Evaluation of a 12-mm diameter covered self-expandable end bare metal stent for malignant biliary obstruction.

Background and study aims Biliary metallic stents are used to drain unresectable malignant distal biliary obstructions. This study aimed to evaluate the efficacy of a novel 12-mm-diameter covered, self-expandable end bare metal stent (12-mm CSEEMS). Patients and methods We evaluated 99 patients with unresectable malignant distal biliary obstructions treated with covered biliary metallic stents. Of the 99 patients, 33 underwent 12-mm CSEEMS placement between June 2015 and April 2017 (12-mm-CSEEMS group) and 66 underwent 10-mm fully-covered self-expandable metal stent (FCSEMS) placement between January 2010 and July 2015 (10-mm-FCSEMS group). The overall survival (OS), the recurrent biliary obstruction (RBO), cause of RBO, time to RBO (TRBO) and adverse events in 12-mm-CSEEMS group and 10-mm-FCSEMS group were evaluated retrospectively. Results The OS tended to be longer in the 12-mm-CSEEMS group (log rank, P  = 0.081) and TRBO was significantly longer in the 12-mm-CSEEMS group (log rank, P  = 0.001) than in the 10-mm-FCSEMS group. Both univariate (HR, 0.449; 95 % CI, 0.27967 - 0.72215; P  = 0.001) and multivariate (HR, 0.458; 95 % CI, 0.28395 - 0.73744; P  = 0.001) Cox hazard analysis found that risk of RBO was significantly lower in 12-mm CSEEMS than in 10-mm FCSEMS. There were no significant differences between the 12-mm-CSEEMS group and 10-mm-FCSEMS group regarding the cause of RBO and adverse events. Conclusions The 12-mm CSEEMS showed a low risk of RBO compared with 10-mm FCSEMS and was considered to be effective and safe for draining unresectable malignant distal biliary obstruction.

HLA-DQ gene polymorphisms are associated with hepatocellular carcinoma and hepatitis B surface antigen in chronic hepatitis B virus infection.

AIM: Genome-wide association studies have revealed that single nucleotide polymorphism (SNP) of human leukocyte antigen (HLA)-DQ is associated with the clearance of hepatitis B surface antigen (HBsAg) in acute hepatitis B virus (HBV) infection. We examined the effects of SNPs on the development of hepatocellular carcinoma (HCC) and markers of HBV in chronic HBV infection. METHODS: The SNPs of HLA-DQ (rs2856718 and rs7453920) were determined in 299 patients with chronic HBV infection. RESULTS: In 224 hepatitis B e antigen (HBeAg)-negative patients, those with rs2856718 genotype AG + GG had significantly lower hepatitis B core-related antigen levels (P = 0.0184), less frequent treatment with nucleotide/nucleoside analogs (NAs) (P = 0.0433), and less frequent HCC development (P = 0.0256) than those with genotype AA. Multivariate analysis selected age (P = 0.0460), platelet count (P = 0.0481), γ-glutamyl transpeptidase (P = 0.0030), and nucleotide/nucleoside analog treatment (P = 0.0003) as factors independently associated with HCC development. HBeAg-negative patients with rs7453920 genotype GG had significantly lower HBsAg levels (P < 0.0001), a higher prevalence of HBV genotype C (P = 0.0063), and a lower prevalence of the wild-type basal core promoter region (P = 0.0045) than those with genotype AA + AG. Multivariate analysis selected age (P < 0.0001), platelet count (P = 0.0021), HBV DNA levels (P = 0.0314), wild type of precore region (P = 0.0015), and rs7453920 (P < 0.0001) as factors independently associated with HBsAg levels. CONCLUSION: This study revealed an association between rs2856718 and HCC development and an association between rs7453920 and HBsAg levels.

PCR-based assessment of the recovery rate of exfoliated colonocytes or cancer cells from fecal samples depends on the storage conditions after defecation.

BACKGROUND AND AIMS: We recently developed a new methodology for isolating colonocytes from fecal samples. We then applied a DNA-based analysis to the isolated colonocytes to detect colorectal cancer cells originating from any part of the colorectum. The purpose of the present study was to determine how long after defecation and at what temperature the fecal samples should be stored to isolate the colonocytes successfully. METHODS: Fecal samples were collected from 6 patients with colorectal cancer and 6 healthy volunteers soon after defecation at the National Cancer Center Hospital. The fecal samples were stored at 4 degrees C, room temperature or 40 degrees C for 0, 24 or 48 hours. Colonocytes were then isolated from the fecal samples, and the DNA was purified. Finally, PCR for p53, K-ras and APC was conducted to determine whether the corresponding PCR products could be obtained. RESULTS: The colonocyte recovery rate was not reduced, when compared with the data for successful PCR amplification, if the fecal samples were kept at 4 degrees C after defecation and if the colonocytes were isolated within 48 hours after defecation. CONCLUSIONS: The present data provided important clinical knowledge regarding the storage of fecal samples for future mass screening tests.

A new method for isolating colonocytes from naturally evacuated feces and its clinical application to colorectal cancer diagnosis.

BACKGROUND & AIMS: The early detection of colorectal cancer is desired because this cancer can be cured surgically if diagnosed early. The purpose of the present study was to determine the feasibility of a new methodology for isolating colonocytes from naturally evacuated feces, followed by cytology or molecular biology of the colonocytes to detect colorectal cancer originating from any part of the colorectum. METHODS: Several simulation studies were conducted to establish the optimal methods for retrieving colonocytes from any portion of feces. Colonocytes exfoliated into feces, which had been retrieved from 116 patients with colorectal cancer and 83 healthy volunteers, were analyzed. Part of the exfoliated colonocytes was examined cytologically, whereas the remainder was subjected to DNA analysis. The extracted DNA was examined for mutations of the APC, K-ras, and p53 genes using direct sequence analysis and was also subjected to microsatellite instability (MSI) analysis. RESULTS: In the DNA analysis, the overall sensitivity and specificity were 71% (82 of 116) of patients with colorectal cancer and 88% (73 of 83) of healthy volunteers. The sensitivity for Dukes A and B was 72% (44 of 61). Furthermore, the sensitivity for cancers on the right side of the colon was 57% (20 of 35). The detection rate for genetic alterations using our methodology was 86% (80 of 93) when the analysis was limited to cases in which genetic alterations were present in the cancer tissue. CONCLUSIONS: We have developed a new methodology for isolating colonocytes from feces. The present study describes a promising procedure for future clinical evaluations and the early detection of colorectal cancers, including right-side colon cancer.