Do tobacco and alcohol modify protective effects of diet on oral carcinogenesis?

A Comparative Analysis of Dominant Dietary Patterns in Patients with and without Oral Squamous Cell Carcinoma

Background

As a modifiable risk factor, nutrition plays a pivotal role in the prevention or delay of oral squamous cell carcinoma (OSCC). This study was aimed to investigate and compare the dominant dietary patterns in the patients with and without OSCC.

Materials and Methods

This case-control study evaluated the usual dietary intake of 80 cases and 120 controls during 2019-2020 using the 117-item Food Frequency Questionnaire, with confirmed validity and reliability. Factor analysis was used to detect the dominant dietary patterns. Data analysis was done by SPSS (version 21) using the Chi-square test, ANOVA, logistic regression analysis, and independent t-test (P < 0.05).

Results

Three dietary patterns were identified, including the western dietary pattern, health dietary pattern, and traditional dietary pattern. The odds ratio (OR) = 1.181 and confidence interval (CI) = 0.671 and 2.082 were found for the western dietary pattern, OR = 1.087 and CI = 0.617 and 1.914 were detected for the healthy dietary pattern, and OR = 0.846 and CI = 0.480 and 1.491 were reported for the traditional dietary pattern. No significant difference was found between the study groups in the dietary pattern and the risk of disease. This relationship remained insignificant after adjustment for the energy intake and confounding factors.

Conclusion

There was no significant relationship between adherence to healthy, traditional, and western dietary patterns and OSCC. Consumption of vegetables and nuts had a protective role against the disease, but risky behaviors such as smoking and alcohol use were directly associated with the incidence of the disease.

Risk factors associated with head and neck cancer in former smokers: A Brazilian multicentric study

BACKGROUND

Reduced tobacco consumption in the population has not been associated with reduced incidence rates of head and neck cancer in several countries.

OBJECTIVE

To explore the associations between HNC and sociodemographic characteristics and lifestyle of former smokers from three Brazilian cancer centers.

METHODS

A multicenter case-control study was conducted with 229 former smokers diagnosed with squamous cell carcinoma of the oral cavity, oropharynx, larynx, and 318 controls (former smokers without head and neck cancer). Bivariate and multiple logistic regression analyses were conducted to estimate odds ratios (ORs) with a 95% confidence interval (CI).

RESULTS

11-20 years after smoking cessation showed significant impact on HNC reduction (OR 0.22, 95% CI, 0.12-0.39), which reached 82% (95% CI, 0.09-0.35) among 20 + former smokers when compared to individuals who had stopped smoking for up to 5 years. A history of high-intensity smoking (>40 pack-years) increased HNC risk by 2.09 times (95% CI 1.13-3.89) when compared to subjects who smoked up to 20 pack-years. Past alcohol consumption (OR 1.99, 95% CI, 1.06-3.82) was also associated with head and neck cancer risk in former smokers when compared to no alcohol consumption. There was a decreased head and neck cancer risk in former smokers who had high school level of education (OR 0.38, 95% CI, 0.16-0.91) compared to illiterate former smokers; and former smokers with moderate intake of vegetables (OR 0.49, 95% CI, 0.28-0.85) and fruits (OR 0.43, 95% CI, 0.25-0.73) compared to those with low intake.

CONCLUSION

Head and neck cancer risk in former smokers decreases after 11 years after smoking cessation, former smokers with past alcohol consumption showed an increased risk of HNC. High school level of education and moderate intake of vegetables and fruits reduced HNC risk among former smokers.

The World of Oral Cancer and Its Risk Factors Viewed from the Aspect of MicroRNA Expression Patterns

Oral cancer is one of the leading causes of death worldwide, with a reported 5-year survival rate of around 50% after treatment. Epigenetic modifications are considered to have a key role in oral carcinogenesis due to histone modifications, aberrant DNA methylation, and altered expression of miRNAs. MicroRNAs (miRNAs) are small non-coding RNAs that have a key role in cancer development by regulating signaling pathways involved in carcinogenesis. MiRNA deregulation identified in oral cancer has led to the idea of using them as potential biomarkers for early diagnosis, prognosis, and the development of novel therapeutic strategies. In recent years, a key role has been observed for risk factors in preventing and treating this malignancy. The purpose of this review is to summarize the recent knowledge about the altered mechanisms of oral cancer due to risk factors and the role of miRNAs in these mechanisms.

