Food groups and alcoholic beverages and the risk of stomach cancer: a case-control study in Italy

The protective effect of dietary folate intake on gastric cancer is modified by alcohol consumption: A pooled analysis of the StoP Consortium

Dietary folate intake has been identified as a potentially modifiable factor of gastric cancer (GC) risk, although the evidence is still inconsistent. We evaluate the association between dietary folate intake and the risk of GC as well as the potential modification effect of alcohol consumption. We pooled data for 2829 histologically confirmed GC cases and 8141 controls from 11 case-control studies from the international Stomach Cancer Pooling Consortium. Dietary folate intake was estimated using food frequency questionnaires. We used linear mixed models with random intercepts for each study to calculate adjusted odds ratios (OR) and 95% confidence interval (CI). Higher folate intake was associated with a lower risk of GC, although this association was not observed among participants who consumed >2.0 alcoholic drinks/day. The OR for the highest quartile of folate intake, compared with the lowest quartile, was 0.78 (95% CI, 0.67-0.90, P-trend = 0.0002). The OR per each quartile increment was 0.92 (95% CI, 0.87-0.96) and, per every 100 μg/day of folate intake, was 0.89 (95% CI, 0.84-0.95). There was a significant interaction between folate intake and alcohol consumption (P-interaction = 0.02). The lower risk of GC associated with higher folate intake was not observed in participants who consumed >2.0 drinks per day, ORQ4v Q1 = 1.15 (95% CI, 0.85-1.56), and the OR100 μg/day = 1.02 (95% CI, 0.92-1.15). Our study supports a beneficial effect of folate intake on GC risk, although the consumption of >2.0 alcoholic drinks/day counteracts this beneficial effect.

Aspirin but not statins is inversely related to gastric cancer with a duration-risk effect: Results from the Stomach Cancer Pooling Project Consortium

BACKGROUND

Aspirin and statins have been suggested to have potential chemopreventive effects against gastric cancer (GC), although the results of previous studies have been inconsistent. This study therefore aimed to investigate the association between the use of aspirin and statins and GC.

METHODS

A pooled analysis of seven case-control studies within the Stomach Cancer Pooling Project, including 3220 cases and 9752 controls, was conducted. Two-stage modeling analyses were used to estimate the association between aspirin and statin use and GC after adjusting for potential confounders.

RESULTS

The pooled odds ratio (OR) of GC for aspirin users versus nonusers was 0.72 (95% confidence interval [CI], 0.54-0.95). The protective effect of aspirin appeared stronger in individuals without a GC family history (OR, 0.60; 95% CI, 0.37-0.95), albeit with borderline heterogeneity between those with and without a family history (p = .064). The OR of GC decreased with increasing duration of aspirin use, with an OR of 0.41 (95% CI, 0.18-0.95) for durations of ≥15 years. An inverse, nonsignificant association with the risk of GC was observed for the use of statins alone (OR, 0.79; 95% CI, 0.52-1.18).

CONCLUSIONS

These findings suggest that aspirin use, particularly long-term use, is associated with a reduced risk of GC, whereas a similar association was not observed with statins, possibly because of the low frequency of use.

The association between dietary fiber intake and gastric cancer: a pooled analysis of 11 case-control studies

PURPOSE

Gastric cancer (GC) is among the leading causes of cancer mortality worldwide. The objective of this study was to investigate the association between dietary fiber intake and GC.

METHODS

We pooled data from 11 population or hospital-based case-control studies included in the Stomach Cancer Pooling (StoP) Project, for a total of 4865 histologically confirmed cases and 10,626 controls. Intake of dietary fibers and other dietary factors was collected using food frequency questionnaires. We calculated the odds ratios (OR) and 95% confidence intervals (CI) of the association between dietary fiber intake and GC by using a multivariable logistic regression model adjusted for study site, sex, age, caloric intake, smoking, fruit and vegetable intake, and socioeconomic status. We conducted stratified analyses by these factors, as well as GC anatomical site and histological type.

RESULTS

The OR of GC for an increase of one quartile of fiber intake was 0.91 (95% CI: 0.85, 0.97), that for the highest compared to the lowest quartile of dietary fiber intake was 0.72 (95% CI: 0.59, 0.88). Results were similar irrespective of anatomical site and histological type.

CONCLUSION

Our analysis supports the hypothesis that dietary fiber intake may exert a protective effect on GC.

Dietary intake of vitamin C and gastric cancer: a pooled analysis within the Stomach cancer Pooling (StoP) Project

BACKGROUND

Previous studies suggest that dietary vitamin C is inversely associated with gastric cancer (GC), but most of them did not consider intake of fruit and vegetables. Thus, we aimed to evaluate this association within the Stomach cancer Pooling (StoP) Project, a consortium of epidemiological studies on GC.

METHODS

Fourteen case-control studies were included in the analysis (5362 cases, 11,497 controls). We estimated odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for the association between dietary intake of vitamin C and GC, adjusted for relevant confounders and for intake of fruit and vegetables. The dose-response relationship was evaluated using mixed-effects logistic models with second-order fractional polynomials.

RESULTS

Individuals in the highest quartile of dietary vitamin C intake had reduced odds of GC compared with those in the lowest quartile (OR: 0.64; 95% CI: 0.58, 0.72). Additional adjustment for fruit and vegetables intake led to an OR of 0.85 (95% CI: 0.73, 0.98). A significant inverse association was observed for noncardia GC, as well as for both intestinal and diffuse types of the disease. The results of the dose-response analysis showed decreasing ORs of GC up to 150-200 mg/day of vitamin C (OR: 0.54; 95% CI: 0.41, 0.71), whereas ORs for higher intakes were close to 1.0.

CONCLUSIONS

The findings of our pooled study suggest that vitamin C is inversely associated with GC, with a potentially beneficial effect also for intakes above the currently recommended daily intake (90 mg for men and 75 mg for women).

Legume intake and cancer risk in a network of case-control studies

Evidence on the relationship between legume consumption and risk of specific cancer sites is inconclusive. We used data from a series of case-controls studies, conducted in Italy and in the Swiss Canton of Vaud between 1991 and 2009 to quantify the association between legume consumption and several cancer sites including oral cavity, esophagus, larynx, stomach, colorectum, breast, endometrium, ovary, prostate and kidney. Multiple logistic regression models controlled for sex, age, education, smoking, alcohol, body mass index, physical activity, comorbidities, and consumption of fruit, vegetables, processed meat and total calorie intake were used to estimate the odds ratios (OR) for different cancer sites and their corresponding 95% confidence intervals(CI). For female hormone-related cancers, the models also included adjustments for age at menarche, menopausal status and parity. Although most of the estimates were below unity, suggesting a protective effect, only colorectal cancer showed a significant association. Compared to no consumption, the OR for consuming at least one portion of legumes was 0.79 (95% CI: 0.68-0.91), the OR for consuming two or more portions was 0.68 (95% CI: 0.57-0.82) and the estimate for an increment of one portion per week was 0.87 (95% CI: 0.81-0.93). The inverse association between legume consumption and colorectal cancer suggests a possible role of legumes in preventing cancer risk.

Prebiotics and the Risk of Upper Digestive Tract and Stomach Cancers: The PrebiotiCa Study

BACKGROUND

Fiber intake may lower digestive tract cancer risk, possibly by modulating the composition of gut microbiota. However, no data are available about the role of specific fiber fractions with prebiotic activity (e.g., inulin-type fructans (ITFs), fructo-oligosaccharides (FOSs) and galactooligosaccharides (GOSs)) on the risk lower digestive tract cancers.

OBJECTIVE

The objective was to assess the association between prebiotic intake and the risk of cancers of the upper digestive tract and stomach.

DESIGN

Within the PrebiotiCa study, data were derived from a network of Italian case-control studies conducted between 1992 and 2009. Participants' usual diet was assessed using a food frequency questionnaire. ITFs, and selected FOSs (nystose, kestose, and 1F-β-fructofuranosylnystose) and GOSs (raffinose and stachyose) were quantified in several food products via laboratory analyses. Participants' prebiotic intake was calculated by multiplying food frequency questionnaire intake by the prebiotic content of each food item.

