Different dietary patterns and reduction of lung cancer risk: A large case-control study in the U.S

A systematic review and dose-response meta-analysis of prospective cohort studies on coffee consumption and risk of lung cancer

Studies on the association between coffee consumption and risk of lung cancer have been conflicting. The aim of this study was to systematically review the current evidence on the association between coffee consumption and risk of lung cancer and to quantify this association by performing a meta-analysis. A comprehensive systematic search was performed on online databases up to July 2023 investigating the association between coffee consumption and risk of lung cancer. All prospective cohort studies reporting odds ratios (ORs), rate or risk ratios (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) in this context were included. The overall effect size was calculated using the random-effects model and statistical between-studies heterogeneity was examined using Cochrane's Q test and I2. A total of 14 prospective cohort studies were included in this systematic review and meta-analysis. We found a significant positive association between coffee consumption and risk of lung cancer (RR: 1.28; 95% CI: 1.12, 1.47). This association remained significant when we included a pooled analysis paper and excluded 5 cohort studies (RR: 1.37; 95% CI: 1.12, 1.66). We observed no proof of significant publication bias using Egger's test (P = 0.58). Moreover, dose-response analysis showed that each one cup/day increase in coffee consumption was related with a 6% higher lung cancer risk (RR: 1.06; 95% CI: 1.03, 1.09). In conclusion, we found a significant positive association between coffee consumption and risk of lung cancer.

Dietary iron and the risk of lung cancer

Animal models have suggested the carcinogenic effect of iron due to its oxidative potential. The lung is particularly vulnerable to oxidative stress. However, epidemiological studies investigating the association between dietary iron and the risk of lung cancer have reported inconclusive results. In this systematic review and meta-analysis, we aimed to clarify this association. Methods: We searched PubMed, Web of Science, Scopus and Google scholar for eligible articles published through May 2023 reporting the Relative Risk (RR), Hazard Ratio (HR) or Odds Ratio (OR) with 95% confidence interval (95% CI). Case-control and cohort studies that examined the relationship between dietary iron and lung cancer risk were included and review and meta-analyses articles, experimental studies, abstracts, letters to editor and studies with insufficient data were excluded. Finally, three case-control studies and 6 cohort studies were included. Random effect models were used to calculate the pooled results. Results: Nine studies (cases n=21,943, participants n=1,542,993) were included. There were no significant associations between the highest dietary total iron (heme and non-heme) (RR: 1.09, 95% CI: 0.78 to 1.51) or heme iron (RR: 1.01, 95% CI: 0.73 to 1.38) intake compared to the lowest intake with lung cancer risk. Null-associations were also observed in the subgroup analysis based on smoking status and lung cancer histology. However, in the subgroup of women (cases n=5074), heme iron was associated with a 14% increase in the risk of lung cancer (RR: 1.14, 95% CI: 1.01 to 1.29). Conclusions: The current results demonstrated that there is no significant relationship between dietary iron intake and the risk of lung cancer. However, a positive association was observed between dietary heme iron and the risk of lung cancer in women, which may require further investigation.

Cancer Incidence Rates in the US in 2016-2020 with Respect to Solar UVB Doses, Diabetes and Obesity Prevalence, Lung Cancer Incidence Rates, and Alcohol Consumption: An Ecological Study

This article reports the results of an ecological study of cancer incidence rates by state in the US for the period 2016-2020. The goals of this study were to determine the extent to which solar UVB doses reduced cancer risk compared to findings reported in 2006 for cancer mortality rates for the periods 1950-1969 and 1970-1794 as well as cancer incidence rates for the period 1998-2002 and to determine which factors were recently associated with cancer risk. The cancer data for non-Hispanic white (European American) men and women were obtained from the Centers for Disease Control and Prevention. Indices were obtained for solar UVB at the surface for July 1992, and alcohol consumption, diabetes, and obesity prevalence near the 2016-2020 period. Lung cancer incidence rates were also used in the analyses as a surrogate for smoking, diet, and air pollution. The cancers for which solar UVB is significantly associated with reduced incidence are bladder, brain (males), breast, corpus uteri, esophageal, gastric, non-Hodgkin's lymphoma, pancreatic, and renal cancer. Lung cancer was significantly associated with colorectal, laryngeal, and renal cancer. Diabetes was also significantly associated with breast, liver, and lung cancer. Obesity prevalence was significantly associated with breast, colorectal, and renal cancer. Alcohol consumption was associated with bladder and esophageal cancer. Thus, diet has become a very important driver of cancer incidence rates. The role of solar UVB in reducing the risk of cancer has been reduced due to people spending less time outdoors, wearing sunscreen that blocks UVB but not UVA radiation, and population increases in terms of overweight and obese individuals, which are associated with lower 25-hydroxyvitamin D concentrations and the generation of systemic inflammation, which is a risk factor for cancer. A dietary approach that would reduce the risk of diabetes, obesity, lung cancer, and, therefore, cancer, would be one based mostly on whole plants and restrictions on red and processed meats and ultraprocessed foods. Solar UVB exposure for a few minutes before applying sunscreen and taking vitamin D supplements would also help reduce the risk of cancer.

