Gastric cancer screening: a systematic review and meta-analysis

The road to a world-unified approach to the management of patients with gastric intestinal metaplasia: a review of current guidelines

OBJECTIVE

During the last decade, the management of gastric intestinal metaplasia (GIM) has been addressed by several distinct international evidence-based guidelines. In this review, we aimed to synthesise these guidelines and provide clinicians with a global perspective of the current recommendations for managing patients with GIM, as well as highlight evidence gaps that need to be addressed with future research.

DESIGN

We conducted a systematic review of the literature for guidelines and consensus statements published between January 2010 and February 2023 that address the diagnosis and management of GIM.

RESULTS

From 426 manuscripts identified, 16 guidelines were assessed. There was consistency across guidelines regarding the purpose of endoscopic surveillance of GIM, which is to identify prevalent neoplastic lesions and stage gastric preneoplastic conditions. The guidelines also agreed that only patients with high-risk GIM phenotypes (eg, corpus-extended GIM, OLGIM stages III/IV, incomplete GIM subtype), persistent refractory Helicobacter pylori infection or first-degree family history of gastric cancer should undergo regular-interval endoscopic surveillance. In contrast, low-risk phenotypes, which comprise most patients with GIM, do not require surveillance. Not all guidelines are aligned on histological staging systems. If surveillance is indicated, most guidelines recommend a 3-year interval, but there is some variability. All guidelines recommend H. pylori eradication as the only non-endoscopic intervention for gastric cancer prevention, while some offer additional recommendations regarding lifestyle modifications. While most guidelines allude to the importance of high-quality endoscopy for endoscopic surveillance, few detail important metrics apart from stating that a systematic gastric biopsy protocol should be followed. Notably, most guidelines comment on the role of endoscopy for gastric cancer screening and detection of gastric precancerous conditions, but with high heterogeneity, limited guidance regarding implementation, and lack of robust evidence.

CONCLUSION

Despite heterogeneous populations and practices, international guidelines are generally aligned on the importance of GIM as a precancerous condition and the need for a risk-stratified approach to endoscopic surveillance, as well as H. pylori eradication when present. There is room for harmonisation of guidelines regarding (1) which populations merit index endoscopic screening for gastric cancer and GIM detection/staging; (2) objective metrics for high-quality endoscopy; (3) consensus on the need for histological staging and (4) non-endoscopic interventions for gastric cancer prevention apart from H. pylori eradication alone. Robust studies, ideally in the form of randomised trials, are needed to bridge the ample evidence gaps that exist.

Gastric Cancer Screening: Intention to Adhere and Patients' Perspective

BACKGROUND AND AIMS

Gastric cancer (GC) is the third cause of cancer mortality worldwide. A screening strategy that combines an upper gastrointestinal endoscopy (UGIE) with a screening colonoscopy may be cost-effective in intermediate-risk regions. This study aimed to evaluate the intention to adhere to combined endoscopic screening and assess knowledge of GC symptoms, risk factors, and barriers to screening.

METHODS

Cross-sectional study enrolling individuals eligible for CRC screening in northern Portugal, where a populational fecal occult blood test (FOBT) program is implemented. The validated PERCEPT-PREVENT tool was applied across three groups: (a) not yet invited to CRC screening, (b) FOBT-positive referred to colonoscopy, and (c) primary colonoscopy screening.

RESULTS

A high acceptance rate was observed for combined endoscopic screening (94%; n = 264) [not yet invited to CRC screening 98% (n = 90) vs. FOBT-positive referred to colonoscopy 90% (n = 103) vs. primary colonoscopy 97% (n = 71); p = 0.017], with the vast majority reporting intention to adhere in the setting of full reimbursement (97%; n = 255). Most respondents were unaware of any possible GC symptom (76%; n = 213), risk factor (73%; n = 205), and UGIE-related complication (85%; n = 237). Regular follow-up with the primary care physician (Odds Ratio (OR) 27.59, 95% confidence interval (CI) 2.99-254.57), lower perceived negative health consequences of UGIE (OR 1.40, 95% CI 1.13-1.74), and lower perceived financial burden (OR 2.46, 95% CI 1.04-5.85) were the only factors independently associated with a higher intention to undergo combined screening.

CONCLUSIONS

Willingness to undergo combined endoscopic screening was notably high and positively impacted by lower perceived barriers. Additional efforts should be undertaken to improve levels of digestive health literacy.

Population effectiveness of endoscopy screening for mortality reduction in gastric cancer

Objectives

No randomized controlled trials have compared endoscopic screening with no screening for gastric cancer on an intention-to-screen basis, and the population-based evidence is insufficient. This study aimed to identify factors contributing to the population effectiveness of cancer screening, estimate the number needed to screen (NNS) to reduce one gastric cancer-related death, and evaluate the expected mortality-rate reduction in endoscopic screening for gastric cancer in 184 countries.

Methods

Factors contributing to the attributable risk, NNS, and mortality-rate reduction were identified. A rapid review was performed in PubMed to estimate the pooled relative risk of endoscopic screening compared to that of no screening for mortality reduction. NNSs and mortality-rate reduction were estimated using the pooled relative risk and GLOBOCAN data.

