Age, period, and cohort effects on gastric cancer mortality

Age, period and cohort effects on gastric cancer mortality in Spain, 1980-2021

BACKGROUND

this study aimed to evaluate the effects of age, time period and cohort (A-P-C) on gastric cancer (GC) mortality in Spain from 1980 to 2021.

METHODS

an ecological trend study was performed (with aggregated data obtained from the Spanish National Statistics Institute (INE). Joinpoint regression software was used to estimate rates by sex and age group (< 35, 35-64, > 64 years) and mortality trends. The National Cancer Institute A-P-C tools were used to assess the effects of age, time of death and birth cohort.

RESULTS

GC mortality rates in Spain decreased significantly in both sexes. In the under-35 age group, rates were stable after an initial significant decline. In the 35-64 age group, the decline was more pronounced in males than in females. In the 65+ age group, rates fell significantly for both sexes, but more so for females than for males. The net drift and local drift also showed significant decreases across all age groups from 24 years onwards. GC mortality rates increased with age and decreased with calendar time and successive birth cohorts, regardless of sex. The ratio of age-specific rates between males and females increased with age, and birth cohort relative risk estimates followed a steady downward trend until the mid-1970s, after which the decline stabilized. The relative risk decreased for both sexes, with a more pronounced decrease in males.

CONCLUSION

GC mortality rates in Spain have been decreasing over time and across successive birth cohorts, with a stabilizing trend observed for those under 35 years of age.

Risk of gastric carcinoma will be low in generations born at turn of the 20th and 21st centuries in Finland. Modelling NORDCAN data of the age group specific incidence rates of gastric cancer with PLS-regression and with attention to age ('age effect') and year of the birth ('cohort effect')

BACKGROUND AND METHODS

We examined in NORDCAN database how the annual age group-specific incidence rates (IR) of gastric cancer (GCA), and correspondingly the GCA risk, have declined in Finland during the twentieth century, and whether this decline corresponds to a decrease in the cohort-specific prevalence rate of Helicobacter pylori (Hp) gastritis that is considered an important precancerous risk condition for GCA.

RESULTS

In modelling with partial least squares regression (PLSR), the logarithmically transformed IRs (ln(IR) of GCA were well explained with age and birth cohort as explanatory model variables. By considering the observed (actual) and the PLSR-modelled IRs, the IR of GCA (and the risk of GCA) has decreased gradually in Finland from 1900 onward, cohort by cohort. By prediction of the future with PLSR, the IRs of GCA will be markedly lower in all cohorts during the twenty-first century than in the twentieth century. By PLSR modelling, less than 10 GCA cases per 100,000 people are predicted to appear annually in cohorts (generations) born at the turn of the 20th and 21st centuries, even when these people will be 60-80 years old in the years 2060-2070.

CONCLUSIONS

The IR of GCA and GCA risk progressively declined by cohort in Finland during the whole twentieth century. This decline corresponds in extent and time window to earlier observations in the decline of the prevalence rate of Hp gastritis in the same birth cohorts and supports the hypothesis of the role of Hp gastritis as an important risk condition of GCA.

Is Helicobacter pylori Anyway Pathogen in Children?

Helicobacter pylori (H. pylori) infection is a continuous challenge for both gastroenterologists and pediatricians. The international guidelines regarding diagnostic and treatment pathways differ between adults and children. The pediatric guidelines are more restrictive because children are rarely affected by serious consequences, particularly in Western countries. Therefore, infected children should be treated only after a careful case-by-case evaluation by a pediatric gastroenterologist. In any case, recent studies are confirming an increasingly all-around pathological role of H. pylori even in asymptomatic children. For these reasons, following the current evidence, we feel that H. pylori-infected children could be treated starting in pre-adolescence, particularly in Eastern countries, because their stomachs have already begun to develop the biomarkers of gastric damage. Therefore, we believe that H. pylori is anyway pathogen in children. Nevertheless, the possible beneficial role of H. pylori in humans has not yet been conclusively disproved.

The relationship of different preoperative inflammatory markers with the prognosis of gastric carcinoma

BACKGROUND

It is aimed to determine the prognostic values of preoperative inflammatory biomarkers in patients undergoing curative surgery for gastric carcinoma and to contribute to the development of prognostic modeling.