Adherence to Data-Driven Dietary Patterns and Lung Cancer Risk: A Systematic Review and Dose-Response Meta-Analysis

The effect of dietary patterns on lung cancer risk is currently debated. In this study, we evaluated the association between different "a posteriori" dietary patterns and lung cancer risk. The search was carried out (February 2023) through Scopus, Web of Science, and PubMed databases. Meta-analysis was performed by a random-effects model using risk values (RR and OR) extracted from the 12 selected studies. Two main dietary patterns were identified and named "Western/meat" and "Healthy/prudent". The highest adherence to the "Western/meat" dietary pattern significantly increased the lung cancer risk (OR = 1.39; 95% CI: 1.17-1.65; p = 0.0002) while the highest adherence to the "Healthy/prudent" pattern reduced it (OR = 0.65; 95% CI: 0.51-0.83; p = 0.001). A linear trend between both dietary patterns and lung cancer risk was observed. However, a statistically significant inverse dose-response trend was found only for the "Healthy/prudent" dietary pattern (regression coefficient = -0.0031, p = 0.003). Subgroup analyses showed that the "Western/meat" pattern significantly increased the lung cancer risk in former (n = 4) (OR = 1.93, 95% CI: 1.11-3.36) and current smokers (n = 7) (OR = 1.35, 95% CI: 1.06-1.71). Similarly, the "Healthy/prudent" pattern exerts a protective effect on former (n = 4) (OR = 0.61, 95% CI: 0.44-0.85) and current smokers (n = 8) (OR = 0.64, 95% CI: 0.46-0.88). For both dietary patterns, no significant effect was observed on never-smokers.

Dietary Patterns and Risk of Lung Cancer: A Systematic Review and Meta-Analyses of Observational Studies

PURPOSE OF REVIEW

Previous literature reviews summarized the associations between individual foods or food groups and lung cancer risk, but the relationship between dietary patterns and lung cancer risk has received less attention. We conducted a systematic review and meta-analyses of observational studies on the associations between dietary patterns and lung cancer risk.

RECENT FINDINGS

PubMed, Embase, and Web of Science were systematically searched from inception to February 2023. Random-effects models were used to pool relative risks (RR) on associations with at least two studies. Twelve studies reported on data-driven dietary patterns, and 17 studies reported on a priori dietary patterns. A prudent dietary pattern (high in vegetables, fruit, fish, and white meat) tended to be associated with a lower risk of lung cancer (RR = 0.81, 95% confidence interval [CI] = 0.66-1.01, n = 5). In contrast, Western dietary patterns, characterized by higher intakes of refined grains and red and processed meat, were significantly positively associated with lung cancer (RR = 1.32, 95% CI = 1.08-1.60, n = 6). Healthy dietary scores were consistently associated with a lower risk of lung cancer (Healthy Eating Index [HEI]: RR = 0.87, 95% CI = 0.80-0.95, n = 4; Alternate HEI: RR = 0.88, 95% CI = 0.81-0.95, n = 4; Dietary Approaches to Stop Hypertension: RR = 0.87, 95% CI = 0.77-0.98, n = 4; Mediterranean diet: RR = 0.87, 95% CI = 0.81-0.93, n = 10) while the dietary inflammatory index was associated with a higher risk of lung cancer (RR = 1.14, 95% CI = 1.07-1.22, n = 6). Our systematic review indicates dietary patterns characterized by a higher intake of vegetables and fruits, a lower intake of animal products, and anti-inflammation may be associated with a reduced risk of lung cancer.

