Role of Serum Pepsinogen II and Helicobacter pylori Status in the Detection of Diffuse-Type Early Gastric Cancer in Young Individuals in South Korea

Helicobacter pylori Infection Status and Gastric Tumor Incidence According to the Year of Birth

Background/Aims

: The prevalence of Helicobacter pylori-naive status is increasing. Nonetheless, biennial gastroscopy is recommended for all Koreans aged 40 to 75 years. This study aimed to determine whether gastric cancer screening guidelines could be changed according to H. pylori infection status and year of birth.

Methods

: Koreans who underwent serum assays and gastroscopy for gastric cancer screening between 2010 and 2016 were included if screening tests were followed up for ≥3 times. H. pylori infection was confirmed when invasive tests or 13C-urea breath tests were positive. In the case of negative test findings, eradication history, serologically detected atrophy, and intestinal metaplasia/atrophy were checked for past infection. If all were absent, H. pylori-naive status was confirmed.

Results

: Two-thousand and two (256 H. pylori-naive, 743 past-infected, and 1,003 infected) Koreans underwent screening tests for 95.5±28.4 months. The mean year of birth in the naive group (1969±7) differed from those of the past-infected (1957±10, p<0.001) and infected (1958±10, p<0.001) groups. H. pylori-naive status was correlated with recent year of birth (r=0.368, p<0.001). No gastric tumors were observed among the naive participants (p=0.007), whereas 23 adenomas, 18 adenocarcinomas, and two neuroendocrine tumors were detected in 1.9% (14/743) of past-infected and 2.5% (25/1,003) of infected participants, including four infected participants with metachronous tumors.

Conclusions

: The prevalence of H. pylori-naive status is increasing in young Koreans, and gastric tumors are rare in this population. Hence, biennial gastroscopy could be waived after the confirmation of naive status.

Utilization of an Automated Latex Agglutination Turbidity Assay for Assessing Gastric Mucosal Alteration during Helicobacter pylori Infection

Background/Aims

: A latex agglutination turbidity (LA) assay to test for serum antibodies has been approved in Japan and Korea for mass screening of Helicobacter pylori infection. In this study, we evaluated the LA assay for diagnosing H. pylori infection and predicting gastric mucosal changes in a Mongolian population.

Methods

: In total, 484 individuals were classified into H. pylori-positive (n=356) and H. pylori-negative (n=128) groups, as determined by histology and H. pylori culture.

Results

: The best cutoff, sensitivity, and specificity values for the LA assay were 18.35 U/mL, 74.2%, and 65.6%, respectively. The LA values in the atrophic gastritis group were statistically higher than those in the other groups (healthy, chronic gastritis, intestinal metaplasia, and gastric cancer, p<0.0001). The cutoff value to distinguish the atrophic gastritis group from the other four groups was 32.0 U/mL, and its area under the curve was 0.673, which was the highest among the E-plate, pepsinogen (PG) I, PG II, and PG I/II ratio tests in our data. The odds ratios for atrophic gastritis determined by the LA assay and PG I test in multiple logistic regression were 2.5 and 1.9, respectively, which were significantly higher than for the other tests.

Conclusions

: The LA assay can determine the risk of atrophic gastritis, which in turn is a considerable risk factor for gastric cancer. We propose using this assay in combination with the PG I/II ratio to avoid missing gastric cancer patients who have a low LA value (less than 32.0 U/mL).

Comparison between the GastroPanel test and the serum pepsinogen assay interpreted with the ABC method-A prospective study

BACKGROUND AND AIMS

This study aimed to validate Helicobacter pylori serological and pepsinogen (PG) assays for detecting infection and gastric neoplasm.

METHODS

Individuals who underwent serum Chorus H. pylori and HBI PG assays were included from May to September 2023. The GastroPanel test was performed using the same blood sample. HBI assay findings were interpreted with the ABC method using the criteria of corpus atrophy (PG I ≤ 70 ng/mL & I/II ≤3) and advanced corpus atrophy (PG I ≤ 30 ng/mL & I/II ≤2).

