Mechanistic Insights on Microbiota-Mediated Development and Progression of Esophageal Cancer

Esophageal cancer (EC) is one of the most common malignant tumors worldwide, and its two major types, esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC), present a severe global public health problem with an increasing incidence and mortality. Established risk factors include smoking, alcohol consumption, and dietary habits, but recent research has highlighted the substantial role of oral microbiota in EC pathogenesis. This review explores the intricate relationship between the microbiome and esophageal carcinogenesis, focusing on the following eight significant mechanisms: chronic inflammation, microbial dysbiosis, production of carcinogenic metabolites, direct interaction with epithelial cells, epigenetic modifications, interaction with gastroesophageal reflux disease (GERD), metabolic changes, and angiogenesis. Certain harmful bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, are specifically implicated in sustaining irritation and tumor progression through pathways including NF-κB and NLRP3 inflammasome. Additionally, the review explores how microbial byproducts, including short-chain fatty acids (SCFAs) and reactive oxygen species (ROS), contribute to DNA harm and disease advancement. Furthermore, the impact of reflux on microbiota composition and its role in esophageal carcinogenesis is evaluated. By combining epidemiological data with mechanistic understanding, this review underscores the potential to target the microbiota-immune system interplay for novel therapeutic and diagnostic strategies to prevent and treat esophageal cancer.

Spatial and temporal patterns of colorectal cancer in Asia, 1990-2019

BACKGROUND

Asia accounts for the largest burden of colorectal cancer (CRC) worldwide. This study examines the temporal patterns of CRC in Asia in the last three decades.

METHODS

The data pertaining to CRC burden measured by incidence, mortality, and disability-adjusted-life-years (DALYs) and its risk factors for 49 countries in the Asian continent were drawn from the Global Burden of Disease 2019 study between 1990 and 2019. Mortality-to-incidence ratio (MIR) was employed as a proxy indicator of 5-year survival rates.

RESULTS

In Asia, incident cases more than tripled from 270,851 to 1.1 million, deaths tripled from 183,252 to 560,426, and DALYs more than doubled from 5 million to 13.4 million between 1990 and 2019. The age-standardized incidence rate (ASIR) increased from 14.0/100,000 to 23.9/100,000, age-standardized mortality rate (ASMR) increased from 10.1/100,000 to 12.5/100,000, and MIR decreased from 0.68 to 0.50 between 1990 and 2019. ASIR varied 10-folds across countries from 5.6/100,000 in Bangladesh to 62.0/100,000 in Taiwan in 2019 and ASMR from 4.9/1000 in Bangladesh to 30.3/100,000 in Brunei. In 2019, diet low in milk (18.7%) and whole grains (15.2%) and calcium (16.6%) were the major contributory risk factors in CRC DALYs in 2019.

CONCLUSION

CRC is a fast-rising neoplasm in Asia and its burden can be curtailed by focusing on primary prevention (e.g., diet and physical activity) and secondary prevention through screening. The policy focus and resources must be directed towards capacity building, including cancer infrastructure and quality data availability from cancer registries.

Updated epidemiology of gastrointestinal cancers in East Asia

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesophageal and gallbladder cancers, was observed in regions in East Asia. The increasing burden of gastrointestinal cancers in East Asian regions is related to population growth, ageing and the westernization of lifestyle habits in this region. Furthermore, the rising incidence of young-onset colorectal cancer is an emerging trend in East Asia. This Review provides a comprehensive and updated summary of the epidemiology of gastrointestinal cancers in East Asia, with emphasis on comparing their epidemiology in East Asia with that in Western regions, and highlights the major risk factors and implications for prevention. Overall, to optimally reduce the disease burden incurred by gastrointestinal cancers in East Asian regions, a concerted effort will be needed to modify unhealthy lifestyles, promote vaccination against the hepatitis virus, control Helicobacter pylori, liver fluke and hepatitis virus infections, increase the uptake rate of colorectal cancer screening, enhance detection of early cancers and their precursors, and improve cancer survivorship through an organized rehabilitation programme.

