Dietary mineral intake and lung cancer risk: the Rotterdam Study

The interaction effects of zinc and polygenic risk score with benzo[a]pyrene exposure on lung cancer risk: A prospective case-cohort study among Chinese populations

The relationship of exposure to benzo[a]pyrene (BaP) with lung cancer risk has been firmly established, but whether this association could be modified by other environmental or genetic factors remains to be explored. To investigate whether and how zinc (Zn) and genetic predisposition modify the association between BaP and lung cancer, we performed a case-cohort study with a 5.4-year median follow-up duration, comprising a representative subcohort of 1399 participants and 359 incident lung cancer cases. The baseline concentrations of benzo[a]pyrene diol epoxide-albumin adduct (BPDE-Alb) and Zn were quantified. We also genotyped the participants and computed the polygenic risk score (PRS) for lung cancer. Our findings indicated that elevated BPDE-Alb and PRS were linked to increased lung cancer risk, with the HR (95%CI) of 1.54 (1.36, 1.74) per SD increment in ln-transformed BPDE-Alb and 1.27 (1.14, 1.41) per SD increment in PRS, but high plasma Zn level was linked to a lower lung cancer risk [HR (95%CI)=0.77 (0.66, 0.91) per SD increment in ln-transformed Zn]. There was evidence of effect modification by Zn on BaP-lung cancer association (P for multiplicative interaction = 0.008). As Zn concentrations increased from the lowest to the highest tertile, the lung cancer risk per SD increment in ln-transformed BPDE-Alb decreased from 2.07 (1.48, 2.89) to 1.33 (0.90, 1.95). Additionally, we observed a significant synergistic interaction of BPDE-Alb and PRS [RERI (95%CI) = 0.85 (0.03, 1.67)], with 42% of the incident lung cancer cases among individuals with high BPDE-Alb and high PRS attributable to their additive effect [AP (95%CI) = 0.42 (0.14, 0.69)]. This study provided the first prospective epidemiological evidence that Zn has protective effect against BaP-induced lung tumorigenesis, whereas high genetic risk can enhance the harmful effect of BaP. These findings may provide novel insight into the environment-environment and environment-gene interaction underlying lung cancer development, which may help to develop prevention and intervention strategies to manage BaP-induced 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.

Iron homeostasis in older adults: balancing nutritional requirements and health risks

Iron plays a crucial role in many physiological processes, including oxygen transport, bioenergetics, and immune function. Iron is assimilated from food and also recycled from senescent red blood cells. Iron exists in two dietary forms: heme (animal based) and non-heme (mostly plant based). The body uses iron for metabolic purposes, and stores the excess mainly in splenic and hepatic macrophages. Physiologically, iron excretion in humans is inefficient and not highly regulated, so regulation of intestinal absorption maintains iron homeostasis. Iron losses occur at a steady rate via turnover of the intestinal epithelium, blood loss, and exfoliation of dead skin cells, but overall iron homeostasis is tightly controlled at cellular and systemic levels. Aging can have a profound impact on iron homeostasis and induce a dyshomeostasis where iron deficiency or overload (sometimes both simultaneously) can occur, potentially leading to several disorders and pathologies. To maintain physiologically balanced iron levels, reduce risk of disease, and promote healthy aging, it is advisable for older adults to follow recommended daily intake guidelines and periodically assess iron levels. Clinicians can evaluate body iron status using different techniques but selecting an assessment method primarily depends on the condition being examined. This review provides a comprehensive overview of the forms, sources, and metabolism of dietary iron, associated disorders of iron dyshomeostasis, assessment of iron levels in older adults, and nutritional guidelines and strategies to maintain iron balance in older adults.

Steady-State Delivery and Chemical Modification of Food Nutrients to Improve Cancer Intervention Ability

Cancer is a crucial global health problem, and prevention is an important strategy to reduce the burden of the disease. Daily diet is the key modifiable risk factor for cancer, and an increasing body of evidence suggests that specific nutrients in foods may have a preventive effect against cancer. This review summarizes the current evidence on the role of nutrients from foods in cancer intervention. It discusses the potential mechanisms of action of various dietary components, including phytochemicals, vitamins, minerals, and fiber. The findings of epidemiological and clinical studies on their association with cancer risk are highlighted. The foods are rich in bioactive compounds such as carotenoids, flavonoids, and ω-3 fatty acids, which have been proven to have anticancer properties. The effects of steady-state delivery and chemical modification of these food's bioactive components on anticancer and intervention are summarized. Future research should focus on identifying the specific bioactive compounds in foods responsible for their intervention effects and exploring the potential synergistic effects of combining different nutrients in foods. Dietary interventions that incorporate multiple nutrients and whole foods may hold promise for reducing the risk of cancer and improving overall health.

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

BACKGROUND

Evidence on the potential association between dietary copper intake and gastric cancer (GC) is lacking. Thus, we aimed to evaluate this association within the Stomach cancer Pooling (StoP) Project-an international consortium of epidemiological studies on GC.

METHODS

Data from five case-control studies within the StoP Project were included (2448 cases, 4350 controls). We estimated adjusted odds ratios (ORs) and 95% CIs for the association between dietary copper intake and GC using multivariable mixed-effects logistic regression models. We also modelled the dose-response relationship between copper intake and GC using a logistic mixed-effects model with fractional polynomial.

RESULTS

The OR for the highest quartile of copper intake compared with the lowest one was 0.78 (95% CI: 0.63-0.95; P for trend = 0.013). Results were similar for non-cardia-type (OR: 0.72; 95% CI: 0.57-0.91), intestinal-type (OR: 0.75; 95% CI: 0.56-0.99) and other histological-type GC (OR: 0.65; 95% CI: 0.44-0.96). The dose-response analysis showed a steep decrease in ORs for modest intakes (<1 mg/day), which were subsequently steady for ≤3 mg/day (OR: 0.09; 95% CI: 0.02-0.41) and slowly increased for higher intakes.

CONCLUSIONS

The findings of our large study suggest that copper intake might be inversely associated with GC, although their confirmation by prospective studies is required.

Copper and Melanoma Risk: Results from NHANES 2007-2018 and Mendelian Randomization Analyses

Copper is an essential trace element obtained from food. There is a paucity of observational or prospective studies that have investigated the relationship between copper and melanoma risk. Copper serves as a cofactor for pivotal enzymes involved in mitochondrial respiration, antioxidant defense, and neurotransmitter synthesis. Undoubtedly, copper plays an indispensable role in the initiation and progression of tumors, particularly melanoma; however, further investigations are warranted to elucidate the underlying mechanisms linking copper and melanoma risk. Given the availability of dietary copper and serum copper data in the NHANES database, we conducted an investigation into the association between dietary copper intake and serum copper levels with melanoma risk. We enrolled 26,401 individuals with dietary copper data in the 2007-2018 NHANES database. To mitigate confounding variables, a propensity score matching (PSM) was performed. To assess the association between dietary copper intake and melanoma risk, we employed a multivariate logistic regression analysis before and after PSM. The restricted cubic spline analysis was utilized to determine whether there is a non-linear relationship between dietary copper intake and melanoma risk, with subgroup analysis conducted to determine beneficiaries. Then, those with blood copper data from the enrolled population with dietary copper intake were screened out, and subsequently, multivariate logistic regression models were subsequently constructed to investigate the association between serum copper levels and melanoma risk after PSM. Mendelian analysis was further utilized to validate the results of the NHANES database using serum copper as the exposure factor and melanoma as the outcome variable. The study found that melanoma risk was associated with dietary copper intake before and after PSM, demonstrated by multiple logistic regression. The relationship between dietary copper intake and melanoma risk was non-linear, with a reduced risk observed above approximately 2.5 mg/day, as shown by the RCS. The evidence suggests that an increased intake of copper is linked to a decreased risk of melanoma. To clarify the mechanism behind the increased risk of melanoma due to higher dietary copper intake, we analyzed the population data from the NHANES database on serum copper and dietary copper intake. Our results indicated that there is no causal relationship between serum copper and melanoma risk. Mendelian randomization analysis of multi-database data sources confirmed the conclusion of the NHANES database analysis. Dietary copper is a protective factor against melanoma, and serum copper or blood copper is not associated with melanoma risk. This suggests that serum or blood copper is not responsible for the protective effect of dietary copper intake on melanoma risk, and the mechanisms need to be further investigated.

