Interobserver reliability of methods to determine complete resection of adenomas in colonoscopy.

BACKGROUND: Forceps margin biopsy and polypectomy specimen margins have both been used to assess for polypectomy resection adequacy. The interobserver reliability of the two methods has not been well described. METHODS: The interpretability of polypectomy specimens for presence of residual neoplasia at the margin was assessed by two blinded pathologists. Next, the concordance of forceps margin biopsy interpretations between three blinded pathologists was evaluated by calculation of interobserver κ. RESULTS: Rates of polypectomy specimen margin interpretability were low: 24/92 (26 %) for pathologist A, 28/92 (30.4 %) for pathologist B. Concordance of forceps margin biopsy interpretations (n = 129) between pathologists was high. Two internal pathologists showed substantial agreement in margin biopsy interpretations (κ 0.779; 95 %CL 0.543, 0.912). The concordance remained strong after biopsies were reviewed by a third, external pathologist (κ 0.829; 95 %CL 0.658, 0.924). There was complete agreement on 123/129 (95.3 %) between all three pathologists for presence of neoplasia. CONCLUSION: The majority of polypectomy specimen margins were uninterpretable by pathologists for presence of residual neoplasia. Forceps margin biopsy shows strong interobserver reliability in adenomatous lesions.

Low Referral Rate for Genetic Testing in Racially and Ethnically Diverse Patients Despite Universal Colorectal Cancer Screening.

BACKGROUND & AIMS: Guidelines recommend that all colorectal tumors be assessed for mismatch repair deficiency, which could increase identification of patients with Lynch syndrome. This is of particular importance for minority populations, in whom hereditary syndromes are under diagnosed. We compared rates and outcomes of testing all tumor samples (universal testing) collected from a racially and ethnically diverse population for features of Lynch syndrome. METHODS: We performed a retrospective analysis of colorectal tumors tested from 2012 through 2016 at 4 academic centers. Tumor samples were collected from 767 patients with colorectal cancer (52% non-Hispanic white [NHW], 26% African American, and 17% Hispanic patients). We assessed rates of tumor testing, recommendations for genetic evaluation, rates of attending a genetic evaluation, and performance of germline testing overall and by race/ethnicity. We performed univariate and multivariate regression analyses. RESULTS: Overall, 92% of colorectal tumors were analyzed for mismatch repair deficiency without significant differences among races/ethnicities. However, minority patients were significantly less likely to be referred for genetic evaluation (21.2% for NHW patients vs 16.9% for African American patients and 10.9% for Hispanic patients; P = .02). Rates of genetic testing were also lower among minority patients (10.7% for NHW patients vs 6.0% for AA patients and 3.1% for Hispanic patients; P < .01). On multivariate analysis, African American race, older age, and medical center were independently associated with lack of referral for genetic evaluation and genetic testing. CONCLUSION: In a retrospective analysis, we found that despite similar rates of colorectal tumor analysis, minority patients are less likely to be recommended for genetic evaluation or to undergo germline testing for Lynch syndrome. Improvements in institutional practices in follow up after tumor testing could reduce barriers to diagnosis of Lynch diagnosis in minorities.

Alternative approaches to polyp extraction in colonoscopy: a proof of principle study.

BACKGROUND AND AIMS: A limitation of determination of the completeness of resection in polypectomy is polyp fragmentation. When a polyp fragments, the pathologist cannot determine resection completeness. Alternative approaches to reduce polyp fragmentation include reducing shearing forces on the polyp or removing polyps through the instrument channel. The primary aim of this study was to assess fragmentation of polyps extracted using different approaches from conventional polyp retrieval. METHODS: Polyps (5-15 mm) resected by cold snare or cautery by 3 colonoscopists were extracted from the colonoscope using 1 of 4 techniques. Method I was the conventional method of pressing the suction valve button and retrieving the polyp through a trap. Method II involved removing the suction valve, covering the open suction valve cylinder with a finger. Method III used a Roth Net polyp retriever placed through the instrument channel. Method IV involved connecting a polyp trap to suction onto the instrument channel port. Fragmentation was defined as multiple pieces of the specimen in formalin, as grossly described by the pathologist. Alternative approaches (methods II, III, and IV) were all compared with the conventional method (method I). RESULTS: The method I fragmentation rate of polyps was 60.3% (123/204). Method II extraction reduced fragmentation to 43.0% (52/121, P = .003), proving that fragmentation occurs with passage through the suction valve channel. Method III had a lower fragmentation rate of 23.1% (6/26, P < .001). Method IV likewise showed a reduced fragmentation rate of 18.5% (5/27, P < .001). CONCLUSIONS: Polyp fragmentation is reduced by removal of the suction valve button. There is also a decrease in fragmentation rates in removing the polyp by connecting the polyp trap to the instrument port. Our study suggests that decreasing polyp fragmentation and improving pathology margin interpretability is possible through methods that extract polyps through the instrument port with currently available devices.

Retrograde Balloon-Assisted Deep Enteroscopy in the Diagnosis of Metastatic Melanoma.

A 74-year-old male with a history of metastatic melanoma presents with persistently abnormal small bowel findings on PET-CT scan. The patient had persistent FDG uptake near the ileocolic junction on imaging, concerning for metastatic melanoma. Capsule endoscopy demonstrated ulcerated mucosa in the distal ileum. This area was biopsied and tattooed via retrograde double-balloon enteroscopy to confirm the diagnosis of metastatic melanoma and facilitate subsequent small bowel resection. The case illustrates a unique case of metastatic melanoma to the small bowel and the utility of capsule endoscopy and balloon-assisted enteroscopy to assist in diagnosis and management of metastatic disease.

γ-Glutamylcysteine ameliorates oxidative injury in neurons and astrocytes in vitro and increases brain glutathione in vivo.

γ-Glutamylcysteine (γ-GC) is an intermediate molecule of the glutathione (GSH) synthesis pathway. In the present study, we tested the hypothesis that γ-GC pretreatment in cultured astrocytes and neurons protects against hydrogen peroxide (H(2)O(2))-induced oxidative injury. We demonstrate that pretreatment with γ-GC increases the ratio of reduced:oxidized GSH levels in both neurons and astrocytes and increases total GSH levels in neurons. In addition, γ-GC pretreatment decreases isoprostane formation both in neurons and astrocytes, as well as nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation in astrocytes in response to H(2)O(2)-induced oxidative stress. Furthermore, GSH and isoprostane levels significantly correlate with increased neuron and astrocyte viability in cells pretreated with γ-GC. Finally, we demonstrate that administration of a single intravenous injection of γ-GC to mice significantly increases GSH levels in the brain, heart, lungs, liver, and in muscle tissues in vivo. These results support a potential therapeutic role for γ-GC in the reduction of oxidant stress-induced damage in tissues including the brain.