Diet, nutrients, and gastrointestinal cancer

Effect of physical activity on incidence and mortality in patients with gastric cancer: evidence from real-world studies

PURPOSE

Physical activity (PA) has been suggested to reduce the risk of cancer. However, previous studies have been inconsistent regarding the relationship between PA and the risk of developing gastric cancer (GC). The purpose of this study was to evaluate the impact of PA on the incidence and mortality risk of GC through a meta-analysis, as well as investigate potential dose-response relationships.

METHODS

A systematic literature search was conducted in 10 electronic databases and 4 registries. The combined relative risks (RRs) were calculated using a random-effects model with 95% confidence interval (CIs) to assess the effect of PA on the risk of GC. Relevant subgroup analyses and sensitivity analyses were performed.

RESULTS

The results showed that PA correlated with lower incidence of GC (RR: 0.83, 95% CI: 0.77-0.90), decreased risk of GC mortality (RR: 0.76, 95% CI: 0.66-0.89). The results of the subgroup analysis showed that PA was associated with reduced incidence of GC across gender, different regions, study designs, different sites of GC and different types of PA. A linear relationship was found for frequency of PA.

CONCLUSIONS

This meta-analysis found that PA was associated with a reduced risk of GC incidence and mortality. The correlation between PA and GC occurrence was in a dose-response relationship.

Deep learning radiomics based on contrast-enhanced ultrasound images for assisted diagnosis of pancreatic ductal adenocarcinoma and chronic pancreatitis

BACKGROUND

Accurate and non-invasive diagnosis of pancreatic ductal adenocarcinoma (PDAC) and chronic pancreatitis (CP) can avoid unnecessary puncture and surgery. This study aimed to develop a deep learning radiomics (DLR) model based on contrast-enhanced ultrasound (CEUS) images to assist radiologists in identifying PDAC and CP.

METHODS

Patients with PDAC or CP were retrospectively enrolled from three hospitals. Detailed clinicopathological data were collected for each patient. Diagnoses were confirmed pathologically using biopsy or surgery in all patients. We developed an end-to-end DLR model for diagnosing PDAC and CP using CEUS images. To verify the clinical application value of the DLR model, two rounds of reader studies were performed.

RESULTS

A total of 558 patients with pancreatic lesions were enrolled and were split into the training cohort (n=351), internal validation cohort (n=109), and external validation cohorts 1 (n=50) and 2 (n=48). The DLR model achieved an area under curve (AUC) of 0.986 (95% CI 0.975-0.994), 0.978 (95% CI 0.950-0.996), 0.967 (95% CI 0.917-1.000), and 0.953 (95% CI 0.877-1.000) in the training, internal validation, and external validation cohorts 1 and 2, respectively. The sensitivity and specificity of the DLR model were higher than or comparable to the diagnoses of the five radiologists in the three validation cohorts. With the aid of the DLR model, the diagnostic sensitivity of all radiologists was further improved at the expense of a small or no decrease in specificity in the three validation cohorts.

CONCLUSIONS

The findings of this study suggest that our DLR model can be used as an effective tool to assist radiologists in the diagnosis of PDAC and CP.

A global assessment of recent trends in gastrointestinal cancer and lifestyle-associated risk factors

BACKGROUND

Gastrointestinal (GI) cancers were responsible for 26.3% of cancer cases and 35.4% of deaths worldwide in 2018. This study aimed to analyze the global incidence, mortality, prevalence, and contributing risk factors of the 6 major GI cancer entities [esophageal cancer (EC), gastric cancer (GC), liver cancer (LC), pancreatic cancer (PC), colon cancer, and rectal cancer].

METHODS

Using the Global Cancer Observatory and the Global Health Observatory databases, we reviewed the current GI cancer incidence, prevalence, and mortality, analyzed the association of GI cancer prevalence with national human development indices (HDIs), identified the contributing risk factors, and estimated developing age- and sex-specific trends in incidence and mortality.