Distinct functions between ferrous and ferric iron in lung cancer cell growth

Accumulating evidence suggests an association between iron metabolism and lung cancer progression. In biological systems, iron is present in either reduced (Fe2+ ; ferrous) or oxidized (Fe3+ ; ferric) states. However, ferrous and ferric iron exhibit distinct chemical and biological properties, the role of ferrous and ferric iron in lung cancer cell growth has not been clearly distinguished. In this study, we manipulated the balance between cellular ferrous and ferric iron status by inducing gene mutations involving the FBXL5-IRP2 axis, a ubiquitin-dependent regulatory system for cellular iron homeostasis, and determined its effects on lung cancer cell growth. FBXL5 depletion (ferrous iron accumulation) was found to suppress lung cancer cell growth, whereas IRP2 depletion (ferric iron accumulation) did not suppress such growth, suggesting that ferrous iron but not ferric iron plays a suppressive role in cell growth. Mechanistically, the depletion of FBXL5 impaired the degradation of the cyclin-dependent kinase inhibitor, p27, resulting in a delay in the cell cycle at the G1/S phase. FBXL5 depletion in lung cancer cells also improved the survival of tumor-bearing mice. Overall, this study highlights the important function of ferrous iron in cell cycle progression and lung cancer cell growth.

Curcumin Analog, HO-3867, Induces Both Apoptosis and Ferroptosis via Multiple Mechanisms in NSCLC Cells with Wild-Type p53

Over the last decade, researchers have paid more and more attention to the natural compound curcumin for its potential application in anticancer therapy. However, the application of curcumin has been limited owing to its rapid metabolism in the body. HO-3867, a stable curcumin analog, shows potent antitumor activities against various tumor cells. Yet, information on HO-3867's impact on non-small-cell lung cancer (NSCLC) cells is lacking. Herein, we evaluated the cytotoxicity of HO-3867 in NSCLC cells. We discovered that HO-3867 suppressed the viability of NSCLC cells containing wild-type p53. In NSCLC cells, HO-3867 promotes both apoptosis and ferroptosis, the latter of which is a newly discovered mode of cell death. Mechanically, HO-3867-induced apoptosis relied on the inhibition of Mcl-1 and Bcl-2 and the upregulation of Bax. Moreover, NSCLC cells undergo ferroptosis when treated with HO-3867 via activating the p53-DMT1 axis and suppressing GPX4. Additionally, HO-3867 caused an accumulation of reactive oxygen species (ROS) in NSCLC in a way that was dependent on the presence of iron. Our findings point to the possibility that HO-3867 might be employed as a therapeutic agent for treating NSCLC.

Association between Dietary and Supplemental Antioxidants Intake and Lung Cancer Risk: Evidence from a Cancer Screening Trial

Previous studies provided inconsistent results on the effects of antioxidant nutrient intake on lung cancer prevention. We aimed to evaluate the association between antioxidant consumption from food and supplemental sources and lung cancer incidence. Data were obtained from the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial. A total of 98,451 participants were included in the data analysis. We used a multivariable Cox proportional hazards regression model to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between antioxidant intake and lung cancer risk. Dose-response assessments for individual nutrients were conducted. We also selected the model for the best combination of antioxidants for reducing lung cancer risk using machine learning methods. After the median follow-up of 12.2 years, 1642 new cases were identified. Intake of the calculated HRs indicated a trend for a higher quartile of food-based Composite Dietary Antioxidant Index (fCDAI) associated with a lower lung cancer risk after adjusting for covariates (HR_Q4vs.Q1 = 0.64, 95% CI: 0.52, 0.79; P for trend < 0.001). Protective effects of dietary antioxidant intake were observed across all individual antioxidant micronutrients except magnesium. Random forests model suggested the dietary intake group of α-carotene, magnesium, vitamin C, vitamin E, lycopene, selenium, lutein, and zeaxanthin, and β-carotene had the most favorable effects on lung cancer prevention. Higher consumption of antioxidants from food sources has a protective effect against lung cancer, while no effects were shown in the supplemental group. It is recommended to consume a combination of various antioxidants due to the potential benefits from the interaction, while more research should be performed to investigate the underlying mechanisms of antioxidant synergic effects on lung cancer risk reduction.

Trabectedin induces ferroptosis via regulation of HIF-1α/IRP1/TFR1 and Keap1/Nrf2/GPX4 axis in non-small cell lung cancer cells

BACKGROUND AND OBJECTIVES

Non-small cell lung cancer (NSCLC) is a global health concern. NSCLC treatment outcomes are generally poor due to treatment resistance or toxicity. Ferroptosis is a novel cell death triggered by iron accumulation, reactive oxygen species (ROS), and lipid peroxidation. Ferroptosis may kill cancer cells, particularly those resistant to apoptosis.

MATERIALS AND METHODS

The Cell Counting Kit-8 assay assessed NSCLC cell viability after trabectedin treatment. Flow cytometry with Annexin V-FITC staining evaluated cell death. ROS, iron, lipid peroxidation, and GSH levels were measured using commercial kits. qRT-PCR and western blots evaluated messenger RNA and protein levels. Proteins were inhibited using short interfering RNA transfection and specific inhibitors.

RESULTS

Trabectedin was cytotoxic to NSCLC cells regardless of p53 status. Trabectedin upregulated iron, ROS, and lipid peroxidation in NSCLC cells, causing ferroptosis. Trabectedin increases iron and ROS levels by upregulating transferrin receptor 1 and the HIF-1/IRP1 axis. In NSCLC cells, trabectedin suppresses glutathione peroxidase 4, followed by the Keap1/Nrf2 axis.

CONCLUSIONS

Our findings imply that trabectedin may treat NSCLC effectively.

Dietary Antioxidants and Lung Cancer Risk in Smokers and Non-Smokers

Smoking is considered a major risk factor in the development of lung diseases worldwide. Active smoking and secondhand (passive) smoke (SHS) are related to lung cancer (LC) risk. Oxidative stress (OS) and/or lipid peroxidation (LP) induced by cigarette smoke (CS) are found to be involved in the pathogenesis of LC. Meta-analyses and other case-control/prospective cohort studies are inconclusive and have yielded inconsistent results concerning the protective role of dietary vitamins C and E, retinol, and iron intake against LC risk in smokers and/or non-smokers. Furthermore, the role of vitamins and minerals as antioxidants with the potential in protecting LC cells against CS-induced OS in smokers and non-smokers has not been fully elucidated. Thus, this review aims to summarize the available evidence reporting the relationships between dietary antioxidant intake and LC risk in smokers and non-smokers that may be used to provide suggestions for future research.

