Possible mechanisms by which alcohol may influence the development of oral cancer--a review

The Combined Effects of Alcohol Consumption and Smoking on Cancer Risk by Exposure Level: A Systematic Review and Meta-Analysis

BACKGROUND

Alcohol consumption is a major risk factor for cancer, and when combined with smoking, the risk increases. Nevertheless, few studies have comprehensively evaluated the combined effects of alcohol consumption and smoking on the risk of various cancer types. Therefore, to assess these effects, we conducted a systematic review and meta-analysis.

METHODS

We performed a systematic search of five literature databases, focusing on cohort and case-control studies. Considering exposure levels, we quantified the combined effects of alcohol consumption and smoking on cancer risk and assessed multiplicative interaction effects.

RESULTS

Of 4,452 studies identified, 24 (4 cohort studies and 20 case-control studies) were included in the meta-analysis. We detected interaction effect of light alcohol and moderate smoking on head and neck cancer risk (relative risk [RR], 4.26; 95% confidence interval [CI], 2.50-7.26; I² = 65%). A synergistic interaction was observed in heavy alcohol and heavy smoking group (RR, 35.24; 95% CI, 23.17-53.58; I² = 69%). In more detailed cancer types, the interaction effect of heavy alcohol and heavy smoking was noticeable on oral (RR, 36.42; 95% CI, 24.62-53.87; I² = 46%) and laryngeal (RR, 38.75; 95% CI, 19.25-78.01; I² = 69%) cancer risk.

CONCLUSION

Our study provided a comprehensive summary of the combined effects of alcohol consumption and smoking on cancers. As their consumption increased, the synergy effect became more pronounced, and the synergy effect was evident especially for head and neck cancer. These findings provide additional evidence for the combined effect of alcohol and smoking in alcohol guidelines for cancer prevention.

The effect of daily usage of Listerine Cool Mint mouthwash on the oropharyngeal microbiome: a substudy of the PReGo trial

Introduction. ListerineÒ is a bactericidal mouthwash widely used to prevent oral health problems such as dental plaque and gingivitis. However, whether it promotes or undermines a healthy oral microbiome is unclear.Hypothesis/Gap Statement. We hypothesized that the daily use of Listerine Cool Mint would have a significant impact on the oropharyngeal microbiome.Aim. We aimed to assess if daily usage of Listerine Cool Mint influenced the composition of the pharyngeal microbiome.Methodology. The current microbiome substudy is part of the Preventing Resistance in Gonorrhoea trial. This was a double-blind single-centre, crossover, randomized controlled trial of antibacterial versus placebo mouthwash to reduce the incidence of gonorrhoea/chlamydia/syphilis in men who have sex with men (MSM) taking HIV pre-exposure prophylaxis (PrEP). Fifty-nine MSM taking HIV PrEP were enrolled. In this crossover trial, participants received 3 months of daily Listerine followed by 3 months of placebo mouthwash or vice versa. Oropharyngeal swabs were taken at baseline and after 3 months use of each mouthwash. DNA was extracted for shotgun metagenomic sequencing (Illumina Inc.). Non-host reads were taxonomically classified with MiniKraken and Bracken. The alpha and beta diversity indices were compared between baseline and after each mouthwash use. Differentially abundant bacterial taxa were identified using ANOVA-like differential expression analysis.Results. Streptococcus was the most abundant genus in most samples (n = 103, 61.7 %) with a median relative abundance of 31.5% (IQR 20.6-44.8), followed by Prevotella [13.5% (IQR 4.8-22.6)] and Veillonella [10.0% (IQR 4.0-16.8)]. Compared to baseline, the composition of the oral microbiome at the genus level (beta diversity) was significantly different after 3 months of Listerine (P = 0.006, pseudo-F = 2.29) or placebo (P = 0.003, pseudo-F = 2.49, permutational multivariate analysis of variance) use. Fusobacterium nucleatum and Streptococcus anginosus were significantly more abundant after Listerine use compared to baseline.Conclusion. Listerine use was associated with an increased abundance of common oral opportunistic bacteria previously reported to be enriched in periodontal diseases, oesophageal and colorectal cancer, and systemic diseases. These findings suggest that the regular use of Listerine mouthwash should be carefully considered.

