Opportunistic upper endoscopy during colonoscopy as a screening strategy for countries with intermediate gastric cancer risk.

BACKGROUND AND AIM: Screening upper endoscopy can detect esophagogastric (OG) cancers early with improved outcomes. Recent cost-utility studies suggest that opportunistic upper endoscopy at the same setting of colonoscopy might be a useful strategy for screening of OG cancers, and it may be more acceptable to the patients due to cost-saving and convenience. We aim to study the diagnostic performance of this screening strategy in a country with intermediate gastric cancer risk. METHODS: A retrospective cohort study using a prospective endoscopy database from 2015 to 2017 was performed. Patients included were individuals age > 40 who underwent opportunistic upper endoscopy at the same setting of colonoscopy without any OG symptoms. Neoplastic OG lesions are defined as cancer and high-grade dysplasia. Pre-neoplastic lesions include Barrett's esophagus (BE), intestinal metaplasia (IM), and atrophic gastritis (AG). RESULTS: The study population involved 1414 patients. Neoplastic OG lesions were detected in five patients (0.35%). Pre-neoplastic lesions were identified in 174 (12.3%) patients. IM was found in 146 (10.3%) patients with 21 (1.4%) having extensive IM. The number needed to scope to detect a neoplastic OG lesion is 282.8 with an estimated cost of USD$141 400 per lesion detected. On multivariate regression, age ≥ 60 (RR: 1.84, 95% CI: 1.29-2.63) and first-degree relatives with gastric cancer (RR: 1.64, 95% CI: 1.06-2.55) were independent risk factors for neoplastic or pre-neoplastic OG lesion. CONCLUSION: For countries with intermediate gastric cancer risk, opportunistic upper endoscopy may be an alternative screening strategy in a selected patient population. Prospective trials are warranted to validate its performance.

Development and validation of a serum microRNA biomarker panel for detecting gastric cancer in a high-risk population.

OBJECTIVE: An unmet need exists for a non-invasive biomarker assay to aid gastric cancer diagnosis. We aimed to develop a serum microRNA (miRNA) panel for identifying patients with all stages of gastric cancer from a high-risk population. DESIGN: We conducted a three-phase, multicentre study comprising 5248 subjects from Singapore and Korea. Biomarker discovery and verification phases were done through comprehensive serum miRNA profiling and multivariant analysis of 578 miRNA candidates in retrospective cohorts of 682 subjects. A clinical assay was developed and validated in a prospective cohort of 4566 symptomatic subjects who underwent endoscopy. Assay performance was confirmed with histological diagnosis and compared with Helicobacter pylori (HP) serology, serum pepsinogens (PGs), 'ABC' method, carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9). Cost-effectiveness was analysed using a Markov decision model. RESULTS: We developed a clinical assay for detection of gastric cancer based on a 12-miRNA biomarker panel. The 12-miRNA panel had area under the curve (AUC)=0.93 (95% CI 0.90 to 0.95) and AUC=0.92 (95% CI 0.88 to 0.96) in the discovery and verification cohorts, respectively. In the prospective study, overall sensitivity was 87.0% (95% CI 79.4% to 92.5%) at specificity of 68.4% (95% CI 67.0% to 69.8%). AUC was 0.848 (95% CI 0.81 to 0.88), higher than HP serology (0.635), PG 1/2 ratio (0.641), PG index (0.576), ABC method (0.647), CEA (0.576) and CA19-9 (0.595). The number needed to screen is 489 annually. It is cost-effective for mass screening relative to current practice (incremental cost-effectiveness ratio=US$44 531/quality-of-life year). CONCLUSION: We developed and validated a serum 12-miRNA biomarker assay, which may be a cost-effective risk assessment for gastric cancer. TRIAL REGISTRATION NUMBER: This study is registered with ClinicalTrials.gov (Registration number: NCT04329299).

Screening and eradication of Helicobacter pylori for gastric cancer prevention: the Taipei global consensus.