Role of iron biomarkers and iron intakes in lung cancer risk: A systematic review and meta-analysis

BACKGROUND

The role of iron biomarkers and iron intake in the susceptibility to lung cancer is unclear. The purpose of this study was to conduct a systematic review and meta-analysis, to assess the relationship between iron levels in the body or iron intake and the risk of lung cancer.

METHOD

This review is registered with PROSPERO (number CRD 42020199776). PubMed, Web of Science, Scopus, Embase and Cochrane were used to search for studies assessing the relationship between iron and lung cancer, up to July 15, 2021. Qualitative and quantitative analysis was carried out to determine if there was a correlation between iron biomarkers/intakes and the risk of lung cancer.

RESULT

Twenty articles were included. Pooled analyses demonstrated that serum ferritin concentrations and transferrin saturation (TSAT) were significantly higher in patients with lung cancer than in healthy controls (ferritin: standardized mean differences [SMD], 0.235, 95% confidence interval [CI], 0.129, 0.341, I² = 32.1 %; TSAT: SMD, 0.07, 95 % CI, 0.018, 0.121, I² = 0 %). In contrast, serum transferrin concentrations were significantly lower in patients with lung cancer than in healthy controls (SMD, -0.591, 95 % CI, -1.18, -0.003, I² = 87.7 %). No significant effects of serum iron, lung tissue iron, bronchoalveolar lavage fluid (BALF) ferritin, or iron intake (total iron, dietary iron, heme iron, or non-heme iron) were found on lung cancer incidence.

CONCLUSION

Among the different iron biomarkers analyzed, a trend in association was only detected with serum ferritin, TSAT and transferrin concentration and no associations were found between iron intakes and the risk of lung cancer. However, more prospective studies are needed to strengthen the current evidence.

Emergence of nutrigenomics and dietary components as a complementary therapy in cancer prevention

Cancer is an illness characterized by abnormal cell development and the capability to infiltrate or spread to rest of the body. A tumor is the term for this abnormal growth that develops in solid tissues like an organ, muscle, or bone and can spread to other parts of the body through the blood and lymphatic systems. Nutrition is a critical and immortal environmental component in the development of all living organisms encoding the relationship between a person's nutrition and their genes. Nutrients have the ability to modify gene expression and persuade alterations in DNA and protein molecules which is researched scientifically in nutrigenomics. These interactions have a significant impact on the pharmacokinetic properties of bioactive dietary components as well as their site of action/molecular targets. Nutrigenomics encompasses nutrigenetics, epigenetics, and transcriptomics as well as other "omic" disciplines like proteomics and metabolomics to explain the vast disparities in cancer risk among people with roughly similar life style. Clinical trials and researches have evidenced that alternation of dietary habits is potentially one of the key approaches for reducing cancer risk in an individual. In this article, we will target how nutrigenomics and functional food work as preventive therapy in reducing the risk of cancer.

Investigating Causal Associations of Circulating Micronutrients Concentrations with the Risk of Lung Cancer: A Mendelian Randomization Study

Previous observational studies have suggested that the effect of diet-derived circulating micronutrient concentrations on lung cancer (LC) risk is controversial. We conducted a two-sample Mendelian randomization (MR) analysis to investigate the causal relationship between circulating micronutrient concentrations and the overall risk of LC and three LC subtypes (namely lung adenocarcinoma (LA), squamous cell lung cancer (SqCLC), and small cell lung cancer (SCLC)). The instrumental variables (IVs) of 11 micronutrients (beta-carotene, calcium, copper, folate, lycopene, magnesium, phosphorus, retinol, selenium, zinc, and vitamin B6) were screened from the published genome-wide association studies (GWAS). Summary statistics related to LC and its subtypes came from the largest meta-analysis, including 29,266 cases and 56,450 controls. Inverse-variance weighted (IVW) method is used as the main MR analysis, and the sensitivity analysis is carried out to ensure the MR assumptions. This MR study found suggestive evidence that genetically predicted 6 circulating micronutrient concentrations was correlated with the risk of overall LC (odds ratio (OR): 1.394, 95% confidence interval (CI): 1.041–1.868, p = 0.026, phosphorus), LA (OR: 0.794, 95% CI: 0.634–0.995, p = 0.045, beta-carotene; OR: 0.687, 95%CI: 0.494–0.957, p = 0.026, calcium), SqCLC (OR: 0.354, 95% CI: 0.145–0.865, p = 0.023, retinol), and SCLC (OR: 1.267, 95% CI: 1.040–1.543, p = 0.019, copper; OR: 0.801, 95% CI: 0.679–0.944, p = 0.008, zinc). We found no evidence that other micronutrients are associated with the risk of overall LC or its subtypes. Our study suggested that the increase in circulating beta-carotene, calcium, retinol, and zinc concentration may reduce the risk of LC; the increase in circulating copper and phosphorus concentration may be related to the increased risk of LC. In the future, larger replication samples of LC genetic data and larger micronutrient-related GWAS will be needed to verify our findings.

Metabolic linkages between zinc exposure and lung cancer risk: A nested case-control study

Epidemiologic studies have suggested that elevated concentrations of zinc are associated with a decreased risk of lung cancer, but the underlying mechanisms remain to be investigated. The metabolites are highly sensitive to environmental stress, which will help to reveal the linkages between zinc exposure and lung cancer risk. We designed a nested case-control study including 101 incident lung cancer cases and 1:2 age- and sex-frequency-matched 202 healthy controls from the Dongfeng-Tongji (DFTJ) cohort. Their plasma level of zinc was determined by using inductively coupled plasma-mass spectrometry (ICP-MS) and plasma profiles of metabolites were detected by using an untargeted metabolomics approach. The generalized linear models (GLM) were applied to assess the associations of plasma zinc with metabolites, and the mediation effects of zinc-related metabolites on zinc-lung cancer association were further testified. The concentrations of 55 metabolites had linear dose-response relationships with plasma zinc at a false discovery rate (FDR) < 0.05, among which L-proline, phosphatidylcholine (PC, 34:2), phosphatidylethanolamine (PE, O-36:5), L-altrose, and sphingomyelin (SM, 40:3) showed different levels between lung cancer cases and healthy controls (fold change = 0.92, 0.95, 1.07, 0.90, and 1.08, respectively, and all P < 0.05). The plasma concentration of SM(40:3) was negatively associated with incident risk of lung cancer [OR(95%CI) = 0.71(0.55, 0.91), P = 0.007] and could mediate 41.7% of the association between zinc and lung cancer risk (P = 0.004). Moreover, compared to the traditional factors, addition of SM(40:3) exerted improved prediction performance for incident risk of lung cancer [AUC(95%CIs) = 0.714(0.654, 0.775) vs. 0.663(0.600, 0.727), P = 0.030]. Our findings revealed metabolic profiles with zinc exposure and provide new insight into the alternations of metabolites underpinning the links between zinc exposure and lung cancer development.