Alcohol and Head and Neck Cancer: Updates on the Role of Oxidative Stress, Genetic, Epigenetics, Oral Microbiota, Antioxidants, and Alkylating Agents

Head and neck cancer (HNC) concerns more than 890,000 patients worldwide annually and is associated with the advanced stage at presentation and heavy outcomes. Alcohol drinking, together with tobacco smoking, and human papillomavirus infection are the main recognized risk factors. The tumorigenesis of HNC represents an intricate sequential process that implicates a gradual acquisition of genetic and epigenetics alterations targeting crucial pathways regulating cell growth, motility, and stromal interactions. Tumor microenvironment and growth factors also play a major role in HNC. Alcohol toxicity is caused both directly by ethanol and indirectly by its metabolic products, with the involvement of the oral microbiota and oxidative stress; alcohol might enhance the exposure of epithelial cells to carcinogens, causing epigenetic modifications, DNA damage, and inaccurate DNA repair with the formation of DNA adducts. Long-term markers of alcohol consumption, especially those detected in the hair, may provide crucial information on the real alcohol drinking of HNC patients. Strategies for prevention could include food supplements as polyphenols, and alkylating drugs as therapy that play a key role in HNC management. Indeed, polyphenols throughout their antioxidant and anti-inflammatory actions may counteract or limit the toxic effect of alcohol whereas alkylating agents inhibiting cancer cells' growth could reduce the carcinogenic damage induced by alcohol. Despite the established association between alcohol and HNC, a concerning pattern of alcohol consumption in survivors of HNC has been shown. It is of primary importance to increase the awareness of cancer risks associated with alcohol consumption, both in oncologic patients and the general population, to provide advice for reducing HNC prevalence and complications.

Consumption of minimally processed foods as protective factors in the genesis of squamous cell carcinoma of the head and neck in Brazil

BACKGROUND

Head and neck cancer (HNC) is the sixth most common cancer, and two-fifths of cases could be avoided by changing lifestyle and eating habits.

METHODS

This multicenter case-control study was conducted under the International Consortium on Head and Neck Cancer and Genetic Epidemiology, coordinated by the International Agency for Research on Cancer. This consortium evaluated associations between minimally processed food consumption and the risk of HNC in three Brazilian states.

RESULTS

We evaluated 1740 subjects (847 cases and 893 controls). In multiple analyses including recognized risk factors for HNC, the consumption of apples and pears was associated with reduced risks of oral cavity and laryngeal cancers; the consumption of citrus fruits and fresh tomatoes was associated with a reduced risk of oral cavity cancer; the consumption of bananas was associated with a reduced risk of oropharynx cancer; the consumption of broccoli, cabbage, and collard greens was associated with reduced risks of laryngeal and hypopharyngeal cancers; and the consumption of carrots and fresh fruits was associated with a reduced risk of hypopharyngeal cancer.

CONCLUSIONS

The consumption of a heathy diet rich in fruits and vegetables was associated with a reduced risk of HNC. Public policies, including government subsidies, are essential to facilitate logistical and financial access to minimally processed foods, thereby strengthening environments that promote healthy behavior.

Knowledge and Attitudes of Primary Health Care Dentists Regarding Oral Cancer in Brazil

Objective

The aim of this study was to evaluate the knowledge and attitudes of dentists working in Primary Health Care Units from a Brazilian city, regarding oral cancer.

Materials and methods

A prospective, cross-sectional, epidemiologic survey was performed. Seventy-one dentists from Primary Health Care Units were contacted at their workplace, and participated of the study. Data were collected through a self-administered questionnaire of 31 multiple-choice questions addressing the main clinical features and risk factors for oral cancer. The questionnaire was divided into two sections: questions related to general data and self-perception of the participants regarding personal knowledge of oral cancer, and objective questions related to general information on oral cancer (clinical features, characteristics, traits, and risk factors). The data were tabulated and analyzed by descriptive statistics.