Alcohol consumption and cancer incidence in women: interaction with smoking, body mass index and menopausal hormone therapy

BACKGROUND

Alcohol consumption has been associated with increased risks of certain site-specific cancers and decreased risks of some other cancers. There is, however, little reliable evidence as to whether the alcohol-associated risks for specific cancers are modified by smoking, body mass index (BMI) and menopausal hormone therapy (MHT) use.

METHODS

In the prospective UK Million Women Study, 1,233,177 postmenopausal women without prior cancer, mean age 56 (SD 5) years, reported their alcohol consumption in median year 1998 (IQR 1998-1999), and were followed by record-linkage for incident cancer. 438,056 women who drank no alcohol or < 1 drink/week were excluded. Cox regression yielded adjusted relative risks (RRs) and 95% confidence intervals (CIs) for 21 cancers by alcohol amount; statistical significance of interactions with smoking, BMI and MHT use was assessed after allowing for multiple testing.

RESULTS

In 795,121 participants, mean consumption was 6.7 (SD 6.4) alcoholic drinks/week. During 17 (SD 5) years of follow-up, 140,203 incident cancers were recorded. There was strong evidence for a substantial association between alcohol intake and risk of upper aero-digestive cancers (oesophageal squamous cell carcinoma, oral cavity, pharynx and larynx; RR per 1 drink/day = 1.38 [95% CI 1.31-1.46]). There was also strong evidence for more moderate positive associations with breast, colorectal and pancreatic cancer (RRs per 1 drink/day = 1.12 [1.10-1.14], 1.10 [1.07-1.13], 1.08 [1.02-1.13] respectively), and moderate negative associations with thyroid cancer, non-Hodgkin's lymphoma, renal cell carcinoma and multiple myeloma (RRs per 1 drink/day = 0.79 [0.70-0.89], 0.91 [0.86-0.95], 0.88 [0.83-0.94], 0.90 [0.84-0.97] respectively). Significant interactions between alcohol and smoking were seen for upper aero-digestive cancers (RRs per 1 drink/day = 1.66 [1.54-1.79], 1.23 [1.11-1.36], 1.12 [1.01-1.25] in current, past, and never smokers respectively). BMI and MHT did not significantly modify any alcohol-associated risks.

CONCLUSIONS

These findings provide robust evidence that greater alcohol intake, even within relatively moderate ranges, increases the risk of cancers of the aerodigestive tract, breast, colorectal and pancreatic cancer, and probably decreases the risk of thyroid cancer, non-Hodgkin's lymphoma, renal cell carcinoma and multiple myeloma. Associations of alcohol intake with cancer risk were not modified by MHT use, adiposity or smoking, except in the case of upper aero-digestive cancers, where the alcohol-associated risk was largely confined to smokers.

Quality of life changes over time and predictors in a large head and neck patients' cohort: secondary analysis from an Italian multi-center longitudinal, prospective, observational study-a study of the Italian Association of Radiotherapy and Clinical Oncology (AIRO) head and neck working group

PURPOSE

The present study examined the longitudinal trajectories, through hierarchical modeling, of quality of life among patients with head and neck cancer, specifically symptoms burden, during radiotherapy, and in the follow-up period (1, 3, 6, and 12 months after completion of radiotherapy), through the M.D. Anderson Symptom Inventory Head and Neck questionnaire, formed by three factors. Furthermore, analyses were conducted controlling for socio-demographic as well as clinical characteristics.

METHODS

Multi-level mixed-effects linear regression was used to estimate the association between quality of life and time, age, gender, household, educational level, employment status, ECOG performance status, human papilloma virus (HPV) status, surgery, chemotherapy, alcohol intake, and smoking.

RESULTS

Among the 166 participants, time resulted to be a predictor of all the three questionnaire factors, namely, general and specific related symptoms and interference with daily life. Moreover, regarding symptom interference with daily activities factor, HPV-positive status played a significant role. Considering only HPV-negative patients, only time predicted patients' quality of life. Differently, among HPV-positive patients, other variables, such as gender, educational level, alcohol use, surgery, age at diagnosis, employment status, and ECOG status, resulted significant.