OBJECTIVE: A global consensus meeting was held to review current evidence and knowledge gaps and propose collaborative studies on population-wide screening and eradication of Helicobacter pylori for prevention of gastric cancer (GC). METHODS: 28 experts from 11 countries reviewed the evidence and modified the statements using the Delphi method, with consensus level predefined as ≥80% of agreement on each statement. The Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach was followed. RESULTS: Consensus was reached in 26 statements. At an individual level, eradication of H. pylori reduces the risk of GC in asymptomatic subjects and is recommended unless there are competing considerations. In cohorts of vulnerable subjects (eg, first-degree relatives of patients with GC), a screen-and-treat strategy is also beneficial. H. pylori eradication in patients with early GC after curative endoscopic resection reduces the risk of metachronous cancer and calls for a re-examination on the hypothesis of 'the point of no return'. At the general population level, the strategy of screen-and-treat for H. pylori infection is most cost-effective in young adults in regions with a high incidence of GC and is recommended preferably before the development of atrophic gastritis and intestinal metaplasia. However, such a strategy may still be effective in people aged over 50, and may be integrated or included into national healthcare priorities, such as colorectal cancer screening programmes, to optimise the resources. Reliable locally effective regimens based on the principles of antibiotic stewardship are recommended. Subjects at higher risk of GC, such as those with advanced gastric atrophy or intestinal metaplasia, should receive surveillance endoscopy after eradication of H. pylori. CONCLUSION: Evidence supports the proposal that eradication therapy should be offered to all individuals infected with H. pylori. Vulnerable subjects should be tested, and treated if the test is positive. Mass screening and eradication of H. pylori should be considered in populations at higher risk of GC.

Evaluating the Use of microRNA Blood Tests for Gastric Cancer Screening in a Stratified Population-Level Screening Program: An Early Model-Based Cost-Effectiveness Analysis.

OBJECTIVES: To evaluate cost-effectiveness of a novel screening strategy using a microRNA (miRNA) blood test as a screen, followed by endoscopy for diagnosis confirmation in a 3-yearly population screening program for gastric cancer. METHODS: A Markov cohort model has been developed in Microsoft Excel 2016 for the population identified to be at intermediate risk (Singaporean men, aged 50-75 years with Chinese ethnicity). The interventions compared were (1) initial screening using miRNA test followed by endoscopy for test-positive individuals and a 3-yearly follow-up screening for test-negative individuals (proposed strategy), and (2) no screening with gastric cancer being diagnosed clinically (current practice). The model was evaluated for 25 years with a healthcare perspective and accounted for test characteristics, compliance, disease progression, cancer recurrence, costs, utilities, and mortality. The outcomes measured included incremental cost-effectiveness ratios, cancer stage at diagnosis, and thresholds for significant variables. RESULTS: The miRNA-based screening was found to be cost-effective with an incremental cost-effectiveness ratio of $40 971/quality-adjusted life-year. Key drivers included test costs, test accuracy, cancer incidence, and recurrence risk. Threshold analysis highlights the need for high accuracy of miRNA tests (threshold sensitivity: 68%; threshold specificity: 77%). A perfect compliance to screening would double the cancer diagnosis in early stages compared to the current practice. Probabilistic sensitivity analysis reported the miRNA-based screening to be cost-effective in >95% of iterations for a willingness to pay of $70 000/quality-adjusted life-year (approximately equivalent to 1 gross domestic product/capita) CONCLUSIONS: The miRNA-based screening intervention was found to be cost-effective and is expected to contribute immensely in early diagnosis of cancer by improving screening compliance.

Yes we can! The Raffles Dialogue on Human Wellbeing and Security.

The future of human wellbeing and security depends on our ability to deal with the multiple effects of globalisation and on adoption of a new paradigm and philosophy for living and for health that emphasises people's wellbeing and social justice. Such was the topic of the inaugural Raffles Dialogue on Human Wellbeing and Security held in Singapore on Feb 2-3, 2015. Participants agreed that, to achieve these goals, four conditions must be met. First, equity must be integral to the implementation of technology. Second, there is an urgent need for innovations within our global institutions to make them "fit for purpose" in a rapidly changing world. Third, we must find the right balance between the roles of government and markets so that all those in need can access affordable medicine and health care. Finally, we must realise that we live in a small and interdependent "global village", where Asian countries need to assume greater leadership of our global village councils. This is the great imperative of our times.

Gender differences in predictors of colorectal cancer screening uptake: a national cross sectional study based on the health belief model.

