Trends of gastric cancer burdens attributable to risk factors in China from 2000 to 2050.

Background: The incidence of gastric cancer (GC) decreased in past decades, which was thought largely attributable to risk factors control, yet China still accounts for 44% of global GC burdens. We aimed to estimate changing trajectories of proportions of GC burdens attributable to modifiable risk factors from 2000 to 2050 in China, to inform future targeted preventive strategies. Methods: The incidence and new cases of GC were predicted to 2050 using Bayesian age-period-cohort model based on incidence data by anatomical subsites drawn from 682 cancer registries from National Central Cancer Registry. Population attributable fractions (PAFs) were calculated based on prevalence of risk factors and relative risks with GC. Temporal trends of PAFs were described by sex and categories of risk factors using joinpoint analysis. Findings: We observed declining trends of PAFs of Helicobacter pylori (H. pylori) infection, smoking, pickled vegetable and alcohol consumption, but increasing trends of PAFs of unhealthy body mass index and diabetes for GC in China. The combined PAFs of these risk factors were estimated to decrease by 10.57% from 2000 to 2050 for GC. We estimated there will be 279,707 GC (122,796 cardia gastric cancer [CGC] and 156,911 non-cardia gastric cancer [NCGC]) cases in 2050. Out of these cases, 70.18% of GC cases could be attributable to modifiable risk factors, while H. pylori infection was predicted to be responsible for 40.7% of CGC and 62.1% of NCGC cases in 2050. Interpretation: More than half of GC remained attributable to modifiable risk factors in China. Continued effective strategies on risk factors control are needed to reduce the burden of this highly life-threatening cancer in future. Funding: Beijing Nova Program (No. Z201100006820069), CAMS Innovation Fund for Medical Sciences (CIFMS, grant No. 2021-I2M-1-023), CAMS Innovation Fund for Medical Sciences (CIFMS, grant No. 2021-I2M-1-010), Talent Incentive Program of Cancer Hospital Chinese Academy of Medical Sciences (Hope Star).

Identifying the optimal treatment strategy in patients with resectable non-cardia gastric cancer.

BACKGROUND: Multimodal treatment strategy including perioperative chemotherapy (PEC), postoperative chemoradiation therapy (POCR), and postoperative chemotherapy (POC) has been accepted as the standard of care in gastric cancer (GC). The ideal sequence and type of therapy remain undetermined. METHOD: The National Cancer Database was examined from 2006 to 2016 to identify patients with resectable non-cardia gastric cancer. Patient outcomes were compared based on the receipt of PEC, POCR, and POC. This comparison was repeated in a sub-group of patients who received optimal treatment. Optimal treatment was defined as initial chemotherapy within 45 days of diagnosis, resection within 45 days of diagnosis, negative margins, adjuvant chemotherapy within 90 days of resection and standard radiation dose (45 Gy). Kaplan-Meier test, log-rank test, and multivariable analysis (MVA) were performed. RESULTS: We identified 9589 patients. Median survival was greater in the PEC group followed by POCR and POC (60.6, 42.3, and 31.2 months, respectively). On MVA, factors associated with worse overall survival included age above median (≥ 63 years), Charlson-Deyo score of ≥ 1, non-academic/research program, poorly differentiated/undifferentiated grade, positive margins, and positive lymph nodes. Both PEC and POCR were associated with improved survival when compared to POC (HR 0.78 and 0.79; p < 0.001). When compared with PEC, no significant difference was noted with POCR (HR 1.01; p = 0.987). These results were maintained in optimally treated cohort (n = 3418). CONCLUSION: In patients with resectable non-cardia gastric cancer, both perioperative chemotherapy and postoperative chemoradiation therapy were associated with improved survival when compared to postoperative chemotherapy. No difference was noted between perioperative chemotherapy and postoperative chemoradiation therapy. These results were maintained in the optimally treated cohort.

Gastric Cancer Risk in Patients with Long-Term Use of Proton Pump Inhibitors: A Systematic Review and Meta-Analysis of Observational and Interventional Studies.

