Hirohito Magari

Cancer High-Risk Subjects Identified by Serum Pepsinogen Tests: Outcomes after 10-Year Follow-up in Asymptomatic Middle-Aged Males

Background: Gastric cancer screening using the pepsinogen filter test is receiving wide recognition in Japan owing to convenience, freedom from discomfort or risk, efficiency, and economy. Because the long-term outcomes of cancer development in extensive atrophic gastritis detected by pepsinogen test are unclear, test-positive and test-negative subjects were investigated in a longitudinal cohort study. Methods: Subjects comprised 5,209 middle-aged men with measured serum pepsinogen levels who were followed for 10 years. Cancer development based on “atrophy-positive” and “atrophy-negative” criteria used for cancer screening was investigated. Results: During the study, 63 cases of cancer developed in the cohort, representing an incidence rate of 125 per 100,000 person-years. Pepsinogen test screening using the most widely used atrophy-positive criterion (pepsinogen I, ≤70 ng/mL; pepsinogen I/II ratio, ≤3.0) displayed 58.7% sensitivity, 73.4% specificity, and 2.6% positive predictive value. Cancer incidence rate was 276 per 100,000 person-years for the atrophy-positive group and 70 per 100,000 person-years for the atrophy-negative group. Incidence rate was higher in groups fulfilling stricter positive criteria detecting more extensive atrophy, reaching 424 per 100,000 person-years. In addition, 9.2% of atrophy-negative subjects with pepsinogen I of >70 ng/mL and pepsinogen I/II ratio of ≤3.0 (reflecting putative inflammation-based high pepsinogen II level) are at high risk for cancer, particularly diffuse-type cancer, with a cancer incidence rate comparable with atrophy-positive subjects (216 per 100,000 person-years). Conclusion: Atrophy-positive subjects by pepsinogen filter test, particularly those fulfilling stricter criteria, and atrophy-negative subjects with low pepsinogen I/II ratio reflecting putative extensive active inflammation constitute populations at high risk for gastric cancer, requiring thorough endoscopic examination. (Cancer Epidemiol Biomarkers Prev 2008;17(4):838–45)

Gastric acid reduction leads to an alteration in lower intestinal microflora

To clarify the alterations in lower intestinal microflora induced by gastric acid reduction, the dynamics of 12 major genera or groups of bacteria comprising the microflora in feces and colonic contents were examined by quantitative real-time PCR in proton pump inhibitor-treated rats and in asymptomatic human subjects with hypochlorhydria. In both rat and human experiments, most genera or groups of intestinal microflora (facultative and obligate anaerobes) proliferated by gastric acid reduction, and marked and significant increases in the Lactobacilli group and Veillonella, oropharyngeal bacteria, were observed. In rats, potent gastric acid inhibition led to a marked and significant increase of intestinal bacteria, including the Bacteroidesfragilis group, while Bifidobacterium, a beneficial bacterial species, remained at a constant level. These results strongly indicate that the gastric acid barrier not only controls the colonization and growth of oropharyngeal bacteria, but also regulates the population and composition of lower intestinal microflora.

Risk of gastric cancer in asymptomatic, middle-aged Japanese subjects based on serum pepsinogen and Helicobacter pylori antibody levels.

A total of 5,209 asymptomatic, middle‐aged subjects, whose serum pepsinogen (PG) and Helicobacter pylori antibody levels had been assessed, were followed for 10 years. Subjects with positive serum H. pylori antibodies (>50 U/mL) had an increased cancer risk (HR = 3.48, 95% CI = 1.26–9.64). Risk of gastric cancer increased as the antibody level increased; the H. pylori‐positive group with antibody levels >500 U/mL had the highest incidence rate (325/100,000 person‐years). Cancer development also increased with a reduced serum PG I level or a reduced PG I/II ratio; the risk was significantly elevated with serum PG I level ≤30 ng/mL (HR = 3.54, 95% CI = 1.95–6.40) or PG I/II ratio ≤3.0 (HR = 4.25, 95% CI = 2.47–7.32). Furthermore, the risk of diffuse‐type cancer increased as PG II level increased; it was significantly elevated with PG II level ≥30 ng/mL (HR = 3.81, 95% CI = 1.10–13.21). Using H. pylori antibody and PG levels, subgroups with an especially high or low cancer incidence rate could be identified. H. pylori‐negative or indeterminate subjects with low PG level (PG I ≤30 ng/mL or PG I/II ratio ≤2.0) or H. pylori‐positive subjects with antibody levels >500 U/mL and a low PG level were among the subgroups with a high cancer incidence rate (over 400/100,000 person‐years). In contrast, H. pylori‐negative subjects with a PG I level >70 ng/mL or a PG I/II ratio >3.0 had the lowest risk; none of these subjects developed cancer. Thus, serum PG levels and/or H. pylori antibody levels can be used to predict the risk of cancer in individuals with H. pylori‐related gastritis from the general population.

