Vitamin E intake from natural sources and head and neck cancer risk: a pooled analysis in the International Head and Neck Cancer Epidemiology consortium

Increased SEC14L2 expression is associated with clinicopathological features and worse prognosis in oral squamous cell carcinoma

Abnormal expression of SEC14L2 has been implicated in many human cancers. However, the role of SEC14L2 in oral squamous cell carcinoma (OSCC) remains unclear. Therefore, this study aimed to evaluate the expression and prognostic roles of SEC14L2 in OSCC. OSCC tumors and adjacent non-tumors were collected from OSCC patients and used for SEC14L2 mRNA expression by quantitative reverse transcription PCR (RT-qPCR). Additionally, the expression of SEC14L2 was further analyzed using The Cancer Genome Atlas-Head Neck Squamous Cell Carcinoma (TCGA-HNSCC) dataset to identify its relationship with HNSCC clinical characteristics. The Kaplan-Meier plot was used to assess survival rates, and the Tumor Immune Estimation Resource (TIMER) database was used to examine the correlation between SEC14L2 expression and tumor immune cell infiltration. In silico tools also looked at SEC14L2 involvement in cancer pathways through its protein network. The mRNA and protein levels of SEC14L2 are notably higher in both OSCC and HNSCC tissues compared to adjacent normal tissues. Upregulation of SEC14L2 was associated with advanced tumor stages, grades, metastasis, HPV-negative, and TP53 mutations in cancer patients. In addition, the high expression of SEC14L2 was negatively correlated with the poor survival of cancer patients and the infiltration of diverse immune cells in cancer patients. According to the findings of this investigation, SEC14L2 is significantly elevated in OSCC/HNSCC patients and associated with a worse prognosis. More investigation and clinical studies are required to completely understand the therapeutic potential of SEC14L2 in HNSCC and convert these findings into better patient outcomes.

Association between the Mediterranean Diet and Vitamin C and the Risk of Head and Neck Cancer

Diet may modulate the risk of head and neck cancer (HNC) through antioxidant and anti-inflammatory effects. To date, there is limited evidence regarding the effects of the Mediterranean diet on HNC risk. The purpose of the study was to assess the association between Mediterranean diet adherence, type of diet, and vitamin C and the risk of HNC. A case-control study was conducted at the Dentistry Hospital, University of Barcelona, including 101 cases of HNC and 101 controls matched by age and sex. Dietary habits were assessed using a 14-question Mediterranean diet score that classified the type of diet into healthy diet (10-14 points), regular diet (5-9 points), and unhealthy diet (≤4 points). Multivariate logistic regression models were used to assess the association between Mediterranean diet adherence, type of diet, and vitamin C and the risk of HNC. Higher adherence to the Mediterranean diet was significantly associated with a lower risk of HNC (OR = 0.88, 95% CI: 0.79-0.98). A healthy diet (OR = 0.29, 95% CI: 0.10-0.84) and vitamin C intake (OR = 0.25, 95% CI: 0.10-0.62) were strongly associated with lower odds of HNC. Moderate egg intake was the only type of food significantly associated with a lower risk of HNC. Dietary patterns that emphasize a high intake of antioxidant and anti-inflammatory bioactive components may have a protective effect on the risk of HNC.

Oral Cavity Squamous Cell Carcinoma Risk Factors: State of the Art

Head and neck (HN) squamous cell carcinomas (SCCs) originate from the epithelial cells of the mucosal linings of the upper aerodigestive tract, which includes the oral cavity, the pharynx, the larynx, and the sinonasal cavities. There are many associated risk factors, including alcohol drinking coupled with tobacco use, which accounts for 70% to 80% of HNSCCs. Human papilloma virus (HPV) is another independent risk factor for oropharyngeal SCC, but it is only a minor contributor to oral cavity SCC (OSCC). Betel quid chewing is also an established risk factor in southeast Asian countries. However, OSCC, and especially oral tongue cancer, incidence has been reported to be increasing in several countries, suggesting risk factors that have not been identified yet. This review summarizes the established risk factors for oral cavity squamous cell carcinomas and examines other undemonstrated risk factors for HNSCC.