Results

Participants were mostly females (81.5%), less than 40 years of age (57.7%), who underwent training 10–20 years ago (47.9%). Most respondents (66.2%) considered their level of knowledge about oral cancer to be satisfactory. However, only 26.8% of tem felt that they were able to carry out diagnostic procedures for oral cancer. Most of them (95.8%) were interested in participating in training courses on Oral Diagnostics; 56.3% of them reported not having received any training or guidance on how to conduct an examination to detect oral cancer during undergraduate training.

Conclusions

These findings are consistent with previous reports and point to the need for new public policies to enable early diagnosis of oral cancer and a review of training in Oral Diagnostics in dental schools.

Citrus fruits intake and oral cancer risk: A systematic review and meta-analysis

OBJECTIVE

To quantify the relationship between Citrus intake and risk of cancer of the oral cavity and pharynx.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Ovid MEDLINE, EMBASE, and Web of Science were searched until September 2017. Search terms included Citrus, Citrus aurantifolia, Citrus sinensis, Citrus paradisi, Citrus fruits, Citrus fruits extract, Citrus oil, fruits, oral cancer, mouth cancer, mouth neoplasm.

STUDY SELECTION

The selection of studies and the systematic review were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A pre-defined inclusion checklist resulted in the inclusion of articles which were (i) published in peer-reviewed scientific journals; (ii) English language; (iii) and included a measure of Citrus fruit intake and risk of oral and pharyngeal cancer. Studies were excluded if (i) preparations derived from other fruits were used, (ii) Citrus intake was combined with intake of other fruits; (iii) in vitro or animal models were used. We also excluded reviews, systematic reviews, meta-analyses, letters, personal opinions, conference abstracts and book chapters.

DATA EXTRACTION

Three reviewers independently performed the extraction of data from studies included.

RESULTS

Seventeen studies met our inclusion criteria and were included in the final review. Pooled analyses showed that those with the highest Citrus fruit intake compared to the lowest intake had a 50% reduction in risk of oral cavity and pharyngeal cancer (OR 0.50; 95% CI 0.43-0.59).

CONCLUSION

The studies included in this review and meta-analysis showed an inverse association between Citrus fruit intake and oral cancer.

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.

Carotenoid intake and head and neck cancer: a pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

Food and nutrition play an important role in head and neck cancer (HNC) etiology; however, the role of carotenoids remains largely undefined. We explored the relation of HNC risk with the intake of carotenoids within the International Head and Neck Cancer Epidemiology Consortium. We pooled individual-level data from 10 case-control studies conducted in Europe, North America, and Japan. The analysis included 18,207 subjects (4414 with oral and pharyngeal cancer, 1545 with laryngeal cancer, and 12,248 controls), categorized by quintiles of carotenoid intake from natural sources. Comparing the highest with the lowest quintile, the risk reduction associated with total carotenoid intake was 39 % (95 % CI 29-47 %) for oral/pharyngeal cancer and 39 % (95 % CI 24-50 %) for laryngeal cancer. Intakes of β-carotene equivalents, β-cryptoxanthin, lycopene, and lutein plus zeaxanthin were associated with at least 18 % reduction in the rate of oral and pharyngeal cancer (95 % CI 6-29 %) and 17 % reduction in the rate of laryngeal cancer (95 % CI 0-32 %). The overall protective effect of carotenoids on HNC was stronger for subjects reporting greater alcohol consumption (p < 0.05). The odds ratio for the combined effect of low carotenoid intake and high alcohol or tobacco consumption versus high carotenoid intake and low alcohol or tobacco consumption ranged from 7 (95 % CI 5-9) to 33 (95 % CI 23-49). A diet rich in carotenoids may protect against HNC. Persons with both low carotenoid intake and high tobacco or alcohol are at substantially higher risk of HNC.