Altered cytokine levels and increased CD4+CD57+ T cells in the peripheral blood of hepatitis C virus-related hepatocellular carcinoma patients

Although CD57+ lymphocytes are closely correlated with prognosis in various cancers, the role of subsets of CD57+ cells in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) is unclear. In the present study, peripheral blood (PB) from HCV-related HCC patients was analyzed. Plasma cytokine levels and in vitro cytokine-producing capabilities were analyzed with enzyme-linked immunosorbent assays, and CD57+ cell subsets were studied using a multi-color FACS system. Interferon (IFN)-γ was undetectable in the plasma of patients with tumors at any stage, whereas the plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-10 and IL-18, but not that of IL-12, were significantly higher in stage IV patients compared to patients with earlier-stage tumors. In contrast, the IFN-γ-producing capability of PB was highest in stage I patients and gradually decreased with tumor progression. The IL-10-, IL-18- and IL-12-producing capabilities of PB increased from stage I to III. However, PB-TNF-α, IL-10- and IL-18-producing capabilities were reduced in stage IV patients, probably due to repeated anti-cancer treatments. The percentage of CD4+CD57+αβTCR+ cells (CD4+CD57+ T cells) in peripheral blood lymphocytes (PBLs) increased with tumor progression. Moreover, the percentage of CD4+CD57+ T cells in PBLs and the ratio of CD4+CD57+ T cells to CD4+αβTCR+ cells (CD4+ T cells), but not that of CD4+CD57+ T cells to CD57+αβTCR+ cells (CD57+ T cells), showed a significant inverse correlation with PB-IFN-γ-producing capability. The present results suggest that an increase in CD4+CD57+ T cells controls the capability of PB to produce the anti-tumor cytokine IFN-γ and that PB-IFN-γ production is impaired with HCC tumor progression.

The Wire-Grasping Method as a New Technique for Forceps Biopsy of Biliary Strictures: A Prospective Randomized Controlled Study of Effectiveness

Background/Aims Transpapillary forceps biopsy is an effective diagnostic technique in patients with biliary stricture. This prospective study aimed to determine the usefulness of the wire-grasping method as a new technique for forceps biopsy. Methods Consecutive patients with biliary stricture or irregularities of the bile duct wall were randomly allocated to either the direct or wire-grasping method group. In the wire-grasping method, forceps in the duodenum grasps a guide-wire placed into the bile duct beforehand, and then, the forceps are pushed through the papilla without endoscopic sphincterotomy. In the direct method, forceps are directly pushed into the bile duct alongside a guide-wire. The primary endpoint was the success rate of obtaining specimens suitable for adequate pathological examination. Results In total, 32 patients were enrolled, and 28 (14 in each group) were eligible for analysis. The success rate was significantly higher using the wire-grasping method than the direct method (100% vs 50%, p=0.016). Sensitivity and accuracy for the diagnosis of cancer were comparable in patients with the successful procurement of biopsy specimens between the two methods (91% vs 83% and 93% vs 86%, respectively). Conclusions The wire-grasping method is useful for diagnosing patients with biliary stricture or irregularities of the bile duct wall.

Simultaneous detection of T lymphocyte-related antigens (CD4/CD8, CD57, TCRβ) with nuclei by fluorescence-based immunohistochemistry in paraffin-embedded human lymph node, liver cancer and stomach cancer.