Diet-wide association study of 92 foods and nutrients and lung cancer risk in the European Prospective Investigation into Cancer and Nutrition study and the Netherlands Cohort Study

It is unclear whether diet, and in particular certain foods or nutrients, are associated with lung cancer risk. We assessed associations of 92 dietary factors with lung cancer risk in 327 790 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC). Cox regression yielded adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) per SD higher intake/day of each food/nutrient. Correction for multiple comparisons was performed using the false discovery rate and identified associations were evaluated in the Netherlands Cohort Study (NLCS). In EPIC, 2420 incident lung cancer cases were identified during a median of 15 years of follow-up. Higher intakes of fibre (HR per 1 SD higher intake/day = 0.91, 95% CI 0.87-0.96), fruit (HR = 0.91, 95% CI 0.86-0.96) and vitamin C (HR = 0.91, 95% CI 0.86-0.96) were associated with a lower risk of lung cancer, whereas offal (HR = 1.08, 95% CI 1.03-1.14), retinol (HR = 1.06, 95% CI 1.03-1.10) and beer/cider (HR = 1.04, 95% CI 1.02-1.07) intakes were positively associated with lung cancer risk. Associations did not differ by sex and there was less evidence for associations among never smokers. None of the six associations with overall lung cancer risk identified in EPIC were replicated in the NLCS (2861 cases), however in analyses of histological subtypes, inverse associations of fruit and vitamin C with squamous cell carcinoma were replicated in the NLCS. Overall, there is little evidence that intakes of specific foods and nutrients play a major role in primary lung cancer risk, but fruit and vitamin C intakes seem to be inversely associated with squamous cell lung cancer.

Lung Cancer Risk in Men and Compliance with the 2018 WCRF/AICR Cancer Prevention Recommendations

Lung cancer is the most common and deadly form of cancer worldwide, especially in men. The 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) updated cancer prevention recommendations, and a standard scoring system (2018 WCRF/AICR Score) was published. The purpose of this study was to develop the adapted version of the 2018 WCRF/AICR Score with respect to lung cancer prevention recommendation (Ad-LC WCRF/AICR Score) and to examine the association between lung cancer risk in men and the Ad-LC WCRF/AICR Score as well as its single components. A case-control study was conducted among 439 men aged 45-80 years (187 controls, 252 primary lung cancer cases). Lifestyle and dietary data were collected with a questionnaire including the 62-item food frequency questionnaire (FFQ-6^®). The Ad-LC WCRF/AICR Score was used as a categorized and continuous variable. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for lung cancer risk were calculated with the partly and fully adjusted model. One component of the score was independently associated with a lower risk of lung cancer in men, regardless of the set of confounders used. In the fully adjusted model following the recommendation "Limit smoking" was associated with a lower risk of lung cancer-in the never smokers by 87% (OR: 0.13; 95% CI: 0.04-0.37; p = 0.0002) and in the moderate smokers by 45% (OR: 0.55; 95% CI: 0.33-0.91; p = 0.0189) compared with the heavy smokers as a reference. By adding the single components making up the Ad-LC WCRF/AICR Score, the combination of three components or more, reducing the risk of lung cancer compared to lower compliance as a reference by 45% to 78% and by 39% to 66% for intermediate compliance (except two models out of seven) and higher compliance, respectively. In the fully adjusted model, the risk of lung cancer for the total Ad-LC WCRF/AICR Score was lower by 47% (OR: 0.53; 95% CI: 0.32-0.88; p = 0.0129) in higher compliance with the score compared to those with the lower compliance. Each one-point increase in the Ad-LC WCRF/AICR Score reduced lung cancer risk by 34% (OR: 0.66; 95% CI: 0.45-0.95; p = 0.0267). The results support previous evidence that limiting smoking reduces the risk of lung cancer in men. It also provides an insight into cancer research by showing that following the combined 2018 cancer prevention recommendations related to diet, lifestyle and body fatness was associated with a lower risk of lung cancer in men.

Association of dietary patterns and food groups intake with multimorbidity: A prospective cohort study

BACKGROUND

Although diet has been extensively studied in relation to individual chronic conditions, studies linking diet with multiple chronic conditions (multimorbidity) remained scarce. We aimed to undertake a comprehensive analysis evaluating associations of overall dietary patterns and specific food groups with long-term risk of multimorbidity.

