Radioimmunoassay of serum group I and group II pepsinogens in normal controls and patients with various disorders

Predictors of the Development of Gastric Cancer in Post-Helicobacter pylori-Eradication Patients Followed Up for More than 10 Years: A Histological, Serological, and Endoscopic Study

BACKGROUND/OBJECTIVES

Although Helicobacter pylori (H. pylori) eradication therapy is important for preventing gastric cancer (GC), the occurrence of GC after H. pylori eradication remains a problem. In this study, the aim was to identify risk factors for GC after H. pylori eradication by comparing long-term histological, endoscopic, and serological evaluations of patients with and without GC.

METHODS

Patients who underwent H. pylori eradication therapy at Oita University Hospital between June 1997 and August 2013 and were followed for at least 3 years with long-term endoscopy, histology, and serum biochemical tests were included, and the GC (215 cases) and non-GC (11 cases) groups were compared.

RESULTS

The GC group was older than the non-GC group at the time of eradication, had lower serum pepsinogen I/II levels, had severe endoscopic atrophic changes, had higher activity at the antrum, and inflammation and intestinal metaplasia (IM) at the corpus on updated Sydney system scoring. On long-term follow-up after eradication, the GC group had a wider range of endoscopic mucosal atrophy and a lower serum pepsinogen I/II ratio at any time point.

CONCLUSIONS

Endoscopic mucosal atrophy and the serum pepsinogen I/II ratio are useful predictors of GC in patients post H. pylori eradication at any time point.

Helicobacter pylori-Related Chronic Gastritis as a Risk Factor for Lower Bone Mineral Density

We evaluated the role of Helicobacter pylori (H. pylori)-related chronic gastritis in the development of osteoporosis in a population-based study. A total of 1690 subjects in the cohort of the Research on Osteoarthritis/ osteoporosis Against Disability (ROAD) were investigated, and the association between gastritis and osteoporosis was evaluated by the presence of serologically assessed H. pylori-related chronic gastritis and its stage, based on H. pylori antibody titer and pepsinogen. The presence of the gastritis was associated with significantly lower bone mineral density (BMD) assessed by dual-energy x-ray absorptiometry and a significant risk of lower BMD was observed in femoral neck (adjusted odds ratio [OR]: 0.78, 95% confidence interval [CI]: 061-0.99). The progression of the gastritis appeared to further increase the risk. In the stage of non-atrophic gastritis, the risk of lower BMD was significantly high, especially in a subgroup with higher gastritis activity in the femoral neck (adjusted OR: 0.61, 95% CI: 0.42-0.89). Meanwhile, in the stage of atrophic gastritis, the highest and significant risk of lower BMD was observed in a subgroup with the most extensive and severe atrophy in femoral neck (adjusted OR: 0.62, 95% CI: 0.42-0.91). These results suggest that H. pylori-related chronic gastritis is involved in the risk of osteoporosis, with higher activity of gastritis and more extensive atrophy leading to further increased risk. The serologically assessed stage of the gastritis could be used to identify a high-risk group for osteoporosis in H. pylori-infected subjects from general population.

Trends in the prevalence of atrophic gastritis and Helicobacter pylori infection over a 10‑year period in Japan: The ROAD study 2005‑2015

Few large population-based studies have examined the prevalence of atrophic gastritis (AG) and Helicobacter pylori infection in Japan. The purpose of the present study was to estimate the prevalence of AG and H. pylori infection by age, in addition to investigating their change rates from 2005 to 2016 in Japan using data from a large population-based cohort. A total of 3,596 participants [1,690 in the baseline survey (2005-2006) and 1,906 at the fourth survey (2015-2016)] aged 18 to 97 years were included in the cohort. The prevalence of AG and H. pylori infection were examined at baseline and in the fourth survey based on serological tests for the H. pylori antibody titer and pepsinogen levels. The prevalence of AG and H. pylori infection were 40.1% (men, 44.1%; women, 38.0%) and 52.2% (men, 54.8%; women, 50.8%), respectively, at baseline. AG seropositivity rates showed a significant decrease from 40.1 to 25.8% in 10 years. H. pylori seropositivity rates decreased significantly from 52.2 to 35.5% in 10 years. Stratified for age, the prevalence of AG showed an increasing trend with age, whereas the prevalence of H. pylori infection increased with aging, except for in the elderly group, showing an inverted U-shaped association. In this population-based, cross-sectional study with a 10-year interval survey, the prevalence of AG and H. pylori infection decreased significantly. This change may influence the prevalence of H. pylori-related diseases, including extra-gastric disorders associated with H. pylori-induced systemic subclinical inflammation and hypochlorhydria, such as colorectal neoplasia and arteriosclerosis.

Diagnostic performance of the normal range of gastrin calculated using strict criteria based on a combination of serum markers and pathological evaluation for detecting gastritis: a retrospective study

BACKGROUND

The ABC method, which combines the pepsinogen method and anti-Helicobacter pylori antibody titers, has been used for risk screening for gastric cancer in Japan. However, it has been reported that there are cases of gastritis and carcinogenesis risk even in group A, which is considered to be a low-risk group based on the ABC method. Currently, in group A, endoscopic examination is needed to strictly discriminate "patients without gastritis" (defined as true A patients) from those "with gastritis." A simple and minimally invasive diagnostic criterion for gastritis using serological markers is desirable. In this study, we aimed to identify the normal serum gastrin concentrations in normal stomach cases based on pathological diagnosis and investigate the usefulness of serum gastrin concentrations in diagnosing gastritis.

METHODS

Patients who underwent endoscopy and blood tests at Hiroshima University Hospital were enrolled in the study and categorized into the "pathologically-evaluated group" and "endoscopically-evaluated group," according to the evaluation method of atrophic gastritis. Initially, we measured serum gastrin concentrations in the normal stomach cases in the pathologically-evaluated group and calculated the normal range of serum gastrin concentrations. We used the upper limit of this normal range of serum gastrin concentrations and performed a validation study to determine its usefulness as a diagnostic marker for distinguishing between cases of gastritis and true A in the endoscopically-evaluated group.

RESULTS

The 95th percentile of serum gastrin concentrations in pathologically-evaluated normal stomach cases was 34.12-126.03 pg/mL. Using the upper limit of this normal range of serum gastrin concentrations, the sensitivity, specificity, positive predictive value, and negative predictive value for gastritis were 52.8%, 92.6%, 97.0%, and 31.0%, respectively. Additionally, the receiver operating characteristic (ROC) curve for the endoscopically-evaluated group showed an area under the ROC curve of 0.80.

CONCLUSION

The gastrin cut-off value of 126 pg/mL has a good positive predictive value (97.0%) for detecting gastritis positing its use as a marker for cases requiring endoscopy. However, the identification of patients with gastritis having normal serum gastrin concentrations due to insufficient sensitivity remains a challenge for the future.

Analysis of long-term serological and histological changes after eradication of <i>Helicobacter pylori</i>

Stratification of gastric cancer risk by measuring serological biomarkers is useful for screening of gastric cancer. However, this method has problem such as overlooking past infected patients. We aimed to evaluate the association between Helicobacter pylori infection status and serological biomarkers. We divided 5,268 patients according to Helicobacter pylori infection status and past infected patients were divided into 12 groups according to time elapsed since eradication. We analyzed mean serum H. pylori immunoglobulin G antibody, pepsinogen titers, histological and endoscopic atrophy score of each group. Mean H. pylori immunoglobulin G antibody showed a decreasing tendency, there was no significant difference from the uninfected group at 11 years after eradication (p = 0.19). PGI, PGII decreased in short term after eradication. However, both PGI and PGII gradually increased as long-term changes after eradication, became comparable to those in the uninfected group (p = 0.41, p = 0.37, respectively). Histological atrophy improved gradually, became equivalent to uninfected group. Endoscopic atrophy score did not improve for long term after eradication. In conclusion, patients with long term after eradication reach the uninfected condition serologically, histologically. Endoscopic assessment of gastric mucosal atrophy may be useful for accurate assessment of gastric cancer risk.