Associations of Body Mass Index and Waist Circumference with the Risk of Head and Neck Cancer: A National Population-Based Study

Background: We investigated the association between BMI and HNC subtype incidence in a cohort study of ten million people, adjusting for the effect of smoking and drinking. We also investigated the relationship between waist circumference (WC) and HNC subtype. Methods: All data used in this study originated from the Korean National Health Insurance Service database. We analysed subjects who had undergone health check-ups in 2009 and monitored subjects until 2018 (n = 10,585,852). Finally, 9,598,085 subjects were included after exclusions. We collected variables that could affect the risk of HNC. Cox proportional hazards regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: The overall incidence of HNC was higher in the low BMI category (BMI < 18.5 according to WHO recommendations for Asian people) (HR: 1.322; 95% CI: 1.195−1.464) compared with the normal BMI category. Among the HNC cases, the incidence rates of laryngeal (HR: 1.3; 95% CI: 1.085−1.558), oral cavity (HR: 1.277; 95% CI: 1.011−1.611), and oropharyngeal (HR: 1.584; 95% CI: 1.25−2.008) cancers were higher in the low BMI category compared with the normal BMI category. No significant association was detected between low BMI and sinus cancer, salivary gland cancer, or nasopharyngeal cancer. The low WC category (<80 cm in men and <75 cm in women) was related to a risk of hypopharyngeal (HR: 1.268; 95% CI: 1.061−1.514) and laryngeal (HR: 1.118; 95% CI: 1.007−1.241) cancers. The HR for occurrence of HNC was high in underweight participants according to smoking status (1.219 for never smoker vs. 1.448 for ever smoker, p for interaction = 0.0015) and drinking status (1.193 for never drinker vs. 1.448 for ever drinker, p for interaction = 0.0044). Conclusions: Low BMI was associated with the risk of some types of HNC. The results of this study could assist etiological investigations and prevention strategies.

Dietary Intake is Associated with miR-31 and miR-375 Expression in Patients with Head and Neck Squamous Cell Carcinoma

MicroRNAs (miRNAs) are important epigenetic regulators in head and neck squamous cell carcinoma (HNSCC), with miR-31 being considered an oncomir and miR-375, a tumor suppressor miR, which are up- and down-regulated in HNSCC, respectively. Nutrients are known to influence miRNA expression; however, this association is poorly explored in HNSCC. This work aimed to identify associations between dietary intake and the expression of miR-31 and miR-375 in patients newly diagnosed with HNSCC. The expression of miR-31 was positively associated with the consumption of iron (β = 16.65) and vitamin C (β = 0.37), and inversely associated with total sugar (β = -0.88), cholesterol (β= -0.23), vitamin B₉ (β= -0.37) and zinc (β = -5.66) intake. The expression of miR-375 was positively associated with the consumption of selenium (β = 1.52), vitamin C (β = 0.17) and vitamin D (β = 13.01), and inversely associated with the consumption of added sugar (β = -0.49), phosphorus (β= -0.27) and vitamin B₁₂ (β = -10.80). Our findings showed important associations between dietary intake and miR-31 and miR-375 expression in HNSCC, offering possible directions for further studies investigating how nutrients interfere with carcinogenesis.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1990972 .

Lessons learned from the INHANCE consortium: An overview of recent results on head and neck cancer

OBJECTIVE

To summarize the latest evidence on head and neck cancer epidemiology from the International Head and Neck Cancer Epidemiology (INHANCE) consortium.

SUBJECTS AND METHODS

INHANCE was established in 2004 to elucidate the etiology of head and neck cancer through pooled analyses of individual-level data on a large scale. We summarize results from recent INHANCE-based publications updating our 2015 overview.