METHODS

The study included 348,290 participants from UK Biobank who completed eligible food frequency questionnaires (FFQ) and were not diagnosed with any of the 38 chronic or mental health conditions of interest at baseline (2006-2010). Dietary patterns were identified using exploratory factor analysis. Cox regression models were used to estimate corresponding hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The median follow-up was 8.01 years, and 50,837 (14.60%) participants developed multimorbidity. Among the three identified dietary patterns, the Western Pattern was associated with an increased risk of multimorbidity (HR_{Q5 vs Q1} = 1.06, 95% CI: 1.03-1.09), while inverse associations were observed for moderate adherence to the White Meat Pattern (HR_{Q3vs Q1} = 0.97, 95% CI: 0.94-0.99) and highest adherence to the Prudent Pattern (HR_{Q5 vs Q1} = 0.92, 95% CI: 0.90-0.95). For specific food groups, more frequent intakes of processed meat and poultry were associated with higher risks of multimorbidity, whereas higher intake frequency of fish and more intakes of fruits and cereal were associated with decreased risks.

CONCLUSION

Dietary patterns and specific food groups are associated with the risk of multimorbidity. These findings suggest the importance of considering dietary interventions in the prevention and management of multimorbidity.

Diet and Risk of Incident Lung Cancer: A Large Prospective Cohort Study in UK Biobank

BACKGROUND

Epidemiological evidence remains conflicting regarding diet and risk of lung cancer.

OBJECTIVES

We sought to systematically investigate whether dietary factors are associated with the risk of incident lung cancer in the UK Biobank.

METHODS

A total of 416,588 participants (54% women) from the UK Biobank were included in the present study. Based on baseline data from FFQs, 3 main dietary patterns were identified by using principal component analysis. Cox proportional hazards models were used to investigate the association of individual food groups and dietary patterns with lung cancer risk.

RESULTS

During a median follow-up of 7.13 y, 1782 incident lung cancer cases were documented. The association analysis showed high intake of red meat and processed meat was associated with an increased risk of lung cancer (HRper 50 g/d: 1.36; 95% CI: 1.13, 1.65 for red meat; HRper 25 g/d: 1.30; 95% CI: 1.10, 1.53 for processed meat). However, the consumption of fruits (HRper 100 g/d: 0.90; 95% CI: 0.84, 0.95), vegetables (HRper 100 g/d: 0.89; 95% CI: 0.81, 0.99), breakfast cereals (HRper 50 g/d: 0.81; 95% CI: 0.74, 0.89), and dietary fiber (HRper 5 g/d: 0.76; 95% CI: 0.69, 0.84) was inversely associated with the risk of lung cancer. For the dietary pattern analysis [quartile (Q) comparison], high adherence to the Prudent pattern (HRQ4 compared with Q1: 0.84; 95% CI: 0.73, 0.96) was associated with a lower risk of lung cancer, whereas the Western pattern (HRQ4 compared with Q1: 1.27; 95% CI: 1.11, 1.46) was associated with a higher risk of lung cancer.

CONCLUSIONS

Our study indicated that a diet characterized by high intake of fruits, vegetables, breakfast cereals, and dietary fiber, as well as low intake of red meat and processed meat, was associated with a lower risk of lung cancer.

Diet Quality and Risk of Lung Cancer in the Multiethnic Cohort Study

Diet quality, assessed by the Healthy Eating Index-2015 (HEI-2015), the Alternative Healthy Eating Index-2010 (AHEI-2010), the alternate Mediterranean Diet (aMED) score, the Dietary Approaches to Stop Hypertension (DASH) score, and the Dietary Inflammatory Index (DII®), was examined in relation to risk of lung cancer in the Multiethnic Cohort Study. The analysis included 179,318 African Americans, Native Hawaiians, Japanese Americans, Latinos, and Whites aged 45-75 years, with 5350 incident lung cancer cases during an average follow-up of 17.5 ± 5.4 years. In multivariable Cox models comprehensively adjusted for cigarette smoking, the hazard ratios (95% confidence intervals) for the highest vs. lowest quality group based on quintiles were as follows: 0.85 (0.77-0.93) for HEI-2015; 0.84 (0.77-0.92) for AHEI-2010; 0.83 (0.76-0.91) for aMED; 0.83 (0.73-0.91) for DASH; and 0.90 (0.82-0.99) for DII. In histological cell type-specific analyses, the inverse association was stronger for squamous cell carcinoma than for adeno-, small cell, and large cell carcinomas for all indexes. There was no indication of differences in associations by sex, race/ethnicity, and smoking status. These findings support that high-quality diets are associated with lower risk of lung cancer, especially squamous cell carcinomas, in a multiethnic population.