BACKGROUND: A growing number of studies that differ in design, quality, and results report an association between the use of proton pump inhibitors (PPIs) and the risk of gastric cancer (GC). We conducted a systematic review and meta-analysis, when possible, of observational and interventional studies examining PPI use and risk of GC. METHODS: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We identified studies fully published in English through January 2023 using MeSH and non-MeSH keywords. We used random effects models to calculate pooled risk estimates with 95% confidence interval (CI) between PPI use and overall GC, cardia GC, and non-cardia GC. We estimated heterogeneity (I2) among studies. We examined the effect of study design and quality, GC site, H. pylori infection, and PPI duration. We assessed quality using the Newcastle-Ottawa Quality Assessment Scale and Risk Of Bias In Non-randomized Studies of Interventions. RESULTS: We identified 15 observational studies, of which 13 were included in the meta-analysis (six cohort and seven case-control). There was a modest 1.67-fold increase in overall GC risk (95% CI 1.39, 2.00) and no increase in cardia GC risk [odds ratio (OR) 1.12; 95% CI 0.80, 1.56] with PPI use. However, there was high heterogeneity (I2 = 61.3%, p = 0.004) among studies. All but one study had at least moderate risk of bias. In the six studies accounting for H. pylori, GC risk associated with PPI use increased slightly (OR 1.78; 95% CI 1.25, 2.52). Duration response was not reported consistently to allow pooled estimates. We identified only one interventional randomized controlled study that included GC as an outcome of interest, and it did not show increased GC risk. CONCLUSIONS: The overall available evidence is not supportive of a meaningful change in GC risk, either cardia or non-cardia, with PPI use.

Rising Incidence of Non-Cardia Gastric Cancer among Young Women in the United States, 2000-2018: A Time-Trend Analysis Using the USCS Database.

INTRODUCTION: Although the global incidence of non-cardia gastric cancer (NCGC) is decreasing, there are limited data on sex-specific incidence in the United States. This study aimed to investigate time trends of NCGC from the SEER database to externally validate findings in a SEER-independent national database, and to further assess trends among subpopulations. METHODS: Age-adjusted incidence rates of NCGC were obtained from the SEER database from 2000 to 2018. We used joinpoint models to calculate average annual percentage change (AAPC) to determine sex-specific trends among older (≥55 years) and younger adults (15-54 years). Using the same methodology, findings were then externally validated using SEER-independent data from the National Program of Cancer Registries (NPCR). Stratified analyses by race, histopathology, and staging at diagnosis were also conducted in younger adults. RESULTS: Overall, there were 169,828 diagnoses of NCGC from both independent databases during the period 2000-2018. In SEER, among those <55 years, incidence increased at a higher rate in women (AAPC = 3.22%, p < 0.01) than men (AAPC = 1.51%, p = 0.03), with non-parallel trends (p = 0.02), while a decreasing trend was seen in both men (AAPC = -2.16%, p < 0.01) and women (AAPC = -1.37%, p < 0.01) of the ≥55 years group. Validation analysis of the SEER-independent NPCR database from 2001 to 2018 showed similar findings. Further stratified analyses showed that incidence is disproportionately increasing in young non-Hispanic White women [AAPC = 2.28%, p < 0.01] while remaining stable in their counterpart men [AAPC = 0.58%, p = 0.24] with non-parallel trends (p = 0.04). This pattern was not observed in other race groups. CONCLUSION: NCGC incidence has been increasing at a greater rate in younger women compared to counterpart men. This disproportionate increase was mainly seen in young non-Hispanic White women. Future studies should investigate the etiologies of these trends.

Does non-metastatic gastric cancer of the cardia warrant a different treatment strategy?

BACKGROUND: Multimodal treatment strategies with surgery as its centerpiece have been accepted as the standard of care in nonmetastatic cardia gastric cancer (CGC). There remains a lack of consensus regarding the optimal multimodal treatment strategy. METHOD: We queried National Cancer Database from 2004 to 2016 to identify patients with resected nonmetastatic CGC who received perioperative chemotherapy (PEC), postoperative chemoradiation therapy (POCR), or postoperative chemotherapy (POC). A subgroup analysis was performed in optimally treated patients defined as initial chemotherapy within 45 days of diagnosis, resection within 45 days of diagnosis, negative margins, adjuvant chemotherapy within 90 days of resection, and standard radiation dose (45 Gy). Kaplan-Meier, Univariate analysis (UVA), and Multivariable analysis (MVA) were performed. RESULTS: We identified 2387 patients. Median survival was 38.8 months in the PEC group, 36 months in the POCR group, and 32.3 months in the POC group (p = 0.1025). On UVA, patients treated with PEC had an association with improved survival (HR, 0.83; p = 0.037) when compared with POC. On MVA, no significant difference was noted in overall survival (OS) between PEC, POCR, and POC, similar to subgroup analysis of optimally treated cohort. CONCLUSION: OS rate in nonmetastatic CGC is not significantly different between patients receiving PEC, POCR, or POC.