RESULTS

In 2020, the trend in age-standardized rate of incidence of GI cancers closely mirrored that of mortality, with the highest rates of LC, EC, and GC in Asia and of colorectal cancer (CRC) and PC mainly in Europe. Incidence and mortality were positively, but the mortality-to-incidence ratio (MIR) was inversely correlated with the national HDI levels. High MIRs in developing countries likely reflected the lack of preventive strategies and effective treatments. GI cancer prevalence was highest in Europe and was also positively correlated with HDIs and lifestyle-associated risk factors, such as alcohol consumption, smoking, obesity, insufficient physical activity, and high blood cholesterol level, but negatively correlated with hypertension and diabetes. Incidences of EC were consistently and those of GC mostly decreasing, whereas incidences of CRC were increasing in most countries/regions, especially in the younger populations. Incidences of LC and PC were also increasing in all age-gender populations except for younger males. Mortalities were decreasing for EC, GC, and CRC in most countries/regions, and age-specific trends were observed in PC and LC with a decrease in the younger but an increase in the older population.

CONCLUSIONS

On the global scale, higher GI cancer burden was accompanied, for the most part, by factors associated with the so-called Western lifestyle reflected by high and very high national HDI levels. In countries/regions with very high HDI levels, patients survived longer, and increasing GI cancer cases were observed with increasing national HDI levels. Optimizing GI cancer prevention and improving therapies, especially for patients with comorbid metabolic diseases, are thus urgently recommended.

Mammea longifolia Planch. and Triana Fruit Extract Induces Cell Death in the Human Colon Cancer Cell Line, SW480, via Mitochondria-Related Apoptosis and Activation of p53

The methanol extract of Mammea longifolia Planch. and Triana (M. longifolia) fruit was studied for anticancer and apoptotic effects in the SW480 colon cancer cell line. The apoptotic and necrotic effects of M. longifolia were detected by 3-(4,5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) and lactate dehydrogenase assays, respectively. One hundred μg/mL of the extract killed ∼82.4% of the cells; however, 2% of the death was related to necrosis. The morphological changes in M. longifolia-stimulated SW480 cells were observed directly by light microscopy. DNA fragmentation assay was employed to analyze the apoptosis induction. M. longifolia-treated SW480 cells promoted the expression of Bax, Bad, cleaved-poly-ADP-ribose polymerase (PARP), and p53 proteins and decreased the protein expression of pro-caspases Bcl-2 and Bcl-XL. The ratios of Bax/Bcl-2 and cleaved-PARP/PARP, predictive markers of apoptotic stimuli in cancer, increased and may play an important role in regulating the progression of apoptosis. The results suggested that M. longifolia induces cell death via mitochondrial-related apoptosis in SW480 cells.

Gastric cancer and allium vegetable intake: a critical review of the experimental and epidemiologic evidence

There are suggestions of an anticancerogenic effect of allium vegetables and their associated organosulfur components against several cancer types, including gastric cancer, but the issue remains open to discussion and quantification. The present critical review discussed the history, the health properties, the chemistry, the anticancerogenic evidences from experimental studies, and the anticancer mechanisms of allium vegetables. We also summarized findings from epidemiological studies concerning the association between different types of allium vegetables and gastric cancer risk, published up to date. Available data, derived mainly from case-control studies, suggested a favorable role of high intakes of allium vegetables, mainly garlic and onion, in the etiology of gastric cancer. In particular, of 10 studies, 7 suggested a favorable role of high intake of total allium vegetables and gastric cancer. All 14 studies on garlic and most studies on onion (more than 80%) reported a beneficial role of these allium types against gastric cancer. However several limitations, including possible publication bias and the difficulty to establish a dose-risk relationship, suggest caution in the interpretation. Evidences on other types of allium vegetables, as well as on the influence of different gastric cancer anatomical and histological types, are less consistent.

Design considerations in a sib-pair study of linkage for susceptibility loci in cancer

BACKGROUND

Modern approaches to identifying new genes associated with disease allow very fine analysis of association and can be performed in population based case-control studies. However, the sibpair design is still valuable because it requires few assumptions other than acceptably high penetrance to identify genetic loci.

METHODS

We conducted simulation studies to assess the impact of design factors on relative efficiency for a linkage study of colorectal cancer. We considered two test statistics, one comparing the mean IBD probability in affected pairs to its null value of 0.5, and one comparing the mean IBD probabilities between affected and discordant pairs. We varied numbers of parents available, numbers of affected and unaffected siblings, reconstructing the genotype of an unavailable affected sibling by a spouse and offspring, and elimination of sibships where the proband carries a mutation at another locus.