Indices of Diet Quality and Risk of Lung Cancer in the Women's Health Initiative Observational Study

BACKGROUND

Prospective evidence on associations between diet quality indices and lung cancer risk is limited, particularly among older women.

OBJECTIVES

We investigated associations between 4 diet quality indices [Healthy Eating Index-2015 (HEI-2015), Alternate Healthy Eating Index 2010 (AHEI-2010), alternate Mediterranean Diet (aMED), and Dietary Approaches to Stop Hypertension (DASH)] and lung cancer incidence and mortality in the Women's Health Initiative Observational Study.

METHODS

Postmenopausal women aged 50-79 y at baseline (1993-1998) self reported their diet intake and information on relevant covariates. We used Cox proportional hazards regression models to estimate HRs and 95% CIs after controlling for age, smoking, and other relevant covariates.

RESULTS

During ∼17 y of follow-up among 86,090 participants, 1491 lung cancer cases and 1393 lung cancer deaths were documented. Dietary indices were not associated with overall lung cancer incidence but were protective against squamous cell carcinoma (12.8% of total lung cancer) cases (HEI-2015: HR: 0.85; 95% CI: 0.76, 0.96; AHEI-2010: HR: 0.87; 95% CI: 0.78, 0.98; aMED: HR: 0.90; 95% CI: 0.81, 0.99; DASH: HR: 0.87; 95% CI: 0.77, 0.98). Among the indices, only HEI-2015 showed an inverse trend (P-trend = 0.02) with overall lung cancer mortality. Smoking status or participant age at baseline did not modify the association between dietary indices and lung cancer incidence or mortality.

CONCLUSIONS

After comprehensive control of smoking exposure, we found that diet quality was not associated with overall lung cancer among postmenopausal women. However, a high-quality diet was inversely related to incident lung cancer of the squamous cell subtype. Future studies in populations with diverse age, smoking history, and dietary intake may further elucidate the relation between diet quality indices and lung cancer, especially by histological subtype.

Dietary quality using four dietary indices and lung cancer risk: the Golestan Cohort Study (GCS)

PURPOSE

The lung cancer incidence in Iran has increased almost ten times over the past three decades. In addition to the known causes such as smoking and certain occupational exposure, dietary quality has been suggested to play a role in lung cancer. We aim to explore the association between dietary pattern and lung cancer risk among a Middle East population.

METHODS

Data came from Golestan Cohort Study which included 48,421 participants with 136 lung cancer cases diagnosed during a median follow-up of 12 years. Multivariable Cox proportional hazards regression models were used to calculate the HRs and 95% CI of lung cancer risk by tertile of the four dietary index scores-the Health Eating Index (HEI)-2015, the Alternative Health Eating Index (AHEI)-2010, the Alternative Mediterranean Diet (AMED), and the Dietary Approach to Stop Hypertension (DASH)-Fung.

RESULTS

A higher DASH-Fung score was inversely associated with risk of lung cancer after adjusting for potential confounders (tertile three vs. tertile one: HR = 0.59 (0.38-0.93); p for trend = 0.07), and pinteraction with smoking was 0.46. Similar findings were observed among current smokers with the HEI-2015 score (tertile three vs. tertile one: HR = 0.22 (0.08-0.60): p for trend < 0.01), and pinteraction between smoking and the HEI-2015 score was 0.03.

CONCLUSION

In the GCS, consuming a diet more closely aligned with the DASH diet was associated with a reduced risk of lung cancer, which appeared to be independent of smoking status. There was also an inverse link between the HEI-2015 score and lung cancer risk among current smokers. Our finding is particularly important for the Middle East population, as diet may play an important role in cancer prevention and overall health.