CONCLUSION

It was evident that quality of life of patients with head and neck cancer declined during RT, whereas it slowly improved after ending treatment. Our results clarified the role of some socio-demographic and clinical variables, for instance, HPV, which would allow to develop treatments tailored to each patient.

Modifiable risk factors for oral cavity cancer in non-smokers: A systematic review and meta-analysis

BACKGROUND

Oral cavity cancer (OCC) is traditionally associated with smoking, but there is an increasing prevalence of the disease among non-smokers. This review investigates possible modifiable risk factors in the development of OCC in non-smokers (OCCNS).

METHODS

PubMed, EMBASE, Web of Science, and Scopus were searched for publications prior to June 2021. Comparative studies investigating modifiable OCCNS risk factors were identified following PRISMA guidelines. Publication date, population size, and results were indexed. Study quality was assessed using MINORS (Methodological Index for Non-Randomized Studies). Factors examined by multiple studies were analyzed using random-effect meta-analysis framework.

RESULTS

Literature search resulted in 1,625 unique publications. 52 records met inclusion criterion, investigating alcohol (n = 22), chewing products (n = 18), diet (n = 7), dental health (n = 11), and medical comorbidities (n = 6).

CONCLUSION

This review demonstrates the paucity of large studies investigating OCCNS risk factors. Further investigation is warranted to help clinicians risk-stratify patients without traditional risk factors.

Induction of Human Oral Squamous Carcinoma Apoptosis by Derris scandens Benth and Elephantopus scaber Linn Extracts

D scandens ( Derris scandens Benth.) and E scaber ( Elephantopus scaber Linn.) contain flavonoids and phenolic acids, which have antitumor activity in various cancer cell lines. Oral cancer is among the most common cancers in Southeast Asia, and the survival rate remains low. Thus, this study screened 2 ethanolic plant extracts for cytotoxicity on the oral human squamous carcinoma cell line (HSC-2), and compared the mechanisms of action. Extracts of D scandens and E scaber showed cytotoxicity against HSC-2 cells in a dose-dependent manner. Observation of nuclear morphology by Hoechst 33342 staining revealed chromatin condensation. Apoptosis was confirmed by Annexin V-FITC staining and cell sorting (fluorescence-activated cell sorting) analysis. We demonstrated that cancer apoptosis was accompanied by changes in the expression of procaspase 3 and that D scandens-mediated apoptosis in HSC-2 cells was potentiated by protein kinase B (Akt) and B-cell lymphoma-2 (Bcl-2), while E scaber apoptosis was mediated by mitogen-activated protein kinase (MAPK) pathways, involving stress-activated protein kinases/jun amino-terminal kinase (SAPK/JNK) and p38-MAPK. Further investigation into targets for apoptosis induction by these plant extracts may have potential in oral cancer therapy.

Smoking-, Alcohol-, and Age-Related Alterations of Blood Monocyte Subsets and Circulating CD4/CD8 T Cells in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) represents a heterogeneous malignant disease of the oral cavity, pharynx, and larynx. Although cigarette smoking, alcohol abuse, and aging are well-established associated factors for HNSCC, their respective influence on immunologic alterations of monocyte subsets or T-cell compositions in the peripheral blood has not yet been fully unveiled. Using flow cytometry, whole blood measurements of CD14/CD16 monocyte subsets and analyses of T-cell subsets in isolated PBMC fractions were carried out in 64 HNSCC patients in view of their tobacco and alcohol consumption, as well as their age, in comparison to healthy volunteers. Flow cytometric analysis revealed significantly increased expression of monocytic CD11b, as well as significantly decreased expression levels of CX3CR1 on classical and intermediate monocyte subsets in smoking-related and in alcohol-related HNSCC patients compared to healthy donors. Peripheral monocytes revealed an age-correlated significant decrease in PD-L1 within the entirety of the HNSCC cohort. Furthermore, we observed significantly decreased abundances of CD8+ effector memory T cells in active-smoking HNSCC patients and significantly increased percentages of CD8+ effector T cells in alcohol-abusing patients compared to the non-smoking/non-drinking patient cohort. Our data indicate an enhanced influence of smoking and alcohol abuse on the dynamics and characteristics of circulating monocyte subsets and CD4/CD8 T-cell subset proportions, as well as an age-related weakened immunosuppression in head and neck cancer patients.