RESULTS

A total of 144 H. pylori-infected and 184 non-infected Koreans were analyzed. The Chorus test (sensitivity 97.2%, specificity 89.1%) showed higher area under the curve (0.993 vs. 0.972, p = 0.003) than the GastroPanel test (sensitivity 95.8%, specificity 86.4%). Using the GastroSoft application, the incidence of gastric neoplasms was highest in the corpus atrophy group (50%), followed by the low acid-output (25.8%), H. pylori infection (11.6%), and antral atrophy (9.1%) groups. There were no gastric neoplasms in the normal and high acid output groups. Using the ABC method, the incidence of gastric neoplasms was highest in the corpus atrophy groups (23.8% in Groups C and D), followed by Group B (12.3%) and Group A (2.4%). Corpus atrophy interpreted with the GastroSoft showed poor agreement (k = 0.225) with corpus atrophy interpreted with the ABC method, whereas it showed excellent agreement (k = 0.854) with advanced corpus atrophy.

CONCLUSIONS

Although the Chorus test was more accurate than the GastroPanel test, both assays discriminated high-risk individuals by detecting atrophy or infection. There were no gastric neoplasms in the normal or high acid-output groups (GastroSoft application), and gastric neoplasm incidence was lowest in Group A (ABC method). Corpus atrophy determined by GastroSoft application is more consistent with advanced corpus atrophy determined by the ABC method than is corpus atrophy.

Development of a modified ABC method among Helicobacter pylori infected but serum pepsinogen test-negative individuals

BACKGROUND

Although the ABC method for gastric cancer (GC) screening has been widely adopted in Japan, it may not be suitable for other countries due to population heterogeneity and different tumor histology. We aim to develop a modified ABC method to improve GC screening performance, especially among Helicobacter pylori (Hp) infected but serum pepsinogen (sPG) test-negative individuals.

METHODS

A total of 4745 participants were recruited from Tianjin, China, and were classified into four groups by combined assay for Hp infection and sPG concentrations: Group A (Hp [-], PG [-]), Group B (Hp [+], PG [-]), Group C (Hp [+], PG [+]), and Group D (Hp [-], PG [+]). We used receiver-operating characteristic (ROC) curves analysis and minimum p value method to determine the optimal cutoff point for PG II in Group B. We performed logistic regressions to examine the risk of GC across different subgroups. In addition to the derivation set, the performance of the modified ABC method was also evaluated in an external set involving 16,292 participants from Liaoning, China.

RESULTS

In the modified ABC method, we further classified Group B as low-risk (Group B1) and high-risk subgroups (Group B2) using optimal sPG II cutoff point (20.0 ng/mL) by ROC curves analysis and minimum p value method. Compared with Group B1, Group B2 had a significantly higher risk of GC (adjusted OR = 2.54, 95% CI = 1.94-3.33). The modified ABC method showed good discrimination for GC (AUC = 0.61, 95% CI = 0.59-0.63) and improved risk reclassification (NRI = 0.11, p < .01). Similar results were observed in the validation dataset.

CONCLUSIONS

The modified ABC method can effectively identify high-risk population for GC among Hp-infected but sPG test-negative participants in China.

Impact of Body Mass Index on Survival Depending on Sex in 14,688 Patients with Gastric Cancer in a Tertiary Hospital in South Korea

Background/Aims

The incidence and prognosis of gastric cancer (GC) shows sex difference. This study aimed to evaluate the effect of body mass index (BMI) on GC survival depending on sex.

Methods

The sex, age, location, histology, TNM stages, BMI, and survival were analyzed in GC patients from May 2003 to February 2020 at the Seoul National University Bundang Hospital.

Results

Among 14,688 patients, there were twice as many males (66.6%) as females (33.4%). However, under age 40 years, females (8.6%) were more prevalent than males (3.1%). Cardia GC in males showed a U-shaped distribution for underweight (9.6%), normal (6.4%), overweight (6.1%), obesity (5.6%), and severe obesity (9.3%) but not in females (p=0.003). Females showed decreased proportion of diffuse-type GC regarding BMI (underweight [59.9%], normal [56.8%], overweight [49.5%], obesity [44.8%], and severe obesity [41.7%]), but males did not (p<0.001). Both sexes had the worst prognosis in the underweight group (p<0.001), and the higher BMI, the better prognosis in males, but not females. Sex differences in prognosis according to BMI tended to be more prominent in males than in females in subgroup analysis of TNM stages I, II, and III and the operative treatment group.