BACKGROUND: Colorectal Cancer (CRC) is rapidly rising in Asia, but screening uptake remains poor. Although studies have reported gender differences in screening rates, there have been few studies assessing gender specific perceptions and barriers towards CRC screening, based on behavioral frameworks. We applied the Health Belief Model to identify gender-specific predictors of CRC screening in an Asian population. METHODS: A nationwide representative household survey was conducted on 2000 subjects aged 50 years and above in Singapore from 2007 to 2008. Screening behaviour, knowledge and beliefs on CRC screening were assessed by face-to-face structured interviews. The response rate was 88.2%. RESULTS: 26.7 percent had undergone current CRC screening with no gender difference in rates. Almost all agreed that CRC would lead to suffering (89.8%), death (84.6%) and would pose significant treatment cost and expense (83.1%). The majority (88.5%) agreed that screening aids early detection and cure but only 35.4% felt susceptible to CRC. Nearly three-quarters (74.3%) of the respondents recalled reading or hearing information on CRC in the print or broadcast media. However, only 22.6% were advised by their physicians to undergo screening. Significantly more women than men had feared a positive diagnosis, held embarrassment, pain and risk concerns about colonoscopy and had friends and family members who encouraged screening. On multivariate analysis, screening uptake showed a positive association with worry about contracting CRC and a physician's recommendation and a negative association with perceived pain about colonoscopy for both genders. For women only, screening was positively associated with having attended a public talk on CRC and having a family member with CRC, and was negatively associated with Malay race and perceived danger of colonoscopy. CONCLUSIONS: CRC screening remains poor despite high levels of awareness of its benefits in this Asian population. Race, worry about contracting cancer, psychological barriers, and cues from the doctor and a public talk on CRC were associated with screening with gender specific differences. Strategies to increase CRC screening uptake should consider gender specific approaches to address psychological barriers and increase disease susceptibility through public health education and active promotion by physicians.

Empirical evidence of the continuing improvement in cost efficiency of an endoscopic surveillance programme for gastric cancer in Singapore from 2004 to 2010.

BACKGROUND: Endoscopic surveillance has been proven effective in prolonging the survival of gastric cancer (GC) patients. However, there is limited evidence on the cost efficiency of delivering this intervention, especially on a national level in spite of cost efficiency being a major determinant of the actual cost-effectiveness of a cancer prevention programme. The Singapore Gastric Cancer Epidemiology Clinical and Genetic Programme (GCEP) is a demonstration project offering scheduled endoscopy to the Chinese population aged 50 years or older in Singapore. By assessing the cost efficiency of the GCEP, this study aimed to provide empirical evidence on the cost structure and mechanisms underlying cost generation in conducting GC surveillance, thus informing resource allocation and programme budgeting for the Singapore government. METHODS: From a societal perspective, we reported on the direct cost (resource consumption) of conducting endoscopic surveillance through the GCEP network. We retrospectively collected individual-level data of 216 subjects recruited at the National University Hospital, Singapore from 01/04/2004 to 31/10/2010. The Overall Cost, Clinical Cost, GCEP Cost and Personal Cost incurred in serving one subject was computed and discounted as 2004 US dollar (US$) per capita for every year. The Generalized Estimation Equation (GEE) was used to model the data. RESULTS: All cost indices continuously declined over the 6.5-year costing period. For the total sample, Overall Cost, Clinical Cost, GCEP Cost and Personal Cost declined by 42.3%, 54.1%, 30% and 25.7% respectively. This downward trend existed for age and gender subgroups and the high risk group only with cost reductions varying between 3.5% and 58.4%. The GEE models confirmed statistical significance of the downward trend and of its association with risk profile, where the moderate risk group had cost indices at most 77% of the high risk group. CONCLUSIONS: Our study offered empirical evidence of improved cost efficiency of a surveillance programme for GC in the early phase of programme implementation. Mechanisms such as economies of scale and self-learning were found to be involved in the cost reduction. Our findings highlighted the importance of assessing the cost efficiency and offered valuable insights for future programme budgeting and policy making.

A cost-effectiveness analysis evaluating endoscopic surveillance for gastric cancer for populations with low to intermediate risk.