Human gastric cancer risk screening: From rat pepsinogen studies to the ABC method

We examined the development of gastric cancer risk screening, from rat pepsinogen studies in an experimental rat gastric carcinogenesis model induced with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and human pepsinogen studies in the 1970s and 1980s to the recent "ABC method" for human gastric cancer risk screening. First, decreased expression or absence of a major pepsinogen isozyme, PG1, was observed in the rat gastric mucosa from the early stages of gastric carcinogenesis to adenocarcinomas following treatment with MNNG. In the 1980s, decreases in PGI in the human gastric mucosa and serum were identified as markers of atrophic gastritis. In the 1990s, other researchers revealed that chronic infection with Helicobacter pylori (Hp) causes atrophic gastritis and later gastric cancer. In the 2000s, a gastric cancer risk screening method combining assays to detect serum anti-Hp IgG antibody and serum PGI and PGII levels, the "ABC method", was established. Eradication of Hp and endoscopic follow-up examination after the ABC method are recommended to prevent gastric cancer.

Cancer/testis antigen, Kita-Kyushu lung cancer antigen-1 and ABCD stratification for diagnosing gastric cancers

BACKGROUND

The ABCD stratification [(combination of serum pepsinogen (PG) levels and titers of antibody (immunoglobulin G, IgG) against Helicobacter pylori (H. pylori)] is effective for the classification of individuals at risk of developing gastric cancer (GC). The Kita–Kyushu lung cancer antigen-1 (KK-LC-1) is a Cancer/Testis antigen frequently expressed in GC.

AIM

To evaluate the effectiveness of KK-LC-1 and ABCD stratification in the diagnosis of GC.

METHODS

We analyzed the gene expression of KK-LC-1 in surgical specimens obtained from GC tumors. The levels of serum PG I/PG II and IgG against H. pylori were measured. According to their serological status, the patients were classified into the four groups of the ABCD stratification.

RESULTS

Of the 77 examined patients, 63 (81.8%) expressed KK-LC-1. The IgG titers of H. pylori and PG II were significantly higher in patients expressing KK-LC-1 than those measured in patients not expressing KK-LC-1 (P = 0.0289 and P = 0.0041, respectively). The expression of KK-LC-1 in group C [PG method (+)/H. pylori infection (+)] was as high as 93.9% high. KK-LC-1 was also detected in group A [-/-].

CONCLUSION

The KK-LC-1 expression in GC was associated with H. pylori infection and atrophic status, so that, KK-LC-1 may be a useful marker for the diagnosis of GC.

Label-free detection of pepsinogen 1 and 2 by polyethylene coating Lamb microfluidic device

Early screening of gastric cancer is a critical importance for the improvement of patients' survival rate. Here, a polyethylene coating Lamb (PE-Lamb) microfluidic device with immune layer for gastric cancer label-free detection was constructed. Two serum pepsinogen 1 (PG1) and pepsinogen 2 (PG2) biomarkers were applied to screen and predict the appearance of gastric cancer. Compared with enzyme-linked immunosorbent assay (ELISA), this method achieved a higher sensitivity and less time (40 min vs 120 min). The limit of detections (LOD) were reached 60 pg/mL for PG1 and 30 pg/mL for PG2, which have two orders of magnitude lower than traditional ELISA. The linearity coefficient indexes (R²) for PG1 and PG2 were 0.992 and 0.953 respectively, which is similar to that of ELISA. In addition, PG1 and PG2 mixed antigens sample with human serum was detected by PE-Lamb approach, and the frequency response showed high reproducibility and specificity. The results indicate that PE-lamb diagnostic technique is a novel and promising method for high-throughput screening and early diagnosis of gastric cancer.

Gastric Cancer Screening by Combined Determination of Serum Helicobacter pylori Antibody and Pepsinogen Concentrations: ABC Method for Gastric Cancer Screening

Objective:

Gastroscopy combined with gastric mucosa biopsies is currently regarded as a gold standard for diagnosis of gastric cancer. However, its application is restricted in clinical practice due to its invasive property. A new noninvasive population screening process combining the assay of anti-Helicobacter pylori antibody and serum pepsinogen (PG) (ABC method) is adopted to recognize the high-risk patients for further endoscopy examination, avoiding the unnecessary gastroscopy for most population and saving the cost consumption for mass screening annually. Nevertheless, controversies exist for the grouping of ABC method and the intervals of gastroscopy surveillance for each group. In this review, we summarized these popular concerned topics for providing useful references to the healthcare practitioner in clinical practice.

Data Sources:

The PubMed databases were systematically searched from the inception dates to November 22, 2017, using the keywords “Helicobacter pylori,” “Pepsinogens,” and “Stomach Neoplasms.”

Study Selection:

Original articles and reviews on the topics were selected.

Results:

Anti-H. pylori antibody and serum PG concentration showed significant changes under the different status of H. pylori infection and the progression of atrophic gastritis, which can be used for risk stratification of gastric cancer in clinic. In addition, anti-H. pylori antibody titer can be used for further risk stratification of gastric cancer contributing to determine better endoscopy surveillance interval.

Conclusions:

The early detection and diagnosis of gastric cancer benefit from the risk stratification, but the cutoff values for H. pylori antibody and serum PG concentration require further modification.

A significant increase in the pepsinogen I/II ratio is a reliable biomarker for successful Helicobacter pylori eradication

Background

Helicobacter pylori (H. pylori) eradication is usually assessed using the ¹³C-urea breath test (UBT), anti-H. pylori antibody and the H. pylori stool antigen test. However, a few reports have used pepsinogen (PG), in particular, the percentage change in the PG I/II ratio. Here, we evaluated the usefulness of the percentage changes in serum PG I/II ratios for determining the success of eradication therapy for H. pylori.

Materials and methods

In total, 650 patients received eradication therapy from October 2008 to March 2013 in our Cancer Institute Hospital. We evaluated the relationship between H. pylori eradication and percentage changes in serum PG I/II ratios before and 3 months after treatment with CLEIA^® (FUJIREBIO Inc, Tokyo, Japan). The gold standard of H. pylori eradication was defined as negative by the UBT performed 3 months after completion of eradication treatment. Cut-off values for percentage changes in serum PG I/II ratios were set as +40, +25 and +10% when the serum PG I/II ratio before treatment was below 3.0, above 3.0 but below 5.0 and 5.0 or above, respectively.

Results

Serum PG I and PG II levels were measured in 562 patients with H. pylori infection before and after eradication therapy. Eradication of H. pylori was achieved in 433 patients studied (77.0%). The ratios of first, second, third-line and penicillin allergy eradication treatment were 73.8% (317/429), 88.3% (99/112), 75% (12/16) and 100% (5/5), respectively. An increasing percentage in the serum levels of the PG I/II ratios after treatment compared with the values before treatment clearly distinguished success from failure of eradication (108.2±57.2 vs. 6.8±30.7, p<0.05). Using the above cut-off values, the sensitivity, specificity and validity for determination of H. pylori were 93.1, 93.8 and 93.2%, respectively.

Conclusion

In conclusion, the percentage changes in serum PG I/II ratios are useful as evaluation criteria for assessing the success of eradication therapy for H. pylori.

The association between objective tongue color and endoscopic findings: results from the Kyushu and Okinawa population study (KOPS)

Background

The relation between tongue color and gastroesophageal disease is unclear. This study was done to investigate the associations between tongue color (TC), endoscopic findings, Helicobacter.pylori infection status, and serological atrophic gastritis (SAG).

Methods

The participants were 896 residents of Ishigaki Island, Okinawa, aged 28–86 years. The tongue was photographed, esophagogastroduodenoscopy was done, and serum antibody to H.pylori was measured. SAG was defined as a serum Pepsinogen (PG)Ilevel ≤70 ng/ml and a PGI/IIratio ≤3.0. TC was measured by the device-independent international commission on Illumination 1976 L*a*b* color space standards at four points: (1) edge, (2) posterior, (3) middle, and (4) apex. We also calculated the ratio of the tongue edge to the three other measured points to examine the association between the coating of the tongue and the endoscopic and laboratory findings.