Conclusions

GC-specific survival was affected by BMI in a sex-dependent manner. These differences may be related to genetic, and environmental, hormonal factors; body composition; and muscle mass (Trial registration number: NCT04973631).

Useful Serum Pepsinogen Levels for Detecting Ongoing Helicobacter pylori Infection in Asymptomatic Subjects: A Cross-Sectional Study Based on 13C-urea Breath Test Findings

BACKGROUND /AIMS

The serum pepsinogen (PG) assay is used to screen subjects at high risk for gastric cancer. Currently, there are few studies on the PG levels for the detection of Helicobacter pylori infection. This study aimed to determine the PG assay findings for detecting ongoing infection.

METHODS

Asymptomatic subjects who underwent a ¹³C-urea breath test (¹³C-UBT) on the day of gastroscopy and serum assay for cancer screening were included. Subjects with a recent intake of acid suppressants or antibiotics, gastrectomy, or renal failure were excluded. H. pylori infection was defined as a positive ¹³C-UBT result.

RESULTS

Among the 500 included subjects, 167 (33.4%) had current infection. The serum PG II levels of > 12.95 ng/mL (area under the curve [AUC] = 0.930, sensitivity 86.5%, specificity 90.7%) and PG I/II ratios of < 4.35 (AUC = 0.875, sensitivity 86.8%, specificity 79.6%) were related to infection. The PG I/II ratios were inversely correlated with age (r = -0.160, p = 0.039). The cutoff values of PG I/II ratios were lower in older subjects aged ≥ 50 years (< 4.05; AUC = 0.875, sensitivity 80.7%, specificity 88.2%) than in younger subjects aged < 50 years (< 4.35; AUC = 0.873, sensitivity 77.4%, specificity 88.9%).

CONCLUSIONS

Serum PG II levels > 12.95 ng/mL and PG I/II ratios < 4.35 suggest ongoing infection in asymptomatic subjects; therefore, H. pylori confirmation tests (i.e., ¹³C-UBT) should be considered under these conditions. Stricter criteria are required in older subjects aged ≥ 50 years (PG I/II ratio < 4.05) to detect ongoing infection than younger subjects.

Diagnostic performances of pepsinogens and gastrin-17 for atrophic gastritis and gastric cancer in Mongolian subjects

In Mongolia, gastric cancer morbidity and mortality are high, and more than 80 percent of cases are diagnosed at an advanced stage. This study aimed to evaluate pepsinogens (PGIs) and gastrin-17 (G-17) levels and to determine the diagnostic performances for gastric cancer and chronic atrophic gastritis among Mongolian individuals. We enrolled a total of 120 subjects, including gastric cancer (40), atrophic gastritis (40), and healthy control (40), matched by age (±2) and sex. Pepsinogen I (PGI), Pepsinogen II (PGII), G-17, and H. pylori IgG levels were measured using GastroPanel ELISA kit (Biohit, Helsinki, Finland). Also, PGI to PGII ratio (PGR) was calculated. For atrophic gastritis, when the optimal cut-off value of PGI was ≤75.07 ng/ml, the sensitivity and specificity were 75% and 50%, respectively; when the optimal cut-off value of PGR was ≤6.25, sensitivity and specificity were 85% and 44.7%, respectively. For gastric cancer, when the optimal cut-off value of PGI was ≤35.25 ng/ml, the sensitivity and specificity were 47.2% and 86.8%, respectively; when the optimal cut-off value of PGR was ≤5.27, sensitivity and specificity were 75% and 60.5%, respectively. Combinations of biomarkers with risk factors could improve diagnostic accuracy (AUC for atrophic gastritis 74.8, 95% CI 64.0–85.7, p<0.001; AUC for gastric cancer 75.5, 95% CI 64.2–86.8, p<0.001). PGI, PGR biomarkers combined with the risk of age, family history of gastric cancer, and previous gastric disease could not be an alternative test for upper endoscopy but might be a supportive method which is identifying individuals at medium- and high risk of gastric cancer and precancerous lesions who may need upper endoscopy.

