Optimal Interval for Repeated Gastric Cancer Screening in Normal-Risk Healthy Korean Adults: A Retrospective Cohort Study

Current therapeutic options for gastric adenocarcinoma

Gastric cancer inflicts significant health issues globally despite its declining incidence. The disease is known to be diagnosed at its advanced stages also corresponding with a poor prognosis for patients. The integral therapeutic choices to cure advanced gastric cancer have progressed swiftly in modern days. The preface of molecularly targeted therapeutic techniques would potentiate the personalized approach depending on patient-specific and tumor-specific features, exasperating the advantages of chemotherapy. Here we have reviewed the modern therapeutics such as immune therapy, chemotherapy, m-RNA based therapeutics, alongside evaluating the influence of age, sex and comorbidities-like factors on the occurrence of gastric cancer. Gastric cancer therapy consolidated target agents comprising inhibitors of programmed death-1(PD-1), human epidermal growth factor receptor 2 (HER2), mRNA, and epidermal growth factor receptor (EPGF). A combination of trastuzumab to platinum-mediated chemotherapy evolved has a typical front-line therapy in advanced gastric cancer. An attempt has been made to epitomize the contemporary-modern research on targeted therapy for advanced gastric cancer.

Comparison of gastric cancer survival after R0 resection in the US and China

BACKGROUND AND OBJECTIVES

Gastric cancer (GC) outcomes differ between Asian and Western countries, even when controlling for contributing factors, but whether this difference holds true for China remains inadequately studied. We sought to compare the presentation, treatment, and outcomes of patients with GC undergoing curative intent (R0) resection between the US and China, and to ascertain whether geography/ institution is an independent predictor of disease-specific survival (DSS).

METHODS

Data were analyzed from patients with GC undergoing R0 resection at high-volume cancer centers in the US (Memorial Sloan Kettering Cancer Center [MSKCC], n = 1378) and China (Fujian Medical University Union Hospital [FMUUH], n = 4262) between 2000 and 2014. Factors associated with DSS were examined by multivariate analysis.

RESULTS

The 5-year DSS ( P < 0.001) for all patients was better at MSKCC than at FMUUH, even among patients not receiving preoperative chemotherapy ( P < 0.001), but stratification by substage eliminated this difference ( P > 0.05). Factors independently associated with DSS included age, histology, tumor size, T category, N category, gastrectomy type, and preoperative chemotherapy, but not institution.

CONCLUSIONS

Although the presentation of patients with GC between MSKCC and FMUUH differs, survival of patients with curatively resected GC, when matched for clinical stage, is comparable.

Endoscopic Screening in Asian Countries Is Associated With Reduced Gastric Cancer Mortality: A Meta-analysis and Systematic Review

BACKGROUND & AIMS

It is not clear how endoscopic screening for gastric cancer affects incidence or mortality. We performed a systematic review and meta-analysis to evaluate the relationship between endoscopic screening for gastric cancer and mortality and incidence.

METHODS

We conducted a systematic search of PubMed and EMBASE for published cohort and case-control studies of adults without gastric cancer who underwent endoscopic screening at least once that included a comparator and reported outcomes of mortality or incidence through March 8, 2018. Two investigators independently reviewed the included studies and extracted relevant data. The effect estimate of interest was the relative risk (RR). We used a random effects model to combine RRs and 95% confidence intervals (Cis).

RESULTS

Our final analysis included 6 cohort studies and 4 nested case-control studies comprising 342,013 individuals, all from Asia. The combined result (RR, 0.60; 95% CI, 0.49-0.73) indicated that endoscopic screening was associated with a 40% RR reduction in gastric cancer mortality. We did not observe an association between endoscopic screening and incidence (RR, 1.14; 95% CI, 0.93-1.40). Subgroup analysis showed significant reductions in gastric cancer mortality after endoscopic screening compared with no screening (RR, 0.58; 95% CI, 0.48-0.70) or radiographic screening (RR, 0.33; 95% CI, 0.12-0.91). However, endoscopic screening did not significantly reduce mortality compared with expected deaths (RR, 0.67; 95% CI, 0.38-1.16).

CONCLUSIONS

In a systematic review and meta-analysis, we found that endoscopic screening may reduce the risk of death from gastric cancer and not affect incidence in Asian countries. Population-based prospective cohort studies are warranted to confirm our findings.

Questionnaire-Based Survey on Diagnostic and Therapeutic Endoscopies and H. pylori Eradication for Elderly Patients in East Asian Countries

BACKGROUND

Gastrointestinal endoscopy and Helicobacter pylori(H. pylori) eradication therapy are commonly performed even among the elderly population. The aim of this study was to understand the way endoscopists viewed the application of endoscopy and H. pylori eradication in the elderly of East Asian countries.

METHODS

Self-administered questionnaires containing 13 questions on endoscopy and H. pylori eradication in the elderly were distributed to major institutions in Japan, South Korea, China, Indonesia, and the Philippines.