Results

Participants were excluded who had two or more endoscopic findings (n = 315) or who had SAG without seropositivity to H.pylori (n = 33). The remaining 548 participants were divided into three groups: SAG and seropositive to H.pylori (n = 67), seropositive to H.pylori alone (n = 56), and without SAG and seronegative for H.pylori (n = 425). We divided 425 residents into a single endoscopic finding positive group (n = 207) and a negative group, which served as a control (n = 218). The most frequent single endoscopic finding was esophageal hernia (n = 110), followed by erosive esophagitis (n = 35) and erosive gastritis (EG) (n = 45). EH was significantly associated with TC (2b*/1b*) (P < 0.05). EG was significantly associated with TC (3a*, 3b*) (P < 0.05). Seropositivity to H.pylori was significantly associated with TC (3 L*, 3 L*/1 L*) (P < 0.05, <0.01), and seropositivity to both H.pylori and SAG was significantly associated with TC (3 L*/1 L*) (P < 0.05). Multivariate analysis extracted TC (3a*, 3b*) as an independent factor associated with a differential diagnosis of EG (Odds ratio (OR) 2.66 P = 0.008, OR 2.17 P = 0.045).

Conclusions

The tongue body color of the middle area reflects acute change of gastric mucosa, such as erosive gastritis. Tongue diagnosis would be a useful, non-invasive screening tool for EG.

Cancer development based on chronic active gastritis and resulting gastric atrophy as assessed by serum levels of pepsinogen and Helicobacter pylori antibody titer

Our study investigated the relationship between gastric cancer development and activity of Helicobacter pylori-associated chronic gastritis or the resulting chronic atrophic gastritis (CAG). A cohort of 4,655 healthy asymptomatic subjects, in whom serum pepsinogen (PG) and H. pylori antibody titer had been measured to assess the activity and stage of H. pylori-associated chronic gastritis, was followed for up to 16 years, and cancer development was investigated. In subjects with a serologically diagnosed healthy stomach (H. pylori-negative/CAG-negative), cancer incidence rate was low, at 16/100,000 person-years. With the establishment of H. pylori infection and progression of chronic gastritis, significant stepwise cancer risk elevations were seen from CAG-free subjects (H. pylori-positive/CAG-negative) [hazard ratio (HR) = 8.9, 95% confidence interval (CI) = 2.7-54.7] to subjects with CAG (H. pylori-positive/CAG-positive) (HR = 17.7, 95% CI = 5.4-108.6) and finally to subjects with metaplastic gastritis (H. pylori-negative/CAG-positive) (HR = 69.7, 95% CI = 13.6-502.9). In H. pylori-infected CAG-free subjects, significantly elevated cancer risk was observed in the subgroup with active inflammation-based high PG II level or potent immune response-based high H. pylori antibody titer; the former was associated with a particularly high risk of diffuse-type cancer, and both subgroups showed high cancer incidence rates of around 250/100,000 person-years, comparable to that in subjects with CAG. No such risk elevation was observed in H. pylori-infected subjects with CAG. These results clearly indicate that gastric cancer develops mainly from the gastritis-atrophy-metaplasia-cancer sequence and partly from active inflammation-based direct carcinogenesis, and that serum levels of PG and H. pylori antibody titer provide indices of cancer development in H. pylori-infected subjects.

Altered mucosal DNA methylation in parallel with highly active Helicobacter pylori-related gastritis

BACKGROUND

Chronic inflammation triggered by Helicobacter pylori causes altered DNA methylation in stomach mucosae, which is deeply involved in gastric carcinogenesis. This study aimed to elucidate the correlation between altered mucosal DNA methylation levels and activity of H. pylori-related gastritis, because inflammatory activity shows particular correlations with the development of diffuse-type cancer.

METHODS

Methylation levels in stomach mucosae of 78 healthy volunteers were determined by real-time methylation-specific PCR or bisulfite pyrosequencing. Examined loci were the promoter CpG islands of six genes (FLNc, HAND1, THBD, p41ARC, HRASLS, and LOX) and the CpG sites of non-coding repetitive elements (Alu and Satα) that are reportedly altered by H. pylori infection. Activity of H. pylori-related gastritis was evaluated using two serum markers: H. pylori antibody titer and pepsinogen II.

RESULTS

Methylation levels of the six CpG islands were consistently increased, and those of the two repetitive elements were consistently decreased in a stepwise manner with the activity of gastric inflammation as represented by serum marker levels. Each serum marker level was well correlated with the overall DNA methylation status of stomach mucosa, and these two serologic markers were additive in the detection of the mucosa with severely altered DNA methylation.

CONCLUSIONS

Alteration in mucosal DNA methylation level was closely correlated with activity of H. pylori-related gastritis as evaluated by serum markers. The observed correlation between altered DNA methylation levels and activity of H. pylori-related gastritis appears to be one of the relevant molecular mechanisms underlying the development of diffuse-type cancer.

Statistical analysis of serum pepsinogen I (PG I) and II (PG II) levels, PG I/PG II ratios and serum gastrin levels in a general population

To allow adoption of serum pepsinogen as a screening indicator of gastric cancer, serum pepsinogen I & II levels, the ratios of PG I / PG II and the serum gastrin levels in a general population were studied using 850 samples selected at random from a rural area in Japan. The collected data were analyzed statistically to determine the distribution characteristics by various categories of sex and age. The following results were obtained:1. The distributions of PG I and PG II, the ratios of PG I/PG II and serum gastrin values largely deviated from the normal distribution. Therefore, the use of non-parametrical methods was recommended for analysis of these data.2. Although no significant difference between all selected men and all selected women was observed in any of the three parameters of PG I and PG II levels and the ratios of PG I / PG II, a significant difference between men and women was observed for PG I levels in under-fifty age groups. On the other hand, the median serum gastrin value (92.0 pg/ml) in all selected men was significantly lower than that (101.0 pg/ml) in all selected women. A statistically significant difference between men and women was observed in serum gastrin levels both in the under-forty age group and in the sixty and over age group.3. No significant difference was observed in the pattern of changes in PG I levels with increasing age in either men or women. While PG II levels in men varied irregularly with advancing age, PG II levels in women showed obvious increases with advancing age. The ratios of PG I / PG II showed a tendency to decrease with advancing age in both men and women. Conversely, serum gastrin levels increased with advancing age in both men and women.

Elevated risk of recurrent colorectal neoplasia with Helicobacter pylori-associated chronic atrophic gastritis: A follow-up study of patients with endoscopically resected colorectal neoplasia

In a previous population-based case-control study, we demonstrated an elevated risk of colorectal neoplasia with Helicobacter pylori (H. pylori) infection. The present study investigated the effects of H. pylori-associated chronic gastritis on the development of colorectal neoplasia by analyzing the recurrence of colorectal neoplasia subsequent to endoscopic resection. Ninety-nine patients who had undergone endoscopic resection of colorectal neoplasia were monitored under colonoscopy, and the recurrence of colorectal neoplasia was prospectively investigated. The stage of H. pylori-associated chronic gastritis in each subject was evaluated using a combination of two serum tests: H. pylori antibody and pepsinogen. In the present cohort, colorectal neoplasia recurred at a rate of 15,296/100,000 person-years during the study period. After adjusting for the confounding factors, chronic atrophic gastritis (CAG) was identified as an independent risk factor [adjusted hazard ratio (HR), 2.72; 95% confidence interval, 1.33-5.57], while H. pylori-infected non-atrophic gastritis was not identified as an independent risk factor for recurrent colorectal neoplasia. Colorectal neoplasia recurred earlier and was significantly more frequent in patients with CAG (22,573/100,000 person-years) compared to patients without CAG (11,089/100,000 person-years; P=0.029, log-rank test). Patients with more extensive CAG showed a higher risk of recurrence. These results demonstrated a significant elevation of the risk of recurrent colorectal neoplasia with the establishment and progression of CAG, indicating the involvement of H. pylori infection in the development of colorectal neoplasia. The two serum tests were useful clinical markers for noninvasively evaluating the risk of each individual for recurrent colorectal neoplasia subsequent to endoscopic resection.