OBJECTIVE

To investigate the effect of various different preoperative inflammatory markers on the prognosis of gastric carcinoma.

MATERIAL AND METHOD

The medical data and the mortality status of 91 patients who underwent total or subtotal gastrectomy operation for gastric carcinoma at Mersin City Training and Research Hospital between 2016 and 2020 were retrospectively reviewed from the hospital records and patient files. The patients' demographic characteristics, tumor location, histopathological diagnosis, pathological stage, tumor markers, and preoperative inflammatory and hematological markers were analyzed. Based on these data, tumor stage, metastatic lymph node ratio (MLR), lactate dehydrogenase albumin ratio (LAR), neutrophil-lymphocyte ratio (NLR), and platelet lymphocyte ratio (PLR) were calculated. The relationship between these parameters and postoperative survival was analyzed. Statistical analyses were performed with IBM SPSS for Windows, version 17.0 (IBM Corporation, Armonk, New York, United States).

RESULTS

The correlation analysis of the parameters affecting survival showed that, in addition to an advanced tumor stage, inflammatory parameters like NLR, PLR, and LAR adversely affected survival.

CONCLUSION

Preoperative NLR, PLR, LAR, and advanced tumor stage may help determine the survival of gastric carcinoma patients. Multiple studies with larger series are needed on this subject.

Higher proportions of a healthy gastric mucosa in healthy Japanese adults with later birth year: analysis of 41 957 participants

BACKGROUND

In Japan, most gastric cancers are associated with gastric mucosal atrophy caused by chronic infection with Helicobacter pylori (H. pylori). Recognizing the condition of the gastric mucosa and determining the infection status of H. pylori are important for predicting the individual risk of gastric cancer. This study aimed to determine the proportion of Japanese adults with a healthy gastric mucosa (without H. pylori infection) among 12 birth-year groups encompassing 1935-1990 by morphological images.

METHODS

The gastric mucosa was classified as healthy or having gastritis based on routine double-contrast upper gastrointestinal barium X-ray radiography. The participants included 41 957 healthy Japanese adults. Serum or urine H. pylori antibody levels were also assessed.

RESULTS

In total, 25 424 participants had healthy mucosa without a history of H. pylori eradication. The proportions of participants with a healthy mucosa by birth year were 19.8% (57/288), 27.1% (306/1128), 32.4% (569/1756), 37.6% (1808/4811), 49.2% (3207/6522), 60.1% (3966/6550), 71.2% (5224/7342), 77.2% (5114/6624), 80.6% (3342/4149), 85.0% (1404/1652), 85.3% (302/354) and 94.7% (125/132) in 1935, 1940, 1945, 1950, 1955, 1960, 1965, 1970, 1975, 1980, 1985 and after 1990, respectively (P for trend <0.01). All the participants with a healthy mucosa showed negative results in the H. pylori antibody tests.

CONCLUSIONS

The proportion of participants with normal gastric mucosa linearly increased with the birth years. The prevalence of morphologically healthy gastric mucosa could have consistently increased with decreasing prevalence of H. pylori infection.

Future projection of the health and functional status of older people in Japan: A multistate transition microsimulation model with repeated cross-sectional data

Accurate future projections of population health are imperative to plan for the future healthcare needs of a rapidly aging population. Multistate-transition microsimulation models, such as the U.S. Future Elderly Model, address this need but require high-quality panel data for calibration. We develop an alternative method that relaxes this data requirement, using repeated cross-sectional representative surveys to estimate multistate-transition contingency tables applied to Japan's population. We calculate the birth cohort sex-specific prevalence of comorbidities using five waves of the governmental health surveys. Combining estimated comorbidity prevalence with death record information, we determine the transition probabilities of health statuses. We then construct a virtual Japanese population aged 60 and older as of 2013 and perform a microsimulation to project disease distributions to 2046. Our estimates replicate governmental projections of population pyramids and match the actual prevalence trends of comorbidities and the disease incidence rates reported in epidemiological studies in the past decade. Our future projections of cardiovascular diseases indicate lower prevalence than expected from static models, reflecting recent declining trends in disease incidence and fatality.