Helicobacter pylori multiplex serology and risk of non-cardia and cardia gastric cancer: a case-cohort study and meta-analysis.

BACKGROUND: Helicobacter pylori infection is a major cause of non-cardia gastric cancer (NCGC), but uncertainty remains about the associations between sero-positivity to different H. pylori antigens and risk of NCGC and cardia gastric cancer (CGC) in different populations. METHODS: A case-cohort study in China included ∼500 each of incident NCGC and CGC cases and ∼2000 subcohort participants. Sero-positivity to 12 H. pylori antigens was measured in baseline plasma samples using a multiplex assay. Hazard ratios (HRs) of NCGC and CGC for each marker were estimated using Cox regression. These were further meta-analysed with studies using same assay. RESULTS: In the subcohort, sero-positivity for 12 H. pylori antigens varied from 11.4% (HpaA) to 70.8% (CagA). Overall, 10 antigens showed significant associations with risk of NCGC (adjusted HRs: 1.33 to 4.15), and four antigens with CGC (HRs: 1.50 to 2.34). After simultaneous adjustment for other antigens, positive associations remained significant for NCGC (CagA, HP1564, HP0305) and CGC (CagA, HP1564, HyuA). Compared with CagA sero-positive only individuals, those who were positive for all three antigens had an adjusted HR of 5.59 (95% CI 4.68-6.66) for NCGC and 2.17 (95% CI 1.54-3.05) for CGC. In the meta-analysis of NCGC, the pooled relative risk for CagA was 2.96 (95% CI 2.58-3.41) [Europeans: 5.32 (95% CI 4.05-6.99); Asians: 2.41 (95% CI 2.05-2.83); Pheterogeneity<0.0001]. Similar pronounced population differences were also evident for GroEL, HP1564, HcpC and HP0305. In meta-analyses of CGC, two antigens (CagA, HP1564) were significantly associated with a higher risk in Asians but not Europeans. CONCLUSIONS: Sero-positivity to several H. pylori antigens was significantly associated with an increased risk of NCGC and CGC, with varying effects between Asian and European populations.

Cardia and non-cardia gastric cancer risk associated with Helicobacter pylori in East Asia and the West: A systematic review, meta-analysis, and estimation of population attributable fraction.

OBJECTIVES: To assess the region-specific relative risk of cardia/non-cardia gastric cancer (CGC/NCGC) associated with Helicobacter pylori (H. pylori) and quantify its contribution to gastric cancer burden using population attributable fraction (PAF). METHODS: PubMed, EMBASE, Web of Science, and Cochrane Central databases were searched by two reviewers until April 20, 2022. The association between H. pylori infection and NCGC/CGC was assessed using pooled odds ratios (ORs) with 95% confidence intervals (CIs). PAF was calculated using the formula of H. pylori prevalence and the pooled OR. RESULTS: One hundred and eight studies were included. A significant association was observed between H. pylori infection and NCGC in East Asia (OR, 4.36; 95% CI: 3.54-5.37) and the West (OR, 4.03; 95% CI: 2.59-6.27). Regarding CGC, a significant association was found only in East Asia (OR, 2.86; 95% CI: 2.26-3.63), not in the West (OR, 0.80; 95% CI: 0.61-1.05). For studies with a follow-up time of ≥10 years, pooled ORs for NCGC and CGC in East Asia were 5.58 (95% CI: 4.08-7.64) and 3.86 (95% CI: 2.69-5.55), respectively. Pooled OR for NCGC was 6.80 (95% CI: 3.78-12.25) in the West. PAFs showed that H. pylori infection accounted for 71.2% of NCGC, 60.7% of CGC in East Asia, and 73.2% of NCGC in the West. CONCLUSIONS: Gastric cancer burden associated with H. pylori infection exhibits important geographical differences. Prolonged follow-up period could overcome the underestimation of the magnitude of the association between H. pylori infection and CGC/NCGC. Customized strategies for H. pylori screening and eradication should be implemented to prevent gastric cancer.

