirmed that serum miR-320e levels were significantly decreased in the BE group compared to the SE (P≤0.001, AUC 0.790) and HGD groups (P≤0.005, AUC 0.786). Serum miR-199a-3p levels were significantly decreased in the BE group compared to the SE group (P≤0.001), area under the curve (AUC) of 0.813. Conclusions: The results of this study suggest that decreased serum miRNA levels of miR-199a-3p and miR-320e could help to identify patients with BE and HGD.

AIMS: Interobserver agreement for dysplasia in Barrett's oesophagus (BO) is low, and guidelines advise expert review of dysplastic cases. The aim of this study was to assess the added value of p53 immunohistochemistry (IHC) for the homogeneity within a group of dedicated gastrointestinal (GI) pathologists.METHODS AND RESULTS: Sixty-single haematoxylin and eosin (HE) slide referral BO cases [20 low-grade dysplasia (LGD); 20 high-grade dysplasia (HGD); and 20 non-dysplastic BO reference cases] were digitalised and independently assessed twice in random order by 10 dedicated GI pathologists. After a 'wash-out' period, cases were reassessed with the addition of a corresponding p53 IHC slide. Outcomes were: (i) proportion of 'indefinite for dysplasia' (IND) diagnoses; (ii) interobserver agreement; and (iii) diagnostic accuracy as compared with a consensus 'gold standard' diagnosis defined at an earlier stage by five core expert BO pathologists after their assessment of this case set. Addition of p53 IHC decreased the mean proportion of IND diagnoses from 10 of 60 to eight of 60 (P = 0.071). Mean interobserver agreement increased significantly from 0.45 to 0.57 (P = 0.0021). The mean diagnostic accuracy increased significantly from 72% to 82% (P = 0.0072) after p53 IHC addition.CONCLUSION: Addition of p53 IHC significantly improves the histological assessment of BO biopsies, even within a group of dedicated GI pathologists. It decreases the proportion of IND diagnoses, and increases interobserver agreement and diagnostic accuracy. This justifies the use of accessory p53 IHC within our upcoming national digital review panel for BO biopsy cases.

Adenoma miss rates in colonoscopy are unacceptably high, especially for sessile serrated adenomas / polyps (SSA/Ps) and in high-risk populations, such as patients with Lynch syndrome. Detection rates may be improved by fluorescence molecular endoscopy (FME), which allows morphological visualization of lesions with high-definition white-light imaging as well as fluorescence-guided identification of lesions with a specific molecular marker. In a clinical proof-of-principal study, we investigated FME for colorectal adenoma detection, using a fluorescently labelled antibody (bevacizumab-800CW) against vascular endothelial growth factor A (VEGFA), which is highly upregulated in colorectal adenomas. Methods: Patients with familial adenomatous polyposis (n = 17), received an intravenous injection with 4.5, 10 or 25 mg of bevacizumab-800CW. Three days later, they received NIR-FME. Results: VEGFA-targeted NIR-FME detected colorectal adenomas at all doses. Best results were achieved in the highest (25 mg) cohort, which even detected small adenomas ( < 3 mm). Spectroscopy analyses of freshly excised specimen demonstrated the highest adenoma-to-normal ratio of 1.84 for the 25 mg cohort, with a calculated median tracer concentration in adenomas of 6.43 nmol/mL. Ex vivo signal analyses demonstrated NIR fluorescence within the dysplastic areas of the adenomas. Conclusion: These results suggest that NIR-FME is clinically feasible as a real-time, red-flag technique for detection of colorectal adenomas.