Epigenome-wide DNA methylation signature of plasma zinc and their mediation roles in the association of zinc with lung cancer risk

Essential trace element zinc is associated with decreased lung cancer risk, but underlying mechanisms remain unclear. This study aimed to investigate role of DNA methylation in zinc-lung cancer association. We conducted a case-cohort study within prospective Dongfeng-Tongji cohort, including 359 incident lung cancer cases and a randomly selected sub-cohort of 1399 participants. Epigenome-wide association study (EWAS) was used to examine association of plasma zinc with DNA methylation in peripheral blood. For the zinc-related CpGs, their mediation effects on zinc-lung cancer association were assessed; their diagnostic performance for lung cancer was testified in the case-cohort study and further validated in another 126 pairs of lung cancer case-control study. We identified 28 CpGs associated with plasma zinc at P < 1.0 × 10^-5 and seven of them (cg07077080, cg01077808, cg17749033, cg15554270, cg26125625, cg10669424, and cg15409013 annotated to GSR, CALR3, SLC16A3, PHLPP2, SLC12A8, VGLL4, and ADAMTS16, respectively) were associated with incident risk of lung cancer. Moreover, the above seven CpGs were differently methylated between 126 pairs of lung cancer and adjacent normal lung tissues and had the same directions with EWAS of zinc. They could mediate a separate 7.05%∼22.65% and a joint 29.42% of zinc-lung cancer association. Compared to using traditional factors, addition of methylation risk score exerted improved discriminations for lung cancer both in case-cohort study [area under the curve (AUC) = 0.818 vs. 0.738] and in case-control study (AUC = 0.816 vs. 0.646). Our results provide new insights for the biological role of DNA methylation in the inverse association of zinc with incident lung cancer.

Ferroptosis and Its Potential Role in Lung Cancer: Updated Evidence from Pathogenesis to Therapy

Lung cancer is characterized by high morbidity and mortality rates, and its occurrence is associated with many types of cell death. As a new form of regulated cell death, ferroptosis is an iron- dependent pattern of cell death and characterized by lethal accumulation of lipid-based reactive oxygen species (ROS), which is different from apoptosis, necrosis and autophagy at both the morphological and biochemical levels. It plays an important role in the development of lung cancer and induction of ferroptosis in lung cancer cells has become a new strategy for anti- lung cancer treatment. However, a few reviews summarized ferroptosis and its role in lung cancer has not been elucidated, and the precise mechanism of ferroptosis modeling lung cancer has not yet been revealed till date. Herein, we review the latest literature on the process of ferroptosis regarding lung cancer, including basic molecular or biology mechanistic studies both in vivo and in vitro, as well as human studies with a more translational or clinical approach. This review provides a practical, concise and updated outline on the mechanisms and therapeutic strategies in lung cancer with ferroptosis alterations. Looking ahead, further studies are required to uncover the possible modulatory relationship between ferroptosis and lung cancer.

Causal associations between dietary antioxidant vitamin intake and lung cancer: A Mendelian randomization study

Background

Oxidative stress is currently considered to be closely related to the occurrence of respiratory tumors, especially lung cancer. Many observational studies have shown that increased antioxidant intake can reduce the risk of lung cancer, but the results are still controversial. Therefore, we performed a two-sample Mendelian randomized (MR) analysis to clarify the causal relationship between antioxidant vitamins and lung cancer.

Methods

To assess the causal effect of dietary antioxidant vitamin intake on lung cancer, we conducted a two-sample MR analysis and we extracted single-nucleotide polymorphisms (SNPs) that are associated with antioxidants from genome-wide association studies (GWASs) of the UK biobank. We gathered summary data for lung cancer from the International Lung Cancer Consortium (ILCCO), including 11,348 cases and 15,861 controls, and applied the inverse-variance weighted (IVW) method as the primary MR analysis, and performed a sensitivity analysis to verify the results.

Results

The results showed that higher dietary retinol intake was causally associated with lung cancer overall [odds ratio (OR) = 1.844, 95% CI, 1.359-2.502, p = 0.00009], squamous cell lung cancer (OR = 2.162, 95% CI, 1.117-4.183, p = 0.022), and lung adenocarcinoma (OR = 1.706, 95% CI, 1.084-2.685, p = 0.021). Additionally, carotene was positively correlated with lung adenocarcinoma (OR = 1.510, 95% CI, 1.002-2.276, p = 0.049). However, there was a non-significant relationship between the intake of other dietary antioxidants (vitamin C and vitamin E) and lung cancer.

Conclusion

Our research showed that dietary retinol intake has an adverse impact on lung cancer, and carotene might increase the risk of adenocarcinoma. This highlights the importance of revealing the underlying mechanisms of dietary antioxidant vitamins in lung cancer and delivers an important health message that dietary antioxidant vitamin intake may not be necessary for the prevention of lung cancer. It also provides a basis for future research.

Trace elements under the spotlight: A powerful nutritional tool in cancer

Cancer is the second leading cause of death worldwide. Research on the relationships between trace elements (TE) and the development of cancer or its prevention is a field that is gaining increasing relevance. This review provides an evaluation of the effects of TE (As, Al, B, Cd, Cr, Cu, F, I, Pb, Li, Mn, Hg, Mo, Ni, Se, Si, Sn, V and Zn) intake and supplementation in cancer risk and prevention, as well as their interactions with oncology treatments. Advancements in the knowledge of TE, their dietary interactions and their main food sources can provide patients with choices that will help them to improve their quality of life and therapy outcomes. This approach could open new opportunities for treatments based on the integration of conventional therapies (chemotherapy, radiotherapy, and immunotherapy) and dietary interventions that provide advanced personalized treatments.

The association of minerals intake in three meals with cancer and all-cause mortality: the U.S. National Health and Nutrition Examination Survey, 2003-2014

BACKGROUND

Intake time of diet has recently been demonstrated to be associated with the internal clock and circadian pattern. However, whether and how the intake time of minerals would influence the natural course of cancer was largely unknown.

METHODS

This study aimed to assess the association of mineral intake at different periods with cancer and all-cause mortality. A total of 27,455 participants aged 18-85 years old in the National Health and Nutrition Examination Survey were recruited. The main exposures were the mineral intakes in the morning, afternoon and evening, which were categorized into quintiles, respectively. The main outcomes were mortality of cancer and all causes.

RESULTS

During the 178,182 person-years of follow-up, 2680 deaths, including 601 deaths due to cancer, were documented. After adjusting for potential confounders, compared to the participants who were in the lowest quintile(quintile-1) of mineral intakes at dinner, the participants in the highest quintile intake(quintile-5) of dietary potassium, calcium and magnesium had lower mortality risks of cancer (HRpotassium = 0.72, 95% CI:0.55-0.94, P for trend = 0.023; HRcalcium = 0.74, 95% CI:0.57-0.98, P for trend = 0.05; HRmagnesium = 0.75, 95% CI:0.56-0.99, P for trend = 0.037) and all-cause (HRpotassium = 0.83, 95% CI:0.73-0.94, P for trend = 0.012; HRcalcium = 0.87, 95% CI:0.76-0.99, P for trend = 0.025; HRmagnesium = 0.85, 95% CI:0.74-0.97, P for trend = 0.011; HRcopper = 0.80, 95%CI: 0.68-0.94, P for trend = 0.012). Further, equivalently replacing 10% of dietary potassium, calcium and magnesium consumed in the morning with those in the evening were associated with lower mortality risk of cancer (HRpotassium = 0.94, 95%CI:0.91-0.97; HRcalcium = 0.95, 95%CI:0.92-0.98; HRmagnesium = 0.95, 95%CI: 0.92-0.98).