Prevalence of Helicobacter pylori in Non-Cardia Gastric Cancer in China: A Systematic Review and Meta-Analysis.

Non-cardia gastric cancer was significantly associated with Helicobacter pylori (H. pylori) infection. Reducing H. pylori prevalence was an important prevention strategy for non-cardia gastric cancer. However, national-level data on the H. pylori prevalence in non-cardia gastric cancer were limited in China. Therefore, we conducted this study to estimate the pooled prevalence of H. pylori in non-cardia gastric cancer in China. We searched PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan Fang, and VIP Database for Chinese Technical Periodicals for studies reporting H. pylori prevalence in non-cardia gastric cancer in China which were published before September 1, 2021. Pooled prevalence was calculated using a random-effect model. Subgroup analysis and meta-regression were used to explore the potential sources of heterogeneity. Egger's test and funnel plot were used to assess publication bias. A total number of 55 studies with 5324 cases of non-cardia gastric cancer were included in this study. The pooled prevalence of H. pylori in non-cardia gastric cancer in China was 66.5% (95%CI: 62%-71%, I 2=93.8%, P<0.0001). In subgroup analysis, a significant difference in the prevalence of H. pylori in non-cardia gastric cancer was noted when stratified by geographic region of China (P=0.0112). The highest H. pylori prevalence (78.9%, 95%CI: 69.9%-87.8%) was noted in Northwest China and the lowest (53.1%, 95%CI: 38.9%-67.3%) was in North China. In meta-regression, a significant association between H. pylori prevalence and geographic region was found, while type of sample, H. pylori testing method, diagnosis period, detection timing, type of study design, quality grade, publication year, and sample size were not associated with the prevalence of H. pylori in non-cardia gastric cancer (P>0.05). A large proportion of non-cardia gastric cancers were associated with H. pylori infection in China, emphasizing the possible benefits of H. pylori eradication for the prevention and control of non-cardia gastric cancer.

Recent incidence trends of oesophago-gastric cancer in Sweden.

BACKGROUND: Oesophago-gastric cancers have had sharply different and changing incidence patterns depending on subsite and histology, but incidence data for the last few years are missing. We aimed to provide updated incidence trends of oesophago-gastric tumours by subsite and histology in Sweden. MATERIAL AND METHODS: The Swedish Cancer Registry provided data for 74,303 patients with oesophago-gastric cancer aged ≥50 years in 1970-2020. The focus was on the last available 6-year period, i.e., from 2015 until 2020 inclusive. We calculated yearly age-standardized and sex-specific incidence rates per 100,000 person-years, with the age distribution (in 5-year age groups) of the Swedish population in year 2000 as reference. RESULTS: For oesophageal squamous cell carcinoma, the incidence continued to decrease between 2015 and 2020 (from 6.46 to 5.53/100,000 person-years in men, and from 4.26 to 3.78/100,000 person-years in women). For oesophageal adenocarcinoma, the earlier increasing incidence rates rather slightly decreased in men between 2015 and 2020 (from 12.39 to 11.70/100,000 person-years) and increased marginally in women (from 2.49 to 2.85/100,000 person-years). The incidence rates of cardia adenocarcinoma were stable between 2015 and 2020 (from 9.83 to 10.13/100,000 person-years in men, and from 2.21 to 2.41/100,000 person-years in women). For gastric non-cardia adenocarcinoma, the incidence rates continued to decrease between 2015 and 2020 (from 14.67 to 13.29/100,000 person-years in men, and from 9.37 to 8.14/100,000 person-years in women). There were no major age-group differences in recent incidence trends. CONCLUSION: The 6-year period from 2015 to 2020 inclusive has witnessed stabilising incidence rates of oesophageal and cardia adenocarcinoma in Sweden, whereas the incidence rates of oesophageal squamous cell carcinoma and non-cardia gastric adenocarcinoma have continued to decrease.