PARTICIPANTS/SETTING

Cases were patients admitted to major hospitals with incident histologically confirmed cancers; there were 946 cases of cancer of the oral cavity/pharynx, 198 of the nasopharynx, 304 of the esophagus, 230 of the stomach. More than 4,000 patients admitted to the same hospitals for acute nonneoplastic and not diet-related conditions were selected as control subjects.

MAIN OUTCOME MEASURES

The outcomes were oral and pharyngeal, nasopharyngeal, esophageal, and stomach cancers.

STATISTICAL ANALYSES PERFORMED

The odds ratios and corresponding 95% CIs of the various cancers were derived using logistic regression models adjusted for major confounders and energy intake.

RESULTS

No association was observed between intake of prebiotics and risk of cancers of the oral cavity and pharynx, nasopharynx, and esophagus. High raffinose intake reduced stomach cancer risk (odds ratio for the third vs the first tertile 0.6, 95% CI 0.3 to 0.9); no other prebiotic was associated with stomach cancer.

CONCLUSIONS

The current study does not support a major role of prebiotic fibers on selected upper digestive tract cancers. The association between high raffinose intake and reduced stomach cancer risk needs further investigation.

Leisure-time physical activity and gastric cancer risk: A pooled study within the Stomach cancer Pooling (StoP) Project

BACKGROUND

Although physical activity (PA) has been recognized as a favourable factor in the prevention of various diseases, including certain forms of cancer, the relationship between PA and gastric cancer (GC) is not yet fully understood. This study aims to provide data from a pooled analysis of case-control studies within the Stomach cancer Pooling (StoP) Project to estimate the association between leisure-time PA and the occurrence of GC.

METHODS

Six case-control studies from StoP project collected data on leisure-time PA, for a total of 2,343 cases and 8,614 controls. Subjects were classified into three leisure-time PA categories, either none/low, intermediate or high, based on study-specific tertiles. We used a two-stage approach. Firstly, we applied multivariable logistic regression models to obtain study-specific odds ratios (ORs) and corresponding 95% confidence intervals (CIs) then, we used a random-effect models to obtain pooled effect estimates. We performed stratified analyses according to demographic, lifestyle and clinical covariates.

RESULTS

The meta-analysis showed ORs of GC with no significant differences between intermediate vs low and high vs low PA level (OR 1.05 [95%CI 0.76-1.45]; OR 1.23 [95%CI 0.78-1.94], respectively). GC risk estimates did not strongly differ across strata of selected covariates except for age ≤ 55 years old (high vs low level: OR 0.72 [95%CI 0.55-0.94]) and for control population-based studies (high vs low level: OR 0.79 [95%CI 0.68-0.93]).

CONCLUSIONS

No association was found between leisure time PA and GC, apart from a slight suggestion of decreased risk below age 55 and in control population-based studies. These results may reflect specific characteristics of GC at a younger age, or the presence of a cohort effect mediating and interacting with socioeconomic determinants of GC The different distribution of PA levels among hospitalized controls could have led to an underestimated effect of PA on GC risk.

Yoghurt Intake and Gastric Cancer: A Pooled Analysis of 16 Studies of the StoP Consortium

BACKGROUND

Yoghurt can modify gastrointestinal disease risk, possibly acting on gut microbiota. Our study aimed at exploring the under-investigated association between yoghurt and gastric cancer (GC).

METHODS

We pooled data from 16 studies from the Stomach Cancer Pooling (StoP) Project. Total yoghurt intake was derived from food frequency questionnaires. We calculated study-specific odds ratios (ORs) of GC and the corresponding 95% confidence intervals (CIs) for increasing categories of yoghurt consumption using univariate and multivariable unconditional logistic regression models. A two-stage analysis, with a meta-analysis of the pooled adjusted data, was conducted.

RESULTS

The analysis included 6278 GC cases and 14,181 controls, including 1179 cardia and 3463 non-cardia, 1191 diffuse and 1717 intestinal cases. The overall meta-analysis revealed no association between increasing portions of yoghurt intake (continuous) and GC (OR = 0.98, 95% CI = 0.94-1.02). When restricting to cohort studies, a borderline inverse relationship was found (OR = 0.93, 95% CI = 0.88-0.99). The adjusted and unadjusted OR were 0.92 (95% CI = 0.85-0.99) and 0.78 (95% CI = 0.73-0.84) for any vs. no yoghurt consumption and GC risk. The OR for 1 category of increase in yoghurt intake was 0.96 (95% CI = 0.91-1.02) for cardia, 1.03 (95% CI = 1.00-1.07) for non-cardia, 1.12 (95% CI = 1.07-1.19) for diffuse and 1.02 (95% CI = 0.97-1.06) for intestinal GC. No effect was seen within hospital-based and population-based studies, nor in men or women.

CONCLUSIONS

We found no association between yoghurt and GC in the main adjusted models, despite sensitivity analyses suggesting a protective effect. Additional studies should further address this association.

Neuroendocrine Tumors: A Comprehensive Review on Nutritional Approaches

Neuroendocrine neoplasms are a heterogeneous group of neoplasms with increasing incidence, high prevalence, and survival worldwide. About 90% of cases are well differentiated forms, the so-called neuroendocrine tumors (NETs), with slow proliferation rates and prolonged survival but frequent development of liver metastases and endocrine syndromes. Both the tumor itself and systemic therapy may have an impact on patient nutrition. Malnutrition has a negative impact on outcome in patients with NETs, as well as obesity. In addition, obesity and metabolic syndrome have been shown to be risk factors for both the development and prognosis of NET. Therefore, dietary assessment based on body composition and lifestyle modifications should be an integral part of the treatment of NET patients. Nutrition plans, properly formulated by a dietician, are an integral part of the multidisciplinary treatment team for patients with NETs because they allow an improvement in quality of life, providing a tailored approach based on nutritional needs and nutritional manageable signs and/or symptoms related to pharmacological treatment. The aim of this review is to condense the latest evidence on the role of the most used dietary models, the Mediterranean diet, the ketogenic diet, and intermittent fasting, in the context of NETs, while considering the clinical and molecular mechanisms by which these dietary models act.

Tea consumption and gastric cancer: a pooled analysis from the Stomach cancer Pooling (StoP) Project consortium

BACKGROUND

Evidence from epidemiological studies on the role of tea drinking in gastric cancer risk remains inconsistent. We aimed to investigate and quantify the relationship between tea consumption and gastric cancer in the Stomach cancer Pooling (StoP) Project consortium.

METHODS

A total of 9438 cases and 20,451 controls from 22 studies worldwide were included. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) of gastric cancer for regular versus non-regular tea drinkers were estimated by one and two-stage modelling analyses, including terms for sex, age and the main recognised risk factors for gastric cancer.

RESULTS

Compared to non-regular drinkers, the estimated adjusted pooled OR for regular tea drinkers was 0.91 (95% CI: 0.85-0.97). When the amount of tea consumed was considered, the OR for consumption of 1-2 cups/day was 1.01 (95% CI: 0.94-1.09) and for >3 cups/day was 0.91 (95% CI: 0.80-1.03). Stronger inverse associations emerged among regular drinkers in China and Japan (OR: 0.67, 95% CI: 0.49-0.91) where green tea is consumed, in subjects with H. pylori infection (OR: 0.68, 95% CI: 0.58-0.80), and for gastric cardia cancer (OR: 0.64, 95% CI: 0.49-0.84).

CONCLUSION

Our results indicate a weak inverse association between tea consumption and gastric cancer.

Peptic ulcer as mediator of the association between risk of gastric cancer and socioeconomic status, tobacco smoking, alcohol drinking and salt intake

BACKGROUND

Peptic ulcer disease (PUD) and gastric cancer (GC) are more prevalent in individuals with low socioeconomic status (SES) and share several risk factors. The aim of this study was to investigate the mediating role of PUD in the association between established risk factors and GC.