Analysing 11 years of incidence trends, clinicopathological characteristics, and forecasts of colorectal cancer in young and old patients: a retrospective cross-sectional study in an Indonesian national referral hospital

OBJECTIVE

To obtain annual incidence trends, understand clinicopathological characteristics, and forecast the future burden of colorectal cancer (CRC) in Indonesia.

DESIGN

11-year retrospective cross-sectional study.

SETTING

A national referral hospital in Jakarta, Indonesia.

PARTICIPANTS

Data from 1584 eligible cases were recorded for trends and forecasting analyses; 433 samples were analysed to determine clinicopathological differences between young (<50 years) and old (≥50 years) patients.

METHODS

Trend analyses were done using Joinpoint software, expressed in annual percentage change (APC), and a regression analysis was executed to generate a forecasting model. Patients' characteristics were compared using χ2 or non-parametric tests.

MAIN OUTCOMES

Analysis of trends, forecasting model, and clinicopathological features between the age groups.

RESULTS

A significant increase in APC was observed among old patients (+2.38%) for CRC cases. Colon cancer increased remarkably (+9.24%) among young patients; rectal cancer trends were either stable or declining. The trend for right-sided CRC increased in the general population (+6.52%) and old patients (+6.57%), while the trend for left-sided CRC was stable. These cases are expected to be a significant health burden within the next 10 years. Patients had a mean age of 53.17±13.94, 38.1% were young, and the sex ratio was 1.21. Prominent characteristics were left-sided CRC, tumour size ≥5 cm, exophytic growth, adenocarcinoma, histologically low grade, pT3, pN0, inadequately dissected lymph nodes (LNs), LN ratio <0.05, no distant metastasis, early-stage cancer, no lymphovascular invasion, and no perineural invasion (PNI). Distinct features between young and old patients were found in the histological subtype, number of dissected LN, and PNI of the tumour.

CONCLUSIONS

Epidemiological trends and forecasting analyses of CRC cases in Indonesian patients showed an enormous increase in colon cancer in young patients, a particularly concerning trend. Additionally, young patients exhibited particular clinicopathological characteristics that contributed to disease severity.

Exercise and colorectal cancer: prevention and molecular mechanisms

Exercise and physical activity have been shown to be strongly associated with a decreased incidence rate of various chronic diseases especially numerous human malignancies. A huge number of clinical trials and meta-analysis have demonstrated that exercise is significantly effective in lowering the risk of colorectal cancer. In addition, it is suggested as an effective therapeutic modality against this cancer type. Therefore, in this review, we will review comprehensibly the effects of exercise in preventing, treating, and alleviating the adverse effects of conventional therapeutic options in colorectal cancer. Moreover, the possible mechanisms underlying the positive effects of exercise and physical activity in colorectal cancer, including regulation of inflammation, apoptosis, growth factor axis, immunity, epigenetic, etc. will be also discussed.

Exercise is an effective post-treatment management program in colorectal cancer survivals

Exercise improves muscle strength, cardiorespiratory fitness, emotional distress, physical activity, fatigue, and sleep quality in colorectal patients undergoing chemotherapy

Targeting and modulating insulin-like growth factor (IGF) system, inflammation, apoptosis, immunity, epigenetic, Leptin and Ghrelin, and signaling pathways are major underlying mechanisms for preventive effects of exercise in colorectal cancer

Biofeedback therapy combined with Baduanjin on quality of life and gastrointestinal hormone level in patients with colorectal cancer

BACKGROUND

With the change in people’s lifestyles, the incidence of colorectal cancer (CRC) is increasing. It is essential to study the efficacy of various treatment methods for CRC patients to prevent and treat CRC.

AIM

To investigate the efficacy of biofeedback therapy combined with Baduanjin in improving the quality of life and gastrointestinal hormone levels of patients with CRC.