The Distinct Impact of TAM Infiltration on the Prognosis of Patients With Cardia and Non-Cardia Gastric Cancer and Its Association With H. pylori Infection.

BACKGROUND: In stage III gastric cancer (GC), the role of tumor-associated macrophages (TAMs) and Helicobacter pylori (H. pylori) infection impact tumor progression; however, the specific mechanisms remain controversial. We speculated whether this controversy is caused by differences in the location of TAM infiltration (in the core (CT) and invasive margin (MI) of primary tumors) and the topographical subsites of GC (cardia and non-cardia). Therefore, in this study, we investigated TAMs in different locations and H. pylori infection status as prognostic biomarkers for GC. METHODS: Immunohistochemical staining for CD68 (pan-macrophage), CD163 (M2-like macrophage), and H. pylori in 200 samples (100 cases of cardia-GC [CGC] and 100 cases of non-cardia GC [NCGC]) was performed. We compared the number of CD68+ and CD163+ macrophages that infiltrated the CT and MI in patients with the prognosis of CGC and NCGC, respectively. In addition, we analyzed the relationship between H. pylori status and the prognosis of patients with GC in different locations, as well as the correlation with TAM infiltration. RESULTS: The distribution of TAMs had distinct characteristics in CGC and NCGC, especially differences between CT and MI subtype. A Kaplan-Meier analysis showed that a high number of CD68+ macrophages that infiltrated the CT in CGC was associated with a better prognosis, whereas infiltration at the MI in NCGC indicated a poor prognosis. Furthermore, a high number of CD163+ macrophages infiltrating the MI resulted in a poor prognosis in CGC and NCGC cohorts. Considering the larger differences in the relationship between the infiltration of CD68+ macrophages at different locations and prognosis, we divided the GC cases into marginal and central GC, based on this difference. This resulted in an accurate estimation of the prognosis. Moreover, positive H. pylori status in central GC was significantly associated with a better prognosis and TAM infiltration. CONCLUSION: TAMs in different locations and H. pylori status were identified as independent prognostic markers, with an obvious correlation between them. Therefore, it is important to clarify the impact of TAM location on the prognosis of patients with GC, which contributes to the development of potential therapeutic strategies.

Association analysis between SNPs in LATS1 and LATS2 and non-cardia gastric cancer.

BACKGROUND: Many studies have found that large tumor suppressor kinase 1 (LATS1) and LATS2 play important roles in many diseases, but studies have been rare on the relationship between these genes and non-cardia gastric cancer (GC). We performed a case-control association study to investigate the associations between single nucleotide polymorphisms (SNPs) in LATS1 and LATS2 genes and Helicobacter pylori (H. pylori) infection as well as the risk of non-cardia GC. METHODS: First, H. pylori infection was determined by the serological test using enzyme-linked immunoassay. Then genotyping of SNPs was performed for 808 samples by the Taqman method. Finally, unconditional logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for age and gender, for the association of each SNP with the infection of H. pylori, the risk of non-cardia gastric cancer, as well as the expression of LATS1 and LATS2 proteins in non-cardia GC tissues, using the codominant, dominant, recessive, overdominant, and log-additive inheritance models, respectively. RESULTS: The statistical results showed that LATS2 rs9552315 was associated with H. pylori infection, and the CC + CT genotype could reduce the risk of H. pylori infection (odds ratio [OR]: 0.549, 95% confidence interval [CI]: 0.339-0.881, P < 0.05) compared with the TT genotype in a dominant model. LATS1 rs9393175 was associated with the risk of non-cardia GC, and the AG genotype reduced the risk of non-cardia GC (OR: 0.702, 95% CI: 0.516-0.952, P < 0.05) compared with the GG + AA genotype in an overdominant model. LATS2 rs9509492 was associated with the risk of GC in an log-additive model. No associations were found between five SNPs and expression of LATS1 and LATS2 proteins in non-cardia GC tissue. CONCLUSIONS: LATS2 rs9552315 CT genotype may be a protective factor against infection of H. pylori. LATS1 rs9393175 AG genotype and LATS2 rs9509492 GG genotype may be protective factors for non-cardia GC.