RESULTS

Power and efficiency were most affected by the number of affected sibs, the number of sib pairs genotyped, and the risk attributable to linked and unlinked loci. Genotyping unaffected siblings added little power for low penetrance models, but improved validity of tests when there was genetic heterogeneity and for multipoint testing. The efficiency of the concordant-only test was nearly always better than the concordant-discordant test. Replacement of an unavailable affected sibling by a spouse and offspring recovered some linkage information, particularly if several offspring were available. In multipoint analysis, the concordant-only test was showed a small anticonservative bias at 5 cM, while the multipoint concordant-discordant test was generally the most powerful test, and was not biased away from the null at 5 cM.

CONCLUSION

Genotyping parents and unaffected siblings is useful for detecting genotyping errors and if allele frequencies are uncertain. If adequate allele frequency data are available, we suggest a single-point affecteds-only analysis for an initial scan, followed by a multipoint analysis of affected and unaffected members of all available sibships with additional markers around initial hits.

Garlic and cancer: a critical review of the epidemiologic literature

Animal and in vitro studies provide evidence of an anticarcinogenic effect of active ingredients in garlic. This review of the epidemiologic literature on garlic consumption addresses cancers of the stomach, colon, head and neck, lung, breast and prostate. Nineteen studies reported relative risk estimates for garlic consumption and cancer incidence. Site-specific case-control studies of stomach and colorectal cancer, in which multiple reports were available, suggest a protective effect of high intake of raw and/or cooked garlic. Cohort studies confirm this inverse association for colorectal cancer. Few cohort and case-control studies for other sites of cancer exist. Garlic supplements, as analyzed in four cohort studies and one case-control report, from two distinct populations, do not appear to be related to risk. Low study power, lack of variability in garlic consumption categorization within studies and poor adjustment for potential cofounders may limit the reliability of any conclusions regarding garlic supplements. However, an indication of publication bias was also found by visual inspection of a funnel plot and in a log-rank test (P = 0.004). Evidence from available studies nevertheless suggests a preventive effect of garlic consumption in stomach and colorectal cancers. The study limitations indicate the need for more definitive research and improved nutritional epidemiologic analyses of dietary data.

Garlic consumption and cancer prevention: meta-analyses of colorectal and stomach cancers

BACKGROUND

Animal and in vitro studies have provided evidence of an anticarcinogenic effect of active ingredients in garlic.

OBJECTIVE

The objective was to conduct meta-analyses of the epidemiologic literature on the association between garlic consumption and risk of stomach, colon, head and neck, lung, breast, and prostate cancers.

DESIGN

Meta-analyses were conducted for all cancers mutually and separately for colorectal and stomach cancers in relation to consumption of exclusively raw garlic, cooked garlic, or both (RC garlic). Eighteen studies reported a relative risk estimate for RC garlic consumption and cancer risk.

RESULTS

In the meta-analyses of colorectal and stomach cancer, the reference categories ranged from no consumption to consumption of 3.5 g/wk, whereas the highest categories ranged from any consumption to >28.8 g/wk. The average difference between the highest and lowest categories was 16 g/wk. The random-effects relative risk (RR) estimate of colorectal cancer and RC garlic consumption, excluding garlic supplements, was 0.69 (95% CI: 0.55, 0.89). For stomach cancer, the random-effects RR estimate was 0.53 (95% CI: 0.31, 0.92). The heterogeneity among studies for the latter outcome (P: = 0.0002) indicates the questionableness of the generalizability of this summary estimate. An indication of publication bias for all cancers combined is evident from a funnel plot of RC garlic consumption and cancer risk and from the results of the Begg and Mazumdar test (P: = 0.049).

CONCLUSIONS

High intake of RC garlic may be associated with a protective effect against stomach and colorectal cancers. Heterogeneity of effect estimates, differences in dose estimation, publication bias, and possible alternative hypotheses (eg, confounding by total vegetable consumption) preclude sole reliance on summary effect estimates.

Nutritional and metabolic aspects of gastrointestinal cancer

The profound impact of nutrition and nutritional support on the development and clinical outcome of gastrointestinal cancer is undeniable. However, scientific investigation into this area is recent, and many questions remain unanswered. While the importance of 'good nutrition' is unchallenged, details relating to which patients should receive nutritional support, when they should receive it, and what type of support they should receive are not known. Recent prospective randomized clinical trials and meta-analysis have provided conflicting results. This review summarizes the results of the published studies that have addressed these issues, and provides specifics regarding the current role of nutritional support in clinical care, and the prospects for future research.