Influence of endoscopic submucosal dissection on serum levels of pepsinogens in patients with early gastric cancer

BACKGROUND

The serum levels of pepsinogens (PG) have been considered to be a useful marker for assessing the risk of metachronous gastric cancer in patients who undergo endoscopic submucosal dissection. However, the influence of endoscopic submucosal dissection (ESD) on serum levels of PG has not yet been examined. The aim of this study was to examine whether the level of PG after ESD can be used to predict the risk of metachronous cancer.

PATIENTS AND METHODS

The study included of 100 consecutive patients who underwent ESD for gastric cancer at Hirosaki University Hospital from September 2009 to February 2011. Serum levels of PG I and II on the day before and after ESD were compared. Stool antigen test was also performed to examine the presence of Helicobacter pylori infection.

RESULTS

The mean serum level of PG I before and after ESD was 34.3 ± 31.6 ng/mL and 70.5 ± 100.0 ng/mL (P < 0.001), respectively. PG I/II ratio before and after ESD was 2.40 ± 1.51 and 2.79 ± 1.70 (P < 0.001). The serum level of PG I and the PG I/II ratio were significantly changed after ESD, regardless of the use of proton pump inhibitor, Helicobacter pylori infection or the location of the tumor.

CONCLUSIONS

ESD treatment modulates the serum level of PG I and significantly increases the PG I/II ratio. Serum levels of PG should be measured before the ESD procedure is performed to predict the risk of developing metachronous gastric cancer after ESD.

Development of gastric cancer in nonatrophic stomach with highly active inflammation identified by serum levels of pepsinogen and Helicobacter pylori antibody together with endoscopic rugal hyperplastic gastritis

This study aimed to elucidate groups at high risk of developing cancer among patients with serologically identified Helicobacter pylori infection and nonatrophic stomach. Annual endoscopy was performed for a mean of 5.4 years in 496 asymptomatic middle-aged men who were H. pylori antibody-positive and pepsinogen (PG) test-negative. Subjects were stratified according to the activity of H. pylori-associated gastritis measured by serum levels of PG and H. pylori antibody, and/or by endoscopic findings of rugal hyperplastic gastritis (RHG), and cancer development was investigated. During the study period, seven cases of cancer developed in the cohort (incidence rate, 261/100,000 person-years), with 85.7% developing in the group showing a PGI/II ratio ≤ 3.0, reflecting active inflammation-based high PGII levels. Cancer incidence was significantly higher in this group (750/100,000 person-years) than in groups with less active gastritis. Furthermore, cancer incidence for this group was significantly higher in the subgroup with high H. pylori antibody titers than in the low-titer subgroup. Meanwhile, endoscopic findings revealed that 11.7% of subjects showed RHG reflecting localized highly active inflammation, and cancer risk was significantly higher in patients with RHG than in patients without. Combining the two serum tests and endoscopic examination for RHG allowed identification of subjects with more active gastritis and higher cancer risk. No cancer development was observed in these high-risk subjects after H. pylori eradication. Subjects with highly active gastritis identified by the two serological tests and endoscopic RHG constitute a group at high risk of cancer development with H. pylori-infected nonatrophic stomach.

Serum pepsinogen and Helicobacter pylori infection--a Japanese population study

The decreased ratio of serum pepsinogen (PG) I and II has good correlation with the presence of atrophic gastritis. A total of 1,540 residents aged 30-89 years were enrolled into this study to investigate which serum PG level of residents with Helicobacter pylori infection would represent an adjunct to the diagnosis and progression of atrophic gastritis. All participants received esophagogastroduodenoscopy. Serum antibody to H. pylori (anti-H. pylori) was measured by an enzyme-linked immunosorbent assay (ELISA). Serological atrophic gastritis was defined as serum PG I isozyme level ≤70 ng/ml and a PG I/II ratio of ≤3.0. Of the 1,540 participants, 923 (59.9%) were positive for anti-H. pylori. Serological atrophic gastritis was found significantly more often in anti-H. pylori-positive participants (40.8%) than in anti-H. pylori-negative participants (7.9%) (p ≤ 0.0001). The endoscopic findings of anti-H. pylori-positive participants with serological atrophic gastritis were significantly more frequent by 4.06 times for atrophic gastritis (p ≤ 0.0001) than anti-H. pylori-negative participants without serological atrophic gastritis. Eight anti-H. pylori-positive participants were diagnosed with gastric cancer, but no cancer was found in anti-H. pylori-negative participants without serological atrophic gastritis. Serum PG testing is clinically useful for the prediction of gastric lesions in H. pylori-infected persons.

Analysis of ABC (D) stratification for screening patients with gastric cancer

AIM: To evaluate the value of ABC (D) stratification [combination of serum pepsinogen and Helicobacter pylori (H. pylori) antibody] of patients with gastric cancer.

METHODS: Ninety-five consecutive patients with gastric cancer were enrolled into the study. The serum pepsinogen I (PG I)/pepsinogen II (PG II) and H. pylori antibody levels were measured. Patients were classified into five groups of ABC (D) stratification according to their serological status. Endoscopic findings of atrophic gastritis and histological differentiation were also analyzed in relation to the ABC (D) stratification.

RESULTS: The mean patient age was (67.9 ± 8.9) years. Three patients (3.2%) were classified into group A, 7 patients (7.4%) into group A’, 27 patients (28.4%) into group B, 54 patients (56.8%) into group C, and 4 patients (4.2%) into group D, respectively. There were only three cases in group A when the patients taking acid proton pump inhibitors and those who had undergone eradication therapy for H. pylori (group A’) were excluded. These three cases had mucosal atrophy in the grey zone according to the diagnostic manual of ABC (D) stratification. Histologically, the mean age of the patients with well differentiated adenocarcinoma was significantly higher than that of the patients with poorly differentiated adenocarcinoma (P < 0.05). There were no differences in the pattern of atrophy in the endoscopies between the well differentiated and poorly differentiated groups.

CONCLUSION: ABC (D) stratification is a good method for screening patients with gastric cancers. Endoscopy is needed for grey zone cases to check the extent of mucosal atrophy.

Assessment of gastroesophageal reflux disease by serodiagnosis of Helicobacter pylori-related chronic gastritis stage

AIM: To evaluate the association of Helicobacter pylori (H.pylori)-related chronic gastritis stage with upper gastrointestinal symptoms and gastroesophageal reflux disease (GERD).

METHODS: Subjects underwent upper gastrointestinal endoscopy, a questionnaire using a frequency scale for symptoms of GERD (FSSG), and measurements of serum H.pylori-antibody and pepsinogen (PG) levels. They were classified into the following 4 groups in terms of H.pylori-related chronic gastritis stage: Group A (n = 219), H.pylori(-)PG(-); Group B (n = 310), H.pylori(+)PG(-); Group C (n = 279), H.pylori(+)PG(+); and Group D (n = 17), H.pylori(-)PG(+).

RESULTS: Reflux esophagitis occurred in 30.6% of Group A, 14.5% of Group B, 6.8% of Group C, and 0% of Group D (P < 0.001). Scores for acid reflux symptoms decreased significantly with chronic gastritis stage (from Group A to D) (P < 0.05), while scores for dysmotility symptoms did not differ significantly. The prevalence of non-erosive reflux disease (NERD) did not differ among groups. However, in subjects with GERD, the prevalence of NERD tended to increase with chronic gastritis stage (P = 0.081).

CONCLUSION: Acid reflux symptoms and the prevalence of reflux esophagitis can be assessed by measuring both serum H.pylori-antibody and PG levels.