BACKGROUND: Gastric cancer (GC) surveillance based on oesophagogastroduodenoscopy (OGD) appears to be a promising strategy for GC prevention. By evaluating the cost-effectiveness of endoscopic surveillance in Singaporean Chinese, this study aimed to inform the implementation of such a program in a population with a low to intermediate GC risk. METHODS: USING A REFERENCE STRATEGY OF NO OGD INTERVENTION, WE EVALUATED FOUR STRATEGIES: 2-yearly OGD surveillance, annual OGD surveillance, 2-yearly OGD screening and 2-yearly screening plus annual surveillance in Singaporean Chinese aged 50-69 years. From a perspective of the healthcare system, Markov models were built to simulate the life experience of the target population. The models projected discounted lifetime costs ($), quality adjusted life year (QALY), and incremental cost-effectiveness ratio (ICER) indicating the cost-effectiveness of each strategy against a Singapore willingness-to-pay of $46,200/QALY. Deterministic and probabilistic sensitivity analyses were used to identify the influential variables and their associated thresholds, and to quantify the influence of parameter uncertainties respectively. RESULTS: With an ICER of $44,098/QALY, the annual OGD surveillance was the optimal strategy while the 2-yearly surveillance was the most cost-effective strategy (ICER = $25,949/QALY). The screening-based strategies were either extendedly dominated or cost-ineffective. The cost-effectiveness heterogeneity of the four strategies was observed across age-gender subgroups. Eight influential parameters were identified each with their specific thresholds to define the choice of optimal strategy. Accounting for the model uncertainties, the probability that the annual surveillance is the optimal strategy in Singapore was 44.5%. CONCLUSION: Endoscopic surveillance is potentially cost-effective in the prevention of GC for populations at low to intermediate risk. Regarding program implementation, a detailed analysis of influential factors and their associated thresholds is necessary. Multiple strategies should be considered in order to recommend the right strategy for the right population.

Validation of the functional assessment of cancer therapy-gastric module for the Chinese population.

BACKGROUND: Quality of life (QoL) assessment has become an important aspect of the clinical management of gastric cancer (GC), which poses a greater health threat in Chinese populations around the world. Functional Assessment of Cancer Therapy-Gastric Module (FACT-Ga), a questionnaire developed specifically to measure QoL of patients with GC, has never been validated in Chinese subjects. The current study was designed to examine the psychometric properties of FACT-Ga as a GC specific QoL instrument for its future use in Chinese populations. METHODS: A sample of 67 Chinese patients with GC in the National University Hospital, Singapore was investigated cross-sectionally. The participants independently completed either English or Chinese versions of the FACT-Ga and the European Quality of Life-5 Dimensions (EQ-5D). Reliability was measured as the Cronbach's α for EQ-5D, and five subscale scores and two total scores of FACT-Ga. The sensitivity to patients' clinical status was evaluated by comparing EQ-5D and FACT-Ga scores between clinical subgroups classified by Clinical Stage and Treatment Intent. The construct validity of FACT-Ga was assessed internally by examining the item-to-scale correlations and externally by contrasting the FACT-Ga subscales with the EQ-5D domains. RESULTS: For both FACT-Ga and EQ-5D, patients treated with curative intent rated their QoL higher than those treated for palliation, and early stage patients scored higher than those in the late stage. The sensitivity to clinical status of FACT-Ga scores were differential as four of seven FACT-Ga scores were significant for Treatment Intent while only one subscale score was significant for Clinical Stage. Six FACT-Ga scores had Cronbach's α of 0.8 or above indicating excellent reliability. For construct validity, 45 of 46 items converged about their respective subscales. The monotrait-multimethod correlations between QoL constructs of FACT-Ga and EQ-5D were stronger than the multitrait-multimethod correlations as theoretically hypothesized, suggesting good convergent and discriminant validities. CONCLUSIONS: Given the excellent reliability and good construct validity, FACT-Ga scores are able to distinguish patient groups with different clinical characteristics in the expected direction. Therefore FACT-Ga can be used as a discriminative instrument for measuring QoL of Chinese patients with GC.

Knowledge of, attitudes toward, and barriers to participation of colorectal cancer screening tests in the Asia-Pacific region: a multicenter study.