METHODS

We conducted a pooled analysis of 12 studies from the Stomach Cancer Pooling Project Consortium, including a total of 4877 GC cases and 11 808 controls. We explored the mediating role of PUD in the association between SES, tobacco smoking, heavy alcohol drinking and salt intake, and GC. Also, we assessed the ORs and 95% CIs of the risk factors and both PUD and GC.

RESULTS

PUD mediated 36% of the smoking effect mainly among men. Other risk factors were only slightly mediated by PUD (SES, 5.3%; heavy alcohol drinking, 3.3%; and salt intake, 2.5%). No significant difference was found when excluding PUD diagnosed within 2 years from GC.

CONCLUSIONS

Our study provides innovative information on the mechanism of stomach mucosal damage leading to PUD and GC, with respect to the effect of tobacco smoking in particular.

Inverse Association between Dietary Iron Intake and Gastric Cancer: A Pooled Analysis of Case-Control Studies of the Stop Consortium

Background: Inconsistent findings have been reported regarding the relationship between dietary iron intake and the risk of gastric cancer (GC). Methods: We pooled data from 11 case-control studies from the Stomach Cancer Pooling (StoP) Project. Total dietary iron intake was derived from food frequency questionnaires combined with national nutritional tables. We derived the odds ratios (ORs) and 95% confidence intervals (CIs) for quartiles of dietary iron through multivariable unconditional logistic regression models. Secondary analyses stratified by sex, smoking status, caloric intake, anatomical subsite and histological type were performed. Results: Among 4658 cases and 12247 controls, dietary iron intake was inversely associated with GC (per quartile OR 0.88; 95% CI: 0.83-0.93). Results were similar between cardia (OR = 0.85, 95% CI = 0.77-0.94) and non-cardia GC (OR = 0.87, 95% CI = 0.81-0.94), and for diffuse (OR = 0.79, 95% CI = 0.69-0.89) and intestinal type (OR = 0.88, 95% CI = 0.79-0.98). Iron intake exerted an independent effect from that of smoking and salt intake. Additional adjustment by meat and fruit/vegetable intake did not alter the results. Conclusions: Dietary iron is inversely related to GC, with no difference by subsite or histological type. While the results should be interpreted with caution, they provide evidence against a direct effect of iron in gastric carcinogenesis.

Allium vegetables intake and the risk of gastric cancer in the Stomach cancer Pooling (StoP) Project

BACKGROUND

The role of allium vegetables on gastric cancer (GC) risk remains unclear.

METHODS

We evaluated whether higher intakes of allium vegetables reduce GC risk using individual participant data from 17 studies participating in the "Stomach cancer Pooling (StoP) Project", including 6097 GC cases and 13,017 controls. Study-specific odds ratios (ORs) were pooled using a two-stage modelling approach.

RESULTS

Total allium vegetables intake was inversely associated with GC risk. The pooled OR for the highest versus the lowest study-specific tertile of consumption was 0.71 (95% confidence interval, CI, 0.56-0.90), with substantial heterogeneity across studies (I² > 50%). Pooled ORs for high versus low consumption were 0.69 (95% CI, 0.55-0.86) for onions and 0.83 (95% CI, 0.75-0.93) for garlic. The inverse association with allium vegetables was evident in Asian (OR 0.50, 95% CI, 0.29-0.86) but not European (OR 0.96, 95% CI, 0.81-1.13) and American (OR 0.66, 95% CI, 0.39-1.11) studies. Results were consistent across all other strata.

CONCLUSIONS

In a worldwide consortium of epidemiological studies, we found an inverse association between allium vegetables and GC, with a stronger association seen in Asian studies. The heterogeneity of results across geographic regions and possible residual confounding suggest caution in results interpretation.

The association between diabetes and gastric cancer: results from the Stomach Cancer Pooling Project Consortium

BACKGROUND

Prior epidemiologic studies on the association between diabetes and gastric cancer risk provided inconclusive findings, while traditional, aggregate data meta-analyses were characterized by high between-study heterogeneity.

OBJECTIVE

To investigate the association between type 2 diabetes and gastric cancer using data from the 'Stomach Cancer Pooling (StoP) Project', an international consortium of more than 30 case-control and nested case-control studies, which is large and provides harmonized definition of participants' characteristics across individual studies. The data have the potential to minimize between-study heterogeneity and provide greater statistical power for subgroup analysis.

METHODS

We included 5592 gastric cancer cases and 12 477 controls from 14 studies from Europe, Asia, North America, and South America in a two-stage individual-participant data meta-analysis. Random-effect models were used to estimate summary odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) by pooling study-specific ORs.

RESULTS

We did not find an overall association between diabetes and gastric cancer (pooled OR = 1.01, 95% CI, 0.94-1.07). However, the risk of cardia gastric cancer was significantly higher among individuals with type 2 diabetes (OR = 1.16, 95% CI, 1.02-1.33). There was no association between diabetes and gastric cancer risk in strata of Helicobacter pylori infection serostatus, age, sex, BMI, smoking status, alcohol consumption, fruit/vegetable intake, gastric cancer histologic type, and source of controls.

CONCLUSION

This study provides additional evidence that diabetes is unrelated to gastric cancer overall but may be associated with excess cardia gastric cancer risk.

Impacts of nutritive and bioactive compounds on cancer development and therapy

For persons who survive with progressive cancer, nutritional therapy and exercise may be significant factors to improve the health condition and life quality of cancer patients. Nutritional therapy and medications are essential to managing progressive cancer. Cancer survivors, as well as cancer patients, are mostly extremely encouraged to search for knowledge about the selection of diet, exercise, and dietary supplements to recover as well as maintain their treatment consequences, living quality, and survival of patients. A healthy diet plays an important role in cancer treatment. Different articles are studied to collect information and knowledge about the use of nutrients in cancer treatment as well as cancer prevention. The report deliberates nutrition and exercise strategies during the range of cancer care, emphasizing significant concerns during treatment of cancer and for patients of advanced cancer, but concentrating mostly on the requirements of the population of persons who are healthy or who have constant disease following their repossession from management. It also deliberates choice nutrition and exercise problems such as dietary supplements, food care, food selections, and weight; problems interrelated to designated cancer sites, and common questions about diet, and cancer survival. Decrease the side effects of medicines both during and after treatment.

Salt intake and gastric cancer: a pooled analysis within the Stomach cancer Pooling (StoP) Project

PURPOSE

Previous studies show that consuming foods preserved by salting increases the risk of gastric cancer, while results on the association between total salt or added salt and gastric cancer are less consistent and vary with the exposure considered. This study aimed to quantify the association between dietary salt exposure and gastric cancer, using an individual participant data meta-analysis of studies participating in the Stomach cancer Pooling (StoP) Project.

METHODS

Data from 25 studies (10,283 cases and 24,643 controls) from the StoP Project with information on salt taste preference (tasteless, normal, salty), use of table salt (never, sometimes, always), total sodium intake (tertiles of grams/day), and high-salt and salt-preserved foods intake (tertiles of grams/day) were used. A two-stage approach based on random-effects models was used to pool study-specific adjusted (sex, age, and gastric cancer risk factors) odds ratios (aORs), and the corresponding 95% confidence intervals (95% CI).

RESULTS

Gastric cancer risk was higher for salty taste preference (aOR 1.59, 95% CI 1.25-2.03), always using table salt (aOR 1.33, 95% CI 1.16-1.54), and for the highest tertile of high-salt and salt-preserved foods intake (aOR 1.24, 95% CI 1.01-1.51) vs. the lowest tertile. No significant association was observed for the highest vs. the lowest tertile of total sodium intake (aOR 1.08, 95% CI 0.82-1.43). The results obtained were consistent across anatomic sites, strata of Helicobacter pylori infection, and sociodemographic, lifestyle and study characteristics.

CONCLUSION

Salty taste preference, always using table salt, and a greater high-salt and salt-preserved foods intake increased the risk of gastric cancer, though the association was less robust with total sodium intake.