Effect of aqueous extract of seed of broccoli on inflammatory cytokines and Helicobacter pylori infection: a randomized, double-blind, controlled trial in patients without atrophic gastritis

The purpose of this study was to investigate the anti-inflammatory effect of an aqueous extract of seed of broccoli (AESB) in Helicobacter pylori (HP)-infected patients without atrophic gastritis. This was a double-centre, randomized, double-blind, controlled study. A total of 110 HP-infected subjects were randomized to receive either AESB or placebo for 2 months. Inflammatory cytokine (IL-8, IFN-γ, TNF-α, CRP, IL-17A, IL-1β, IL-18), pepsinogen I, II (PG I, PG II), and gastrin-17 (G-17) measurements and ¹³C-urea breath tests were performed at baseline and at 60 days. At 60 days, there was no significant difference in any of the inflammatory cytokines, pepsinogen or gastrin between the two groups. However, IL-8, IFN-γ, PG I, PG I/PG II ratio (PGR), and G-17 were reduced by 9.02 pg/mL, 5.08 pg/mL, 24.56 ng/mL, 1.75 and 0.3 pmol/L, respectively, in the AESB group compared with baseline (all P < 0.05). The HP eradication rates in the AESB group and placebo group were 11.11 and 3.70% at 60 days, respectively (P > 0.05). No treatment-related adverse events were reported. Thus, AESB may reduce the risk of gastric mucosal lesions and decrease the risk of gastric cancer by relieving inflammatory cytokines. The safety profile of AESB was satisfactory. This study is registered with the Chinese Clinical Trials Registry (Registration No. ChiCTR2100054249).

The immune microenvironment in gastric adenocarcinoma

Like most solid tumours, the microenvironment of epithelial-derived gastric adenocarcinoma (GAC) consists of a variety of stromal cell types, including fibroblasts, and neuronal, endothelial and immune cells. In this article, we review the role of the immune microenvironment in the progression of chronic inflammation to GAC, primarily the immune microenvironment driven by the gram-negative bacterial species Helicobacter pylori. The infection-driven nature of most GACs has renewed awareness of the immune microenvironment and its effect on tumour development and progression. About 75-90% of GACs are associated with prior H. pylori infection and 5-10% with Epstein-Barr virus infection. Although 50% of the world's population is infected with H. pylori, only 1-3% will progress to GAC, with progression the result of a combination of the H. pylori strain, host susceptibility and composition of the chronic inflammatory response. Other environmental risk factors include exposure to a high-salt diet and nitrates. Genetically, chromosome instability occurs in ~50% of GACs and 21% of GACs are microsatellite instability-high tumours. Here, we review the timeline and pathogenesis of the events triggered by H. pylori that can create an immunosuppressive microenvironment by modulating the host's innate and adaptive immune responses, and subsequently favour GAC development.

The risk of diffuse-type gastric cancer following diagnosis with gastric precancerous lesions: a systematic review and meta-analysis

PURPOSE

Gastric cancers are classified as diffuse-type (DTGC) or intestinal-type (ITGC). DTGCs have distinct clinical and histopathologic features, and carry a worse overall prognosis compared to ITGCs. Atrophic gastritis (AG) and intestinal metaplasia (IM) are known precursors to ITGC. It is unknown if AG and IM increase risk for DTGC.

METHODS

We performed a systematic review to identify studies reporting on the association of AG/IM and DTGC. We extracted the odds ratio (OR) of the association from studies, and performed pool analysis. Subgroup analysis was performed on studies reporting histologic severity (using operative link systems) to assess if histologic severity of AG/IM was associated with higher risk.

RESULTS

We identified six case-control and eight cohort studies for inclusion. Both AG (pooled OR = 1.9, 95% CI 1.5 to 2.4, p < 0.001) and IM (pooled OR = 2.3, 95% CI 1.9 to 2.9, p < 0.001) demonstrated an association with DTGC. High AG severity was associated with increased risk for DTGC compared to low AG severity (OR = 1.7, 95% CI 1.2 to 2.3, p = 0.002). Similarly, high IM severity was associated with increased risk compared to low IM severity (OR = 1.9, 95% CI 1.3 to 2.7, p = 0.001).

CONCLUSION

Both AG and IM are associated with DTGC. Increasing histologic severity of both AG and IM increases risk for DTGC. There may exist a common pathway between ITGC and some DTGCs mediated through mucosal precursor lesions. These data may inform future strategies of cancer risk attenuation and control.