Potential utility of nano-based treatment approaches to address the risk of Helicobacter pylori

INTRODUCTION

Helicobacter pylori (H. pylori) has occupied a significant place among infectious pathogens and it has been documented as a leading challenge due to its higher resistance to the commonly used drugs, higher adaptability, and lower targeting specificity of the available drugs.

AREAS COVERED

New treatment strategies are urgently needed in order to improve the current advancement in modern medicine. Nanocarriers have gained an advantage of drug encapsulation and high retention time in the stomach with a prolonged drug release rate at the targeted site. This article aims to highlight the recent advances in nanotechnology with special emphasis on metallic, polymeric, lipid, membrane coated, and target-specific nanoparticles (NPs), as well as, natural products for treating H. pylori infection. We discussed a comprehensive approach to understand H. pylori infection and elicits to rethink about the increasing threat posed by H. pylori and its treatment strategies.

EXPERT OPINION

To address these issues, nanotechnology has got huge potential to combat H. pylori infection and has made great progress in the field of biomedicine. Moreover, combinatory studies of natural products and probiotics in conjugation with NPs have proven efficiency against H. pylori infection, with an advantage of lower cytotoxicity, minimal side effects, and stronger antibacterial potential.[Figure: see text].

Statins' Regulation of the Virulence Factors of Helicobacter pylori and the Production of ROS May Inhibit the Development of Gastric Cancer

Conventionally, statins are used to treat high cholesterol levels. They exhibit pleiotropic effects, such as the prevention of cardiovascular disease and decreased cancer mortality. Gastric cancer (GC) is one of the most common cancers, ranking as the third leading global cause of cancer-related deaths, and is mainly attributed to chronic Helicobacter pylori infection. During their co-evolution with hosts, H. pylori has developed the ability to use the cellular components of the host to evade the immune system and multiply in intracellular niches. Certain H. pylori virulence factors, including cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA), and cholesterol-α-glucosyltransferase (CGT), have been shown to exploit host cholesterol during pathogenesis. Therefore, using statins to antagonize cholesterol synthesis might prove to be an ideal strategy for reducing the occurrence of H. pylori-related GC. This review discusses the current understanding of the interplay of H. pylori virulence factors with cholesterol and reactive oxygen species (ROS) production, which may prove to be novel therapeutic targets for the development of effective treatment strategies against H. pylori-associated GC. We also summarize the findings of several clinical studies on the association between statin therapy and the development of GC, especially in terms of cancer risk and mortality.

Impact of the Gut Microbiota Balance on the Health-Disease Relationship: The Importance of Consuming Probiotics and Prebiotics

Gut microbiota is a group of microorganisms that are deposited throughout the entire gastrointestinal tract. Currently, thanks to genomic tools, studies of gut microbiota have pointed towards the understanding of the metabolism of important bacteria that are not cultivable and their relationship with human homeostasis. Alterations in the composition of gut microbiota could explain, at least in part, some epidemics, such as diabetes and obesity. Likewise, dysbiosis has been associated with gastrointestinal disorders, neurodegenerative diseases, and even cancer. That is why several studies have recently been focused on the direct relationship that these types of conditions have with the specific composition of gut microbiota, as in the case of the microbiota-intestine-brain axis. In the same way, the control of microbiota is related to the diet. Therefore, this review highlights the importance of gut microbiota, from its composition to its relationship with the human health-disease condition, as well as emphasizes the effect of probiotic and prebiotic consumption on the balance of its composition.