Cardia Gastric Cancer in the Gastric Pouch 5 Years after Gastric Bypass: A Case Report.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is one of the most frequently performed bariatric procedures worldwide. Remnant gastric cancer after RYGB is a rare complication. There were about seventeen cases reported in the world. The location of the tumor in these cases occurs mainly in the gastric antrum, followed by the body, then the pylorus and linitis plastica, and the last was fundus of the stomach. To the best of our knowledge, this is the first case that gastric cancer located in the cardia of stomach after RYGB. CASE REPORT: A 68-year-old male patient had chronic esophagitis, bile reflux gastritis, and erosive antral gastritis 5 years after RYGB and now developed to aggressive carcinoma in the gastric pouch. In spite of having chemotherapy and traditional Chinese medicine therapy, the patient died of multiple organ failure after 15 months. CONCLUSIONS: This case report highlights the importance to have gastroscopy to observe the proximal small remnant stomach after RYGB in long-term follow-up. Attention must be paid when patients develop symptoms like abdominal pain or excessive weight loss after RYGB. For patients at high risk such as those who have a family history of gastric cancer or presenting abnormal levels of tumor markers should rather undergo Sleeve Gastrectomy plus Jejunojejunal Bypass (SGJB) instead of RYGB.

Polymorphisms of TLR9 gene are associated with a decreased risk of H. pylori infection in a Chinese population.

BACKGROUND: A series of evidence suggests that genetic variation in toll-like receptor (TLR) 9 might influence the outcome of Helicobacter pylori (H. pylori) infection and play an important role in gastric carcinogenesis. METHODS: We conducted a case-control study to evaluate TLR9 polymorphisms on the risk of H. pylori infection and non-cardia gastric cancer (GC) in a Chinese population. We genotyped a tagging single-nucleotide polymorphism (SNP), rs164640, and a potentially functional SNP, rs187084, by TaqMan technique among 288 patients with non-cardia GC and 281 controls. Unconditional logistic regression (LR) was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for SNPs in association with H. pylori infection and non-cardia GC risk. RESULTS: Our results indicated that among normal controls, the minor allele homozygotes of both SNPs were significantly associated with a decreased risk of H. pylori infection when compared with their major allele homozygotes (for rs164640: OR =0.41, 95% CI, 0.18-0.93; for 187084: OR =0.38, 95% CI, 0.17-0.85). However, neither of the two SNPs demonstrated a significant association with non-cardia GC risk. CONCLUSIONS: Our results revealed that TLR9 polymorphisms might have effects on the risk of H. pylori infection, but they do not seem to contribute to the risk of non-cardia GC in our studied population.

Distribution of gastric adenocarcinoma subtypes in different ethnicities in Kuala Lumpur, Malaysia

The multiracial population in Malaysia has lived together for almost a century, however, the risk ofgastric cancer among them varies. This study aimed to determine the distribution of different gastricadenocarcinoma subtypes and Helicobacter pylori infection status among gastric adenocarcinomapatients. Patients with gastric adenocarcinoma were enrolled from November 2013 to June 2015.Blood samples were collected for detection of H. pylori using ELISA method. Gastric adenocarcinomacases were more prevalent in the Chinese (52.8%), followed by the Malays (41.7%) and leastprevalent in the Indians (5.6%). Gastric adenocarcinoma located in the cardia was significantly moreprevalent in the Malays (66.7%) compared to the Chinese (26.3%), whereas non-cardia cancer wasdiagnosed more in the Chinese (73.7%) compared to the Malays (33.3%) [P = 0.019; OR = 5.6, 95CI: 1.27 to 24.64]. The Malays also had significantly higher prevalence of gastric tumour locatedat the cardia or fundus than other gastric sites compared to the Chinese (P = 0.002; OR: 11.2, 95%CI: 2.2 to 56.9). Among the cardia gastric cancer patients, 55.6% of the Malays showed intestinalhistological subtype, whereas all the Chinese had the diffuse subtype. More than half of the patients(55.3%) with gastric adenocarcinoma were positive for H. pylori infection and among them, 66.7%were Chinese patients. The risk of gastric adenocarcinoma in our population is different amongethnicities. Further studies on host factors are needed as it might play an important role in gastriccancer susceptibility in our population.