Prognosis of Seronegative Subjects with a Helicobacter pylori-infected Spouse

Background/Aims: Helicobacter pylori (H. pylori) can disseminate between couples. The present study compared the findings of gastric cancer screening between seronegative subjects according to the presence of an infected spouse.Materials and Methods: Follow-up data of seronegative subjects were analyzed among married couples who underwent gastric cancer screening via gastroscopy, serum pepsinogen, and anti-H. pylori IgG assays between January 2010 and May 2016. New detection rates of H. pylori infection and gastric neoplasm at the follow-up screening were compared between seronegative subjects according to the H. pylori-infected status of spouse.Results: Among 246 seronegative subjects with an H. pylori-infected spouse, 92 underwent follow-up tests (case group). Among 278 seronegative subjects with seronegative spouse, 94 underwent follow-up tests (control group). The past infection rate was higher in the case group than in the control group (52/92 vs. 34/94; P=0.005). New H. pylori infection was diagnosed in three of the 92 cases and two of the 94 controls (3.2% vs. 2.1%; P=0.681). During the mean follow-up of 67.9±36.0 months, three adenocarcinomas and two adenomas (5/184) were newly detected among the cases and their spouses, whereas none (0/188) were detected among the controls and their spouses (2.7% vs. 0%; P=0.029).Conclusions: Gastric neoplasm occurred more frequently in couples with an H. pylori-infected spouse. Because the past infection rate is higher among seronegative subjects with an infected spouse, gastric cancer screening is recommended in both partners when the spouse is infected.

Serum Assay Findings after Successful Helicobacter pylori Eradication

Serum pepsinogen (PG), anti-Helicobacter pylori (H. pylori) immunoglobulin G (IgG), and gastrin-17 (G-17) are plasma biomarkers for gastritis. H. pylori serology titers and PG levels increase during active H. pylori infection; moreover, elevated PG II levels indicate a high risk for diffuse-type gastric cancer in East Asian populations. Serum PG I/II ratios and PG I levels decrease with the progression of gastric corpus atrophy; thus, a combination of serum PG I levels ≤70 ng/mL and a PG I/II ratio ≤3 (serologic atrophy) indicates a high risk of intestinal-type gastric cancer. Serum G-17 is often not used as an indicator in H. pylori-seroprevalent populations because it is usually elevated in subjects with H. pylori infections. When H. pylori is eradicated, most patients show a rapid decrease in serum PG II levels and anti-H. pylori IgG titers within a few months. Seroreversion is required for several months to years after regression of H. pylori. Moreover, seroreversion may not always be achieved in all eradicated cases. The serum PG I/II ratio starts to increase after eradication; therefore, serologic atrophy improves accordingly, unless severe atrophy is present. Thus, some eradicated patients may show normal serum assay findings but have a higher risk for developing gastric cancer than H. pylori-naive subjects. Furthermore, serum PG levels decrease after gastrectomy and increase with the intake of certain drugs (e.g., aspirin or acid suppressants) or in renal failure patients. Due to such wide variations, serum assays are inadequate for the confirmation of H. pylori eradication. It is useful when interpreted with gastroscopy and other H. pylori test findings.

Helicobacter pylori Eradication Induced Constant Decrease in Interleukin- 1B Expression over More Than 5 Years in Patients with Gastric Cancer and Dysplasia

Background/Aims

Helicobacter pylori (Hp) suppresses gastric acid secretion by repressing the expression of the H⁺, K⁺-adenosine triphosphatase (H⁺, K⁺-ATPase) and stimulating interleukin-1 (IL-1β; encoded by IL-1B). This study was aimed at evaluating the expression of the H⁺, K⁺-ATPase and IL-1β after Hp eradication.

Methods

Two hundred twenty-one subjects were categorized as Hp-negative (n=84) or Hp-positive (n=137) according to the results of Hp tests (histology, CLO test, culturing, and serology). The mRNA expression levels of IL-1B and ATP4A (the gene encoding the α-subunit of H⁺, K⁺-ATPase) were measured in biopsy specimens from the gastric corpus using real-time polymerase chain reaction.