Burden of pancreatic cancer along with attributable risk factors in Europe between 1990 and 2019, and projections until 2039

Projecting the burden of pancreatic cancer over time provides essential information to effectively plan measures for its management and prevention. Here, we obtained data from the Global Burden of Disease (GBD) Study between 1990 and 2019, to model how pancreatic cancer will affect the 27 countries of the European Union (EU) plus the United Kingdom (the pre-Brexit EU-28) until 2039 by conducting the Bayesian age-period-cohort analysis. The number of new pancreatic cancer cases in the EU-28 was 59 000 in 1990, 109 000 in 2019 and projected to be 147 000 in 2039. This corresponded to 60 000, 109 000 and 155 000 for deaths, and a loss of 1.3 million, 2.0 million and 2.7 million for disability-adjusted life years (DALYs), respectively. The most pronounced increase of the crude incidence rate was observed and projected to be in the population older than 80 years. The age-standardized rate (ASR) of incidence, however, increased from 8.6 to 10.1 per 100 000 person-years during 1990-2019 but was projected to remain stable during 2019-2039. At the same time, our models only predicted a mild increase in the ASR of mortality until 2039. The fraction of pancreatic cancer mortality attributable to tobacco consumption decreased during 1990-2019, but we found upward trends for the attributable fractions for high fasting plasma glucose and high body mass index. In conclusion, a substantial increase in counts of incidence, mortality and DALYs lost of pancreatic cancer in the EU-28 is projected over the next two decades, which indicates the need for future health policies and interventions.

An age-period-cohort analysis of mortality rates for stomach, colorectal, liver, and lung cancer among prefectures in Japan, 1999-2018

BACKGROUND

Although change in the birth cohort effect on cancer mortality rates is known to be highly associated with the decreasing rates of age-standardized cancer mortality rates in Japan, the differences in the trends of cohort effect for representative cancer types among the prefectures remain unknown. This study aimed to investigate the differences in the decreasing rate of cohort effects among the prefectures for representative cancer types using age-period-cohort (APC) analysis.

METHODS

Data on stomach, colorectal, liver, and lung cancer mortality for each prefecture and the population data from 1999 to 2018 were obtained from the Vital Statistics in Japan. Mortality data for individuals aged 50 to 79 years grouped in 5-year increments were used, and corresponding birth cohorts born 1920-1924 through 1964-1978 were used for analysis. We estimated the effects of age, period, and cohort on each type of mortality rate for each prefecture by sex. Then, we calculated the decreasing rates of cohort effects for each prefecture. We also calculated the mortality rate ratio of each prefecture compared with all of Japan for cohorts using the estimates.

RESULTS

As a result of APC analysis, we found that the decreasing rates of period effects were small and that there was a little difference in the decreasing rates among prefectures for all types of cancer among both sexes. On the other hand, there was a large difference in the decreasing rates of cohort effects for stomach and liver cancer mortality rates among prefectures, particularly for men. For men, the decreasing rates of cohort effects in cohorts born between 1920-1924 and 1964-1978 varied among prefectures, ranging from 4.1 to 84.0% for stomach cancer and from 20.2 to 92.4% for liver cancers, respectively. On the other hand, the differences in the decreasing rates of cohort effects among prefectures for colorectal and lung cancer were relatively smaller.

CONCLUSIONS

The decreasing rates of cohort effects for stomach and liver cancer varied widely among prefectures. It is possible that this will influence cancer mortality rates in each prefecture in the future.

Differences in Cancer Mortality Trends between Metropolitan and Non-Metropolitan Areas in Japan, 1999-2018

Background:

Although socioeconomic statuses affect cancer mortality rates, the specific difference between metropolitan and non-metropolitan areas in Japan has not been evaluated. This study analyzed differences in cancer mortality between metropolitan and non-metropolitan areas in Japan, using an age-period-cohort (APC) analysis.

Methods:

Data on cancer mortality from 1999 to 2018 for metropolitan and non-metropolitan areas in Japan were used. Here metropolitan areas were defined as government ordinance-designated municipalities in 1999 and special wards of Tokyo. In addition to general mortality data for all cancer sites, data on mortality for stomach, colorectal, liver, gallbladder, pancreatic, lung, prostate, and breast cancers were used for analysis. A Bayesian APC analysis was administered to the data for each type of cancer for area and for sex-distinguished data. Additionally, the ratios for estimated mortality rate by periods and cohorts between the two areas were calculated.