Objective: To develop a method for immunohistochemical staining of three different T lymphocyte antigens (CD4 or CD8, CD57 and TCRβ) on the same tissue section and to determine whether tissues have been infiltrated with T lymphocytes expressing these markers. Study Design: Commercially available antibodies were tested for immunohistochemical usefulness in a dye-based conventional single-immunostaining method after antigen retrieval on paraffin-embedded human lymph nodes. We searched for the combination of antibodies that could detect T lymphocyte antigens on the same section without any cross-reactivity and that have fluorescent signals robust enough to overcome paraffin autofluorescence. Results: Application of the antigen retrieval technique and the Sudan black B quenching technique enabled staining of paraffin-embedded tissue sections with fluorescent-labeled secondary antibodies. The combination of primary and secondary antibodies that could simultaneously detect the T lymphocyte antigens CD4 or CD8, CD57 and TCRβ in histochemical analysis of a paraffin-embedded human lymph node section was established, and was successfully applied to a human tissue section infiltrated with T lymphocytes that express these markers. Conclusion: The antibodies listed here would be helpful for histopathologists who wish to investigate T lymphocytes in the paraffin-embedded sections that have accumulated in pathology labs throughout the world.

Potent induction therapy with interferon and ribavirin combination therapy does not achieve a higher sustained virological response rate in chronic hepatitis C with genotype 1b and high hepatitis C virus RNA level

Aims:  To compare twice‐daily interferon (IFN)‐β administration and once‐daily IFN‐α‐2b administration as induction therapy in ribavirin combination therapy in chronic hepatitis C with a high viral load of genotype‐1b hepatitis C virus (HCV).

Gastric Cancer Risk Diagnosis and Prevention in Subjects with Helicobacter pylori-related Chronic Gastritis

Helicobacter pylori (HP) is recognized as a major pathogenic factor for persistent inflammation in the human stomach (Dooley et al., 1989; Marshall & Warren, 1984). In 1994, the International Agency for Research on Cancer (IARC) classified HP infection as a definite class I carcinogen (International Agency for Research on Cancer (IARC), 1994). HP triggers chronic inflammation of the infected stomach mucosa and is considered a major risk factor for gastric cancer (GC) and associated precursor lesions. Long-lasting inflammation in the stomach mucosa leads to a cascade of molecular and morphological changes, representing the gastritis-atrophymetaplasia-dysplasia-cancer sequence (Correa, 1992). The HP infection rate is higher in Japan than in Western countries, with nearly all cases of GC occurring in subjects with underlying HP-related chronic gastritis. HP infection is widely accepted as a major risk factor for the development of GC and its precursor lesions, based on extensive evidence derived from many studies (Blaser et al., 1995; EUROGAST Study Group, 1993; Forman et al., 1991; Hirayama et al., 1999; Honda et al., 1998; Huang et al., 1998; Nomura et al., 1991; Parsonnet et al., 1991; Shimizu et al., 1999; Sipponen et al., 1992; Sugiyama et al., 1998; Talley et al., 1991; Tokieda et al., 1999; Uemura et al., 2001; Watanabe et al., 1998; Zheng et al., 2004). However, in countries such as Japan, where the HP infection rate is high, prediction of GC risk based solely on the presence or absence of HP infection does not offer sufficient specificity. Elucidation of groups at high risk based on the natural history of GC is clearly necessary. The identification of useful markers of GC risk is thus hoped for. Evaluating HPrelated chronic gastritis and determining which subjects are at high risk for developing GC is very important, and would likely increase the efficacy of GC screening by endoscopic or other examinations (Enomoto et al., 2010a; Mukoubayashi et al., 2007; Ohata et al., 2005), and strategic approaches to metachronous multiple GC after endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) performed as minimally invasive treatment for early GC (Gotoda, 2007; Kakushima & Fujishiro, 2008; Nakajima et al., 2006). In addition, in terms of GC prevention, it has become clear that HP-related chronic gastritis cannot be ignored as an origin of carcinogenesis.