CONCLUSIONS

This study demonstrated that the optimal intake time of potassium, calcium and magnesium for reducing the risk of cancer and all-cause mortality was in the evening.

Are trace element concentrations suitable biomarkers for the diagnosis of cancer?

Despite advances in cancer research, cancer is still one of the leading causes of death worldwide. An early diagnosis substantially increases the survival rate and treatment success. Thus, it is important to establish biomarkers which could reliably identify cancer patients. As cancer is associated with changes in the systemic trace element status and distribution, serum concentrations of selenium, iron, copper, and zinc could contribute to an early diagnosis. To test this hypothesis, case control studies measuring trace elements in cancer patients vs. matched controls were selected and discussed focusing on lung, prostate, breast, and colorectal cancer. Overall, cancer patients had elevated serum copper and diminished zinc levels, while selenium and iron did not show consistent changes for all four cancer types. Within the tumor tissue, mainly copper and selenium are accumulating. Whether these concentrations also predict the survival probability of cancer patients needs to be further investigated.

Dietary acid load and lung cancer risk: A case-control study in men

BACKGROUND

Dysregulation of the endogenous acid-base balance can contribute to inflammation and cancer development if metabolic acidosis is sustained. The epidemiologic evidence on the association between diet-dependent acid load and cancer risk is scarce and inconsistent. We aim to explore the possible role of dietary acid load in lung cancer (LC) risk.

METHODS

A case-control study was performed on 843 LC cases and 1466 controls by using a multi-topic questionnaire, including a food frequency questionnaire. Controls were matched to cases by age-frequency, urban/rural residence, and region. Food-derived nutrients were calculated from available databases. The dietary acid load was calculated using validated measures as potential renal acid load (PRAL) score and net endogenous acid production (NEAP) score. Odds ratios (ORs) were estimated by logistic regression.

RESULTS

We found direct associations between dietary acid load and LC risk. The highest quartile of the NEAP score was significantly associated (OR=2.22, p_trend<0.001). The PRAL score displayed similar associations in simpler regression models, but there was no association when a more complex one was used (OR=0.99, p_trend =0.94). The NEAP score was associated with a significant risk increase in all cell types, except for small cell cancers, but the PRAL score did not show any association.

CONCLUSIONS

The NEAP scores, directly associated with meat intake and inversely associated with plant-based foods intake, suggest that a high acid load dietary style may increase LC risk. Studies focused on food groups, and nutritional patterns are in line with our findings. Although the data shown here represent the first one to be published on this issue, further studies are needed to confirm these findings.

Integrative Treatment of Lung Cancer Patients: Observational Study of 57 Cases

Introduction A retrospective clinical study was performed to identify the characteristics of patients with lung cancer treated with integrative cancer treatment in addition to conventional medicine.

Materials and Methods We reviewed medical records for lung cancer patients who visited a single integrative setting in Rome, Italy. A total of 57 patients were included, and the majority had advanced-stage cancer. All of them underwent integrative therapy with nutrition and phytotherapy indications. The diet was designed to reduce most of possible factors promoting cancer proliferation, inflammation, and obesity. Foods with anti-inflammatory, prebiotic, antioxidant, and anticancer properties had been chosen. Herbal supplements with known effects on lung cancer were prescribed. In particular, astragal, apigenine, fucosterol, polydatin, epigallocatechin gallate, cannabis, curcumin, and inositol were used. Furthermore, medical mushrooms and other substances were used to improve the immune system and to reduce chemotherapy side effects. Five key parameters have been evaluated for 2 years starting at the first surgery: nutritional status, immune status, discontinuation of therapy, quality of life, and prognosis of the disease.

Results A relevant improvement in parameters relative to nutritional status, immune status, and quality of life has been observed after integrative therapy compared with the same parameters at the first medical visit before starting such approach.

Conclusion The results suggest that integrative therapy may have benefits in patients with lung cancer. Even though there are limitations, the study suggests that integrative therapy could improve nutritional status and quality of life, with possible positive effect on overall survival.

Red and processed meat consumption and cancer outcomes: Umbrella review

The purpose of this umbrella review was to evaluate the quality of evidence, validity and biases of the associations between red and processed meat consumption and multiple cancer outcomes according to existing systematic reviews and meta-analyses. The umbrella review identified 72 meta-analyses with 20 unique outcomes for red meat and 19 unique outcomes for processed meat. Red meat consumption was associated with increased risk of overall cancer mortality, non-Hodgkin lymphoma (NHL), bladder, breast, colorectal, endometrial, esophageal, gastric, lung and nasopharyngeal cancer. Processed meat consumption might increase the risk of overall cancer mortality, NHL, bladder, breast, colorectal, esophageal, gastric, nasopharyngeal, oral cavity and oropharynx and prostate cancer. Dose-response analyses revealed that 100 g/d increment of red meat and 50 g/d increment of processed meat consumption were associated with 11%-51% and 8%-72% higher risk of multiple cancer outcomes, respectively, and seemed to be not correlated with any benefit.

Association between aspirin use and lung cancer incidence depends on high-frequency use, bodyweight, and age in U.S. adults

Background

Chemoprevention of cancer with aspirin is controversial as a primary prevention strategy. We sought to investigate the association between aspirin frequency and risk of lung cancer in The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

Methods

Using data from 101,722 participants in PLCO, we used a Cox regression model coupling with propensity score to detect the association between aspirin frequency and lung cancer risk.

Results

High-frequency aspirin use significantly increased risk of lung cancer by 28% compared to no use (HR =1.28; 95% CI, 1.14–1.45; P=3.37×10⁻⁵), especially for current smoker (HR =1.30; 95% CI, 1.07–1.57; P=6.82×10⁻³). However, the increased lung cancer risk due to high-frequency aspirin use significantly decreased with increasing bodyweight (HR_interaction =0.96; 95% CI, 0.94–0.99; P=1.26×10⁻²). Further, for participants with bodyweight <80 kg, high-frequency aspirin use showed an elevated risk at <76 years of age (HR_age<76 =1.47; 95% CI, 1.25–1.73; P=3.81×10⁻⁶). Our study used propensity score under various confounding and stratification analyses by cardio-cerebrovascular status, which all presented similar evidences.

Conclusions

High-frequency aspirin use is associated with the increased risk of lung cancer. Current smoker or people with age <76 years and bodyweight <80 kg should be more cautious to high-frequency aspirin use for lung cancer chemoprevention. This study provides a new insight for lung cancer chemoprevention.

Association between dietary sodium, potassium intake and lung cancer risk: evidence from the prostate, lung, colorectal and ovarian cancer screening trial and the Women's Health Initiative

Background

Epidemiological studies have reported that dietary mineral intake plays an important role on lung cancer risk, but the association of sodium, potassium intake is still unclear.

Methods

We determined the association between dietary sodium, potassium intake and lung cancer risk based on the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial and the Women's Health Initiative (WHI). Totally 165,409 participants who completed the baseline questionnaire (BQ) and diet history questionnaire (DHQ) were included into the analytical dataset, including 92,984 (44,959 men and 48,025 women) from the PLCO trial and 72,425 (women only) from the WHI cohort. Multivariable Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident lung cancer associated with dietary potassium and sodium intake. The dose-response relationship was also described using the spline smoothed curve after adjusting covariates.