Foods, nutrients and the risk of oral and pharyngeal cancer

BACKGROUND

Besides tobacco and alcohol, dietary habits may have a relevant role in oral cavity and pharyngeal (OCP) cancer.

METHODS

We analysed the role of selected food groups and nutrients on OCP cancer in a case-control study carried out between 1997 and 2009 in Italy and Switzerland. This included 768 incident, histologically confirmed squamous cell carcinoma cases and 2078 hospital controls. Odds ratios (ORs) were estimated using logistic regression models including terms for tobacco, alcohol and other relevant covariates.

RESULTS

Significant inverse trends in risk were observed for all vegetables (OR=0.19, for the highest vs the lowest consumption) and all fruits (OR=0.39), whereas significant direct associations were found for milk and dairy products (OR=1.50), eggs (OR=1.71), red meat (OR=1.55), potatoes (OR=1.85) and desserts (OR=1.68), although trends in risk were significant only for potatoes and desserts. With reference to nutrients, significant inverse relations were observed for vegetable protein (OR=0.45, for the highest vs the lowest quintile), vegetable fat (OR=0.54), polyunsaturated fatty acids (OR=0.53), α-carotene (OR=0.51), β-carotene (OR=0.28), β-cryptoxanthin (OR=0.37), lutein and zeazanthin (OR=0.34), vitamin E (OR=0.26), vitamin C (OR=0.40) and total folate (OR=0.34), whereas direct ones were observed for animal protein (OR=1.57), animal fat (OR=2.47), saturated fatty acids (OR=2.18), cholesterol (OR=2.29) and retinol (OR=1.88). Combinations of low consumption of fruits and vegetables, and high consumption of meat with high tobacco and alcohol, led to 10- to over 20-fold excess risk of OCP cancer.

CONCLUSION

Our study confirms and further quantifies that a diet rich in fruits and vegetables and poor in meat and products of animal origin has a favourable role against OCP cancer.

Joint and independent effects of alcohol drinking and tobacco smoking on oral cancer: a large case-control study

Alcohol drinking and tobacco smoking are assumed to have significant independent and joint effects on oral cancer (OC) development. This assumption is based on consistent reports from observational studies, which, however, overestimated the independent effects of smoking and drinking, because they did not account for the interaction effect in multivariable analyses. This case-control study sought to investigate the independent and the joint effects of smoking and drinking on OC in a homogeneous sample of adults. Case patients (N = 1,144) were affected by invasive oral/oropharyngeal squamous cell carcinoma confirmed histologically, diagnosed between 1998 and 2008 in four hospitals of São Paulo (Brazil). Control patients (N = 1,661) were not affected by drinking-, smoking-associated diseases, cancers, upper aero-digestive tract diseases. Cumulative tobacco and alcohol consumptions were assessed anamnestically. Patients were categorized into never/ever users and never/level-1/level-2 users, according to the median consumption level in controls. The effects of smoking and drinking on OC adjusted for age, gender, schooling level were assessed using logistic regression analysis; Model-1 did not account for the smoking-drinking interaction; Model-2 accounted for this interaction and included the resultant interaction terms. The models were compared using the likelihood ratio test. According to Model-1, the adjusted odds ratios (ORs) for smoking, drinking, smoking-drinking were 3.50 (95% confidence interval –95CI, 2.76–4.44), 3.60 (95CI, 2.86–4.53), 12.60 (95CI, 7.89–20.13), respectively. According to Model-2 these figures were 1.41 (95CI, 1.02–1.96), 0.78 (95CI, 0.48–1.27), 8.16 (95CI, 2.09–31.78). Analogous results were obtained using three levels of exposure to smoking and drinking. Model-2 showed statistically significant better goodness-of-fit statistics than Model-1. Drinking was not independently associated with OC, while the independent effect of smoking was lower than expected, suggesting that observational studies should be revised adequately accounting for the smoking-drinking interaction. OC control policies should focus on addictive behaviours rather than on single lifestyle risk factors.