RESULTS

Seventeen papers were published between 2015 and May 2020. These studies further define the nature of risks associated with tobacco and alcohol, and occupational exposures on head and neck cancer. The beneficial effects on incidence of head and neck cancer were identified for good oral health, endogenous and exogenous hormonal factors, and selected aspects of diet related to fruit and vegetables. INHANCE has begun to develop risk prediction models and to pool follow-up data on their studies, finding that ~30% of cases had cancer recurrence and 9% second primary cancers, with overall- and disease-specific 5-year-survival of 51% and 57%, respectively.

CONCLUSIONS

The number and importance of INHANCE scientific findings provides further evidence of the advantages of large-scale internationally collaborative projects and will support the development of prevention strategies.

Epidemiology of head and neck cancers: an update

PURPOSE OF REVIEW

This review attempts to give an update of epidemiological knowledge on head and neck cancers (HNC).

RECENT FINDINGS

Worldwide, from 1990 to 2017, incidence rates for larynx and nasopharyngeal cancers decreased, whereas they increased for oro/hypopharyngeal cancers and lip/oral cavity cancers. They are still markedly higher among men than women. South Asia has the highest HNC incidence rate, followed by Europe, North America, and Australasia.Tobacco and alcohol remain the major risk factors. Rate of cancers attributable to human papillomavirus (HPV) among HNCs is highly depending on world region and tobacco use prevalence. It increases in high-income countries. In the US population, the number of HPV-attributable oropharyngeal cancers now exceeds the number of cervix cancers. HPV vaccination for boys is recommended in an increasing number of countries. Many occupations are associated with an increased HNC risk. Fruits and vegetables intake have a protective effect against HNC.

SUMMARY

To decrease HNC incidence, measures to reduce tobacco use and alcohol consumption remain essential. Improvement of HPV vaccination coverage is also a major objective. Reduction of carcinogens at occupation, protection of workers from carcinogen exposures, education for better diet, and easy and affordable access to fruits and vegetables can contribute to incidence decrease.

Meta-analysis of the association between dietary inflammatory index (DII) and upper aerodigestive tract cancer risk

BACKGROUND

Epidemiological studies have reported an inconsistent relationship between dietary inflammatory index (DII) and upper aerodigestive tract (UADT) cancer risk. However, no systematic review or meta-analysis has been reported up to now. To quantify the association between DII and UADT cancer risk, we performed this meta-analysis.

METHODS

The PubMed, EMBASE, Web of Science and Cochrane Library database were searched for relevant studies from inception December 2018. All case-control studies investigating the association between DII and UADT cancer risk were selected.

RESULTS

A total of 9 case-control studies were identified, involving 13,714 participants. The adjusted pooled OR of UADT cancer for the highest (the most pro-inflammatory diet) vs lowest (the most anti-inflammatory diet) DII categories were 2.27 (95% CI: 1.89-2.73). Subgroup analysis showed that individuals with the highest category of DII score were independently associated with esophagus cancer (OR = 2.53, 95% CI: 1.74-3.68), oral cavity cancer (OR = 2.23, 95% CI: 1.73-2.86), pharyngeal cancer (OR = 2.02, 95% CI: 1.54-2.64), and laryngeal cancer (OR = 2.05, 95% CI: 0.85-4.93).

CONCLUSION

This meta-analysis suggested that the most pro-inflammatory diets (the highest DII scores) are associated with increased UADT cancer risk. However, the association between DII and laryngeal cancer risk need to be further investigated.

Association between dietary inflammatory index and upper aerodigestive tract cancer risk: A systematic review and dose-response meta-analysis

OBJECTIVES

The relationship between dietary inflammatory index (DII) and upper aerodigestive tract (UADT) cancer risk have been investigated in a growing number of epidemiological studies. However, their findings were inconsistent, and no systematic review or meta-analysis has been conducted up to now. This meta-analysis was carried out to examine potential dose-response relationship between DII score and UADT cancer risk.