BACKGROUND: The rapid increase in the incidence of colorectal cancer (CRC) in the Asia-Pacific region in the past decade has resulted in recommendations to implement mass CRC screening programs. However, the knowledge of screening and population screening behaviors between countries is largely lacking. OBJECTIVE: This multicenter, international study investigated the association of screening test participation with knowledge of, attitudes toward, and barriers to CRC and screening tests in different cultural and sociopolitical contexts. METHODS: Person-to-person interviews by using a standardized survey instrument were conducted with subjects from 14 Asia-Pacific countries/regions to assess the prevailing screening participation rates, knowledge of and attitudes toward and barriers to CRC and screening tests, intent to participate, and cues to action. Independent predictors of the primary endpoint, screening participation was determined from subanalyses performed for high-, medium-, and low-participation countries. RESULTS: A total of 7915 subjects (49% male, 37.8% aged 50 years and older) were recruited. Of the respondents aged 50 years and older, 809 (27%) had undergone previous CRC testing; the Philippines (69%), Australia (48%), and Japan (38%) had the highest participation rates, whereas India (1.5%), Malaysia (3%), Indonesia (3%), Pakistan (7.5%), and Brunei (13.7%) had the lowest rates. Physician recommendation and knowledge of screening tests were significant predictors of CRC test uptake. In countries with low-test participation, lower perceived access barriers and higher perceived severity were independent predictors of participation. Respondents from low-participation countries had the least knowledge of symptoms, risk factors, and tests and reported the lowest physician recommendation rates. "Intent to undergo screening" and "perceived need for screening" was positively correlated in most countries; however, this was offset by financial and access barriers. LIMITATIONS: Ethnic heterogeneity may exist in each country that was not addressed. In addition, the participation tests and physician recommendation recalls were self-reported. CONCLUSIONS: In the Asia-Pacific region, considerable differences were evident in the participation of CRC tests, physician recommendations, and knowledge of, attitudes toward, and barriers to CRC screening. Physician recommendation was the uniform predictor of screening behavior in all countries. Before implementing mass screening programs, improving awareness of CRC and promoting the physicians' role are necessary to increase the screening participation rates.

Screening based on risk for colorectal cancer is the most cost-effective approach.

BACKGROUND & AIMS: Performing single endoscopic examinations or selective screening based on risk might be more practical than recommended screening strategies for colorectal cancer (CRC). We investigated the cost effectiveness of these strategies, under real-life conditions of suboptimal compliance, and the societal cost perspective. METHODS: We used Markov modeling to analyze data from 787,000 individuals in Singapore, aged 50 to 75 years, with an age-standardized rate of CRC of 30 to 40/100,000 in 2009. Potential outcomes, incremental cost-effectiveness ratio, and net health benefit were compared between single sigmoidoscopy or colonoscopy and current recommended screening strategies, and also with a strategy of selective screening based on risk of CRC. RESULTS: Performing single sigmoidoscopies on individuals when they are 60 years old was the cheapest screening strategy; it would reduce CRC incidence by 19% and mortality by 16%, compared with no screening. A single colonoscopy is less cost effective than a single sigmoidoscopy, unless the proportion of right-sided lesions exceeds 65%. The fecal occult blood test (iFOBT) had the lowest incremental cost-effectiveness ratio when all strategies were compared with no screening; iFOBT and colonoscopic examinations every 10 years each had extended dominance over other strategies. Screening subjects 50 to 60 years old by iFOBT and subjects 60 to 72 years old with colonoscopies every 10 years was the most cost-effective strategy (US$25,000/quality-adjusted life-years). Risk for CRC, adherence, and cost of colonoscopy were the main determinants of cost effectiveness, based on sensitivity analysis. CONCLUSIONS: Markov modeling analysis indicates that selectively screening individuals for CRC based on risk is the most cost-effective approach; it limits the cost and number of colonoscopies needed and significantly reduces CRC mortality.

Screening for gastric cancer in Asia: current evidence and practice.