Results:

The age-standardized mortality rate for cancer in all sites in non-metropolitan areas was lower than that in metropolitan areas throughout the analyzed years for both men and women, but the mortality difference decreased during the periods for men. The rates of decrease in mortality rate in cohorts differed for some cancers between the two area types, and the mortality rate ratios of metropolitan compared with non-metropolitan areas decreased for cancer in all sites over the analyzed cohorts for men. Also, the rate of decrease in mortality rate over the cohorts was completely different between the areas for stomach cancer in men and for liver cancer for women.

Conclusion:

Mortality rates for cancer in all sites tended to diverge between the two area types in younger cohorts for men, and people in younger cohorts in non-metropolitan areas should take more extensive preventive measures against cancer than their counterparts in metropolitan areas.

Age-Based Trends of Gastric Adenocarcinoma in the United States

BACKGROUND

Recent studies have shown an increase in the incidence of gastric cancer (GC) among young adults in Asia and Latin America. However, it is unknown if a similar trend is happening in the United States (US).

METHODS

A retrospective review of the National Cancer Data Base was conducted to identify patients diagnosed with gastric adenocarcinoma between the years of 2004 and 2013.

RESULTS

A total of 93 734 patients were included. The 2 age groups below 40 did not see a change in GC incidence; however, age groups above 40 had increasing incidence. Patients aged 18-25 had the largest proportion of stage 4 disease and a poor survival (median 11.5 months), compared to older patients.

CONCLUSION

Despite the increasing trend of GC among individuals, the incidence of GC among young adults is not increasing. However, this subpopulation presents at more advanced stages (clinical stage 4) and thus has worse survival.

Age-Based Trends of Gastric Adenocarcinoma in the United States

BACKGROUND

Recent studies have shown an increase in the incidence of gastric cancer (GC) among young adults in Asia and Latin America. However, it is unknown if a similar trend is happening in the United States.

METHODS

A retrospective review of the National Cancer Database was conducted to identify patients diagnosed with gastric adenocarcinoma between the years of 2004 and 2013.

RESULTS

A total of 93 734 patients were included. The two age groups below 40 did not see a change in GC incidence; however, age groups above 40 had increasing incidence. Patients aged 18 to 25 had the largest proportion of stage 4 disease and a poor survival (median 11.5 months), compared to older patients.

CONCLUSION

Despite the increasing trend of GC among individuals, the incidence of GC among young adults is not increasing. However, this subpopulation presents at more advanced stages (clinical stage 4) and thus has worse survival.

Age-Period-Cohort Analysis of the Sex Differences in Cancer Mortality Rates in Japan from 1995 to 2015

BACKGROUND

The current study aimed to analyze the sex differences in cancer mortality rates in Japan via an age-period-cohort (APC) analysis.

METHODS

We used data about cancer mortality rates from 1995 to 2015 in Japan based on the Vital Statistics survey. In addition to the data about mortality from all sites of cancer, we specifically used data about stomach, lung, colorectal, and liver cancers. A Bayesian APC analysis was performed to identify changes in mortality rates based on three effects, which were as follows: age, period, and cohort. Then, we finally calculated the mortality rate ratios for each effect between men and women.

RESULTS

The sex differences in age-adjusted mortality rates for all-sites cancer, lung cancer, and liver cancer were decreasing from 1995 to 2015, and the mortality rate ratios in terms of sex decreased from 2.17 in 1995 to 1.93 in 2015. Based on the results of the APC analyses, only minimal changes were observed in the mortality rate ratios for all types of cancer between men and women during the analyzed periods. The cohort effects began to decrease from the early 20th century in all types of cancer in both men and women, and the mortality rate ratios for all types of cancer between men and women began to increase in the cohorts born from 1926 to 1935. For all-sites cancer, the ratio increased from 0.49 (0.44, 0.57) in the cohort born from 1926 to 1930 to 0.81 (0.60, 1.03) in the cohort born from 1971 to 1975.

CONCLUSION

The sex differences in cancer mortality rates were decreasing in the more recent born generations in Japan. If this trend continues, there will be a minimal difference in the morality rates in the following generations.<br />.

