Comparative molecular subtypes of index and metachronous gastric adenocarcinomas: a study of 42 Korean patients

To date, there have been no studies comparing the molecular subtypes of Index gastric cancers (IGCs) and metachronous gastric cancers (MGCs). We evaluated a cohort of 42 patients with 43 IGCs and 45 MGCs. Molecular subtyping was performed by immunohistochemistry of mismatch repair (MMR) proteins, E-cadherin, p53, and Epstein-Barr virus- (EBV-) in situ hybridization (ISH). Gastric adenocarcinomas were classified into 5 subtypes: EBV-associated, MMR deficient (MMRD), E-cadherin aberrant, p53-aberrant [p53(+)], and p53 non-aberrant [p53(neg)]. All IGCs had been successfully treated by either surgery (19%) or endoscopic resection (81%). The mean interval between IGCs and MGCs was 85 months. Among the IGCs, EBV-associated, MMRD, E-cadherin-aberrant, p53(+), and p53(neg) molecular subtypes represented 2 (5%), 4 (9%), 2 (5%), 21 (49%), and 14 (32%) of the cases, respectively. Two cases had concomitant p53(+) and aberrant E-cadherin molecular subtypes. Among metachronous cancers, EBV-associated, MMRD, E-cadherin-aberrant, p53(+), and p53(neg) molecular subtypes represented 3 (7%), 11 (24%), 0 (0%), 22 (49%), and 9 (20%) cases. Concomitant p53(+) was observed in 1 EBV-associated and 2 MMRD MGCs. Although, there was no significant difference in the frequency of most molecular subtypes in IGCs and MGCs, the number of MMRD gastric cancers more than doubled in the MGC group. Half of the MGCs had a divergent molecular subtype compared to that of the IGCs. Notably, the interval between the development of IGCs and MGCs was significantly longer in patients with divergent molecular subtypes (P = 0.010). All 4 patients with MMRD IGC developed MMRD MGCs. Although the concept of mucosal field cancerization may explain the matching molecular subtypes in early-developing MGCs, the presence of divergent subtypes in late-occurring MGCs suggests a shift in the carcinogenic mechanism affecting the residual mucosa possibly related to Helicobacter pylori eradication.

Gastric cancer screening in low incidence populations: Position statement of AEG, SEED and SEAP

This positioning document, sponsored by the Asociación Española de Gastroenterología, the Sociedad Española de Endoscopia Digestiva and the Sociedad Española de Anatomía Patológica, aims to establish recommendations for the screening of gastric cancer (GC) in low incidence populations, such as the Spanish. To establish the quality of the evidence and the levels of recommendation, we used the methodology based on the GRADE system (Grading of Recommendations Assessment, Development and Evaluation). We obtained a consensus among experts using a Delphi method. The document evaluates screening in the general population, individuals with relatives with GC and subjects with GC precursor lesions (GCPL). The goal of the interventions should be to reduce GC related mortality. We recommend the use of the OLGIM classification and determine the intestinal metaplasia (IM) subtype in the evaluation of GCPL. We do not recommend to establish endoscopic mass screening for GC or Helicobacter pylori. However, the document strongly recommends to treat H.pylori if the infection is detected, and the investigation and treatment in individuals with a family history of GC or with GCPL. Instead, we recommend against the use of serological tests to detect GCPL. Endoscopic screening is suggested only in individuals that meet familial GC criteria. As for individuals with GCPL, endoscopic surveillance is only suggested in extensive IM associated with additional risk factors (incomplete IM and/or a family history of GC), after resection of dysplastic lesions or in patients with dysplasia without visible lesion after a high quality gastroscopy with chromoendoscopy.

Long-term natural history after endoscopic resection for gastric dysplasia

BACKGROUND AND STUDY AIMS

Natural history after endoscopic resection (ER) for gastric dysplasia is still unclear. The aim of this study was to evaluate the long-term clinical outcomes and risk factors after ER for gastric dysplasia between control and cases with synchronous or metachronous gastric neoplasm.

METHODS

A total of 1090 patients who had undergone ER for gastric dysplasia and been followed up for at least one year from December 2002 to December 2013 were finally analyzed. Risk factors affecting the development of synchronous or metachronous neoplasm (SMN) and long-term clinical outcomes after ER for gastric dysplasia were evaluated.