Health, lifestyle and sociodemographic characteristics are associated with Brazilian dietary patterns: Brazilian National Health Survey

This study aimed to identify Brazilian dietary patterns and their associations with health, lifestyle and sociodemographic characteristics. Data from the Brazilian National Health Survey conducted in 2013 were used. A questionnaire was applied containing 22 items related to dietary consumption. Dietary patterns were determined through factor analysis (FA). Poisson regression models, with robust variance, were used to identify associations between dietary patterns and independents variables. Statistical significance was defined as p-value<0.05. Data were analysed for 60,202 adults (estimated population size: 146,308,458). FA identified three dietary patterns: healthy, protein, and western. The younger age group (18-24 years) had a lower adherence to the healthy pattern (PR:0.53; 95%CI:0.49-0.58) and greater adherence to the protein (PR:1.52; 95%CI:1.42-1.62) and western (PR:1.80; 95%CI:1.68-1.93) patterns compared to the elderly (≥60 years). Women had a greater association with the healthy pattern (PR:1.32; 95%CI:1.28-1.38) and lower association with the protein pattern (PR:0.80; 95%CI:0.77-0.82) compared to men. Illiterate participants showed lower adherence to the healthy (PR:0.58; 95%CI:0.53-0.63) and western (PR:0.54; 95%CI:0.48-0.62) patterns compared to those with higher educational levels. Smokers had lower adherence to the healthy (PR:0.76; 95%CI:0.71-0.81) and higher adherence to the protein (PR:1.14; 95%CI:1.11-1.19) patterns compared to non-smokers. Participants with poor/very poor self-rated health status had a lower adherence to the healthy (PR:0.79; 95%CI:0.73-0.86) and western (PR:0.81; 95%CI:0.73-0.89) patterns compared to those in a very good/good self-rated health status. Multimorbidity was positively associated with the healthy pattern (PR:1.18; 95%CI:1.11-1.26) and inversely associated with the protein pattern (PR:0.88; 95%CI:0.80-0.96) compared to participants without comorbidities. We suggest that strategies to promote healthy eating should consider health, lifestyle and sociodemographic characteristics in the Brazilian population.

Adherence to Prudent and Mediterranean Dietary Patterns Is Inversely Associated with Lung Cancer in Moderate But Not Heavy Male Polish Smokers: A Case-Control Study

Lung cancer is the most commonly diagnosed cancer in men worldwide. Studies regarding dietary patterns (DPs) and lung cancer are limited, with results remaining inconclusive, and the association of DPs with lung cancer in smokers is unclear. This study analyzed the associations between DPs, including the Polish-adapted Mediterranean diet (Polish-aMED) score, and lung cancer risk in Polish adult male smokers. This case-control study involved 439 men aged 45–80 years from northeastern Poland, including 187 newly diagnosed lung cancer cases. Dietary data was collected with a 62-item food frequency questionnaire (FFQ-6). Two approaches were applied to identify dietary patterns. The Polish-aMED score was calculated (hypothesis-driven approach) and a principal component analysis (PCA) was used to identify PCA-driven DPs (data-driven approach). A logistic regression analysis was performed to estimate the odds ratio (OR) and 95% confidence interval (95% CI) of the lung cancer risk associated with the adherence to DPs overall as well as for moderate (2.5–11 pack-years) and heavy (>11 pack-years) smokers. Among moderate smokers, the risk of lung cancer was lower by 41% (OR: 0.59; 95% CI: 0.39–0.90; p < 0.05; adjusted model) in the higher adherence to the prudent DP when compared to the lower adherence, and by 66% (OR: 0.34; 95% CI: 0.15–0.76; p < 0.05; adjusted model) in the high adherence (7–9 points) to the Polish-aMED score when compared to the low adherence (0–3 points). No significant association between the westernized traditional DP or the sweet dairy DP and lung cancer was revealed. In conclusion, the current study suggests that pro-healthy dietary patterns, including the Mediterranean pattern, may favour lower risk of lung cancer in moderate smokers, although it was not confirmed in heavy smokers.

Dietary patterns, BCMO1 polymorphisms, and primary lung cancer risk in a Han Chinese population: a case-control study in Southeast China

BACKGROUND

We investigated whether BCMO1 variants and dietary patterns are associated with lung cancer risk.

METHODS

Case-control study including 1166 lung cancer cases and 1179 frequency matched controls was conducted for three BCMO1 variants (rs6564851, rs12934922, and rs7501331) and four dietary patterns were investigated. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

The rs6564851, rs12934922, and rs7501331 were not found to be associated with lung cancer risk (P > 0.05). In multivariable-adjusted models, compared to the lowest quartile of the score on the "fruits and vegetables" pattern, the highest quintile was associated with a 78.4% decreased risk (OR _{Q4 vs. Q1} = 0.216; 95% CI, 0.164-0.284; P for trend < 0.001). Other patterns were not found the association. The "fruits and vegetables" pattern was associated with a reduced risk of lung cancer with all 3 SNPs irrespective of genotypes (all P for trend< 0.001). The association for the "Frugal" pattern was associated with increased risk of lung cancer among smokers (P for interaction = 0.005). The protective effects of the "cereals/wheat and meat" pattern was more evident for squamous cell carcinoma and other histological type.