Elevated risk of colorectal adenoma with Helicobacter pylori-related chronic gastritis: a population-based case-control study

This study investigated correlations between Helicobacter pylori infection or chronic atrophic gastritis (CAG) and risk of colorectal adenoma in a population-based case-control study. Subjects comprised asymptomatic, middle-aged, male Japanese factory workers who participated in an annual health check-up program, including cancer screening with colonoscopy. We selected 239 colorectal adenoma cases based on histological evaluation and 239 age-matched adenoma-free controls, and evaluated colorectal adenoma risk according to stage of H. pylori-related chronic gastritis as determined by serum tests for H. pylori antibody titer and pepsinogen. Subjects with colorectal adenoma were more likely to be smokers and have hypercholesterolemia. H. pylori infection was a risk factor for adenoma as a whole (crude odds ratio [OR]: 2.26, 95% confidence interval [CI]: 1.44-3.55). Analysis of distal adenoma cases showed that adenoma risk was significantly increased in the presence of H. pylori infection, but there was no further increase in risk with CAG. In contrast, proximal adenoma risk increased stepwise with the presence and progression of H. pylori-related chronic gastritis and showed a maximal and significant increase with CAG (crude OR: 4.51, 95% CI: 1.43-14.2). Subjects with more extensive and severe gastritis showed still higher risk not only for proximal but also for distal adenoma. H. pylori-related chronic gastritis is likely to be involved in the development of colorectal neoplasms, and its progression appears to increase the risk, particularly for proximal adenomas. Knowing the H. pylori-related chronic gastritis stage will probably be useful for evaluation of risk for colorectal neoplasia.

Gastric cancer screening by combined assay for serum anti-Helicobacter pylori IgG antibody and serum pepsinogen levels - "ABC method"

The current status of screening for gastric cancer-risk (gastritis A, B, C, D) method using combined assay for serum anti-Helicobacter pylori (Hp) IgG antibody and serum pepsinogen (PG) levels, "ABC method", was reviewed and the latest results of our ongoing trial are reported. It was performed using the following strategy: Subjects were classified into 1 of 4 risk groups based on the results of the two serologic tests, anti-Hp IgG antibody titers and the PG I and II levels: Group A [Hp(-)PG(-)], infection-free subjects; Group B [Hp(+)PG(-)], chronic atrophic gastritis (CAG) free or mild; Group C [Hp(+)PG(+)], CAG; Group D [Hp(-)PG(+)]), severe CAG with extensive intestinal metaplasia. Continuous endoscopic follow-up examinations are required to detect early stages of gastric cancer. Asymptomatic Group A, which accounts for 50-80% of all the subjects may be excluded from the secondary endoscopic examination, from the viewpoint of efficiency. Hp-infected subjects should be administered eradication treatment aimed at the prevention of gastric cancer.

Prescreening of a high-risk group for gastric cancer by serologically determined Helicobacter pylori infection and atrophic gastritis

BACKGROUND

Though gastric cancer screening by X-ray examination has been confirmed to be effective for reducing gastric cancer mortality, decreases in efficiency have been pointed out. Establishment of an effective screening system, focusing on high-risk status such as Helicobacter pylori infection and atrophic gastritis, is desirable. To date, combined use of serum anti-Helicobacter pylori antibodies and pepsinogen measurement has been assessed prospectively in participants in opportunistic and workplace health check-ups; however, there are no reports of population-based cohort study.

AIMS

To clarify the population-based risk of Helicobacter pylori infection and atrophic gastritis for gastric cancer, a cohort study was conducted in rural towns in Kyoto Prefecture.

METHODS

Subjects were 1,011 males and 1,848 females recruited in a health check-up in 1987. Their serum was examined for anti-Helicobacter pylori antibodies and pepsinogen I and II. Gastric cancer cases were assessed from the cancer registry of those towns.

RESULTS

Up to the end of 1996, 33 males and 28 females developed gastric cancer. A sex- and age-adjusted hazard ratio was calculated by Cox's proportional model. Helicobacter pylori infection increased the risk of gastric cancer even when the subjects had no atrophy (hazard ratio =4.20; 95% confidence interval, 0.96-18.40). The risk increased further when they had both Helicobacter pylori infection and atrophy (hazard ratio =11.23; 95% confidence interval, 2.71-46.51). Subjects with atrophy but negative for anti-Helicobacter pylori antibodies had the highest risk (hazard ratio =14.81; 95% confidence interval, 2.47-88.80).

CONCLUSIONS

A high-risk group for gastric cancer can be selected by serological prescreening.

The role of serum pepsinogen in the detection of gastric cancer

The incidence of gastric cancer is very high in Japan, Korea, and China. Reducing the morbidity and mortality associated with gastric cancer requires early diagnosis, which can be facilitated by applying gastroscopy more frequently in high-risk groups. A strategy of population screening for gastric cancer is currently being adopted in Korea, Japan, and the Matsu region of Taiwan, but using different screening methods. In addition, the history of pepsinogen (PG) in research as a gastric cancer biomarker has varied, in that the use of serum levels of PGI and PGII and the PGI/PGII ratio as gastric cancer screening tools was introduced in Japan before 1990, but in Korea the first research results were only reported in 2008. This review first evaluates the physiology of PG, followed by the usefulness or limitations of serum PG testing with regard to the detection of gastric cancer. Finally, the factors affecting the efficacy of PG tests as a gastric cancer biomarker (i.e., Helicobacter pylori infection status, gender, histopathologic features, and cancer location and depth) are evaluated. It was found that the strategies used to increase the efficacy of PG tests should be individualized in each country according to the seroprevalence of H. pylori.

Preventive effects of etodolac, a selective cyclooxygenase-2 inhibitor, on cancer development in extensive metaplastic gastritis, a Helicobacter pylori-negative precancerous lesion

The present study investigated the preventive effects of etodolac, a selective cyclo-oxygenase (COX)-2 inhibitor, on metachronous cancer development after endoscopic resection of early gastric cancer. Among 267 early gastric cancer patients who underwent endoscopic resection, 47 patients with extensive metaplastic gastritis were selected based on endoscopic findings and our previously described criteria of serum pepsinogen (PG) test-positive and Helicobacter pylori antibody-negative conditions. Nonrandomized etodolac treatment (300 mg/day) was administered to 26 patients (Group A), while the remaining 21 patients were untreated (Group B). No significant differences in age, sex distribution, lifestyle factors or extent of metaplastic gastritis at baseline were identified between groups. Patients were followed for metachronous cancer development with endoscopy every 6-12 months for up to 5 years. Mean (standard deviation) follow-up period was 4.2 (0.9) years. In Group B, 5 cancers developed (incidence rate = 6,266/100,000 person-years), significantly more than the 1 cancer in Group A (incidence rate = 898/100,000 person-years; p < 0.05). Long-term etodolac treatment did not influence the extent of metaplastic gastritis as revealed by endoscopic findings or by serum PG levels, but effectively reduced metachronous cancer development in patients with extensive metaplastic gastritis. These results strongly suggest that chemoprevention of cancer in the metaplastic stomach is possible by controlling COX-2 expression.

Eradication of Helicobacter pylori prevents cancer development in subjects with mild gastric atrophy identified by serum pepsinogen levels

A longitudinal cohort study was conducted in Helicobactor pylori-infected middle-aged Japanese males to evaluate the preventive effects of H. pylori eradication on the development of gastric cancer according to the extent of chronic atrophic gastritis (CAG). The extent of CAG was monitored by baseline serum pepsinogen (PG) levels. We followed 3,656 subjects with persistent H. pylori infection and 473 subjects with successful H. pylori eradication for cancer development for a mean (SD) of 9.3 (0.7) years. Groups with and without extensive CAG were categorized based on PG test-positive criteria to detect extensive CAG of PG I <or= 70 ng/ml and PG I/II ratio <or= 3.0. During the study period, 5 and 55 gastric cancers developed in H. pylori-eradicated and the noneradicated subjects, respectively, indicating no significant reduction in cancer incidence after H. pylori eradication. Among the noneradicated subjects, 1,329 were PG test-positive and 2,327 were PG test-negative. Gastric cancer was confirmed in 30 and 25 subjects, respectively. Among subjects whose infection was eradicated, 155 were PG test-positive and 318 were PG test-negative. Of these subjects, gastric cancer was confirmed in 3 and 2 subjects, respectively. Significant reduction in cancer incidence after eradication was observed only in PG test-negative subjects (p < 0.05; log-rank test). The results of this study strongly indicate that cancer development after eradication depends on the presence of extensive CAG before eradication and that H. pylori eradication is beneficial to most PG test-negative subjects with mild CAG as defined by the aforementioned criteria.