Results

The crude mortality rate, the effectiveness of the screening modality, and the screened rate contributed to the attributable risk, NNS, and mortality-rate reduction in cancer screening. The pooled relative risk was 0.58 in endoscopy screening compared to that in no screening. NNSs and expected mortality-rate reduction differed across countries and ranged from 2522 to 91,575 and 0.2 to 7.9 (per 100,000 individuals) for the screened rate of 20%, respectively.

Conclusions

In addition to the effectiveness of the used modality, the disease burden and screened rate were important in the population effectiveness of cancer screening. Regarding the high NNSs and the low expected mortality-rate reduction, population-based endoscopic screening seems not to be effective in many countries, and these results are meaningful in decision-making regarding the introduction of endoscopic screening.

Combined gastric and colorectal cancer endoscopic screening may be cost-effective in Europe with the implementation of artificial intelligence: an economic evaluation

BACKGROUND/AIMS

Endoscopic screening for gastric cancer (GC) is not recommended in low-intermediate incidence countries. Artificial intelligence (AI) has high accuracy in GC detection and might increase the cost-effectiveness of screening strategies. We aimed to assess the cost-effectiveness of AI for GC detection in settings with different GC incidence and different accuracies of AI systems.

METHODS

Cost-effectiveness analysis (using Markov model) comparing different screening strategies (no screening versus single esophagogastroduodenoscopy (EGD) at 50 years versus stand-alone EGD every 5/10 years versus combined EGD and screening colonoscopy once or twice per decade in Netherlands, Italy and Portugal) with variable AI accuracy settings. The primary outcome was the incremental cost-effectiveness ratio of the different strategies versus no screening. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

Without AI, one single EGD at 50 years (Netherlands, Italy, Portugal), EGD combined with screening colonoscopy once per decade (Italy and Portugal) and EGD combined with screening colonoscopy twice per decade (Portugal) are cost-effective when compared with no screening. If AI increases the accuracy of EGD by at least 1% in comparison to the accuracy of white-light endoscopy accuracy (89%), combined screening twice per decade also becomes cost-effective in Italy. If AI accuracy reaches at least 96%, combined screening once per decade is also cost-effective in the Netherlands.

DISCUSSION

In European countries, AI-assisted EGD may improve the cost-effectiveness of GC screening with combined EGD and screening colonoscopy. The actual effect of AI on cost-effectiveness may vary dependent on the accuracy and costs of the AI system.

Development and validation of the PERCEPT-PREVENT tool to determine risk perception and attitudes towards digestive cancer screening

BACKGROUND AND AIMS

Colorectal cancer (CRC) screening is recommended worldwide, while gastric cancer (GC) screening may also be defendable in some settings. However, adherence rates and factors influencing participation are not well characterized. This study aimed to validate a tool to determine risk perception of CRC and GC and also of endoscopy-related complications.

METHODS

A questionnaire in CRC risk perception based on the Health Belief Model was used. Forward/backward translation (English-Portuguese) and cultural adaptation were performed. After revision by a panel of experts, the questionnaire was adapted to target GC risk perception and perceptions towards endoscopy-related complications. The final version of the questionnaire (PERCEPT-PREVENT tool) was applied to 44 individuals, through telephonic interview, at enrolment and at intervals ≤3 weeks. Test-retest reliability and agreement were assessed.

RESULTS

Almost perfect reliability between test and retest was obtained for CRC symptom knowledge score (ICC = 0.88), risk factor knowledge score (ICC = 0.89), and perceived severity (ICC = 0.84). At least moderate agreement between test and retest was obtained for GC symptom knowledge score (ICC = 0.94), risk factor knowledge score (ICC = 0.92), and perceived severity (ICC = 0.58). Test-retest reliability was assessed for barrier domains [faecal occult blood test ICC = 0.63; colonoscopy ICC = 0.79; upper GI endoscopy (UGIE) ICC = 0.83]. A total of 91% and 98% of participants gave the same answer in the test and retest for preferred method of CRC screening and intention to undergo UGIE for GC screening combined with a screening colonoscopy, respectively.

DISCUSSION

PERCEPT-PREVENT is a valid and reliable tool for CRC and GC risk perception evaluation.

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.

Endoscopic Imaging for the Diagnosis of Neoplastic and Pre-Neoplastic Conditions of the Stomach

Gastric cancer is an aggressive disease with low long-term survival rates. An early diagnosis is essential to offer a better prognosis and curative treatment. Upper gastrointestinal endoscopy is the main tool for the screening and diagnosis of patients with gastric pre-neoplastic conditions and early lesions. Image-enhanced techniques such as conventional chromoendoscopy, virtual chromoendoscopy, magnifying imaging, and artificial intelligence improve the diagnosis and the characterization of early neoplastic lesions. In this review, we provide a summary of the currently available recommendations for the screening, surveillance, and diagnosis of gastric cancer, focusing on novel endoscopy imaging technologies.