CONCLUSIONS

We did not observe associations of BCMO1 variants and lung cancer. Diets rich in fruits and vegetables may be protective against lung cancer.

Is folic acid safe for non-muscle-invasive bladder cancer patients? An evidence-based cohort study

Background

Patients with cancer are highly concerned about food choices and dietary supplements that may affect their treatment outcomes. Excess folic acid (synthetic folate) from supplements or fortification can lead to accumulation of unmetabolized folic acid in the systemic circulation and urine and may promote cancer growth, especially among those with neoplastic alterations.

Objective

We investigated the prospective association between synthetic compared with natural folate intake and clinical outcomes in non-muscle-invasive bladder cancer (NMIBC), which is a highly recurrent disease.

Design

In a cohort of 619 NMIBC patients, folate intake at diagnosis was assessed with a previously validated food-frequency questionnaire and categorized according to tertiles. After a median follow-up of 5.2 y, 303 tumor recurrence and 108 progression events were documented from medical record review. Multivariable Cox proportional hazards and logistic models were used to estimate adjusted HRs and ORs with 95% CIs.

Results

Synthetic folic acid intake was positively associated with a risk of recurrence among NMIBC patients (medium compared with low intake-HR: 1.72; 95% CI: 1.20, 2.48; P = 0.003; high compared with low intake-HR: 1.80; 95% CI: 1.14, 2.84; P = 0.01). Patients with a higher folic acid intake were more likely to have multifocal tumors at diagnosis (medium or high compared with low-OR: 2.08; 95% CI: 1.08, 4.02; P = 0.03). In contrast, natural folate intake tended to be inversely associated with the risk of progression (medium or high compared with low-HR: 0.68; 95% CI: 0.44, 1.04; P = 0.08).

Conclusions

A high intake of synthetic folic acid, in contrast to the natural forms, is associated with an increased risk of recurrence in NMIBC and multifocal tumors at diagnosis, which suggests that folic acid may be unsafe for NMIBC patients. These findings provide some evidence for nutritional consultation with regard to folate intake among NMIBC patients.

Dietary patterns and risk of recurrence and progression in non-muscle-invasive bladder cancer

The association of dietary factors with urinary bladder cancer prognosis has scarcely been investigated, and results of studies conducted to date are inconsistent. We investigated whether empirically derived dietary patterns are associated with risks of recurrence and progression in non-muscle-invasive bladder cancer (NMIBC) patients. Data from 595 newly diagnosed NMIBC patients from an ongoing prospective cohort study were used to derive dietary patterns using exploratory factor analysis. Factor scores were calculated and then categorized in sex-specific tertiles. Multivariable-adjusted proportional hazards regression models were used to estimate hazard ratios and 95% confidence intervals for the associations between tertiles of adherence to the dietary patterns and risks of recurrence and progression. We identified four dietary patterns: "fruits and vegetables," "Western," "low-fat," and "Tex-Mex." Patients in the highest tertile of adherence to the Western pattern experienced a 1.48 times higher risk of recurrence (95% CI 1.06-2.06) compared to patients in the lowest tertile. No statistically significant associations of a Western diet with risk of progression or of the other dietary patterns with risk of recurrence and progression were found. Overall, we found that adherence to a Western diet was associated with a higher risk of recurrence but further studies are needed to confirm our findings.

[Study on Effects and Mechanisms of Phytochemicals in Vegetables and Fruits in Preventing and Treating Lung Cancer]

无论是在全球还是我国，肺癌都是严重危害人类健康的恶性肿瘤。研究表明肺癌与环境因素以及生活方式密切相关，流行病学发现多吃蔬菜水果可以预防肺癌。蔬菜水果中含有丰富的植物化学物质，如异硫氰酸酯类、吲哚类、黄酮类等。这些植物化学物质通过调节与抗肿瘤相关的通路从而抑制肿瘤细胞增殖、诱导肿瘤细胞凋亡，降低肺癌发生的危险性。本文旨在对蔬菜水果中的植物化学物质在肺癌发生发展中的作用机制进行综述，为更好地预防和治疗肺癌提供理论依据与方向。