Alteration of correlation between serum pepsinogen concentrations and gastric acid secretion after H. pylori eradication

PURPOSE

The measurement of serum pepsinogens is clinically useful to represent gastric acid secretion. Since both serum pepsinogens and gastric acid secretion are considerably altered by H. pylori eradication, the correlation between these two parameters could be different prior to and after eradication. In this study, we investigated the correlation between the two parameters prior to and after eradication.

METHODS

One hundred eighteen H. pylori-positive patients with peptic ulcers or chronic gastritis were enrolled in this retrospective analysis. In all participants both the measurement of serum pepsinogens and the determination of gastric acid secretion were performed prior to and at 1 month after successful eradication. In 85 subjects, the same assessments were repeated at 7 months. Correlations between serum pepsinogens and gastric acid secretion were assessed using linear regression analysis.

RESULTS

The pepsinogen I/II ratio (r = 0.56) was a better indicator of gastric acid secretion in H. pylori-infected subjects than pepsinogen I itself (r = 0.31). Eradication of H. pylori altered the association, causing pepsinogen I (r = 0.55) to become a better indicator of gastric acid secretion compared with the pepsinogen I/II ratio (r = 0.40) at 1 month after eradication, followed by similar tendencies at 7 months.

CONCLUSION

Using different serum biomarkers (pepsinogen I/II ratio prior to eradication or pepsinogen I after eradication), the measurement of serum pepsinogens is useful for predicting the individual gastric acid secretion level not only in H. pylori-infected subjects, but also in subjects with histories of eradication of the infection.

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.

Barrett's esophagus is characterized by the absence of Helicobacter pylori infection and high levels of serum pepsinogen I concentration in Japan

BACKGROUND AND AIM

It has been reported that patients with Barrett's esophagus (BE) may have gastric acid hypersecretion. Serological markers such as serum pepsinogen or gastrin have been used to estimate the gastric secretory function. The aim of this study was to compare the serum pepsinogen and gastrin concentrations in view of Helicobacter pylori infection status between BE patients and the controls.

METHODS

Thirty-six patients with long-segment BE were enrolled in this study. Three age- and sex-matched controls were assigned to each patient. Serum pepsinogen and gastrin concentrations were measured by radioimmunoassay and H. pylori infection was determined by histology and serum IgG antibodies.

RESULTS

Helicobacter pylori infection was present in 4 of 36 patients (11%) with BE and in 80 of 108 controls (74%), being less prevalent in BE patients than in the controls (P < 0.0001). When examined in the H. pylori-negative subjects, both the serum pepsinogen I and pepsinogen II concentrations in BE patients were significantly higher than those in the controls (mean pepsinogen I:BE 51.0 +/- 14.0 ng/mL vs control 38.9 +/- 13.5 ng/mL, P = 0.0012; mean pepsinogen II:BE 10.8 +/- 4.0 ng/mL vs control 7.9 +/- 2.0 ng/mL, P = 0.0097). There was no significant difference in the serum gastrin levels between BE patients and the controls irrespective of the H. pylori infection status.

CONCLUSIONS

Most of the Japanese BE patients are characterized by the absence of H. pylori infection and high levels of serum pepsinogen. Determination of the serum pepsinogen level in combination with the H. pylori infection status could be a useful serological marker for BE screening.

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, < or =70 ng/mL; pepsinogen I/II ratio, < or =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 < or =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.

Incidence of reflux esophagitis and Helicobacter pylori infection in diabetic patients

AIM: To investigate the incidence of reflux esophagitis (RE) and H pylori infection in the diabetic patient.

METHODS: The incidence of RE and H pylori infection were investigated in 85 patients with diabetes mellitus and the results were compared with controls.

RESULTS: The incidence of RE in diabetic patients was 17.6%. Although this tended to be higher in diabetic patients, there were no statistically significant differences between diabetic patients and controls. The incidence of H pylori infection in diabetic patients was 53.7% but no statistically significant difference was seen between diabetic patients and controls in the incidence of H pylori infection.

CONCLUSION: No significant differences could be seen between diabetic patients and controls in the incidence of RE and H pylori infection.

Gastric cancer screening using the serum pepsinogen test method

The current status of gastric cancer screening, worldwide, as well as in Japan, using the serum pepsinogen test method, was reviewed. We performed a metaanalysis of sensitivity and specificity results from 42 individual studies (27 population-based screening studies: n = 296 553 and 15 selected groups: n = 4 385). Pooled pairs of sensitivity and false-positive rates (FPr) for pepsinogen I level < or = 70 ng/ml; pepsinogen I/II ratio < or = 3, had a sensitivity of 77%/FPr27%. The positive predictive value varied between 0.77% and 1.25%, and the negative predictive value varied between 99.08% and 99.90%. Therefore, we concluded that the definition of the pepsinogen test should include the pepsinogen I/II ratio, as consistency was obtained for both the population-based studies and the selected groups for those studies that used pepsinogen I serum levels together with the pepsinogen I/II ratio for screening for gastric cancer in high-incidence regions other than Japan. Individuals testing positive for extensive atrophic gastritis by serum pepsinogen levels undergo endoscopic examination to test for the presence of gastric cancer. We should increase the efficacy and cost-effectiveness of the gastric cancer screening system, by the identification of groups, at low-risk, as well as those at high-risk, of developing gastric cancer, using a combination of assays of serum Helicobacter pylori antibody titers and the concentration of pepsinogen I and II. In conclusion, the pepsinogen test method can be used as a screening test for high-risk subjects, rather than as a tool for screening for cancer itself. I hope that this pepsinogen test method will become a world standard for gastric cancer prevention in the near future, in other countries, as well as in Japan.

Cytochrome P450 2C19 polymorphism influences the preventive effect of lansoprazole on the recurrence of erosive reflux esophagitis

BACKGROUND

The efficacy of lansoprazole (LPZ) at inhibiting gastric acid secretion is influenced by cytochrome P450 2C19 (CYP2C19) polymorphism. The purpose of the present study was to investigate whether CYP2C19 polymorphism had an influence on the remission of erosive reflux esophagitis (RE) during maintenance therapy with LPZ.

METHODS

Eighty-two Japanese patients with initial healing of erosive RE by 8 weeks of LPZ therapy were enrolled. As maintenance therapy, the patients were treated with LPZ (15 mg/day) for 6 months. The CYP2C19 genotype, Helicobacter pylori infection status, and serum pepsinogen (PG) I/II ratio were assessed before treatment. The patients were investigated for relapse by endoscopy at 6 months or when symptoms recurred.

RESULTS

The proportion of patients in remission after 6 months was 61.5%, 78.0%, and 100% among homozygous extensive metabolizers (homo-EM), heterozygous EM (hetero-EM), and poor metabolizers (PM), respectively. The percentage of PM patients who remained in remission was significantly higher than that of homo-EM or hetero-EM.

CONCLUSIONS

The efficacy of LPZ (15 mg/day) as maintenance therapy for erosive RE is influenced by CYP2C19 polymorphism.

Serum pepsinogen and gastric cancer screening

Since the 1990's, the test for serum pepsinogen as a marker for chronic atrophic gastritis has been incorporated into gastric cancer screening programs, on a trial basis, to identify people at high risk for gastric cancer. The addition of the serum test to the cancer screening program has been shown to improve the detection rate of cancer and pepsinogen testing is useful in detecting early-stage gastric cancers arising from atrophic gastric mucosa, which macroscopically tend to be elevated and histologically differentiated. Furthermore, the cost for the detection of a single cancer case is much less than that for conventional screening. Thus, with the introduction of pepsinogen testing, complimenting barium X-ray, a more efficient screening system is available.

Helicobacter pylori infection in combination with the serum pepsinogen I/II ratio and interleukin-1beta-511 polymorphisms are independent risk factors for gastric cancer in Thais

BACKGROUND

Thailand has the lowest incidence of gastric cancer in the world. Helicobacter pylori infection, a low serum pepsinogen I/II ratio, and interleukin (IL)-1beta-511 polymorphisms are suspected to be risk factors for gastric cancer.