MATERIAL AND METHODS

A systematic search was conducted for relevant studies in PubMed and Web of Science up to March 28, 2019. Categorical meta-analysis as well as linear and non-linear dose-response meta-analysis were performed to evaluate association between DII and UADT cancer risk.

RESULTS

Nine case-control studies with a total of 4138 cases and 15,326 healthy controls were eligible in the present meta-analysis. The pooled odds ratios (ORs) of UADT cancer risk were 2.07 [95% confidence interval (CI): 1.82, 2.35] for the highest DII score compared with the lowest and 1.53 (95% CI: 1.39, 1.69) for higher DII score compared with lower score, respectively. Furthermore, a one-unit increment in DII score was associated with an increased risk of 18% for UADT cancers (OR: 1.18; 95% CI: 1.15, 1.21). An upward trend towards a positive association between elevated DII score and UADT cancer risk was also observed in non-linear dose-response meta-analysis.

CONCLUSIONS

The present meta-analysis provides evidence of highly pro-inflammatory diets that might increase risk of UADT cancers. Therefore, reducing pro-inflammatory components in diets should be considered to prevent and control UADT cancers.

Vitamin E and cancer prevention: Studies with different forms of tocopherols and tocotrienols

α-Tocopherol (α-T) is the major form of vitamin E (VE) in animals and has the highest activity in carrying out the essential antioxidant functions of VE. Because of the involvement of oxidative stress in carcinogenesis, the cancer prevention activity of α-T has been studied extensively. Lower VE intake or nutritional status has been shown to be associated with increased cancer risk, and supplementation of α-T to populations with VE insufficiency has shown beneficial effects in lowering the cancer risk in some intervention studies. However, several large intervention studies with α-T conducted in North America have not demonstrated a cancer prevention effect. More recent studies have centered on the γ- and δ-forms of tocopherols and tocotrienols (T3). In comparison with α-T, these forms have much lower systemic bioavailability but have shown stronger cancer-preventive activities in many studies in animal models and cell lines. γ-T3 and δ-T3 generally have even higher activities than γ-T and δ-T. In this article, we review recent results from human and laboratory studies on the cancer-preventive activities of different forms of tocopherols and tocotrienols, at nutritional and pharmacological levels. We aim to elucidate the possible mechanisms of the preventive actions and discuss the possible application of the available information for human cancer prevention by different VE forms.

A Prospective Study of Serum Vitamin E and 28-Year Risk of Lung Cancer

BACKGROUND

Epidemiologic data are inconsistent regarding the vitamin E-lung cancer association, and no study to our knowledge has examined serologic changes in vitamin E status in relation to subsequent risk.

METHODS

In a cohort of 22 781 male smokers in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, we ascertained 3184 lung cancer cases during up to 28 years of observation. Cox proportional hazards models examined whether higher serum alpha-tocopherol concentrations at baseline, 3 years, or the interval change were associated with lower lung cancer risk. All statistical tests were two-sided.

RESULTS

After adjustment for age, body mass index, smoking intensity and duration, serum total cholesterol, and trial intervention group, we found lower lung cancer risk in men with high baseline alpha-tocopherol (fifth quintile [Q5] vs Q1, hazard ratio [HR] = 0.76, 95% confidence interval [CI] = 0.66 to 0.87, Ptrend < .001). A similar reduction in risk was seen for serum alpha-tocopherol at 3 years (Q5 vs Q1, HR = 0.78, 95% CI = 0.67 to 0.91, Ptrend = .004). The inverse risk association appeared stronger for younger men and those who had smoked fewer years but was similar across trial intervention groups. We also found reduced risk among men not supplemented with vitamin E who had a lower serum alpha-tocopherol at baseline and greater increases in concentrations at 3 years (third tertile vs first tertile of serum alpha-tocopherol change, HR = 0.74, 95% CI = 0.59 to 0.91, P = .005).