Results

After the median follow-up of 8.55 and 18.56 years, 1,278 and 1,631 new cases of lung cancer were identified in the PLCO trial and WHI cohort, respectively. Intake of sodium was significantly associated with the incidence of lung cancer in the PLCO trial after multivariate adjustment for men (HR: 1.19, 95% CI: 1.05-1.35; P for linear trend =0.044). There was a suggestion that lung cancer risk had a quadratic curve correlation with the increase of potassium intake for women (third vs. lowest quintile: HR: 0.72, 95% CI: 0.54-0.96; P for quadratic trend =0.042). The similar results showing an inverse association between potassium intake and lung cancer risk were also observed in the WHI cohort for women (highest vs. lowest quintile: HR: 0.82, 95% CI: 0.70-0.97; P for linear trend =0.009).

Conclusions

Appropriate intake of potassium has a protective effect against lung cancer, while high consumption of sodium is associated with an increased risk of lung cancer.

Zinc, ω-3 polyunsaturated fatty acids and vitamin D: An essential combination for prevention and treatment of cancers

Zinc, ω-3 polyunsaturated fatty acids (PUFAs) and vitamin D are essential nutrients for health, maturation and general wellbeing. Extensive literature searches have revealed the widespread similarity in molecular biological properties of zinc, ω-3 PUFAs and vitamin D, and their similar anti-cancer properties, even though they have different modes of action. These three nutrients are separately essential for good health, especially in the aged. Zinc, ω-3 PUFAs and vitamin D are inexpensive and safe as they are fundamentally natural and have the properties of correcting and inhibiting undesirable actions without disturbing the normal functions of cells or their extracellular environment. This review of the anticancer properties of zinc, ω-3 PUFAs and vitamin D is made in the context of the hallmarks of cancer. The anticancer properties of zinc, ω-3 PUFAs and vitamin D can therefore be used beneficially through combined treatment or supplementation. It is proposed that sufficiency of zinc, ω-3 PUFAs and vitamin D is a necessary requirement during chemotherapy treatment and that clinical trials can have questionable integrity if this sufficiency is not checked and maintained during efficacy trials.

Selenium donors inhibits osteoclastogenesis through inhibiting IL-6 and plays a pivotal role in bone metastasis from breast cancer

Bone metastases are a frequent complication of breast cancer, and there has been little progress in the treatment of breast cancer patients with bone metastases. The cytotoxicity of selenium donors, including organic selenium and selenium nanoparticles (SeNPs), to cancer cells has been reported previously, but their relationship with bone metastases progression is not fully clear yet. In this study, multicenter clinical exploration was conducted to obtain dietary selenium intakes of breast cancer patients with or without bone metastasis, to study the relationship between selenium and breast cancer prognosis and bone metastasis. We found that dietary selenium intakes were significantly lower in breast cancer patients with bone metastasis, comparing with the non-bone metastasis cases. Selenium lower group of bone metastasis breast cancer patients had worse prognosis, whereas the daily selenium intakes could not predict the prognosis of breast cancer patients without bone metastasis. Subsequently, we study the regulatory role of selenium donors on bone metastasis at the cellular level, by challenging the cells with SeNPs. SeNPs showed potent cytotoxicity in breast cancer cells, no matter whether they were primary or bone-metastatic. SeNPs treated cancer cell inhibited the survival and differentiation of osteoclast progenitor cells. At the molecular level, we demonstrated that IL-6 partially mediated osteoclastogenesis suppression by SeNPs. These results provide a new way for biomarkers or drug development to treat and even prevent bone metastases of breast cancer by using selenium donors.

Objectives, design and main findings until 2020 from the Rotterdam Study

The Rotterdam Study is an ongoing prospective cohort study that started in 1990 in the city of Rotterdam, The Netherlands. The study aims to unravel etiology, preclinical course, natural history and potential targets for intervention for chronic diseases in mid-life and late-life. The study focuses on cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1700 research articles and reports. This article provides an update on the rationale and design of the study. It also presents a summary of the major findings from the preceding 3 years and outlines developments for the coming period.

Respiratory

Lung disease rivals the position for the top cause of death worldwide. Causes and pathology of the myriad lung diseases are varied, yet nutrition can either affect the outcome or support treatment in the majority of cases. This chapter explores the modifiable risk factors, from lifestyle changes to dietary intake to specific nutrients, anti-nutrients, and toxins helpful for the nutritionist or dietitian working with lung disease patients. General lung health is discussed, and three major disease states are explored in detail, including alpha-1 antitrypsin deficiency, asthma, and idiopathic pulmonary fibrosis. Although all lung diseases have diverse causes, many integrative and functional medical nutrition therapies are available and are not being utilized in practice today. This chapter begins the path toward better nutrition education for the integrative and functional medicine professional.

Haem iron intake and risk of lung cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

BACKGROUND

Epidemiological studies suggest that haem iron, which is found predominantly in red meat and increases endogenous formation of carcinogenic N-nitroso compounds, may be positively associated with lung cancer. The objective was to examine the relationship between haem iron intake and lung cancer risk using detailed smoking history data and serum cotinine to control for potential confounding.

METHODS

In the European Prospective Investigation into Cancer and Nutrition (EPIC), 416,746 individuals from 10 countries completed demographic and dietary questionnaires at recruitment. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident lung cancer (n = 3731) risk relative to haem iron, non-haem iron, and total dietary iron intake. A corresponding analysis was conducted among a nested subset of 800 lung cancer cases and 1489 matched controls for whom serum cotinine was available.

RESULTS

Haem iron was associated with lung cancer risk, including after adjustment for details of smoking history (time since quitting, number of cigarettes per day): as a continuous variable (HR per 0.3 mg/1000 kcal 1.03, 95% CI 1.00-1.07), and in the highest versus lowest quintile (HR 1.16, 95% CI 1.02-1.32; trend across quintiles: P = 0.035). In contrast, non-haem iron intake was related inversely with lung cancer risk; however, this association attenuated after adjustment for smoking history. Additional adjustment for serum cotinine did not considerably alter the associations detected in the nested case-control subset.

CONCLUSIONS

Greater haem iron intake may be modestly associated with lung cancer risk.

Magnesium intake and lung cancer risk: A systematic review and meta-analysis

Magnesium may reduce the risk of lung cancer by affecting cell proliferation, inflammation and by preserving lung function; however, the results of epidemiological studies on the potential benefits of magnesium in lung pathology are inconclusive. We conducted this meta-analysis to investigate the association between magnesium intake and the risk of lung cancer. A total of 5 studies were extracted from PubMed, SCOPUS, and the Cochrane Review (to May 2018). These studies involved 58,5821 participants with 8,977 lung cancer cases. The pooled relative risk (RR) indicated a significant association between lung cancer incidence and magnesium intake (RR = 0.88, 95% CI = 0.79 to 0.98; p = 0.018). To investigate the cause of heterogeneity of these studies (I² = 75.8%, p < 0.001), we performed a subgroup analysis which was affected by the mean dose of magnesium intake, where doses of magnesium intake lower than 300 mg/d significantly decreased lung cancer risk (RR = 0.83, 95% CI = 0.70 to 0.99; p = 0.034). Increasing magnesium intake doses to over 300 mg/d did not reduce the incidence of lung cancer (RR = 0.89, 95% CI = 0.78 to 1.01; p = 0.076). Our meta-analysis suggests that magnesium intake of less than 300 mg/d may have protective effects in lung cancer.