Coffee consumption and gastric cancer: a pooled analysis from the Stomach cancer Pooling Project consortium

OBJECTIVE

This study aimed to evaluate and quantify the relationship between coffee and gastric cancer using a uniquely large dataset from an international consortium of observational studies on gastric cancer, including data from 18 studies, for a total of 8198 cases and 21 419 controls.

METHODS

A two-stage approach was used to obtain the pooled odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for coffee drinkers versus never or rare drinkers. A one-stage logistic mixed-effects model with a random intercept for each study was used to estimate the dose-response relationship. Estimates were adjusted for sex, age and the main recognized risk factors for gastric cancer.

RESULTS

Compared to never or rare coffee drinkers, the estimated pooled OR for coffee drinkers was 1.03 (95% CI, 0.94-1.13). When the amount of coffee intake was considered, the pooled ORs were 0.91 (95% CI, 0.81-1.03) for drinkers of 1-2 cups per day, 0.95 (95% CI, 0.82-1.10) for 3-4 cups, and 0.95 (95% CI, 0.79-1.15) for five or more cups. An OR of 1.20 (95% CI, 0.91-1.58) was found for heavy coffee drinkers (seven or more cups of caffeinated coffee per day). A positive association emerged for high coffee intake (five or more cups per day) for gastric cardia cancer only.

CONCLUSIONS

These findings better quantify the previously available evidence of the absence of a relevant association between coffee consumption and gastric cancer.

Aspartame-True or False? Narrative Review of Safety Analysis of General Use in Products

Aspartame is a sweetener introduced to replace the commonly used sucrose. It was discovered by James M. Schlatter in 1965. Being 180-200 times sweeter than sucrose, its intake was expected to reduce obesity rates in developing countries and help those struggling with diabetes. It is mainly used as a sweetener for soft drinks, confectionery, and medicines. Despite its widespread use, its safety remains controversial. This narrative review investigates the existing literature on the use of aspartame and its possible effects on the human body to refine current knowledge. Taking to account that aspartame is a widely used artificial sweetener, it seems appropriate to continue research on safety. Studies mentioned in this article have produced very interesting results overall, the current review highlights the social problem of providing visible and detailed information about the presence of aspartame in products. The studies involving the impact of aspartame on obesity, diabetes mellitus, children and fetus, autism, neurodegeneration, phenylketonuria, allergies and skin problems, its cancer properties and its genotoxicity were analyzed. Further research should be conducted to ensure clear information about the impact of aspartame on health.

Potato Consumption and Risk of Site-Specific Cancers in Adults: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies

The etiology of cancer type may vary significantly due to anatomy, embryology, and physiology of the cancer site. Although the association between potato consumption and colorectal cancer (CRC) was summarized in a 2018 meta-analysis of 5 cohort studies, to the best of our knowledge, no meta-analysis has evaluated potato consumption in relation to multiple cancer sites in adults. Medline/PubMed, ISI Web of Knowledge, Scopus, and the Cochrane Database of Systematic Reviews were searched for relevant publications through August 2020. We selected cohort or case-control studies conducted in adults that reported risk estimates (relative risk [RRs], HRs, and ORs) of potato intake for any cancer type. Random effects meta-analyses compared high and low intake categories. Twenty prospective cohort studies (total n = 785,348) including 19,882 incident cases, and 36 case-control studies (21,822 cases; 66,502 controls) were included. Among cohort studies, we did not find an association between high versus low intake of total potato (white and yellow) consumption and overall cancers: 1.04 (95% CI: 0.96, 1.11; tau2 = 0.005, n = 18). We found no relation between total potato consumption (high compared with low intake) and risk of CRC, pancreatic cancer, colon, gastric, breast, prostate, kidney, lung, or bladder cancer in cohort or case-control studies. We did not find an association between high versus low consumption of potato preparations (boiled/fried/mashed/roasted/baked) and risk of gastrointestinal-, sex-hormone-, or urinary-related cancers in cohort or case-control studies. Certainty of the evidence was low for total cancer, CRC, colon, rectal, renal, pancreatic, breast, prostate, and lung cancer and very low for gastric and bladder cancer. In conclusion, potato intake or potato preparations were not associated with multiple cancer sites when comparing high and low intake categories. This finding was consistent with the findings from the 2018 meta-analysis regarding potato intake and risk of CRC.

Alcohol consumption and risk of stomach cancer: A meta-analysis

Stomach cancer is one of the most common cancers in the world. The relationship between alcohol consumption and the risk of stomach cancer remains unclear. Epidemiology studies investigating this relationship have shown inconsistent findings. A meta-analysis was performed to explore the association between alcohol consumption and increased stomach cancer risk. Eighty-one epidemiology studies, including 68 case-control studies and 13 cohort studies, were included in this study. A significant association was found between alcohol consumption and increased risk of stomach cancer (OR = 1.20, 95% CI 1.12-1.27). To explore the source of the significant heterogeneity (p < 0.05, I² = 86%), analysis was stratified by study type (case-control study and cohort study), control type (hospital-based control and population-based control), gender (male, female, and mix), race (White and Asian), region (United States, Sweden, China, Japan), subsite of stomach cancer, and type of alcohol. The stratified analyses found that region and cancer subsite are major sources of the high heterogeneity. The inconsistent results in different regions and different subsites might be related to smoking rates, Helicobacter pylori infection, obesity, and potential genetic susceptibility. The positive association between drinking and increased risk of stomach cancer is consistent in stratified analyses. The dose-response analysis showed a clear trend that a higher daily intake of alcohol is associated with a higher risk of stomach cancer.

Fruits and vegetables intake and gastric cancer risk: A pooled analysis within the Stomach cancer Pooling Project

A low intake of fruits and vegetables is a risk factor for gastric cancer, although there is uncertainty regarding the magnitude of the associations. In our study, the relationship between fruits and vegetables intake and gastric cancer was assessed, complementing a previous work on the association betweenconsumption of citrus fruits and gastric cancer. Data from 25 studies (8456 cases and 21 133 controls) with information on fruits and/or vegetables intake were used. A two-stage approach based on random-effects models was used to pool study-specific adjusted (sex, age and the main known risk factors for gastric cancer) odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). Exposure-response relations, including linear and nonlinear associations, were modeled using one- and two-order fractional polynomials. Gastric cancer risk was lower for a higher intake of fruits (OR: 0.76, 95% CI: 0.64-0.90), noncitrus fruits (OR: 0.86, 95% CI: 0.73-1.02), vegetables (OR: 0.68, 95% CI: 0.56-0.84), and fruits and vegetables (OR: 0.61, 95% CI: 0.49-0.75); results were consistent across sociodemographic and lifestyles categories, as well as study characteristics. Exposure-response analyses showed an increasingly protective effect of portions/day of fruits (OR: 0.64, 95% CI: 0.57-0.73 for six portions), noncitrus fruits (OR: 0.71, 95% CI: 0.61-0.83 for six portions) and vegetables (OR: 0.51, 95% CI: 0.43-0.60 for 10 portions). A protective effect of all fruits, noncitrus fruits and vegetables was confirmed, supporting further dietary recommendations to decrease the burden of gastric cancer.

Polyphenol Intake and Gastric Cancer Risk: Findings from the Stomach Cancer Pooling Project (StoP)

Simple Summary

Gastric cancer (GC) has the fifth highest incidence of any cancer type worldwide and the third highest mortality rate, so its prevention is very important. Among dietary factors, the consumption of fruit and vegetables has been inversely related to GC risk. Phenolic compounds may exert a favorable effect on the risk of several cancer types, including gastric cancer. However, selected polyphenol classes have not been adequately investigated in relation to GC. There is, however, no comprehensive analysis of polyphenols and GC risk methods to date. In order to provide a detailed evaluation of the relationship between dietary intake of polyphenols and GC risk, we analyzed data from the Stomach cancer Pooling (StoP) Project consortium.