CONCLUSIONS

Higher vitamin E status, as measured by serum alpha-tocopherol concentration, as well as repletion of a low vitamin E state, was related to decreased lung cancer risk during a 28-year period. Our findings provide evidence supporting the importance of adequate physiological vitamin E status for lung cancer risk reduction.

Dietary inflammatory index and risk of upper aerodigestive tract cancer in Japanese adults

Background

The inflammatory potential of diet that has been shown to be associated with cancer risk. We examined the association between dietary inflammatory potential as measured by the dietary inflammatory index (DII^®) and risk of upper aerodigestive tract cancers in a Japanese case-control study.

Results

A positive association was observed between increasing DII scores and overall upper aerodigestive tract cancers, and across anatomic subsites. For upper aerodigestive tract cancers, the OR_Q4vsQ1 = 1.73 (95% CI: 1.37–2.20); head and neck cancer, the OR_Q4vsQ1 was 1.92 (95% CI: 1.42–2.59); and for esophageal cancer, the OR_Q4vsQ1 was1.71 (95% CI: 1.54–1.90). Risks for hypopharyngeal and nasopharyngeal cancers were greatly elevated: (OR_Q4vsQ1 = 4.05 (95% CI: 1.24–13.25) for hypopharyngeal cancer and OR_Q4vsQ1 = 4.99 (95% CI: 1.14–21.79) for nasopharyngeal cancer.

Conclusion

A more pro-inflammatory diet was associated with an elevated risk of upper aerodigestive tract cancers after accounting for important confounders. All anatomic subsites, except larynx, showed the consistently elevated risk with increasing DII score. Those subsites with known etiological associations with persistent infection showed the largest elevation in risk. These results warrant further evaluation in future studies.

Materials and Methods

This is a case-control study of 1,028 cases and 3,081 age- and sex-matched non-cancer controls recruited at Aichi Cancer Center. DII scores were computed based on estimates of macro- and micro-nutrients from a self-administered food frequency questionnaire. Scores were further categorized into quartiles (based on the distribution in controls). Conditional logistic regression models were fit to estimate odds ratio (OR) and 95% confidence intervals (CIs) adjusted for smoking, ethanol consumption, alcohol flushing, number of teeth, and occupation group.

Association between Mediterranean diet and head and neck cancer: results of a large case-control study in Italy

The Mediterranean diet (MD) is a known protective factor for head and neck cancer (HNC); however, there is still a lack of studies investigating this association by HNC subsite. The aim of the present study was therefore to evaluate the association between adherence to MD and HNC overall and by cancer subsite, as well as the effect of the individual food components on HNC risk. A case-control study was carried out at the Gemelli Hospital of Rome (Italy). A total of 500 HNC cases and 433 controls were interviewed. Dietary intake was assessed through a validated food frequency questionnaire that collected information on over 25 food items. Odds ratios (ORs) and 95% confidence intervals (CI) of HNC were calculated using a multiple logistic regression model. We found a reduced risk of both oral cavity and pharynx cancer (OR=0.61; CI: 0.54-0.70) and larynx cancer (OR=0.64; CI: 0.56-0.73) with increasing adherence to MD. We also found a high consumption of fruit, vegetables, and legumes to be significantly associated with a lower risk of larynx as well as oral cavity and pharynx cancers. Our study showed that adherence to MD acts protectively against HNC overall and by cancer subsite.