METHODS

A total of 120 patients with CRC who were admitted to our hospital from June 2020 to June 2021 were included in the study. They were randomly divided into four groups (n = 30): the control group (group A), the biofeedback therapy intervention group (group B), the Baduanjin exercise intervention group (group C), and the combination group (group D). Patients in group A adopted the standard nursing mode and necessary health education. Patients in group B were treated with biofeedback therapy based on routine nursing care. Patients in group C were given Baduanjin intervention for 12 wk based on conventional drug treatment and care. Patients in group D were treated with biofeedback therapy and Baduanjin exercise. In this study, patients’ quality of life, gastrointestinal hormone levels, and clinical efficacy in the four groups were observed at baseline and 12 wk after intervention. Meanwhile, the correlation between gastrointestinal hormone levels and various functional areas of quality of life was analyzed. By comparing the observed indicators of patients in the four groups, the efficacy of biofeedback therapy combined with Baduanjin in improving the quality of life and gastrointestinal hormone levels of patients with CRC was explored.

RESULTS

At baseline, there were no significant differences in quality of life, gastrointestinal hormone levels, or clinical efficacy among the four groups (P > 0.05). Twelve weeks after the intervention, the combination group’s quality of life, gastrointestinal hormone levels, and clinical effectiveness were better than those of the three other groups.

CONCLUSION

On the basis of routine nursing care, patients with CRC combined with biofeedback therapy and Baduanjin exercise can improve the quality of life of patients with CRC and the efficacy of gastrointestinal hormone levels.

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

Walking time, sports activity, job type, and body posture during work in relation to incident colorectal cancer: the JACC prospective cohort study

PURPOSE

An inverse association between physical activity and colorectal cancer (CRC) has been suggested. We aimed to assess the specific and combined effects of leisure-time and occupational physical activities on CRC risk among Japanese adults.

METHODS

Using Cox proportional hazard models, we tested whether walking time, sports activity, body posture during work, and job type-or the combination of these variables-were associated with CRC incidence in a prospective cohort of 26,897 Japanese adults aged 40-79 years.

RESULTS

During a median 17-year follow-up (1990-2009) period, we ascertained 423 incident cases of CRC (267 colon and 156 rectum cancer). Time spent walking suggested a dose-response inverse relationship with CRC risk (p-trend = 0.051). Manual labor was associated with lower CRC risk when compared to office work with HRs (95% CIs) of 0.74 (0.56-0.97) for CRC and 0.68 (0.48-0.96) for colon cancer. Compared to sitting, moving during work tended to be inversely associated with rectal cancer risk, especially after censoring early incident cases within 3 years after baseline; HR (95% CI) = 0.63 (0.40-0.99). Combining walking and job type suggested mutual and synergistic benefits on the risk of colon cancer (p-interaction = 0.03). Compared to office workers walking < 1 h/day, the HR (95% CI) of colon cancer was 0.48 (0.23-0.98), 0.61 (0.42-0.89), and 0.59 (0.41-0.87) in office workers walking ≥ 1 h/day, non-office workers walking < 1 h/day, and non-office workers walking ≥ 1 h/day, respectively.

CONCLUSION

The time spent walking, job type, and posture during work were independently associated with the reduced incident CRC risk among Japanese men and women.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Epidemiology and risk factors of colorectal cancer in China

In China, colorectal cancer (CRC) ranked fourth and fifth in the highest incidence and mortality rates of all malignancies in 2018, respectively. Although these rates are below the world average, China placed first worldwide in the number of new CRC cases and CRC-related deaths because of its comparatively large population. This disease represents a threat to the health of population and incurs a heavy economic burden on the society and individuals. CRC has various risk factors, including age, sex, lifestyle, genetic factors, obesity, diabetes, gut microbiota status, and precancerous lesions. Furthermore, incidence and mortality rates of CRC are closely related to socioeconomic development levels, varying according to regional and population characteristics. Prevention is the main strategy to reduce incidence and mortality rates of CRC. This can be achieved through strategies stimulating lifestyle changes, healthy diet habits, and early screening for high-risk individuals. To reduce the burden of CRC, public health officials should promote prevention and management of modifiable risk factors through national policies. The rising incidence and mortality rates of CRC in China may be timely curbed by clarifying specific epidemiological characteristics, optimizing early screening strategies, and strictly implementing diagnosis and treatment guidelines. Thus, this study aimed to collect and report the current research status on epidemiology and risk factors of CRC in China.