RESULTS

Synchronous and metachronous neoplasms had developed in 126 (11.6%) and 133 patients (12.2%) during the mean follow-up duration of 63.6 months, respectively. Five-year and 10-year risk of metachronous neoplasm were 9.8% and 27.2%, respectively. Median duration to the development of metachronous neoplasm was 103.1 months. While age (P < 0.001) and mucosal atrophy (P = 0.09) of index cases were associated with the development of synchronous neoplasm, age (P = 0.017), incomplete resection (P = 0.025), and intestinal metaplasia (P = 0.017) of background mucosa of index cases were significantly related to the development of metachronous neoplasm in multivariate analysis. Cumulative incidence of SMN was not significantly different among H. pylori negative, eradicated, and persistent group.

CONCLUSIONS

Age, incomplete ER, and background intestinal metaplasia of index gastric dysplasia were significantly associated with metachronous recurrence. Endoscopic surveillance for metachronous recurrence after ER for gastric dysplasia is mandatory for longer than 10 years.

Long-term outcomes of patients with gastric adenoma in Korea: A retrospective observational study

New endoscopic resection techniques are constantly being developed for gastric adenoma, which can be classified as low or high grade according to the Vienna classification. However, long-term data on gastric adenoma (e.g., removal or follow-up after resection via endoscopy) remain lacking.We retrospectively analyzed 133 cases with gastric adenoma that underwent endoscopic resection from January 2010 to November 2018. We analyzed the risk factors and frequency of patients with synchronous and metachronous lesions after endoscopic resection for gastric adenoma and followed them for more than 2 years.One hundred six (79.7%) and 27 patients (20.3%) received endoscopic resection (ER) once and more than twice, respectively. Compared with the initial endoscopic biopsy pathological results, the upgraded and downgraded histological discrepancy rates were 10.5% (n = 14) and 3.0% (n = 4) after resection, respectively. The mean time to synchronous/metachronous recurrence was 2.23 years. The average lesion size at first procedure was larger in the multiple ER group than in the single ER group (2.00 vs 1.10 cm; P = .040). Eleven (8.3%) and 16 patients (12.0%) had recurred synchronous and metachronous lesions, respectively. In the multivariate Cox analysis of the recurrence group, intestinal metaplasia (hazard ratio, 2.761; 95% confidence interval, 1.117-6.820; P = .028) and lesion size (hazard ratio, 1.607; 95% confidence interval, 1.082-2.385; P = .019) were independent factors for receiving endoscopic resection more than twice.If patients have severe intestinal metaplasia or large size of lesion at endoscopic resection for gastric adenoma, periodic observation is necessary.

Clinicopathologic Characteristics of Patients with Gastric Superficial Neoplasia and Risk Factors for Multiple Lesions after Endoscopic Submucosal Dissection in a Western Country

Background

Endoscopic submucosal dissection (ESD) is a treatment for early gastric neoplasms that preserves the stomach. However, the risk of multiple lesions persists.

Objectives

To assess clinicopathologic characteristics of patients with early gastric neoplasms in a Western country and evaluate risk factors for multiple gastric lesions, synchronous, or metachronous.

Methods

A retrospective cohort of 230 consecutive patients who underwent ESD for primary neoplasms from 2012 to 2017 (median follow-up: 33 months) was assessed to determine the clinicopathologic characteristics and risk factors for multiple lesions.

Results

The mean age was 68 years, and 53.9% were male. Current/former smoking status was present in 40.4%, and 29.5% had family history of gastric cancer. A third of the patients had only focal gastric atrophy/metaplasia (operative link on gastritis assessment/operative link on gastric intestinal metaplasia assessment [OLGA/OLGIM] I/II; endoscopic grading of gastric intestinal metaplasia [EGGIM] 1-4). Synchronous and me-tachronous lesions occurred in 14.3 and 8.6% of patients, respectively. There was a trend for higher risk of multiple lesions in smokers and patients with extensive metaplasia (EGGIM >4), but only older age was an independent risk factor (OR 3.30; 95% CI 1.05-10.34). Age >60 years (OR 10.10, 95% CI 1.40-88.04), current/former smoking status (OR 3.64, 95% CI 1.07-12.40), and OLGIM III/IV (OR 3.07, 95% CI 1.01-9.36) were independent risk factors for synchronous lesions. No risk factors for metachronous lesions were found.

Conclusions

Surveillance limited to patients with advanced stages of gastritis may miss some primary superficial neoplasms. Although older age increases the risk of multiple lesions, no risk factors were found for metachronous lesions. Therefore, endoscopic surveillance after ESD should be done equally in all patients.