Results

The Hp-positive group had significantly higher IL-1B mRNA levels than the whole Hp-negative group and the intestinal metaplasia (IM)-negative subgroup. After Hp eradication, the difference between the Hp-negative and Hp-eradicated groups disappeared, including in the IM-negative subgroup. The IL-1B mRNA level did not significantly change from the baseline level. Within the gastric cancer (GC)/dysplasia subgroup, the IL-1B mRNA levels at 1, 2, 3–4, and ≥5 years after Hp eradication were significantly lower than the baseline level. The difference in ATP4A mRNA levels between the Hp-negative and Hp-positive groups was not significant at baseline, and the changes in the ATP4A mRNA levels after Hp eradication compared to the baseline levels in the whole group and subgroups stratified by the presence of IM and GC/dysplasia were not significant.

Conclusions

Infection with Hp has an effect on the level of IL-1B mRNA in IM-negative subjects. The continuous reduction in the IL-1B mRNA level in patients with GC/dysplasia after Hp eradication contributes to the prevention of metachronous GC after Hp eradication.

Population Attributable Fraction of Helicobacter pylori Infection-Related Gastric Cancer in Korea: A Meta-Analysis

PURPOSE

This study aimed to determine the proportion of gastric cancer attributable to Helicobactor pylori in the Korean population. Infection with H. pylori has been recognized as the most significant risk factor for gastric cancer. In Korea, gastric cancer is the most common cancer that accounted for 13.3% of all cancers in 2016. In particular, men are most commonly diagnosed with gastric cancer; the age-standardized incidence rate in men is 49.6 per 100,000, which is more than twice the incidence in women.

MATERIALS AND METHODS

The population attributable fraction (PAF) was calculated as a function of the relative risk (RR) of gastric cancer associated with H. pylori infections. To estimate PAF of gastric cancer due to H. pylori, the prevalence of H. pylori infections was extrapolated for the year of 1990 and a pooled RR was obtained by conducting a meta-analysis of studies recently published in Korea.

RESULTS

The estimated prevalence of H. pylori was 76.4% in men and 71.9% in women. The RRs (95% confidence interval) pooled from case-control studies using a random effects model was 1.69 (1.29-2.22) for overall gastric cancer and 2.17 (1.04-4.55) for non-cardia gastric cancer. Using the RR for overall gastric cancer, the estimated PAFs due to H. pylori were 34.5% in men and 33.2% in women.

CONCLUSION

The occurrence of gastric cancer in Koreans may be affected by other risk factors in addition to H. pylori infection, which may contribute to increasing baseline risk for gastric cancer.

Effect of Helicobacter pylori eradication after subtotal gastrectomy on the survival rate of patients with gastric cancer: follow-up for up to 15 years

OBJECTIVE

Helicobacter pylori (HP) is known to play an important role in the development of gastric cancer (GC). The aim of this study was to analyze the effect of HP eradication on the survival rate and cancer recurrence in patients who underwent subtotal gastrectomy for GC.

DESIGN

Totally 1,031 patients diagnosed with gastric adenocarcinoma who received surgical treatment at the Seoul National University Bundang Hospital from 2003 to 2017 and positive for HP infection were analyzed. The overall and GC-related survival according to HP eradication were compared; risk factors for GC-specific death and cancer recurrence were analyzed, and propensity score matching (PSM) was performed.

RESULTS

Statistically significant benefits of overall and GC-specific survival were observed in the eradicated group compared to the non-eradicated group (P < 0.001), and these benefits were maintained after PSM (P < 0.001) in both of early and advance stage. In Cox proportional hazards multivariate analyses, cancer stage (stage II, adjusted hazard ratio [aHR] = 9.33, P < 0.001; stage III or IV, aHR = 26.17, P < 0.001), and HP positivity (aHR = 3.41, P = 0.001) were independent risk factors for GC-specific death; cancer stage (cancer stage II, aHR = 7.08, P < 0.001; cancer stage III or IV, aHR = 19.64, P < 0.001) and HP positivity (aHR = 2.70; P = 0.005) were independent risk factors for cancer recurrence.

CONCLUSION

Our results suggest that HP needed to be conducted more intensively in patients who are surgically treated for GC, regardless of cancer stage.