Digital single-operator cholangioscopy interobserver study using a new classification: the Mendoza Classification (with video).

BACKGROUND AND AIMS: Digital single-operator cholangioscopy (DSOC) allows direct visualization of the biliary tree for evaluation of biliary strictures. Our objective was to assess the interobserver agreement (IOA) of DSOC interpretation for indeterminate biliary strictures using newly refined criteria. METHODS: Fourteen endoscopists were asked to review an atlas of reference clips and images of 5 criteria derived from expert consensus. They then proceeded to score 50 deidentified DSOC video clips based on the visualization of tortuous and dilated vessels, irregular nodulations, raised intraductal lesions, irregular surface with or without ulcerations, and friability. The endoscopists then diagnosed the clips as neoplastic or non-neoplastic. Intraclass correlation (ICC) analysis was done to evaluate inter-rater agreement for both criteria sets and final diagnosis. RESULTS: Clips of 41 malignant lesions and 9 benign lesions were scored. Three of 5 revised criteria had almost perfect agreement. ICC was almost perfect for presence of tortuous and dilated vessels (.86), raised intraductal lesions (.90), and presence of friability (.83); substantial agreement for presence of irregular nodulations (.71); and moderate agreement for presence of irregular surface with or without ulcerations (.44). The diagnostic ICC was almost perfect for neoplastic (.90) and non-neoplastic (.90) diagnoses. The overall diagnostic accuracy using the revised criteria was 77%, ranging from 64% to 88%. CONCLUSIONS: The IOA and accuracy rate of DSOC using the new Mendoza criteria shows a significant increase of 16% and 20% compared with previous criteria. The reference atlas helps with formal training and may improve diagnostic accuracy. (Clinical trial registration number: NCT02166099.).

Is mitochondrial DNA copy number associated with clinical characteristics and prognosis in gastric cancer?

Alterations in mitochondrial DNA (mtDNA) have been studied in various cancers. However, the clinical value of mtDNA copy number (mtCN) alterations in gastric cancer (GC) is poorly understood. In the present study, we investigated whether alterations in mtCNs might be associated with clinicopathological parameters in GC cases. mtCN was measured in 109 patients with GC by quantitative real-time PCR. Then, correlations with clinicopathological characteristics were analyzed. mtCN was elevated in 64.2% of GC tissues compared with paired, adjacent, non-cancerous tissue. However, the observed alterations in mtCN were not associated with any clinicopathological characteristics, including age, gender, TN stage, Lauren classification, lymph node metastasis, and depth of invasion. Moreover, Kaplan-Meier survival curves revealed that mtCN was not significantly associated with the survival of GC patients. In this study, we demonstrated that mtCN was not a significant marker for predicting clinical characteristics or prognosis in GC.