Effect of physical fitness on colorectal tumor development in patients with familial adenomatous polyposis

Although accumulated epidemiological evidence indicates that a good physical fitness level may prevent the development of sporadic colorectal cancer (CRC), few studies have examined the effect of physical fitness level on familial adenomatous polyposis (FAP). This cross-sectional study aimed to examine the relationship between physical fitness and CRC development in patients with FAP.A total of 119 patients (54 male; 65 female) with FAP, aged 17 to 73 years, underwent a step test to induce exercise stress. Predicted maximal oxygen uptake (VO2max) was calculated for each patient by using heart rate as an index of physical fitness. The association of VO2max with the presence or absence of CRC and polyp diameter was examined. Patients with FAP were divided into 3 categories according to their VO2max (high, medium, and low). The association between maximum polyp size and VO2max among the patients with FAP without a history of colectomy was examined.The risk of CRC was significantly higher in the low VO2max group than in the high VO2max group (odds ratio = 4.07; 95% confidence interval, 1.02-16.26). The maximum polyp diameter was significantly negatively correlated with the VO2max among the patients with FAP without a history of colectomy (r = -.44, P = .01). In the multiple linear regression analysis, maximum polyp diameter was independently correlated with VO2max.Our results suggest a preventive association between physical fitness and CRC development or colorectal adenoma growth exists in patients with FAP.

Prevalence and risk factors of colorectal cancer in Asia

Globally, colorectal cancer (CRC) is a substantial public health burden, and it is increasingly affecting populations in Asian countries. The overall prevalence of CRC is reported to be low in Asia when compared with that in Western nations, yet it had the highest number of prevalent cases. This review described the prevalence of CRC in Asia according to the International Agency for Research on Cancer from World Health Organization (WHO) database and summarized its major risk factors. Non-modifiable factors include genetic factors, ethnicity, age, gender, family history and body height; smoking, alcohol drinking, weight, Westernized diet, physical inactivity, chronic diseases and microbiota were involved in environmental factors. These risk factors were separately discussed in this review according to published literature from Asian countries. CRC screening has been playing an important role in reducing its disease burden. Some recommendations on its screening practices have been formulated in guidelines for Asia Pacific countries.

Progress in primary prevention of colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumors in the digestive tract, with high incidence and mortality. Most of CRC cases are diagnosed at the late stage, and the treatment effect is therefore poor. Thus, the prevention of CRC is particularly important. There have been many studies on the prevention of CRC in recent years. This paper will summarize the latest research on the primary prevention of CRC.

Evidence-based cancer prevention recommendations for Japanese

A comprehensive evidence-based cancer prevention recommendation for Japanese was developed. We evaluated the magnitude of the associations of lifestyle factors and infection with cancer through a systematic review of the literature, meta-analysis of published data, and pooled analysis of cohort studies in Japan. Then, we judged the strength of evidence based on the consistency of the associations between exposure and cancer and biological plausibility. Important factors were extracted and summarized as an evidence-based, current cancer prevention recommendation: 'Cancer Prevention Recommendation for Japanese'. The recommendation addresses six important domains related to exposure and cancer, including smoking, alcohol drinking, diet, physical activity, body weight and infection. The next step should focus on the development of effective behavior modification programs and their implementation and dissemination.