Microbiome and Gastric Cancer

The late 1800s Louis Pasteur and Robert Koch introduced and popularized the germ theory of disease. At that time, gastric cancer was the most common cause of cancer deaths in most countries making the stomach an early site of microbial research with a focus on gastric luminal and mucosal bacteria and the role of Boas-Oppler bacillus (Lactobacillus) in the diagnosis of gastric cancer. In the 1970s, the research focus evolved to studies of the gastric microbiome in the production of nitrosamines and included development of the Correa cascade. Interest in nitrosamine production peaked in the late 1980s and was replaced by studies of the newly described Helicobacter pylori and studies of its role in gastritis, gastric atrophy, and gastric cancer. The last decade has witnessed a rebirth in interest in the gastric microbiota as part of worldwide interest in the human microbiome. Although fungi were prominent in the studies of gastric microbiology in the nineteenth century, their potential role in disease pathogenesis has yet to be addressed using modern techniques. Overall, current studies of the gastric bacterial microbiome do not provide convincing evidence to expand the role of the gastric microbiome in cancer pathogenesis beyond what is directly attributable to the oncogenic potential of H. pylori and its role in persisting acute-on-chronic inflammation.

The long-term population impact of endoscopic screening programmes on disease burdens of gastric cancer in China: A mathematical modelling study

BACKGROUND

Gastric cancer (GC) incidence and mortality in China remained high due to delayed diagnosis and accounted for about half of the world's GC cases and deaths. Early detection with endoscopic screening and consequent timely treatment can significantly improve survival. This study aimed to explore the long-term population impact of endoscopic screening on national GC disease burdens in China.

METHODS

Most of previous studies investigated the disease burdens of cancer using Markov model or age-period-cohort (APC) model, which are difficult to estimate the population size of undiagnosed cases. In this paper, we proposed a new dynamic compartmental model based on GC natural history and calibrated model outputs to diagnosed GC cases and GC-related death counts using Markov Chain Monte Carlo methods. We investigated the impact of screening strategies with various coverage (10%, 40%, 70%) and frequency (every 1, 3, 5 years) on disease burdens.

RESULTS

We estimated that 2.22 (95%CI: 1.97-2.47) million Chinese are living with GC in 2019, among which, 42.7% (40.3-45.0%) remained undiagnosed. Without systematic screening, we projected 10.46 (9.07-11.86) million incident cases and 7.35 (6.59-8.11) million GC-related deaths over the next 30 years (2019-2049). Screening with coverage rate at 10%, 40%, 70% every 3 years could prevent 0.85 (0.63-1.06), 2.32 (1.79-2.86), and 3.04 (2.38-3.70) million incident cases, and prevent 1.17 (1.01-1.32), 3.08 (2.70-3.46), and 3.93 (3.46-4.40) million deaths respectively, compared with 'no screening' scenario. Screening would substantially increase the number of diagnosed GC cases within the first three years of program initiation, but this number would quickly reduce below 'no screening' scenario. Three-yearly screening at the above coverage rates would reduce the proportion of undiagnosed GC cases to 38.8% (36.9-40.7%), 25.5% (23.4-27.6%), and 17.8% (16.0-19.6%) by 2049, respectively. Delaying implementation of the screening program would substantially reduce its effectiveness.

CONCLUSIONS

Initiating national endoscopic screening programmes would likely have a major effect on reducing GC incidence and mortality in China. Health resources should be substantially increased and directed to treatment of GC to cope with the initial rise in diagnosed GC cases.

Changing Trends in Stomach Cancer Throughout the World

PURPOSE OF REVIEW

The paper aims to discuss the global trends in gastric cancer incidence in relation to important factors involved in the pathogenesis of gastric cancer.

RECENT FINDINGS

Despite a significant worldwide decline, gastric cancer remains a common cause of cancer death. The decline has been multifactorial and preceded the fall in Helicobacter pylori prevalence. The initial decline was associated with changes in food preservation and availability, especially of fresh fruits and vegetables, followed by a decline in the primary etiologic factor, H. pylori. Gastric cancer incidence remains high in East Asia, intermediate in Latin America, and low in developed countries. Significant racial/ethnic variability exists. The rapid decline in incidence in East Asia will continue as primary and secondary prevention strategies are implemented. The incidence in Latin America is unlikely to decline significantly over the next few decades given high H. pylori prevalence in the young. Ultimately, global H. pylori eradication will be needed to largely eliminate gastric cancer.