Abstract

Phenolic compounds may exert a favorable effect on the risk of several cancer types, including gastric cancer (GC). However, selected polyphenol classes have not been adequately investigated in relation to GC. The aim of this study is to evaluate the association between the intake of polyphenols in relation to GC risk. We used data from the Stomach cancer Pooling (StoP) Project, including 10 studies from six countries (3471 GC cases and 8344 controls). We carried out an individual participant data pooled analysis using a two-stage approach. The summary odds ratios (ORs) of GC for each compound, and the corresponding 95% confidence intervals (95% CI), were computed by pooling study specific ORs obtained through multivariate logistic regression, using random effect models. Inverse associations with GC emerged for total polyphenols (OR = 0.67, 95% CI = 0.54–0.81, for the highest versus lowest quartile of intake), total flavonoids (OR = 0.73, 95% CI = 0.55–0.90), anthocyanidins (OR = 0.74, 95% CI = 0.56–0.92), flavanols (OR = 0.77, 95% CI = 0.66–0.88), flavanones (OR = 0.57, 95%CI = 0.44–0.69), total phenolic acids (OR = 0.75, 95%CI = 0.55–0.94), and hydroxybenzoic acids (OR = 0.73, 95%CI = 0.57–0.89). Results were consistent across strata of age, sex, social class, and smoking habit. Suggestive inverse associations were also found for flavonols (OR = 0.76, 95%CI = 0.51–1.01) and hydroxycinnamic acids (OR = 0.82, 95%CI = 0.58–1.06). Further investigations from longitudinal data are needed to confirm this association.

Association between Nutrient-Based Dietary Patterns and Bladder Cancer in Italy

Limited knowledge is available on dietary patterns and bladder cancer risk. We analyzed data from an Italian case-control study carried out between 2003 and 2014, including 690 incident bladder cancer cases and 665 hospital-controls. We derived nutrient-based dietary patterns applying principal component factor analysis on 28 selected nutrients. We categorized factor scores according to quartiles, and estimated the odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) through logistic regression models, adjusted for major confounding factors. We identified four dietary patterns named "Animal products", "Vitamins and fiber", "Starch-rich", and "Animal unsaturated fatty acids". We found an inverse association between the "Vitamins and fiber" pattern and bladder cancer (OR = 0.70, 95% CI: 0.48-0.99, IV versus I quartile category). Inverse relationships of borderline significance were also found for the "Animal products" and the "Animal unsaturated fatty acids" dietary patterns. No significant association was evident for the "Starch-rich" pattern. The current study allowed us to identify major dietary patterns in this Italian population. Our study confirms available evidence and shows that scoring high on a fruit-and-vegetables pattern provides beneficial effects on bladder cancer risk.

Meat intake and risk of gastric cancer in the Stomach cancer Pooling (StoP) project

The consumption of processed meat has been associated with noncardia gastric cancer, but evidence regarding a possible role of red meat is more limited. Our study aims to quantify the association between meat consumption, namely white, red and processed meat, and the risk of gastric cancer, through individual participant data meta-analysis of studies participating in the "Stomach cancer Pooling (StoP) Project". Data from 22 studies, including 11,443 cases and 28,029 controls, were used. Study-specific odds ratios (ORs) were pooled through a two-stage approach based on random-effects models. An exposure-response relationship was modeled, using one and two-order fractional polynomials, to evaluate the possible nonlinear association between meat intake and gastric cancer. An increased risk of gastric cancer was observed for the consumption of all types of meat (highest vs. lowest tertile), which was statistically significant for red (OR: 1.24; 95% CI: 1.00-1.53), processed (OR: 1.23; 95% CI: 1.06-1.43) and total meat (OR: 1.30; 95% CI: 1.09-1.55). Exposure-response analyses showed an increasing risk of gastric cancer with increasing consumption of both processed and red meat, with the highest OR being observed for an intake of 150 g/day of red meat (OR: 1.85; 95% CI: 1.56-2.20). This work provides robust evidence on the relation between the consumption of different types of meat and gastric cancer. Adherence to dietary recommendations to reduce meat consumption may contribute to a reduction in the burden of gastric cancer.

Education and gastric cancer risk-An individual participant data meta-analysis in the StoP project consortium

Low socioeconomic position (SEP) is a strong risk factor for incidence and premature mortality from several cancers. Our study aimed at quantifying the association between SEP and gastric cancer (GC) risk through an individual participant data meta-analysis within the "Stomach cancer Pooling (StoP) Project". Educational level and household income were used as proxies for the SEP. We estimated pooled odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) across levels of education and household income by pooling study-specific ORs through random-effects meta-analytic models. The relative index of inequality (RII) was also computed. A total of 9,773 GC cases and 24,373 controls from 25 studies from Europe, Asia and America were included. The pooled OR for the highest compared to the lowest level of education was 0.60 (95% CI, 0.44-0.84), while the pooled RII was 0.45 (95% CI, 0.29-0.69). A strong inverse association was observed both for noncardia (OR 0.39, 95% CI, 0.22-0.70) and cardia GC (OR 0.47, 95% CI, 0.22-0.99). The relation was stronger among H. pylori negative subjects (RII 0.14, 95% CI, 0.04-0.48) as compared to H. pylori positive ones (RII 0.29, 95% CI, 0.10-0.84), in the absence of a significant interaction (p = 0.28). The highest household income category showed a pooled OR of 0.65 (95% CI, 0.48-0.89), while the corresponding RII was 0.40 (95% CI, 0.22-0.72). Our collaborative pooled-analysis showed a strong inverse relationship between SEP indicators and GC risk. Our data call for public health interventions to reduce GC risk among the more vulnerable groups of the population.

Tobacco smoking and gastric cancer: meta-analyses of published data versus pooled analyses of individual participant data (StoP Project)

Tobacco smoking is one of the main risk factors for gastric cancer, but the magnitude of the association estimated by conventional systematic reviews and meta-analyses might be inaccurate, due to heterogeneous reporting of data and publication bias. We aimed to quantify the combined impact of publication-related biases, and heterogeneity in data analysis or presentation, in the summary estimates obtained from conventional meta-analyses. We compared results from individual participant data pooled-analyses, including the studies in the Stomach Cancer Pooling (StoP) Project, with conventional meta-analyses carried out using only data available in previously published reports from the same studies. From the 23 studies in the StoP Project, 20 had published reports with information on smoking and gastric cancer, but only six had specific data for gastric cardia cancer and seven had data on the daily number of cigarettes smoked. Compared to the results obtained with the StoP database, conventional meta-analyses overvalued the relation between ever smoking (summary odds ratios ranging from 7% higher for all studies to 22% higher for the risk of gastric cardia cancer) and yielded less precise summary estimates (SE ≤2.4 times higher). Additionally, funnel plot asymmetry and corresponding hypotheses tests were suggestive of publication bias. Conventional meta-analyses and individual participant data pooled-analyses reached similar conclusions on the direction of the association between smoking and gastric cancer. However, published data tended to overestimate the magnitude of the effects, possibly due to publication biases and limited the analyses by different levels of exposure or cancer subtypes.

Cigarette smoking and gastric cancer in the Stomach Cancer Pooling (StoP) Project

Tobacco smoking is a known cause of gastric cancer, but several aspects of the association remain imprecisely quantified. We examined the relation between cigarette smoking and the risk of gastric cancer using a uniquely large dataset of 23 epidemiological studies within the 'Stomach cancer Pooling (StoP) Project', including 10 290 cases and 26 145 controls. We estimated summary odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) by pooling study-specific ORs using random-effects models. Compared with never smokers, the ORs were 1.20 (95% CI: 1.09-1.32) for ever, 1.12 (95% CI: 0.99-1.27) for former, and 1.25 (95% CI: 1.11-1.40) for current cigarette smokers. Among current smokers, the risk increased with number of cigarettes per day to reach an OR of 1.32 (95% CI: 1.10-1.58) for smokers of more than 20 cigarettes per day. The risk increased with duration of smoking, to reach an OR of 1.33 (95% CI: 1.14-1.54) for more than 40 years of smoking and decreased with increasing time since stopping cigarette smoking (P for trend<0.01) and became similar to that of never smokers 10 years after stopping. Risks were somewhat higher for cardia than noncardia gastric cancer. Risks were similar when considering only studies with information on Helicobacter pylori infection and comparing all cases to H. pylori+ controls only. This study provides the most precise estimate of the detrimental effect of cigarette smoking on the risk of gastric cancer on the basis of individual data, including the relationship with dose and duration, and the decrease in risk following stopping smoking.