Iron and Cancer

This review explores the multifaceted role that iron has in cancer biology. Epidemiological studies have demonstrated an association between excess iron and increased cancer incidence and risk, while experimental studies have implicated iron in cancer initiation, tumor growth, and metastasis. The roles of iron in proliferation, metabolism, and metastasis underpin the association of iron with tumor growth and progression. Cancer cells exhibit an iron-seeking phenotype achieved through dysregulation of iron metabolic proteins. These changes are mediated, at least in part, by oncogenes and tumor suppressors. The dependence of cancer cells on iron has implications in a number of cell death pathways, including ferroptosis, an iron-dependent form of cell death. Uniquely, both iron excess and iron depletion can be utilized in anticancer therapies. Investigating the efficacy of these therapeutic approaches is an area of active research that promises substantial clinical impact.

Circulating essential metals and lung cancer: Risk assessment and potential molecular effects

OBJECTIVE

Essential metals play important roles in the carcinogenic process. However, seldom longitudinal investigations have evaluated their roles in lung cancer development. We aimed to investigate the associations between multiple essential metals and lung cancer incidence and to explore the potential mechanisms.

METHODS

A nested case-control study of 440 incident lung cancer cases and 1:3 frequency matched 1320 healthy controls from the Dongfeng-Tongji Cohort was conducted. The baseline plasma concentrations of 11 essential metals (cobalt, copper, iron, manganese, molybdenum, rubidium, selenium, strontium, stannum, vanadium, and zinc) were measured, and their associations with lung cancer incidence were estimated. Effect of positive metal (zinc) on 4-year telomere attrition was then evaluated among an occupational cohort of 724 workers. We also assessed the transcriptional regulation effects of plasma zinc on mRNA expression profiles, and the expressions of zinc-related genes were further compared in pair-wised lung tumor and normal tissues.

RESULTS

Elevated plasma level of zinc was associated with lower incident risk of lung cancer [OR (95% CI) = 0.89 (0.79, 0.99)] and decreased 4-year telomere attrition [β (95% CI) = -0.73 (-1.27, -0.19)]. These effects were pronounced among males. In particularly, zinc could regulate the expressions of 8 cancer-related genes, including SOD1, APE, TP53BP1, WDR33, LAPTM4B, TRIT1, HUWE1, and ZNF813, which were over-expressed in lung tumor tissues.

CONCLUSIONS

We propose that high plasma zinc could prevent incident lung cancer, probably by slowing down telomere attrition and regulating the expressions of cancer-related genes. These results provided a new insight into lung cancer prevention.

Iron levels, genes involved in iron metabolism and antioxidative processes and lung cancer incidence

Background

Lung cancer is the most common adult malignancy accounting for the largest proportion of cancer related deaths. Iron (Fe) is an essential trace element and is a component of several major metabolic pathways playing an important role in many physiological processes. In this study we evaluated the association between Fe concentration in serum, iron metabolism parameters and genetic variaton in 7 genes involved in iron metabolism and anti-oxidative processes with the incidence of lung cancer in Poland.

Materials and methods

The study included 200 lung cancer patients and 200 matched healthy control subjects. We analyzed serum iron concentration and iron metabolism parameters (TIBC, UIBC, serum ferritin and transferrin saturation), and genotyped seven variants in seven genes: HFE, TFR1, HAMP, TF, SOD2, CAT and GPX1.

Results

Lung cancer patients compared to their matched controls had significantly higher mean serum iron level (p = 0.01), ferritin level (p = 0.007) and TIBC (p = 0.006). Analysis revealed that higher concentration of iron and ferritin (IVth quartile) compared to the lower concentration (Ist quartile) was associated with over 2-fold increased lung cancer incidence. We also found that higher transferrin saturation (p = 0.01) and lower TIBC (p<0.01) are associated with better survival of lung cancer patients. The analysis of polymorphisms in iron related genes did not reveal a significant difference between lung cancer patients and controls. However, rs10421768 in HAMP showed a borderline statistically significant correlation with lung cancer risk (OR = 2.83, p = 0.05).

Conclusions

The results of this case control study indicate that higher body iron represented by higher Fe and ferritin levels may be associated with lung cancer incidence. Rs10421768 in HAMP may be associated with about 3-times higher lung cancer risk. Higher Fe body content may be associated with better survival of lung cancer patients.

Does dietary intake of selenium protect against cancer? A systematic review and meta-analysis of population-based prospective studies

Current evidence on selenium and its effects on cancer is conflicting. This study aimed at assessing the association between dietary intake of selenium and incidence of cancers by performing systematic review and meta-analysis of population-based prospective studies. We systematically searched for articles in Medline (Ovid), Embase, Web of Science (Thomson Reuters), China National Knowledge Infrastructure, Wanfang Database and VIP Chinese Scientific Journals. Analysis was performed in Stata version 14.2. Of the 2,564 articles obtained from the databases, 39 met our inclusion criteria, 37 were included in the final analysis. Selenium at recommended daily allowance levels of ≥55 μg/day decreased the risk of cancer [relative risk (RR) = 0.94, 95% confidence interval (CI): 0.90-0.98]. A protective effect was found in men at levels ≥55 μg/day (RR = 0.97, 95% CI: 0.94-0.99). Extra selenium intake from supplements was protective at levels ≥55 μg/day (RR = 0.89, 95% CI: 0.82-0.97). There was an inverse relationship (p value = 0.020) between selenium intake and overall cancer risk after adjusting for age, body mass index, and smoking but there was no evidence of nonlinear relationship (p value = 0.261). The findings in this study suggest that selenium is protective against cancer however the effects vary with different cancers.

Mild Cognitive Impairment and Dementia Show Contrasting Associations with Risk of Cancer

BACKGROUND

To investigate and to compare the relation between dementia and cancer with the association between mild cognitive impairment (MCI) and cancer.

METHODS

A total of 13,207 persons from the Rotterdam Study were followed between 1990 and 2013 for the onset of dementia and cancer (sample 1). Between 2002 and 2005, a subset of 5,181 persons underwent extensive cognitive testing for MCI and subsequently were followed up for cancer until 2013 (sample 2). We used Cox proportional hazard models to determine the association between dementia and cancer, and MCI and cancer.

RESULTS

In sample 1, 1,404 patients were diagnosed with dementia, and 2,316 developed cancer (63 among dementia cases). Dementia was associated with a decreased risk of cancer (hazard ratio [HR] 0.53; 95% CI 0.41-0.68). In sample 2, 513 persons were diagnosed with MCI and 670 persons developed cancer (81 among MCI cases). In contrast to individuals with dementia, those with MCI tended to have an increased risk of cancer (HR 1.25; 95% CI 0.99-1.58).

CONCLUSIONS

We found that persons with MCI tended to have an increased risk of cancer, whereas those with dementia have a decreased risk. These findings call into question a biological explanation for the inverse link between dementia and cancer, thereby suggesting the presence of methodological bias.