Gastric cancer is the second most common cause of death from cancer in Asia. Although surgery is the standard treatment for this disease, early detection and treatment is the only way to reduce mortality. This Review summarises the epidemiology of gastric cancer, and the evidence for, and current practices of, screening in Asia. Few Asian countries have implemented a national screening programme for gastric cancer; most have adopted opportunistic screening of high-risk individuals only. Although screening by endoscopy seems to be the most accurate method for detection of gastric cancer, the availability of endoscopic instruments and expertise for mass screening remains questionable--even in developed countries such as Japan. Therefore, barium studies or serum-pepsinogen testing are sometimes used as the initial screening tool in some countries, and patients with abnormal results are screened by endoscopy. Despite the strong link between infection with Helicobacter pylori and gastric cancer, more data are needed to define the role of its eradication in the prevention of gastric cancer in Asia. At present, there is a paucity of quality data from Asia to lend support for screening for gastric cancer.

Endoscopic screening for gastric cancer.

BACKGROUND & AIMS: Population endoscopic screening for gastric cancer is generally deemed not to be cost-effective except in Japan, where its prevalence is very high. However, in the absence of screening, patients present with advanced disease, and prognosis is poor. We conducted a cost utility analysis to determine whether endoscopic screening for stomach cancer in intermediate-risk population would be cost-effective and to better define the high-risk groups in the population who would benefit from such strategy. METHODS: Cost-effectiveness analysis was performed by using a Markov Model. Simulation was performed on Singapore (intermediate-risk) population and various high-risk subgroups. Comparison was made between 2-yearly endoscopic mass screening program versus no screening. Data sources were extracted from relevant studies published from 1980-2004 identified via systematic PUBMED search. Main outcome measures were deaths caused by stomach cancer averted, cost per life saved, and incremental cost-effectiveness ratio expressed as cost per quality-adjusted life year (QALY) saved. RESULTS: Screening of high-risk group of Chinese men (age-standardized rate, 25.9/100,000) from 50-70 years old is highly cost-effective, with cost benefit of United States $26,836 per QALY. Screening this cohort of 199,000 subjects prevents 743 stomach cancer deaths and saves 8234 absolute life years. Cost of averting 1 cancer death is United States $247,600. Cost-effectiveness was most sensitive to incidence of stomach cancer and cost of screening endoscopy. CONCLUSIONS: Screening of stomach cancer in moderate to high-risk population subgroups is cost-effective. Targeted screening strategies for stomach cancer should be explored.

Prophylactic strategies for hepatitis B patients undergoing liver transplant: a cost-effectiveness analysis.

Hepatitis B immunoglobulin with lamivudine prophylaxis (LAM/HBIG) is effective in preventing Hepatitis B (HBV) recurrence posttransplant but is expensive and inconvenient. Lamivudine-resistant HBV, which has limited the usefulness of lamivudine monoprophylaxis in transplant, can now be effectively controlled with adefovir dipivoxil. We performed a cost-effectiveness analysis on the strategies of lamivudine prophylaxis with adefovir rescue(LAM/ADV) compared to combination LAM/intravenous fixed high-dose HBIG prophylaxis(LAM/ivHBIG) or LAM/intramuscular HBIG prophylaxis(LAM/imHBIG). Markov modeling was performed with analysis from societal perspective. Probability rates were derived from systematic review of the literature and cost taken from MEDICARE database. Outcome measures were incremental cost-effectiveness ratio(ICER) and cost to prevent each HBV recurrence and death. Analysis was performed at 5 years posttransplant as well as at end of life expectancy (15 years). Combination LAM/ivHBIG cost an additional USD562,000 at 15 years, while LAM/imHBIG cost an additional USD139,000 per patient compared to LAM/ADV. Although there is an estimated increase in recurrence of 53% with LAM/ADV and 7.6% increased mortality at the end of life expectancy (15 years), the ICER of LAM/ivHBIG over LAM/ADV treatment is USD760,000 per quality-adjusted life-years and for LAM/imHBIG, USD 188,000. Cost-effectiveness is most sensitive to cost of HBIG. Lamivudine prophylaxis with adefovir dipivoxil salvage offers the more cost-effective option for HBV patients undergoing liver transplant but with higher recurrence and death rate using a model that favors LAM/HBIG. Lowering the cost of HBIG maintenance will improve cost-effectiveness of LAM/HBIG strategy. In conclusion, a tailored approach based on individual risks will optimize the cost-benefit of HBV transplant prophylaxis.