The Health System and Policy Implications of Changing Epidemiology for Oral Cavity and Oropharyngeal Cancers in the United States From 1995 to 2016

Oral cavity and oropharyngeal cancers are typically grouped under the general term, "oral cancer." Yet, the incidence of oropharyngeal cancers is increasing in the United States, while the incidence of oral cavity cancers has declined. These 2 distinct but conflated groups of oral cancers are attributed to different risk factors. Incidence and survival trends were examined across US population groups and by anatomical subsite. Disparities in incidence and survival by sex, race/ethnicity, and subsite were identified. Risk factors are complex, interactive, and not fully identified. Cancer control research illustrates health disparities in access to care and patient outcomes. Database and supplemental searches yielded 433 articles published between 1995 and 2016 characterizing aspects of oral cancer epidemiology relating to incidence, survival, risk, disparities, and cancer control. Oral cavity cancer survival in black men remains the most intractable burden. Although understanding of oral cancer etiology is improving, application to policy is limited. Cancer control efforts are diverse, sporadic, limited in scope, and generally lacking in success, and they need stratification by oral cavity cancers/oropharyngeal cancers. Further intervention and epidemiologic research, improved workforce capacity, and integrated care delivery are identified as important directions for public health policy. Sustained, multilevel campaigns modeled on tobacco control success are suggested.

Differential Gene Regulation and Tumor-Inhibitory Activities of Alpha-, Delta-, and Gamma-Tocopherols in Estrogen-Mediated Mammary Carcinogenesis

Despite experimental evidence elucidating the antitumor activities of tocopherols, clinical trials with α-tocopherol (α-T) have failed to demonstrate its beneficial effects in cancer prevention. This study compared the chemopreventive efficacy of individual tocopherols (α-, δ-, and γ-T) and a γ-T-rich tocopherol mixture (γ-TmT) in the August-Copenhagen Irish (ACI) rat model of estrogen-mediated mammary cancer. Female ACI rats receiving 17β-estradiol (E2) implants were administered with 0.2% α-T, δ-T, γ-T, or γ-TmT for 30 weeks. Although α-T had no significant effects on mammary tumor growth in ACI rats, δ-T, γ-T, and γ-TmT reduced mammary tumor volume by 51% (P < 0.05), 60% (P < 0.01), and 59% (P < 0.01), respectively. Immunohistochemical analysis revealed that δ-T, γ-T, and γ-TmT reduced levels of the cell proliferation marker, proliferating cell nuclear antigen, in the rat mammary tumors. To gain further insight into the biological functions of different forms of tocopherols, RNA-seq analysis of the tumors was performed. Treatment with γ-T induced robust gene expression changes in the mammary tumors of ACI rats. Ingenuity Pathway Analysis identified "Cancer" as a top disease pathway and "Tumor growth" and "Metastasis" as the top signaling pathways modulated by γ-T. Although the results need further functional validation, this study presents an unbiased attempt to understand the differences between biological activities of individual forms of tocopherols at the whole transcriptome level. In conclusion, δ-T and γ-T have superior cancer preventive properties compared to α-T in the prevention of estrogen-mediated mammary carcinogenesis. Cancer Prev Res; 10(12); 694-703. ©2017 AACR.

Dietary fiber intake and head and neck cancer risk: A pooled analysis in the International Head and Neck Cancer Epidemiology consortium

The possible role of dietary fiber in the etiology of head neck cancers (HNCs) is unclear. We used individual-level pooled data from ten case-control studies (5959 cases and 12,248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium, to examine the association between fiber intake and cancer of the oral cavity/pharynx and larynx. Odds Ratios (ORs) and their 95% Confidence Intervals (CIs) were estimated using unconditional multiple logistic regression applied to quintile categories of non-alcohol energy-adjusted fiber intake and adjusted for tobacco and alcohol use and other known or putative confounders. Fiber intake was inversely associated with oral and pharyngeal cancer combined (OR for 5th vs. 1st quintile category = 0.49, 95% CI: 0.40-0.59; p for trend <0.001) and with laryngeal cancer (OR = 0.66, 95% CI: 0.54-0.82, p for trend <0.001). There was, however, appreciable heterogeneity of the estimated effect across studies for oral and pharyngeal cancer combined. Nonetheless, inverse associations were consistently observed for the subsites of oral and pharyngeal cancers and within most strata of the considered covariates, for both cancer sites. Our findings from a multicenter large-scale pooled analysis suggest that, although in the presence of between-study heterogeneity, a greater intake of fiber may lower HNC risk.