Selenium for preventing cancer

BACKGROUND

This review is the third update of the Cochrane review "Selenium for preventing cancer". Selenium is a naturally occurring element with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancer.

OBJECTIVES

To gather and present evidence needed to address two research questions:1. What is the aetiological relationship between selenium exposure and cancer risk in humans?2. Describe the efficacy of selenium supplementation for cancer prevention in humans.

SEARCH METHODS

We updated electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE (Ovid, 2013 to January 2017, week 4), and Embase (2013 to 2017, week 6), as well as searches of clinical trial registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and longitudinal observational studies that enrolled adult participants.

DATA COLLECTION AND ANALYSIS

We performed random-effects (RE) meta-analyses when two or more RCTs were available for a specific outcome. We conducted RE meta-analyses when five or more observational studies were available for a specific outcome. We assessed risk of bias in RCTs and in observational studies using Cochrane's risk assessment tool and the Newcastle-Ottawa Scale, respectively. We considered in the primary analysis data pooled from RCTs with low risk of bias. We assessed the certainty of evidence by using the GRADE approach.

MAIN RESULTS

We included 83 studies in this updated review: two additional RCTs (10 in total) and a few additional trial reports for previously included studies. RCTs involved 27,232 participants allocated to either selenium supplements or placebo. For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence). The RR for estimated cancer mortality was 1.02 (95% CI 0.80 to 1.30; 1 study, 17,444 participants). For the most frequently investigated site-specific cancers, investigators provided little evidence of any effect of selenium supplementation. Two RCTs with 19,009 participants indicated that colorectal cancer was unaffected by selenium administration (RR 0.99, 95% CI 0.69 to 1.43), as were non-melanoma skin cancer (RR 1.16, 95% CI 0.30 to 4.42; 2 studies, 2027 participants), lung cancer (RR 1.16, 95% CI 0.89 to 1.50; 2 studies, 19,009 participants), breast cancer (RR 2.04, 95% CI 0.44 to 9.55; 1 study, 802 participants), bladder cancer (RR 1.07, 95% CI 0.76 to 1.52; 2 studies, 19,009 participants), and prostate cancer (RR 1.01, 95% CI 0.90 to 1.14; 4 studies, 18,942 participants). Certainty of the evidence was high for all of these cancer sites, except for breast cancer, which was of moderate certainty owing to imprecision, and non-melanoma skin cancer, which we judged as moderate certainty owing to high heterogeneity. RCTs with low risk of bias suggested increased melanoma risk.Results for most outcomes were similar when we included all RCTs in the meta-analysis, regardless of risk of bias. Selenium supplementation did not reduce overall cancer incidence (RR 0.99, 95% CI 0.86 to 1.14; 5 studies, 21,860 participants) nor mortality (RR 0.81, 95% CI 0.49 to 1.32; 2 studies, 18,698 participants). Summary RRs for site-specific cancers showed limited changes compared with estimates from high-quality studies alone, except for liver cancer, for which results were reversed.In the largest trial, the Selenium and Vitamin E Cancer Trial, selenium supplementation increased risks of alopecia and dermatitis, and for participants with highest background selenium status, supplementation also increased risk of high-grade prostate cancer. RCTs showed a slightly increased risk of type 2 diabetes associated with supplementation. A hypothesis generated by the Nutritional Prevention of Cancer Trial - that individuals with low blood selenium levels could reduce their risk of cancer (particularly prostate cancer) by increasing selenium intake - has not been confirmed. As RCT participants have been overwhelmingly male (88%), we could not assess the potential influence of sex or gender.We included 15 additional observational cohort studies (70 in total; over 2,360,000 participants). We found that lower cancer incidence (summary odds ratio (OR) 0.72, 95% CI 0.55 to 0.93; 7 studies, 76,239 participants) and lower cancer mortality (OR 0.76, 95% CI 0.59 to 0.97; 7 studies, 183,863 participants) were associated with the highest category of selenium exposure compared with the lowest. Cancer incidence was lower in men (OR 0.72, 95% CI 0.46 to 1.14, 4 studies, 29,365 men) than in women (OR 0.90, 95% CI 0.45 to 1.77, 2 studies, 18,244 women). Data show a decrease in risk of site-specific cancers for stomach, colorectal, lung, breast, bladder, and prostate cancers. However, these studies have major weaknesses due to study design, exposure misclassification, and potential unmeasured confounding due to lifestyle or nutritional factors covarying with selenium exposure beyond those taken into account in multi-variable analyses. In addition, no evidence of a dose-response relation between selenium status and cancer risk emerged. Certainty of evidence was very low for each outcome. Some studies suggested that genetic factors might modify the relation between selenium and cancer risk - an issue that merits further investigation.

AUTHORS' CONCLUSIONS

Well-designed and well-conducted RCTs have shown no beneficial effect of selenium supplements in reducing cancer risk (high certainty of evidence). Some RCTs have raised concerns by reporting a higher incidence of high-grade prostate cancer and type 2 diabetes in participants with selenium supplementation. No clear evidence of an influence of baseline participant selenium status on outcomes has emerged in these studies.Observational longitudinal studies have shown an inverse association between selenium exposure and risk of some cancer types, but null and direct relations have also been reported, and no systematic pattern suggesting dose-response relations has emerged. These studies suffer from limitations inherent to the observational design, including exposure misclassification and unmeasured confounding.Overall, there is no evidence to suggest that increasing selenium intake through diet or supplementation prevents cancer in humans. However, more research is needed to assess whether selenium may modify the risk of cancer in individuals with a specific genetic background or nutritional status, and to investigate possible differential effects of various forms of selenium.

The Rotterdam Study: 2018 update on objectives, design and main results

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1500 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Calcium plus vitamin D supplementation and lung cancer incidence among postmenopausal women in the Women's Health Initiative

BACKGROUND

Magnesium and calcium are antagonistic in many physiologic processes. However, few studies have investigated the associations of supplemental calcium with lung cancer risk taking this antagonism into account. We evaluated the effect of calcium and vitamin D supplementation on lung cancer incidence and explored whether the ratio of baseline calcium to magnesium (Ca:Mg) intake modifies the association in the Women's Health Initiative (WHI) calcium plus vitamin D supplementation (CaD) trial.

METHODS

The intervention phase of the WHI CaD was a double-blinded, randomized, placebo-controlled trial in 36,382 postmenopausal women aged 50-79 years, recruited at 40U.S. centers. Post-intervention follow-up continued among 29,862 (86%) of the surviving participants. Risk of lung cancer in association with CaD supplementation was evaluated using proportional hazard regression models.

RESULTS

After 11 years' cumulative follow-up, there were 207 lung cancers (incidence 0.11% per year) in the supplement arm and 241 (0.12%) in the placebo arm (hazard ratio (HR) for the intervention, 0.91; 95% confidence interval (CI), 0.71-1.17). Subgroup analyses suggested that the HR for lung cancer varied by baseline Ca:Mg intake ratio among women who were current smokers at enrollment (p=0.04 for interaction).

CONCLUSIONS

Over the entire follow-up period, calcium and vitamin D supplementation did not reduce lung cancer incidence among postmenopausal women. In exploratory analyses, an interaction was found for the baseline Ca:Mg intake ratio on lung cancer among current smokers at the trial entry. This findings need to be further studied for the role of calcium with magnesium in lung carcinogenesis in current smokers.