Association of whole grain, refined grain, and cereal consumption with gastric cancer risk: A meta-analysis of observational studies

Many studies have analyzed the relationship between cereal, whole, or refined grain and the risk of gastric cancer (GC) and have yielded mixed results. Therefore, we performed a meta-analysis of observational studies to summarize the available evidence on this topic. Databases such as PubMed, EMBASE, Web of Science, MEDLINE, and the Cochrane Library were searched for studies focusing on these associations from inception to October 2017. Summary odd ratios (OR) and 95% confidence intervals (CI) were calculated by using either a random- or fixed-effect model according to the between-studies heterogeneity. Subgroup analysis was also performed. In total, eleven studies that included 530,176 participants were identified. In a pooled analysis of all studies, cereal exposure was not associated with GC risk (OR, 1.11, 95%CI, 0.85-1.36). Specific analyses indicated that whole grain consumption was associated with decreased GC risk (OR, 0.61, 95%CI, 0.40-0.83) and that refined grain consumption was associated with increased GC risk (OR, 1.65, 95%CI, 1.36-1.94). Higher whole grain and lower refined grain intake but not cereal consumption reduces GC risk. This study has been registered at ClinicalTrials.gov (ID: NCT03419663).

Adherence to Mediterranean diet and risk of gastric cancer: results of a case-control study in Italy

The aim of this study is to evaluate the association between adherence to Mediterranean diet (MD) and gastric cancer (GC). A case-control study was carried out at the Fondazione Policlinico 'A. Gemelli' (Rome, Italy) from 2003 to 2015. A total of 223 incident cases and 223 controls were interviewed. Dietary intake was assessed through a validated food frequency questionnaire that collected information on more than 25 food items. The association between adherence to MD and risk of GC was quantified by calculating Odds Ratios (OR) and 95% confidence intervals (CI). The analysis reports that a higher adherence to MD is associated with a reduced risk of GC (OR: 0.70; 95% CI: 0.61-0.81). A high consumption of vegetables (OR: 0.34; 95% CI: 0.14-0.85), legumes (OR: 0.13; 95% CI: 0.06-0.29), and fish (OR: 0.33; 95% CI: 0.15-0.68), as well as low consumption of meat (OR: 0.29; 95% CI: 0.10-0.85) and alcohol (OR: 0.46; 95% CI: 0.24-0.90) are consistently related to a lower risk of GC. Our study indicates a protective role of the MD eating pattern and MD individual components against GC. Our results showed a beneficial role of high vegetable, legume, and fish consumption, along with low intake of alcohol and meat in the development of GC.

Alcohol intake and gastric cancer: Meta-analyses of published data versus individual participant data pooled analyses (StoP Project)

BACKGROUND

Individual participant data pooled analyses allow access to non-published data and statistical reanalyses based on more homogeneous criteria than meta-analyses based on systematic reviews. We quantified the impact of publication-related biases and heterogeneity in data analysis and presentation in summary estimates of the association between alcohol drinking and gastric cancer.

METHODS

We compared estimates obtained from conventional meta-analyses, using only data available in published reports from studies that take part in the Stomach Cancer Pooling (StoP) Project, with individual participant data pooled analyses including the same studies.

RESULTS

A total of 22 studies from the StoP Project assessed the relation between alcohol intake and gastric cancer, 19 had specific data for levels of consumption and 18 according to cancer location; published reports addressing these associations were available from 18, 5 and 5 studies, respectively. The summary odds ratios [OR, (95%CI)] estimate obtained with published data for drinkers vs. non-drinkers was 10% higher than the one obtained with individual StoP data [18 vs. 22 studies: 1.21 (1.07-1.36) vs. 1.10 (0.99-1.23)] and more heterogeneous (I²: 63.6% vs 54.4%). In general, published data yielded less precise summary estimates (standard errors up to 2.6 times higher). Funnel plot analysis suggested publication bias.

CONCLUSION

Meta-analyses of the association between alcohol drinking and gastric cancer tended to overestimate the magnitude of the effects, possibly due to publication bias. Additionally, individual participant data pooled analyses yielded more precise estimates for different levels of exposure or cancer subtypes.

Milk/dairy products consumption and gastric cancer: an update meta-analysis of epidemiological studies

The relationship between dairy consumption and gastric cancer risk has not been well studied. We therefore performed a update meta-analysis to evaluate the relationship. Published cohort and case-control studies were identified via computer searches and reviewing the reference lists of the key articles. Random effects meta-analysis was used to pool effects from 5 cohort and 29 case-control studies. The odds ratio for the overall association between dairy consumption and gastric cancer was 1.20 (95%confidence interval: 1.04–1.39). The combined risk estimate was similar for population-based case-control studies (odds ratio = 1.27, 95%confidence interval: 1.00–1.61), but was reduced for hospital-based studies (odds ratio = 1.22; 95%confidence interval: 0.95–1.57) and cohort studies (odds ratio = 0.99; 95%confidence interval: 0.77–1.28). There was high heterogeneity in overall analyses. In the population-based subgroup analyses, the odds ratio was 0.96 (95%confidence interval: 0.69–1.34) when considering five studies assessing exposure two or more years before interview, and the association strengthened (odds ratio = 1.91, 95%confidence interval: 1.60–2.28) when dairy consumption was evaluated one year or less prior to interview. In conclusion, we found adverse effect of dairy consumption associated with gastric cancer.

Alcohol consumption and gastric cancer risk-A pooled analysis within the StoP project consortium

An association between heavy alcohol drinking and gastric cancer risk has been recently reported, but the issue is still open to discussion and quantification. We investigated the role of alcohol drinking on gastric cancer risk in the "Stomach cancer Pooling (StoP) Project," a consortium of epidemiological studies. A total of 9,669 cases and 25,336 controls from 20 studies from Europe, Asia and North America were included. We estimated summary odds-ratios (ORs) and the corresponding 95% confidence intervals (CIs) by pooling study-specific ORs using random-effects meta-regression models. Compared with abstainers, drinkers of up to 4 drinks/day of alcohol had no increase in gastric cancer risk, while the ORs were 1.26 (95% CI, 1.08-1.48) for heavy (>4 to 6 drinks/day) and 1.48 (95% CI 1.29-1.70) for very heavy (>6 drinks/day) drinkers. The risk for drinkers of >4 drinks/day was higher in never smokers (OR 1.87, 95% CI 1.35-2.58) as compared with current smokers (OR 1.14, 95% CI 0.93-1.40). Somewhat stronger associations emerged with heavy drinking in cardia (OR 1.61, 95% CI 1.11-2.34) than in non-cardia (OR 1.28, 95% CI 1.13-1.45) gastric cancers, and in intestinal-type (OR 1.54, 95% CI 1.20-1.97) than in diffuse-type (OR 1.29, 95% CI 1.05-1.58) cancers. The association was similar in strata of H. pylori infected (OR = 1.52, 95% CI 1.16-2.00) and noninfected subjects (OR = 1.69, 95% CI 0.95-3.01). Our collaborative pooled-analysis provides definite, more precise quantitative evidence than previously available of an association between heavy alcohol drinking and gastric cancer risk.

Association between Dietary Inflammatory Index and Gastric Cancer Risk in an Italian Case-Control Study

BACKGROUND

In this study, we explored the association between the dietary inflammatory index (DII) and gastric cancer risk in an Italian case-control study.

MATERIALS AND METHODS

Cases were 230 patients with incident, histologically confirmed cases of gastric cancer from the Greater Milan area, Northern Italy. Controls were 547 frequency-matched subjects admitted to the same network of hospitals as cases for a wide spectrum of acute, non-neoplastic conditions. The DII was computed using a reproducible and valid 78-item food frequency questionnaire. Odds ratios (ORs) were estimated through logistic regression models conditioned on age and sex and adjusted for recognized confounding factors, including total energy intake.