METHODS

A total of 167 Thais, comprising 56 cancer patients and 111 volunteers without cancer, underwent an esophagogastroduodenoscopic examination and three fixed-point biopsies; a cancer tissue biopsy was also done, and blood samples were collected. The subjects without cancer were divided into normal subjects and chronic gastritis patients. IL-1beta-511 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism, and the serum levels of pepsinogen I and II were determined by a radioimmunoassay. Helicobacter pylori IgG antibody and tissue pathology were tested in all groups.

RESULTS

The pepsinogen I/II ratio was significantly lower in the gastric cancer group than in the normal and chronic gastritis groups [odds ratio (OR), 2.3; 95% confidence interval (CI), 1.10-4.80; P = 0.025]. Gastric cancer patients were positive for the H. pylori IgG antibody more frequently than negative (OR, 2.946; 95% CI, 1.4-6.39; P = 0.005). However, only 15 (27%) cancer patients were both positive for H. pylori IgG antibody and had low serum pepsinogen I/II. The C/C genotype was found more frequently in the gastric cancer group than in the group with a normal gastric mucosa (OR, 0.64; 95% CI, 0.50-0.81; P = 0.014).

CONCLUSIONS

A low serum pepsinogen I/II ratio combined with positivity for H. pylori IgG, and a IL-1beta-511 C/C genotype may be independent risk factors for gastric cancer in Thais.

Therapeutic effects of 10 mg/day rabeprazole administration on reflux esophagitis was not influenced by the CYP2C19 polymorphism

BACKGROUND

The acid suppressive effects of omeprazole (OPZ) and lansoprazole (LPZ) are influenced by the CYP2C19 polymorphism. On the other hand, some investigators have reported that acid suppressive effect of rabeprazole (RPZ) was not significantly affected by CYP2C19. The present study was designed to investigate whether the CYP2C19 genotype is related to the healing of reflux esophagitis (RE) in treatment with RPZ 10 mg.

METHODS

One hundred and three Japanese patients with RE were treated with daily oral administration of 10 mg RPZ. At 4 and 8 weeks after the start of treatment, healing of RE was evaluated endoscopically. The CYP2C19 genotype was investigated before the treatment.

RESULTS

At 4 weeks after the start of treatment, the healing rates for homo-extensive metabolizer, hetero-extensive metabolizer, and poor metabolizer patients were 83.3% (15/18), 77.3% (17/22), and 88.9% (8/9) [corrected] respectively, and at 8 weeks after the start of treatment, the healing rates were 86.1% (31/36), 92.0% (46/50), and 82.4% (14/17), respectively. There were no significant differences in the healing rate of RE among the three genotypes at either 4 or 8 weeks after the start of treatment.

CONCLUSIONS

The therapeutic effects of 10 mg/day RPZ administration on RE may be uninfluenced by the CYP2C19 polymorphism.

The serum pepsinogen test as a predictor of gastric cancer: the Hisayama study

The authors examined whether a serum pepsinogen test (SPT) based on the combination of the serum pepsinogen I level and pepsinogen I/II ratio is a good predictor of gastric cancer occurrence in a general Japanese population. A total of 2,446 subjects aged > or =40 years were classified into negative, positive, and strong-positive SPT groups and were followed prospectively for 14 years (1988-2002). Compared with that for the negative SPT group (26 men, 10 women), gastric cancer incidence increased significantly for both men (n = 17; age-adjusted hazard ratio = 4.56, 95% confidence interval: 2.42, 8.60) and women (n = 6; age-adjusted hazard ratio = 5.84, 95% confidence interval: 2.00, 17.11) in the strong-positive SPT group. It was also significantly higher in the positive SPT group for men (n = 23; age-adjusted hazard ratio = 3.91, 95% confidence interval: 2.23, 6.86). These associations did not attenuate even after adjustment for other comprehensive risk factors. Stratified analysis revealed significant associations between the SPT and development of intestinal-type gastric cancer as well as of cancer in both Helicobacter pylori-negative and -positive subjects. These findings suggest that the SPT can serve as a predictor of intestinal-type gastric cancer, irrespective of H. pylori infection.

Gastric cancer screening of a high-risk population in Japan using serum pepsinogen and barium digital radiography

With the aim of developing more efficient gastric cancer screening programs for use in Japan, we studied a new screening program that combines serum pepsinogen (PG) testing and barium digital radiography (DR). A total of 17 647 middle-aged male subjects underwent workplace screening over a 7-year period using a combination of PG testing and DR. This program's effectiveness, as well as other characteristics of the program, was analyzed. Forty-nine cases of gastric cancer were detected (comprising 88% early cancer cases). The detection rate was 0.28%, and the positive predictive value was 0.85%. The PG test detected 63.3% of cases, DR detected 69.4% of cases, and both tests were positive in 32.7% of cancer cases. The two methods were almost equally effective, and were considerably more effective than conventional screening using photofluorography. Each screening method detected a distinct gastric cancer subgroup; the PG test efficiently detected asymptomatic small early cancer with intestinal type histology, while DR was efficient at detecting cancers with depressed or ulcerated morphology and diffuse type histology. The cost for the detection of a single cancer was much less than that for conventional screening. In fact, it is possible to further reduce the cost of detecting a single cancer to a cost comparable to that of surgically resecting a single gastric cancer. Thus, it is probable that a highly efficient gastric cancer screening system can be implemented by combining the two screening methods. Such a screening program would be beneficial in a population at high risk for gastric cancer.

Serum pepsinogen concentrations as a measure of gastric acid secretion in Helicobacter pylori-negative and -positive Japanese subjects

BACKGROUND

Although previous studies have indicated that serum pepsinogen I levels, as well as the pepsinogen I/II ratio, were positively correlated with maximal gastric output, the relationship may be different between Helicobacter pylori-negative and -positive subjects. The aim of this study was to investigate the relation between serum pepsinogen concentrations and gastric acid secretion in H. pylori-positive and -negative subjects separately.

METHODS

The presence of H. pylori infection, the serum pepsinogen concentrations, and gastric acid secretion were investigated in 182 subjects without localized lesions in the upper gastrointestinal tract. Serum pepsinogen concentration was measured by radioimmunoassay, and maximal gastric acid output was estimated by an endoscopic gastrin test, as we have previously shown.

RESULTS

In H. pylori-positive subjects, serum pepsinogen I levels and the pepsinogen I/II ratio were significantly correlated with gastric acid secretion, although the latter showed a better correlation (r=0.40 and 0.53, respectively). On the other hand, in H. pylori-negative subjects, serum pepsinogen concentrations were well correlated with acid secretion (r=0.57), but there was no relation between the pepsinogen I/II ratio and acid secretion.

CONCLUSIONS

The correlations between serum pepsinogens and gastric acid secretion differ, depending on the presence or absence of H. pylori infection. With the use of serum pepsinogens as a simple measure of gastric acid secretion, therefore, consideration of H. pylori infection status is needed. Because the determination of the acid secretory level has some clinical implications in both H. pylori-positive and -negative subjects, its estimation by serum pepsinogen concentrations can be of practical use.

Gastrobiliary motility is not coordinated in patients with non-ulcer dyspepsia of normal gastric emptying time: simultaneous sonographic study

BACKGROUND

Disorders of the motor function of the upper gastrointestinal tract have been implicated in the pathogenesis of non-ulcer dyspepsia. Approximately 50% of patients with abdominal symptoms (without ulcer) have normal gastric emptying. Apart from gastric emptying, other mechanisms are very important in the etiology of non-ulcer dyspepsia.

METHODS

Gastric emptying and gallbladder motility were simultaneously investigated in 16 patients with non-ulcer dyspepsia and in 15 healthy controls. Fasting blood samples were taken, and pepsinogen levels were assayed.

RESULTS

Gastric emptying time, fasting antral diameter, and post-prandial antral diameter were not significantly different between the patients with non-ulcer dyspepsia and the controls. Fasting gallbladder volume, the time required to reach minimal gallbladder residual volume, minimal gallbladder residual volume, and the serum levels of pepsinogen were not significantly different. Simple linear regression was used to summarize the relationship between gastric emptying time and time required to reach minimal gallbladder residual volume. In the controls, the gastric emptying time and time required to reach minimal gallbladder residual volume were linearly related. However, in the patients with non-ulcer dyspepsia, they were not related.