Air pollution, UV irradiation and skin carcinogenesis: what we know, where we stand and what is likely to happen in the future?

The link between air pollution, UV irradiation and skin carcinogenesis has been demonstrated within a large number of epidemiological studies. Many have shown the detrimental effect that UV irradiation can have on human health as well as the long-term damage which can result from air pollution, the European ESCAPE project being a notable example. In total, at present around 2800 different chemical substances are systematically released into the air. This paper looks at the hazardous impact of air pollution and UV and discusses: 1) what we know; 2) where we stand; and 3) what is likely to happen in the future. Thereafter, we will argue that there is still insufficient evidence of how great direct air pollution and UV irradiation are as factors in the development of skin carcinogenesis. However, future prospects of progress are bright due to a number of encouraging diagnostic and preventive projects in progress at the moment.

Inflammatory potential of diet and risk of laryngeal cancer in a case-control study from Italy

BACKGROUND

Besides tobacco and alcohol, diet and inflammation have been suggested to be important risk factors for laryngeal cancer. In this study, we examined the role of diet-associated inflammation, as estimated by dietary inflammatory index (DII) scores, in laryngeal cancer in a multicentre case-control study conducted between 1992 and 2000 in Italy.

METHODS

This study included 460 cases with incident, histologically confirmed laryngeal cancer, and 1,088 controls hospitalized for acute non-neoplastic diseases unrelated to tobacco and alcohol consumption. DII scores were computed from a reproducible and valid 78-item food-frequency questionnaire. Logistic regression models controlling for age, sex, study center, education, body mass index, tobacco smoking, alcohol drinking, and non-alcohol energy intake were used to estimate odds ratios (ORs) and the corresponding 95 % confidence intervals (CIs).

RESULTS

Subjects with higher DII scores (i.e., with a more pro-inflammatory diet) had a higher risk of laryngeal cancer. The OR was 3.30 (95 % CI 2.06, 5.28; p for trend <0.0001) for the highest versus the lowest DII quartile. When DII was considered as a continuous variable, the OR was 1.27 (95 % CI 1.15, 1.40) for a one-unit (9 % of the DII range) increase. Stratified analyses produced slightly stronger associations between DII and laryngeal cancer risk among Subjects <60 years old (ORquartile4vs1 = 4.68), overweight subjects (ORQuartile4vs1 = 3.62), and among those with higher education (ORQuartile4vs1 = 3.92). We also observed a strong combined effect of higher DII and tobacco smoking or alcohol consumption on risk of laryngeal cancer. Compared with non-smokers having low DII scores, the OR was 6.64 for smokers with high DII scores. Likewise, compared with non/moderate drinkers with low DII, the OR was 5.82 for heavy drinkers with high DII.

CONCLUSION

These results indicate that a pro-inflammatory diet is associated with increased risk of laryngeal cancer.

Tocopherols in cancer: An update

Tocopherols exist in four forms designated as α, β, δ, and γ. Due to their strong antioxidant properties, tocopherols have been suggested to reduce the risk of cancer. Cancer prevention studies with tocopherols have mostly utilized α-tocopherol. Large-scale clinical trials with α-tocopherol provided inconsistent results regarding the cancer-preventive activities of tocopherols. This review summarizes our current understanding of the anticancer activities of different forms of tocopherols based on follow-up of the clinical trials, recent epidemiological evidences, and experimental studies using in vitro and in vivo models. The experimental data provide strong evidence in support of the anticancer activities of δ-tocopherol, γ-tocopherol, and the natural tocopherol mixture rich in γ-tocopherol, γ-TmT, over α-tocopherol. Such outcomes emphasize the need for detailed investigation into the cancer-preventive activities of different forms of tocopherols to provide a strong rationale for intervention studies in the future.