Changing trends in the prevalence of H. pylori infection in Japan (1908-2003): a systematic review and meta-regression analysis of 170,752 individuals

Changing trends in the prevalence of H. pylori infection in the general population over time are thought to be the main driving force behind the declining gastric cancer mortality in Japan. However, whether the prevalence of H. pylori infection itself shows a birth-cohort pattern needs to be corroborated. We performed a systematic review of studies that reported the prevalence of H. pylori infection among Japanese individuals. Meta-regression was conducted in the framework of a generalized additive mixed model (GAMM) to account for heterogeneity in the prevalence of H. pylori infection as a function of birth year. The prevalence of H. pylori infection confirmed a clear birth cohort pattern: the predicted prevalence (%, 95% CI) was 60.9 (56.3–65.4), 65.9 (63.9–67.9), 67.4 (66.0–68.7), 64.1 (63.1–65.1), 59.1 (58.2–60.0), 49.1 (49.0–49.2), 34.9 (34.0–35.8), 24.6 (23.5–25.8), 15.6 (14.0–17.3), and 6.6 (4.8–8.9) among those who were born in the year 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, and 2000, respectively. The present study demonstrated a clear birth-cohort pattern of H. pylori infection in the Japanese population. The decreased prevalence of H. pylori infection in successive generations should be weighed in future gastric cancer control programs.

Helicobacter pylori as an oncogenic pathogen, revisited

Gastric cancer is an inflammation-associated malignancy aetiologically related to infection with the bacterium, Helicobacter pylori, which is considered a necessary but insufficient cause. Unless treated, H. pylori causes life-long acute and chronic gastric inflammation resulting in progressive gastric mucosal damage that may result in gastric cancer. The rate of progression from superficial gastritis, to an atrophic metaplastic mucosa, and ultimately to cancer relates to the virulence of the infecting H. pylori as well as host and environmental factors. H. pylori virulence is a reflection of its propensity to cause severe gastric inflammation. Both mucosal inflammation and H. pylori can cause host genomic instability, including dysregulation of DNA mismatch repair, stimulation of expression of activation-induced cytidine deaminase, abnormal DNA methylation and dysregulation of  micro RNAs, which may result in an accumulation of mutations and loss of normal regulation of cell growth. The difference in cancer risk between the most and least virulent H. pylori strain is only approximately 2-fold. Overall, none of the putative virulence factors identified to date have proved to be disease-specific. The presence, severity, extent and duration of inflammation appear to be the most important factors and current evidence suggests that any host, environmental or bacterial factor that reliably enhances the inflammatory response to the H. pylori infection increases the risk of gastric cancer.

Detection and Clinical Significance of COX-2 Gene SNPs in Gastric Cancer

Gastric cancer has high morbidity and mortality. Identification of patients with high gastric cancer risk at early stage will improve patient prognosis. In this study, we examined two single nucleotide polymorphism (SNP) sites of COX-2 gene in gastric cancer patients and explored the effect of the SNPs on the morbidity of gastric cancer. We found that the SNPs COX-2-1195G/A and COX-2-8473T/C are correlated with the occurrence of gastric cancer, and the patients with variants A and C of the SNPs are liable to have gastric cancer. Our study provides a potential method for screening of susceptible population of gastric cancer for early-stage intervention in patients.

Trends and predictions for gastric cancer mortality in Brazil

AIM: To analyze the effect of age-period and birth cohort on gastric cancer mortality, in Brazil and across its five geographic regions, by sex, in the population over 20 years of age, as well as make projections for the period 2010-2029.

METHODS: An ecological study is presented herein, which distributed gastric cancer-related deaths in Brazil and its geographic regions. The effects of age-period and birth cohort were calculated by the Poisson regression model and projections were made with the age-period-cohort model in the statistical program R.

RESULTS: Progressive reduction of mortality rates was observed in the 1980’s, and then higher and lower mortality rates were verified in the 2000’s, for both sexes, in Brazil and for the South, Southeast and Midwest regions. A progressive decrease in mortality rates was observed for the Northeast (both sexes) and North (men only) regions within the period 1995-1999, followed by rising rates.