Hypoxia and inactivity related physiological changes precede or take place in absence of significant rearrangements in bacterial community structure: The PlanHab randomized trial pilot study

We explored the assembly of intestinal microbiota in healthy male participants during the randomized crossover design of run-in (5 day) and experimental phases (21-day normoxic bed rest (NBR), hypoxic bed rest (HBR) and hypoxic ambulation (HAmb) in a strictly controlled laboratory environment, with balanced fluid and dietary intakes, controlled circadian rhythm, microbial ambiental burden and 24/7 medical surveillance. The fraction of inspired O₂ (F_iO₂) and partial pressure of inspired O₂ (P_iO₂) were 0.209 and 133.1 ± 0.3 mmHg for NBR and 0.141 ± 0.004 and 90.0 ± 0.4 mmHg for both hypoxic variants (HBR and HAmb; ~4000 m simulated altitude), respectively. A number of parameters linked to intestinal environment such as defecation frequency, intestinal electrical conductivity (IEC), sterol and polyphenol content and diversity, indole, aromaticity and spectral characteristics of dissolved organic matter (DOM) were measured (64 variables). The structure and diversity of bacterial microbial community was assessed using 16S rRNA amplicon sequencing. Inactivity negatively affected frequency of defecation and in combination with hypoxia increased IEC (p < 0.05). In contrast, sterol and polyphenol diversity and content, various characteristics of DOM and aromatic compounds, the structure and diversity of bacterial microbial community were not significantly affected over time. A new in-house PlanHab database was established to integrate all measured variables on host physiology, diet, experiment, immune and metabolic markers (n = 231). The observed progressive decrease in defecation frequency and concomitant increase in IEC suggested that the transition from healthy physiological state towards the developed symptoms of low magnitude obesity-related syndromes was dose dependent on the extent of time spent in inactivity and preceded or took place in absence of significant rearrangements in bacterial microbial community. Species B. thetaiotamicron, B. fragilis, B. dorei and other Bacteroides with reported relevance for dysbiotic medical conditions were significantly enriched in HBR, characterized with most severe inflammation symptoms, indicating a shift towards host mucin degradation and proinflammatory immune crosstalk.

Hypoxia and Inactivity Related Physiological Changes (Constipation, Inflammation) Are Not Reflected at the Level of Gut Metabolites and Butyrate Producing Microbial Community: The PlanHab Study

We explored the assembly of intestinal microbiota in healthy male participants during the run-in (5 day) and experimental phases [21-day normoxic bed rest (NBR), hypoxic bedrest (HBR)], and hypoxic ambulation (HAmb) in a strictly controlled laboratory environment, balanced fluid, and dietary intakes, controlled circadian rhythm, microbial ambiental burden, and 24/7 medical surveillance. The fraction of inspired O₂ (F_iO₂) and partial pressure of inspired O₂ (P_iO₂) were 0.209 and 133.1 ± 0.3 mmHg for NBR and 0.141 ± 0.004 and 90.0 ± 0.4 mmHg for both hypoxic variants (HBR and HAmb; ~4,000 m simulated altitude), respectively. A number of parameters linked to intestinal transit spanning Bristol Stool Scale, defecation rates, zonulin, α₁-antitrypsin, eosinophil derived neurotoxin, bile acids, reducing sugars, short chain fatty acids, total soluble organic carbon, water content, diet composition, and food intake were measured (167 variables). The abundance, structure, and diversity of butyrate producing microbial community were assessed using the two primary bacterial butyrate synthesis pathways, butyryl-CoA: acetate CoA-transferase (but) and butyrate kinase (buk) genes. Inactivity negatively affected fecal consistency and in combination with hypoxia aggravated the state of gut inflammation (p < 0.05). In contrast, gut permeability, various metabolic markers, the structure, diversity, and abundance of butyrate producing microbial community were not significantly affected. Rearrangements in the butyrate producing microbial community structure were explained by experimental setup (13.4%), experimentally structured metabolites (12.8%), and gut metabolite-immunological markers (11.9%), with 61.9% remaining unexplained. Many of the measured parameters were found to be correlated and were hence omitted from further analyses. The observed progressive increase in two immunological intestinal markers suggested that the transition from healthy physiological state toward the developed symptoms of low magnitude obesity-related syndromes was primarily driven by the onset of inactivity (lack of exercise in NBR) that were exacerbated by systemic hypoxia (HBR) and significantly alleviated by exercise, despite hypoxia (HAmb). Butyrate producing community in colon exhibited apparent resilience toward short-term modifications in host exercise or hypoxia. Progressive constipation (decreased intestinal motility) and increased local inflammation marker suggest that changes in microbial colonization and metabolism were taking place at the location of small intestine.

