Current issues and future perspectives of gastric cancer screening

Gastric cancer remains the second leading cause of cancer death worldwide. About half of the incidence of gastric cancer is observed in East Asian countries, which show a higher mortality than other countries. The effectiveness of 3 new gastric cancer screening techniques, namely, upper gastrointestinal endoscopy, serological testing, and “screen and treat” method were extensively reviewed. Moreover, the phases of development for cancer screening were analyzed on the basis of the biomarker development road map. Several observational studies have reported the effectiveness of endoscopic screening in reducing mortality from gastric cancer. On the other hand, serologic testing has mainly been used for targeting the high-risk group for gastric cancer. To date, the effectiveness of new techniques for gastric cancer screening has remained limited. However, endoscopic screening is presently in the last trial phase of development before their introduction to population-based screening. To effectively introduce new techniques for gastric cancer screening in a community, incidence and mortality reduction from gastric cancer must be initially and thoroughly evaluated by conducting reliable studies. In addition to effectiveness evaluation, the balance of benefits and harms must be carefully assessed before introducing these new techniques for population-based screening.

Stomach cancer screening and preventive behaviors in relatives of gastric cancer patients

AIM:To investigate gastric cancer screening and preventive behaviors among the relatives of patients with gastric cancer[i.e.,gastric cancer relatives(GCRs)].METHODS:We examined the Korean National Health and Nutrition Examination Survey 2005(KNHANESⅢ) database and compared the gastric cancer screening and preventive behaviors of GCRs(n=261)with those of non-GCRs(n=454)and controls without a family history of cancer(n=2842).RESULTS:The GCRs were more likely to undergo gastric cancer screening compared with the control group(39.2%vs 32.3%,adjusted odds ratio:1.43,CI:1.05-1.95),although the absolute screening rate was low.Dietary patterns and smoking rates did not differ significantly between the groups,and a high proportion of GCRs reported inappropriate dietary habits(i.e.,approximately 95%consumed excessive sodium,30% were deficient in vitamin C,and 85%were deficient in dietary fiber).CONCLUSION:The gastric cancer screening and preventive behaviors of GCRs have yet to be improved.To increase awareness among GCRs,systematic family education programs should be implemented.

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 pepsinogenⅠ(PGⅠ) /pepsinogenⅡ(PGⅡ) 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 4patients(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.

Serum pepsinogen Ⅱ is a better diagnostic marker in gastric cancer

AIM:To investigate screening makers for gastric cancer,we assessed the association between gastric cancer and serum pepsinogens(PGs).METHODS:The subjects comprised 450 patients with gastric cancer,111 individuals with gastric atrophy,and 961 healthy controls.Serum anti-Helicobacter pylori(H.pylori) immunoglobulin G(IgG),PGⅠand PG Ⅱ were detected by enzyme-linked immunosorbent assay.Gastric atrophy and gastric cancer were diagnosed by endoscopy and histopathological examinations.Odds ratios and 95%CIs were calculated using multivariate logistic regression.RESULTS:Rates of H.pylori infection remained high in Northeastern China.Rates of H.pylori IgG positivity were greater in the gastric cancer and gastric atrophy groups compared to the control group(69.1% and 75.7% vs 49.7%,P < 0.001).Higher levels of PG Ⅱ(15.9 μg/L and 13.9 μg/L vs 11.5 μg/L,P < 0.001) and lower PGⅠ/PG Ⅱ ratio(5.4 and 4.6 vs 8.4,P < 0.001) were found in patients with gastric cancer or gastric atrophy compared to healthy controls,whereas no correlation was found between the plasma PGⅠconcentration and risk of gastric cancer(P = 0.537).In addition,multivariate logistic analysis indicated that H.pylori infection and atrophic gastritis were independent risk factors for gastric cancer.Lower plasma PGⅠ/PG Ⅱ ratio was associated with higher risks of atrophy and gastric cancer.Furthermore,plasma PG Ⅱ?level?significantly?correlated?with?H.pyloriinfected gastric cancer.CONCLUSION:Serum PG Ⅱ concentration and PG Ⅰ/PG Ⅱ ratio are potential biomarkers for H.pyloriinfected gastric disease.PG Ⅱ is independently associated with risk of gastric cancer.

LGFFN-GHI: A Local-Global Feature Fuse Network for Gastric Histopathological Image Classification

Gastric cancer remains the third most common cause of cancer-related death. Histopathological examination of gastric cancer is the gold standard for the diagnosis of gastric cancer. However, manual pathology examination is time-consuming and laborious. Computer-aided diagnosis (CAD) systems can assist pathologists in diagnosing pathological images, thus improving the efficiency of disease diagnosis. In this paper, we propose a two-branch network named LGFFN-GHI, which can classify histopathological images of gastric cancer into two categories: normal and abnormal. LGFFN-GHI consists of two parallel networks, ResNet18 and Pvt-Tiny, which extract local and global features of microscopic gastric tissue images, respectively. We propose a feature blending module (FFB) that fuses local and global features at the same resolution in a cross-attention manner. This enables ResNet18 to acquire the global features extracted by Pvt-Tiny, while enabling Pvt-Tiny to acquire the local features extracted by ResNet18. We conducted experiments on a novel publicly available subsize image database of gastric histopathology (GasHisSDB). The experimental results show that LGFFN-GHI achieves an accuracy of 96.814%, which is 2.388% and 3.918% better than the baseline methods ResNet18 and Pvt-Tiny, respectively. Our proposed network exhibits high classification performance, demonstrating its effectiveness and future potential for the gastric histopathology image classification (GHIC) task.