RESULTS

Two hundred and fifteen endoscopists (111 in Japan, 39 in China, 24 in Korea, 21 in Indonesia, and 20 in the Philippines) participated in this study. In the institutions where these endoscopists were associated, around 50% of patients undergoing endoscopy were above the age of 60 years. The participating endoscopists indicated that the necessity of screening esophagogastroduodenoscopy and colonoscopy was lower in populations aged over 81 than the other age groups. They hesitated to perform therapeutic endoscopy, such as endoscopic submucosal dissection or endoscopic retrograde cholangiopancreatography, more often in patients over 85. They also hesitated to perform H. pylori eradication in patients aged over 81, especially in Japan.

CONCLUSION

Endoscopists had significantly different attitudes regarding the indications for screening or therapeutic endoscopy and H. pylori eradication therapy in younger and elderly populations in East Asian countries.

Does the interval of screening endoscopy affect survival in gastric cancer patients?: A cross-sectional study

Gastric cancer remains the second most common cancer in Korea; however, its mortality has decreased due to earlier diagnosis. In Korea, screening endoscopy has been performed nationwide since 1999. The aim of this study was to elucidate the benefit of screening endoscopy on actual survival in gastric cancer patients and to determine the optimal interval of screening endoscopy.We analyzed 1651 patients diagnosed with gastric adenocarcinoma who underwent surgical treatment between June 2008 and December 2014. Patients were divided into 4 groups according to the interval of screening endoscopy prior to their gastric cancer diagnosis. (Group I = within 1 year, Group II = >1 but <2 years, Group III = more than 2 years, Group IV = no prior endoscopic examination). Patient demographics, clinicopathologic characteristics, and postoperative surgical outcomes including overall survival were compared.The 5-year gastric cancer-specific survival rates of groups I and II were significantly higher than groups III and IV (90.9% vs 85.4%, P = 0.002, respectively). Multivariate analysis showed that screening interval was an independent factor for the diagnosis of advanced gastric cancer. The risk of advanced gastric cancer decreased in group I (odds ratio: 0.515, 95% confidence interval [CI] 0.369-0.719; P < 0.001) and group II (odds ratio: 0.678, 95% CI 0.517-0.889, P = 0.005).Screening endoscopy was helpful in increasing the survival of gastric cancer patients. A 2-year endoscopic screening interval is suitable to detect early-stage gastric cancer.

DNA Methylation as Surrogate Marker For Gastric Cancer

Stomach cancer remains, stubbornly, highly prevalent in East Asia. Still, stomach cancer has few biomarkers by which it can be predicted. Helicobacter pylori infection, a known carcinogen of stomach cancer, usually goes undetected prior to cancer diagnosis, due to the poor mucosal environments that its related gastric atrophy causes. We propose, herein, an endoscopic-biopsy-based cancer-predicting DNA methylation marker. We semi-quantitatively examined the methylation-variable sites near the CpG-island margins by radioisotope-labeling methylation-specific polymerase chain reaction in association with H. pylori, which increases age-related over-methylation in CpG islands of gastric mucosa. These age-related methylation patterns of the transitional-CpG sites are proposed as useful surrogate markers for stomach cancer. It would be helpful for setting the optimal screening interval for high-risk subjects as well as for estimating the prognosis and the predictability for recurrence of early gastric cancer in patients having undergone endoscopic submucosal dissection. New screening-interval guidelines for gastric cancer should be suggested considering individual risk based on age, severity of atrophy, H. pylori status, and DNA methylation pattern.

Rates of change to a positive result in subsequent screening mammography in Korean women: a retrospective observational study

OBJECTIVES

This retrospective cohort study aimed at calculating some parameters of changes in the findings of the subsequent screening mammography (SSM) in female Korean volunteers.

METHODS

The study included screenees aged 30 to 79 years who underwent SSM voluntarily after testing negative in the baseline screenings performed between January 2007 and December 2011. A change to a positive result was defined as category 4 or 5 by using the American College of Radiology Breast Imaging Reporting and Data System. The proportion of results that had changed to positive (CP, %) was calculated by dividing the number of cases with results that were positive in the SSM by the total number of study participants. The rate of results that had changed to positive (CR, cases per 100 000 screenee-months) was calculated by dividing the number of cases with results that were positive in the SSM by the total number of months of the follow-up period.

RESULTS

The overall CP and CR in all age groups (n=77 908) were 2.26% and 93.94 cases per 100 000 screenee-months, respectively. The median CP interval in the subjects who had positive SSM results was 30 to 36 months, while that in the age group of 30 to 39 years was shorter.

CONCLUSIONS

Different screening intervals should be considered among women aged between 30 and 59 years. In addition, a strategy for a screening program should be developed for the age group of 30 to 39 years, in particular.

Methodological issues for determining intervals of subsequent cancer screening

The gap between nationwide recommendations of cancer screening and the related evidences obtained from Korean adults should be filled. Estimation of the mean sojourn time (MST) in a specific cancer is important to determine the intervals of subsequent screening. This author arranged the methods for calculating MST into 5 categories based on the parameters used. Under the legal barrier for protection of individual privacy and confidentiality in a Korean academic situation, the methods involving the use of transition rates or prevalence/incidence ratio would be applicable among these methods.