Comparison of Segmental Colon Transit Time With Total Energy Expenditure in Psychiatry Unit Patients

Physical activity is associated with a reduced risk of colorectal cancer. We examined the colon transit time (CTT) according to the total energy expenditure (TEE) in psychiatry unit patients. The study participants included 67 adults, with a mean age of 49.8 years. The participants used an accelerometer for 7 days to measure their 1-week TEE. They took a capsule containing 20 radio-opaque markers for 3 days. On the 4th day and 7th day, a supine abdominal radiography was performed. According to the TEE of all study participants, the upper 30%, middle 30%, and lower 40% were classified into groups according to high (H), moderate (M), and low (L) physical activity. The mean total CTT was 52.0 hours. The segmental CTT for the right, left, and recto-sigmoid colon were 15.3 hours, 19.2 hours, and 17.4 hours. Total CTT in the H group was significantly shorter than that in the L group (p = .010). A comparison of the segmental CTT between the L, M, and H groups showed that the right CTT (p = .010) of the H group was significantly shorter than that of the M group. The left CTT of the M group (p = .028) and H group (p = .004) was significantly shorter than that of the L group. The recto-sigmoid CTT (p = .016) of the M group was significantly shorter than that of the L group. The study showed that moderate and high TEE was assisted with reduced CTT.

Survivorship care plans for people with colorectal cancer: do they reflect the research evidence?

AIM

In the present study, we synthesized the published literature about the psychosocial aspects of colorectal cancer (crc) survivorship to support an update of the evidentiary base of the survivorship care plans (scps) created in our jurisdiction.

METHODS

The psychosocial topics identified in the crc scps created by two different initiatives in our province were used as search criteria: quality of life (qol), sexual function, fatigue, and lifestyle behaviors. An umbrella review was conducted to retrieve the best possible evidence. Only reviews that investigated the intended outcomes in crc survivors and those with moderate-to-high methodologic quality scores were included.

RESULTS

Of 462 retrieved reports, eight reviews met the inclusion criteria for the synthesis. Of those eight, six investigated the challenges of crc survivors and two investigated the effect of physical activity on survivor well-being. Our results indicate that emotional and physical challenges are common in crc survivors and that physical activity is associated with clinically important benefits for the fatigue and physical functioning of crc survivors.

CONCLUSIONS

Our study findings update the evidence and indicate that existing scps in our province concerning the physical and emotional challenges of crc survivors reflect the evidence at the time of their issue. However, the literature concerning cancer risks specific to crc survivors is lacking. Although systematic reviews are considered to be the "gold standard" in knowledge synthesis, our findings suggest that much remains to be done in the area of synthesis research to better guide practice in cancer survivorship.

Exercise, fitness, and the gut

PURPOSE OF REVIEW

Exercise and gut symptomatology have long been connected. The possibility that regular exercise fosters intestinal health and function has been somewhat overlooked in the scientific literature. In this review, we summarize current knowledge and discuss a selection of recent, relevant, and innovative studies, hypotheses and reviews that elucidate a complex topic.

RECENT FINDINGS

The multiorgan benefits of regular exercise are extensive. When taken in moderation, these benefits transcend improved cardio-respiratory fitness and likely reach the gut in a metabolic, immunological, neural, and microbial manner. This is applicable in both health and disease. However, further work is required to provide safe, effective recommendations on physical activity in specific gastrointestinal conditions.