RESULTS

Subjects with the most pro-inflammatory diet had a higher risk of gastric cancer compared to subjects with the most anti-inflammatory diet (ORQuartile4vs1 = 2.35, 95% confidence interval, 1.32, 4.20; P-trend = 0.004).

CONCLUSION

These results indicate that a pro-inflammatory diet, as indicated by higher DII score, was associated with increased risk of gastric cancer.

Systematic review of the relationship between artificial sweetener consumption and cancer in humans: analysis of 599,741 participants

BACKGROUND

The effect of artificial sweetener consumption on cancer risk has been debated in animal models for over four decades. To further investigate this relationship, this study aims to synthesise results from several of the most recent studies in humans.

METHODS

An online literature search was performed in MEDLINE from 2003 to 2014 using Ovid, PubMed, Web of Science, and Scopus using keywords 'artificial', 'sweetener' and 'cancer'. Ninety-two results were then manually assessed for eligibility. Studies were included if the relationship between artificial sweeteners and cancer was their central hypothesis, and if they adjusted for age, gender, smoking status and body mass index. Extracted data included study design, patient characteristics, outcome measure and results.

RESULTS

In the five publications that satisfied the inclusion criteria, significant direct associations with artificial consumption were found for laryngeal (odds ratio, OR 2.34, 95% CI: 1.20-4.55), urinary tract tumours (OR 2.12, 95% CI: 1.22-3.89), non-Hodgkin lymphoma in men (RR 1.31, 95% CI: 1.01-1.72), multiple myeloma in men (RR 2.02, 95% CI: 1.20-3.40) and leukaemia (RR 1.42, 95% CI: 1.00-2.02). Inverse relationships were found in breast (OR 0.70, 95% CI: 0.54-0.91, p trend = 0.015) and ovarian (OR 0.56, 95% CI: 0.38-0.81, p trend < 0.001) cancers.

CONCLUSION

The statistical value of this review is limited by the heterogeneity and observational designs of the included studies. Although there is limited evidence to suggest that heavy consumption may increase the risk of certain cancers, overall the data presented are inconclusive as to any relationship between artificial sweeteners and cancer.

Fruit and vegetables and cancer risk: a review of southern European studies

High intakes of fruit and vegetables may reduce the risk of cancer at several sites. Evidence has been derived mainly from case-control studies. We reviewed the relationship between consumption of vegetables and fruit and the risk of several common cancers in a network of Italian and Swiss case-control studies including over 10,000 cases of fourteen different cancers and about 17,000 controls. Data were suggestive of a protective role of vegetable intake on the risk of several common epithelial cancers. OR for the highest compared with the lowest levels of consumption ranged from 0.2 (larynx, oral cavity and pharynx) to 0.9 (prostate). Inverse associations were found for both raw and cooked vegetables, although for upper digestive tract cancers the former were somewhat stronger. Similar inverse associations were found for cruciferous vegetables. Frequent consumption of allium vegetables was also associated with reduced risk of several cancers. Fruit was a favourable correlate of the risk of several cancers, particularly of the upper digestive tract, with associations generally weaker than those reported for vegetables. A reduced risk of cancers of the digestive tract and larynx was found for high consumption of citrus fruit. Suggestive protections against several forms of cancer, mainly digestive tract cancers, were found for high consumption of apples and tomatoes. High intakes of fibres, flavonoids and proanthocyanidins were inversely related to various forms of cancer. In conclusion, data from our series of case-control studies suggested a favourable role of high intakes of fruit and vegetables in the risk of many common cancers, particularly of the digestive tract. This adds evidence to the indication that aspects of the Mediterranean diet may have a favourable impact not only on CVD, but also on several common (epithelial) cancers, particularly of the digestive tract.

Non-enzymatic antioxidant capacity and risk of gastric cancer

BACKGROUND

Consumption of fruit and vegetables has been inversely related to gastric cancer. Two studies found that dietary antioxidant capacity has some role in explaining this association. We investigated the overall antioxidant effect from diet on gastric cancer using three measures of non-enzymatic antioxidant capacity (NEAC).

METHODS

We used data from an Italian case-control study including 230 patients with incident, histologically confirmed gastric cancer, and 547 frequency matched controls admitted to the same hospitals for acute non-neoplastic diseases. A reproducible and valid food frequency questionnaire was used to assess subjects' usual diet. NEAC was measured using Italian food composition tables in terms of Trolox equivalent antioxidant capacity (TEAC), Ferric reducing-antioxidant power (FRAP) and Total radical-trapping antioxidant parameter (TRAP). We estimated the odds ratios (OR) of gastric cancer and the corresponding 95% confidence intervals (CI) using conditional logistic regression models including terms for recognized gastric cancer risk factors and total energy intake.

RESULTS

NEAC was inversely related with gastric cancer risk with ORs for the highest versus the lowest quintile of 0.54 (95%CI, 0.33-0.88) for TEAC, 0.67 (95%CI, 0.42-1.07) for FRAP and 0.57 (95%CI, 0.36-0.90) for TRAP.

CONCLUSIONS

A diet rich in antioxidant capacity reduced gastric cancer risk, suggesting a high consumption of fruit and vegetables and a moderate consumption of wine and whole cereals.

Dairy product consumption and gastric cancer risk: A meta-analysis

AIM: To investigate whether dairy product consumption is a risk factor for gastric cancer.

METHODS: We searched the PubMed and Web of Science databases for English-language studies on dairy product consumption and gastric cancer risk that were published between October 1980 and September 2013. One author independently extracted data and assessed study quality. Based on the heterogeneity results, we used either the fixed effects model or the random effects model to compute the summary relative risks and 95% confidence intervals (CIs). We also analyzed subgroups according to the study design, geographic region, sex, and whether there were adjustments for confounders (smoking and drinking) with respect to the sources of heterogeneity.

RESULTS: We found 39 studies that were potentially eligible for inclusion in this meta-analysis, including 10 cohort studies and 29 case-control studies. The summary relative risk for gastric cancer, comparing the highest and lowest dairy product consumption categories, was 1.06 (95%CI: 0.95-1.18). Specific analyses for milk, butter, and margarine yielded similar results, but the results for cheese and yogurt were different. There was significant heterogeneity for all studies (Q = 112.61; P = 0.000; I² = 67.1%). No publication bias was observed (Egger’s test: P = 0.135; Begg’s test: P = 0.365). There was a nonsignificant association between dairy product consumption and gastric cancer risk in the subgroup analysis for the study design, sex, geographic region, and whether there were adjustments for confounders (smoking and drinking).

CONCLUSION: In our meta-analysis, dairy product consumption was associated with a nonsignificantly increased risk of gastric cancer. However, this result should be verified using large, well-designed prospective studies.

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.

Adherence to the Mediterranean diet and gastric cancer risk in Italy

We investigated gastric cancer risk in relation to the adherence to the Mediterranean diet using data from two case-control studies conducted in Italy between 1985 and 2007, including 999 incidents, histologically confirmed gastric cancers and 2,628 controls admitted to hospital for acute non-neoplastic diseases. Adherence to the Mediterranean diet was assessed using the Mediterranean Diet Score (MDS) based on nine of the major characteristics of the Mediterranean diet in the overall dataset. The Mediterranean Dietary Pattern adherence index (MDP) and the Mediterranean Adequacy Index (MAI) were considered in the second study only. We estimated odds ratios (OR) and corresponding 95% confidence intervals (CI) of gastric cancer for categories of the three scores using multiple logistic regression models. We found a reduced risk of gastric cancer for increasing levels of the MDS: as compared to subjects in the lowest category of the MDS, the ORs were 0.78, 0.61 and 0.57 in subsequent levels of MDS, with a significant trend in risk. Risk estimates were consistent across strata of age, sex, education, smoking, body mass index, and family history of gastric cancer. We also observed a decreased risk of gastric cancer for the highest versus the lowest quintile for MDP and MAI, with OR of 0.58 and 0.71, respectively. Our study provides convincing evidence of a beneficial role of the Mediterranean diet on gastric cancer.