CONCLUSIONS

These observations suggest that disturbance of coordination between gastric emptying and gallbladder emptying is a cause of the symptoms of non-ulcer dyspepsia.

Interleukin-2 gene polymorphisms associated with increased risk of gastric atrophy from Helicobacter pylori infection

BACKGROUND

Gastric atrophy induced by Helicobacter pylori is thought to predispose patients to noncardiac gastric cancer development. However, the host genetic factors that influence the progression of gastric atrophy have not been elucidated. In this study, we examined the effects of cytokine polymorphisms on H. pylori-induced gastric atrophy.

METHODS

Blood samples were taken from 454 Japanese subjects. The interleukin-2 (IL-2; T-330G), IL-4 (C-33T), and IL-13 (C-1111T) polymorphisms were genotyped by polymerase chain reaction with confronting two-pair primers (PCR-CTPP). Anti-H. pylori IgG antibody and pepsinogen I and II were measured to diagnose H. pylori infection and atrophic gastritis.

RESULTS

The odds ratios (ORs) for the association between IL-2 polymorphism [OR = 2.78, 95% CI (confidence interval) = 1.26-6.17 (T/T to G/G)] or IL-4 polymorphism [OR = 2.22, 95% CI = 1.01-4.89 (T/C to C/C)] were increased significantly with gastric atrophy, whereas the corresponding OR of IL-13 polymorphism was decreased with gastric atrophy [OR = 0.61, 95% CI = 0.39-0.96 (C/T and T/T to C/C)]. There were no significant H. pylori seropositivity-related differences between these polymorphisms. We examined the relationship between these polymorphisms and gastric atrophy separately in H. pylori-seropositive and -seronegative groups. In the H. pylori-seropositive group, the IL-2 T/T (OR = 2.78, 95% CI = 1.12-6.93) had a significant association with gastric atrophy.

CONCLUSIONS

These results reveal that the IL-2 gene polymorphism is associated with an increased risk of gastric atrophy induced by H. pylori infection and might predispose to gastric cancer.

Validity of serum pepsinogen levels and quininium resin test combined for gastric cancer screening

BACKGROUND

To investigate the feasibility of combining several serum markers into a valid serum screening tool for gastric cancer, we performed a study evaluating the association between gastric cancer and precancerous conditions and a blood test for gastric acidity (the blood quininium resin test [QRT]) combined with serum pepsinogen levels.

METHODS

We performed immunoradiometric assays of serum pepsinogen I (PG I), II (PG II) levels, and QRT's in 10 endoscopically normal subjects, in 20 patients with chronic atrophic gastritis, and in 13 patients with biopsy-confirmed gastric adenocarcinoma.

RESULTS

Serum PG I, II levels, I/II ratio were significantly different among normal, gastritis, and cancer patients. Serum PG I/II ratios were much lower in cancer patients. Serum quinine levels by QRT were correlated with PG I/II ratio (rs=0.39, p<0.01). Age was negatively correlated both with PG I/II ratio (rs=-0.58, p<0.01) and serum quinine level (rs=-0.45, p<0.01). The screening using serum PG levels was more valid (sensitivity of 69%, specificity of 77%) than that using QRT alone. The combination of serum PG levels and QRT increased specificity for detecting gastric cancer to 87% without altering sensitivity.

CONCLUSION

Although blood QRT is a useful addition to other serum screening tests for gastric cancer, these tests alone are not sufficiently accurate as screening tools for gastric cancer.

Increased breath nitrous oxide after ingesting nitrate in patients with atrophic gastritis and partial gastrectomy

BACKGROUND

Toxic nitrite and N-nitroso compounds due to gastric bacterial growth are often detected in the stomach of patients with atrophic gastritis and partial gastrectomy. The aim of this study is to investigate whether breath N2O, a major metabolite of denitrification, detected after ingestion of nitrate is associated with atrophic gastritis and partial gastrectomy.

METHODS

Nine young, 16 normal older, nine atrophic gastritis and six partial gastrectomy subjects ingested 100 g lettuce, equal to 130 mg nitrate, and breath N2O was measured at 15-min intervals for 5 h. N2O was analyzed using an infrared-photoacoustic analyzer, and atrophic gastritis was diagnosed by pepsinogen test.

RESULTS

The mean breath N2O concentrations were higher in the following order at all times: partial gastrectomy>atrophic gastritis>normal>young. The maximum N2O concentrations in the patients with partial gastrectomy and atrophic gastritis were 1655 +/- 296 and 1350 +/- 200 (mean +/- S.E.) ppb, respectively, which were higher than that of the normal subjects, 827 +/- 91 ppb (P < 0.05). The maximum N2O concentration in young people was 527 +/- 86 ppb, which was lower than that of the normal older people (P < 0.051).

CONCLUSION

These higher N2O concentrations in gastric patients reflect bacterial growth in the stomach due to the reduction of gastric acid.

Long-term effect of Helicobacter pylori eradication on the reversibility of acid secretion in profound hypochlorhydria

BACKGROUND

Although profound hypochlorhydria is considered to be an important risk factor for development of gastric cancer, long-term effect of Helicobacter pylori eradication on its reversibility remains uncertain.

AIM

To clarify the change in acid secretion after eradication in a long-term follow-up over 5 years in patients with profound hypochlorhydria.

METHODS

Twenty-three H. pylori-positive patients with hypochlorhydria (<0.6 mmol/10 min) were enrolled prospectively. Assessment of gastrin-stimulated acid output and histologic evaluation of biopsy specimens were performed prior to, and 1, 7 months after eradication. Subsequently, gastric acid secretion was assessed for long-term period over 5 years after eradication in 12 patients.

RESULTS

Gastric acid secretion was reversed to normal range in nine of 23 patients (39%) at 7 months after eradication. In the long-term follow-up, gradual and significant recovery in gastric acid secretion was observed up to 2 years post-therapy. However, there was no additional increase during the last 3 years of 5-year follow-up period, leaving the acid secretory levels subnormal in the majority of the patients.

CONCLUSIONS

This long-term follow-up study suggests that the pathologic process has already progressed to an irreversible stage in the majority of H. pylori-positive patients with marked body atrophy and profound hypochlorhydria.

Progression of chronic atrophic gastritis associated with Helicobacter pylori infection increases risk of gastric cancer

We conducted a longitudinal cohort study to determine the association of Helicobacter pylori infection and the progression of chronic atrophic gastritis (CAG) with gastric cancer. A cohort of 4655 healthy asymptomatic subjects was followed for a mean period of 7.7 years. H. pylori infection was established by serum specific antibodies and the presence of CAG was confirmed by serum pepsinogen. During the follow-up period, 45 gastric cancer cases were detected (incidence rate, 126/100000 person-years). A univariate analysis after adjustment for age showed that both H. pylori and CAG were significantly associated with gastric cancer. To clarify the interaction between H. pylori and CAG, an analysis stratified by H. pylori- and CAG-status was performed. No cancer developed in the H. pylori(-)/CAG(-) group during the study period. This supports the theory that it is quite rare for any type of gastric cancer to develop in an H. pylori-free healthy stomach. With the progression of H. pylori-induced gastritis, the risk of gastric cancer increased in a stepwise fashion from CAG-free gastritis [H. pylori(+)/CAG(-) group] (HR=7.13, 95%CI=0.95-53.33) to CAG [H. pylori(+)/CAG(+) group] (HR=14.85, 95%CI=1.96-107.7) and finally to severe CAG with extensive intestinal metaplasia [H. pylori(-)/CAG(+) group] (HR=61.85, 95%CI=5.6-682.64) in which loss of H. pylori from the stomach is observed. Therefore, it is probable that H. pylori alone is not directly associated with stomach carcinogenesis. Instead, H. pylori appears to influence stomach carcinogenesis through the development of CAG. The observed positive correlation between the extent of H. pylori-induced gastritis and the development of cancer was strong, especially for the intestinal type. These results are compelling evidence that severe gastritis with extensive intestinal metaplasia is a major risk factor for gastric cancer, and they confirm the previously described model of stomach carcinogenesis: the gastritis-metaplasia-carcinoma sequence.