SUMMARY

Challenging methodology investigating the relationship between exercise and gut health should not deter from exploring exercise in the promotion of gastrointestinal health.

Advances in cancer epidemiology in Japan

Epidemiologists in Japan have been performing calculations to estimate nationwide cancer incidence rates as well as 5-year survival rates using population-based cancer registry data. There have been remarkable changes in cancer incidence and/or mortality in cancers of the lung, liver and stomach, which were thought to be attributed to the changing impact of exposure to cigarette smoking, chronic hepatitis C virus infection and Helicobacter pylori infection, respectively. In systematic reviews providing evidence in risk/protective factors for cancer sites using case-control and cohort studies of the Japanese population, there were associations between cancer sites (esophagus, stomach, colo-rectum, liver, pancreas, lung and breast) and various lifestyle factors. In the past 10 years, a hospital-based case-control study at Aichi Cancer Center provided valuable evidence of gene-environment interaction on the development of cancer [i.e., the effects of aldehyde dehydrogenase-2 (ALDH2) polymorphism and heavy alcohol drinking on esophageal cancer, ALDH2 polymorphism and smoking on lung cancer, methylenetetrahydrofolate reductase polymorphism and heavy alcohol drinking on pancreatic cancer]. The database with stored DNA was also used and identified seven loci containing significant but low-penetrance polymorphisms associated with the development of breast cancer. These findings together with established risk factors are likely to be useful to predict personalized breast cancer risk in East Asian women. In 2005, the Japan Multi-Institution Collaborative Cohort (J-MICC) study was launched to elucidate gene-environment interactions as well as to confirm preclinical diagnostic biomarkers of cancer. J-MICC, which has recruited 92,000 healthy individuals by the end of 2012, will follow the individuals until 2025.

Social disparities, health risk behaviors, and cancer

BACKGROUND

Overall cancer incidence rates decreased in the most recent time period in both men and women, largely due to improvements in surgical therapeutic approaches (tertiary prevention) and screening programs (secondary prevention), but differences in cancer incidence and survival according to socioeconomic status are documented worldwide. Health risk behaviors, defined as habits or practices that increase an individual's likelihood of harmful health outcomes, are thought to mediate such inequalities.

DISCUSSION

Obesity has been related with increased cancer incidence and mortality due to imbalance of leptin and adiponectin which are connected to activation of PI3K, MAPK, and STAT3 pathways and decreasing insulin/insulin-like growth factor (IGF)-1 and mTOR signaling via activation of 5 AMP-activated protein kinase (AMPK), respectively. Physical activity has been associated to prevent cancer by the aforementioned obesity-related mechanisms, but also increasing level of circulating vitamin D, which has been related to lower risk of several cancers, and increasing prostaglandin F2a and reducing prostaglandin E2, which are both related with cancer prevention and promotion, respectively. A large number of different substances may induce themselves a direct cytotoxicity and mutagenic action on cells by smoking, whereas alcohol promote immune suppression, the delay of DNA repair, inhibition of the detoxification of carcinogens, the production of acetaldehyde, and the contribution to abnormal DNA methylation. The combined smoking and alcohol drinking habits have been shown to increase cancer risk by smoke action of increasing the acetaldehyde burden following alcohol consumption and alcohol action of enhancing the activation of various procarcinogens contained in tobacco smoke.

CONCLUSIONS

Interventions at the social level may be done to increase awareness about cancer risks and promote changing in unhealthy behaviors.

Meat intake and cause-specific mortality: a pooled analysis of Asian prospective cohort studies

BACKGROUND

Total or red meat intake has been shown to be associated with a higher risk of mortality in Western populations, but little is known of the risks in Asian populations.

OBJECTIVE

We examined temporal trends in meat consumption and associations between meat intake and all-cause and cause-specific mortality in Asia.