CONCLUSION: Regional differences were demonstrated in the mortality rates for gastric cancer in Brazil, and the least developed regions of the country will present increases in projected mortality rates.

[Infections and epigenetic changes in cancer]

The role of epigenetics and infectious diseases at early stages of life influence pre-malignant lesions of cancer, in particular, gastric cancer, one of the most frequent tumours in Chile, Latin America, and worldwide. This article examines the role of H.pylori and epigenetic alterations (i.e. DNA methylation) at early stages of gastric cancer and proposes, from the paediatric point of view, strategies for prevention and early detection.

Eradication of Helicobacter pylori and Gastric Cancer: A Systematic Review and Meta-analysis of Cohort Studies

BACKGROUND

Helicobacter pylori (H. pylori) is associated with an increased risk of gastric adenocarcinoma and gastric mucosa associated lymphoid tissue (MALT) lymphoma and a decreased risk of esophageal adenocarcinoma. We aimed to assess how eradication therapy for H. pylori influences the risk of developing these cancers.

METHODS

This was a systematic review and meta-analysis. We searched PubMed, Web of Science, Embase, and the Cochrane Library and selected articles that examined the risk of gastric cancer, MALT lymphoma, or esophageal cancer following eradication therapy, compared with a noneradicated control group.

RESULTS

Among 3629 articles that were considered, nine met the inclusion criteria. Of these, eight cohort studies assessed gastric cancer while one randomized trial assessed esophageal cancer. Out of 12 899 successfully eradicated patients, 119 (0.9%) developed gastric cancer, compared with 208 (1.1%) out of 18 654 noneradicated patients. The pooled relative risk of gastric cancer in all eight studies was 0.46 (95% confidence interval [CI] = 0.32 to 0.66, I(2) = 32.3%) favoring eradication therapy. The four studies adjusting for time of follow-up and confounders showed a relative risk of 0.46 (95% CI = 0.29 to 0.72, I(2) = 44.4%).

CONCLUSIONS

This systematic review and meta-analysis indicates that eradication therapy for H. pylori prevents gastric cancer. There was insufficient literature for meta-analysis of MALT lymphoma or esophageal cancer.

Helicobacter pylori update: gastric cancer, reliable therapy, and possible benefits

Helicobacter pylori infection contributes to the development of diverse gastric and extragastric diseases. The infection is necessary but not sufficient for the development of gastric adenocarcinoma. Its eradication would eliminate a major worldwide cause of cancer death, therefore there is much interest in identifying how, if, and when this can be accomplished. There are several mechanisms by which H pylori contributes to the development of gastric cancer. Gastric adenocarcinoma is one of many cancers associated with inflammation, which is induced by H pylori infection, yet the bacteria also cause genetic and epigenetic changes that lead to genetic instability in gastric epithelial cells. H pylori eradication reduces both. However, many factors must be considered in determining whether treating this bacterial infection will prevent cancer or only reduce its risk-these must be considered in designing reliable and effective eradication therapies. Furthermore, H pylori infection has been proposed to provide some benefits, such as reducing the risks of obesity or childhood asthma. When tested, these hypotheses have not been confirmed and are therefore most likely false.

Roadmap for elimination of gastric cancer in Korea

Most gastric cancers are caused by infection with the common human bacterial pathogen, Helicobacter pylori. It is now accepted that gastric cancer can be prevented and virtually eliminated by H. pylori eradication and this knowledge was responsible for country-wide H. pylori eradication combined with secondary cancer prevention for those with residual risk that was introduced in Japan in 2013. Korea is a high H. pylori prevalence and high gastric cancer incidence country and a good candidate for a gastric cancer elimination program. The presence of an H. pylori infection is now considered as an indication for treatment of the infection. However, antimicrobial drug resistance is common among H. pylori in Korea making effective therapy problematic. Country-wide studies of the local and regional antimicrobial resistance patterns are needed to choose the most appropriate therapies. H. pylori and gastric cancer eradication can be both efficient and cost effective making it possible and practical to make Korea H. pylori and gastric cancer free. There is no reason to delay.