Red meat and cancer risk in a network of case-control studies focusing on cooking practices

BACKGROUND

Consumption of red meat has been related to increased risk of several cancers. Cooking methods could modify the magnitude of this association, as production of chemicals depends on the temperature and duration of cooking.

METHODS

We analyzed data from a network of case-control studies conducted in Italy and Switzerland between 1991 and 2009. The studies included 1465 oral and pharyngeal, 198 nasopharyngeal, 851 laryngeal, 505 esophageal, 230 stomach, 1463 colon, 927 rectal, 326 pancreatic, 3034 breast, 454 endometrial, 1031 ovarian, 1294 prostate and 767 renal cancer cases. Controls included 11 656 patients admitted for acute, non-neoplastic conditions. Odds ratios (ORs) and confidence intervals (CIs) were estimated by multiple logistic regression models, adjusted for known confounding factors.

RESULTS

Daily intake of red meat was significantly associated with the risk of cancer of the oral cavity and pharynx (OR for increase of 50 g/day = 1.38; 95% CI: 1.26-1.52), nasopharynx (OR = 1.29; 95% CI: 1.04-1.60), larynx (OR = 1.46; 95% CI: 1.30-1.64), esophagus (OR = 1.46; 95% CI: 1.23-1.72), colon (OR = 1.17; 95% CI: 1.08-1.26), rectum (OR = 1.22; 95% CI:1.11-1.33), pancreas (OR = 1.51; 95% CI: 1.25-1.82), breast (OR = 1.12; 95% CI: 1.04-1.19), endometrium (OR = 1.30; 95% CI: 1.10-1.55) and ovary (OR = 1.29; 95% CI: 1.16-1.43). Fried meat was associated with a higher risk of cancer of oral cavity and pharynx (OR = 2.80; 95% CI: 2.02-3.89) and esophagus (OR = 4.52; 95% CI: 2.50-8.18). Risk of prostate cancer increased for meat cooked by roasting/grilling (OR = 1.31; 95% CI: 1.12-1.54). No heterogeneity according to cooking methods emerged for other cancers. Nonetheless, significant associations with boiled/stewed meat also emerged for cancer of the nasopharynx (OR = 1.97; 95% CI: 1.30-3.00) and stomach (OR = 1.86; 95% CI: 1.20-2.87).

CONCLUSIONS

Our analysis confirmed red meat consumption as a risk factor for several cancer sites, with a limited impact of cooking methods. These findings, thus, call for a limitation of its consumption in populations of Western countries.

Sex composition of the workplace and mortality risk

This study uses Swedish occupational register data to examine whether the proportion of men in administrative workplaces in the Swedish public service affects all-cause mortality risks amongst both males and females of working age. Using piecewise constant survival models to analyse occupational data from the Swedish administrative registers from 1995 to 2007, it was found that for males, a 1% increase in the proportion of males was associated with a 1.3% increase in mortality risk (hazard ratio, HR 1.013, 95% CI 1.007-1.020, p<0.001), but no association was found for females (HR 1.004, 95% CI 0.996-1.012, p=0.297). Adjustments were made for age, family status, education, occupational status, occupational segregation by sex, the total number of individuals in the workplace, level of government, region, period and variables reflecting the workplace structure by age, age by sex, occupation and education. A higher proportion of males may be related to (i) an increased exposure to risky health behaviours such as alcohol consumption and unhealthy dietary patterns, (ii) a tendency towards sickness presenteeism, and (iii) an increase in the levels of several well-established emotional stressors in the workplace, leading to an increased level of psychosocial stress. The findings and potential extensions of this research are discussed.

Dietary folates and cancer risk in a network of case-control studies

BACKGROUND

Folate deficiency leads to DNA damage and inadequate repair, caused by a decreased synthesis of thymidylate and purines. We analyzed the relationship between dietary folate intake and the risk of several cancers.

PATIENTS AND METHODS

The study is based on a network of case-control studies conducted in Italy and Switzerland in 1991-2009. The odds ratios (ORs) for dietary folate intake were estimated by multiple logistic regression models, adjusted for major identified confounding factors.

RESULTS

For a few cancer sites, we found a significant inverse relation, with ORs for an increment of 100 μg/day of dietary folate of 0.65 for oropharyngeal (1467 cases), 0.58 for esophageal (505 cases), 0.83 for colorectal (2390 cases), 0.72 for pancreatic (326 cases), 0.67 for laryngeal (851 cases) and 0.87 for breast (3034 cases) cancers. The risk estimates were below unity, although not significantly, for cancers of the endometrium (OR = 0.87, 454 cases), ovary (OR = 0.86, 1031 cases), prostate (OR = 0.91, 1468 cases) and kidney (OR = 0.88, 767 cases), and was 1.00 for stomach cancer (230 cases). No material heterogeneity was found in strata of sex, age, smoking and alcohol drinking.

CONCLUSIONS

Our data support a real inverse association of dietary folate intake with the risk of several common cancers.

History of cholelithiasis and cancer risk in a network of case-control studies

BACKGROUND

We analyzed the relationship between cholelithiasis and cancer risk in a network of case-control studies conducted in Italy and Switzerland in 1982-2009.

METHODS

The analyses included 1997 oropharyngeal, 917 esophageal, 999 gastric, 23 small intestinal, 3726 colorectal, 684 liver, 688 pancreatic, 1240 laryngeal, 6447 breast, 1458 endometrial, 2002 ovarian, 1582 prostate, 1125 renal cell, 741 bladder cancers, and 21 284 controls. The odds ratios (ORs) were estimated by multiple logistic regression models.

RESULTS

The ORs for subjects with history of cholelithiasis compared with those without were significantly elevated for small intestinal (OR=3.96), prostate (OR=1.36), and kidney cancers (OR=1.57). These positive associations were observed ≥10 years after diagnosis of cholelithiasis and were consistent across strata of age, sex, and body mass index. No relation was found with the other selected cancers. A meta-analysis including this and three other studies on the relation of cholelithiasis with small intestinal cancer gave a pooled relative risk of 2.35 [95% confidence interval (CI) 1.82-3.03].

CONCLUSION

In subjects with cholelithiasis, we showed an appreciably increased risk of small intestinal cancer and suggested a moderate increased risk of prostate and kidney cancers. We found no material association with the other cancers considered.

Cruciferous vegetables and cancer risk in a network of case-control studies

BACKGROUND

Cruciferous vegetables have been suggested to protect against various cancers, though the issue is open to discussion. To further understand their role, we analyzed data from a network of case-control studies conducted in Italy and Switzerland.

PATIENTS AND METHODS

The studies included a total of 1468 cancers of the oral cavity/pharynx, 505 of the esophagus, 230 of the stomach, 2390 of the colorectum, 185 of the liver, 326 of the pancreas, 852 of the larynx, 3034 of the breast, 367 of the endometrium, 1031 of the ovary, 1294 of the prostate, 767 of the kidney, and 11,492 controls. All cancers were incident, histologically confirmed; controls were subjects admitted to the same network of hospitals as cases for a wide spectrum of acute nonneoplastic conditions.

RESULTS

The multivariate odds ratio (OR) for consumption of cruciferous vegetables at least once a week as compared with no/occasional consumption was significantly reduced for cancer of the oral cavity/pharynx (OR=0.83), esophagus (OR=0.72), colorectum (OR=0.83), breast (OR=0.83), and kidney (OR=0.68). The OR was below unity, but not significant, for stomach (OR=0.90), liver (OR=0.72), pancreatic (OR=0.90), laryngeal (OR=0.84), endometrial (OR=0.93), ovarian (OR=0.91), and prostate (OR=0.87) cancer.

CONCLUSION

This large series of studies provides additional evidence of a favorable effect of cruciferous vegetables on several common cancers.