DESIGN

We used ecological data from the United Nations to compare country-specific meat consumption. Separately, 8 Asian prospective cohort studies in Bangladesh, China, Japan, Korea, and Taiwan consisting of 112,310 men and 184,411 women were followed for 6.6 to 15.6 y with 24,283 all-cause, 9558 cancer, and 6373 cardiovascular disease (CVD) deaths. We estimated the study-specific HRs and 95% CIs by using a Cox regression model and pooled them by using a random-effects model.

RESULTS

Red meat consumption was substantially lower in the Asian countries than in the United States. Fish and seafood consumption was higher in Japan and Korea than in the United States. Our pooled analysis found no association between intake of total meat (red meat, poultry, and fish/seafood) and risks of all-cause, CVD, or cancer mortality among men and women; HRs (95% CIs) for all-cause mortality from a comparison of the highest with the lowest quartile were 1.02 (0.91, 1.15) in men and 0.93 (0.86, 1.01) in women.

CONCLUSIONS

Ecological data indicate an increase in meat intake in Asian countries; however, our pooled analysis did not provide evidence of a higher risk of mortality for total meat intake and provided evidence of an inverse association with red meat, poultry, and fish/seafood. Red meat intake was inversely associated with CVD mortality in men and with cancer mortality in women in Asian countries.

Fish consumption and colorectal cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population

OBJECTIVE

The association between fish consumption and colorectal cancer risk remains inconclusive. The present study systematically reviewed and meta-analyzed epidemiologic data on the association between fish consumption and colorectal cancer risk among Japanese.

METHODS

Original data were obtained from MEDLINE searched using PubMed or from searches of the Ichushi database, complemented with manual searches. The associations were evaluated based on the strength of evidence, the magnitude of association and biologic plausibility. Meta-analysis was conducted according to the study design.

RESULTS

Five cohort studies and 12 case-control studies were identified. Fish consumption was not significantly associated with colorectal, colon or rectal cancer risks. One cohort study showed a weak positive association with colorectal cancer, and another showed a weak inverse association with colon cancer in men and a moderate and weak inverse association with colon and rectal cancers in women. As regards case-control studies, four studies reported a weak inverse association, whereas one showed a weak positive association with colon cancer. Regarding rectal cancer, four case-control studies showed a weak inverse association, but two reported a weak-to-moderate positive association. The pooled relative risk/odds ratio (95% confidence interval) of colorectal cancer for the highest versus lowest category of fish consumption was 1.03 (0.89-1.18) and 0.84 (0.75-0.94) for cohort and case-control studies, respectively.

CONCLUSIONS

There was insufficient evidence to support an association between fish consumption and the risk of colorectal cancer among Japanese.

Impact of brief exercise on peripheral blood NK cell gene and microRNA expression in young adults

Natural killers (NK) cells are unique innate immune cells that increase up to fivefold in the circulating blood with brief exercise and are known to play a key role in first-response defense against pathogens and cancer immunosurveillance. Whether exercise alters NK cell gene and microRNA (miRNA) expression is not known. Thirteen healthy men (20-29 yr old) performed ten 2-min bouts of cycle ergometer exercise at a constant work equivalent to an average of 77% of maximum O2 consumption interspersed with 1-min rest. Blood was drawn before and immediately after the exercise challenge. NK cells were isolated from peripheral blood mononuclear cells using a negative magnetic cell separation method. We used Affymetrix U133+2.0 arrays for gene expression and Agilent Human miRNA V2 Microarray for miRNAs. A stringent statistical approach (false discovery rate < 0.05) was used to determine that exercise significantly altered the expression of 986 genes and 23 miRNAs. Using in silico analysis, we found exercise-related gene pathways where there was a high likelihood of gene-miRNA interactions. These pathways were predominantly associated with cancer and cell communication, including p53 signaling pathway, melanoma, glioma, prostate cancer, adherens junction, and focal adhesion. These data support the hypothesis that exercise affects the gene and miRNA expression pattern in the population of NK cells in the circulation and suggest mechanisms through which physical activity could alter health through the innate immune system.