Betel quid chewing and oral potential malignant disorders and the impact of smoking and drinking: A meta-analysis

BACKGROUND

Oral potential malignant disorders (OPMDs) are a precancerous condition of oral disease. Several studies have found that betel quid chewing, smoking and alcohol drinking might be the risk factors of OPMDs. But the relationships of them, especially their interaction are still inconclusive.

AIM

To evaluate the relationship between betel quid chewing and OPMDs and to explore the interaction of smoking and alcohol drinking on the relationship.

METHODS

We searched PubMed, Web of Science, Embase and the Cochrane Library databases with items complete until January 2021 for relevant studies. The research data were extracted according to the inclusion criteria. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the effect size. Subgroup analysis was performed to assess interactions between exposures and OPMDs. Relative excess risk of interaction (RERI) was used to estimate the size of interaction.

RESULTS

Nine articles were selected in the final meta-analysis. The results showed that betel quid chewing (pooled OR: 8.70, 95%CI: 5.18-14.61), alcohol consumption (pooled OR: 1.95, 95%CI: 1.5-2.55), and smoking (pooled OR:4.35, 95%CI: 3.06-6.2) could significantly increase the risk of OPMDs compared to individuals without these behaviors. Smoking and alcohol drinking synergistically increased the association between betel quid chewing and OPMDs (pooled OR_(BQ+SM):14.38, 95%CI: 7.14-28.95; pooled OR_(BQ+DK): 11.12, 95%CI: 8.00-15.45, respectively). The RERI_(BQ+SM) and RERI_(BQ+DK) were 2.33 and 1.47, respectively.

CONCLUSION

The synergistic effects between smoking/drinking and betel quid highlights the importance of focusing on individuals with multiple exposures. Further study should be conducted to confirm these interactions.

Damage to Oral Mucosae Induced by Weekend Alcohol Consumption: The Role of Gender and Alcohol Concentration

The damage caused by chronic alcohol consumption is frequently reported, but the effects caused by weekend recreational consumption, which is much more frequent than even daily consumption, have not, to our knowledge, been reported. The metabolism of ethanol, once consumed, starts from the mouth, and the biotransformation process follows different routes. In this study, the effect of weekend alcohol consumption on the oral cavity was observed. Methods: Thirty male and female rats were divided into six groups (n = 5), with control groups (male/female) and groups administered with 5% and 40% ethanol solution ad libitum consumption 2 days a week for 3 months. After treatment, the animals were sacrificed, an incisional slice of the cheek and back of the tongue was obtained, and the tissues were processed according to the histological technique and routine staining (hematoxylin-eosin, H&E). Samples were observed using light microscopy. Results: Histological changes were observed in samples of tongue and cheek mucosa including different levels of keratinization of the surface layer. Epithelial dysplasia, acanthosis, and chronic inflammation were also observed. The vascularization level also increased because of the ethanol-induced damage. The results were very similar between female and male groups. Conclusion: Weekend alcohol consumption for a period of 3 months causes oral-cavity tissue alterations that could contribute to tumor growth and the development of cancer in the oral cavity.

Intake of Lactobacillus rhamnosus GG (LGG) fermented milk before drinking alcohol reduces acetaldehyde levels and duration of flushing in drinkers with wild-type and heterozygous mutant ALDH2: a randomized, blinded crossover controlled trial

Alcohol consumption leads to acetaldehyde accumulation, especially in people with mutant aldehyde dehydrogenase 2 gene (ALDH2). Novel strategies to promote acetaldehyde detoxification are required to prevent alcohol-related toxicity. Probiotic bacteria such as Lactobacillus rhamnosus GG (LGG) were shown to have in vitro capacity to detoxify acetaldehyde. This randomized, blinded, placebo-controlled cross-over trial investigated the effect of LGG fermented milk in people with ALDH2 polymorphisms after moderate alcohol intake. Ten healthy wild-type and ten heterozygous mutant ALDH2 Thai men were block randomized into two groups. Each group consumed a different sequence of 150 mL fermented milk containing 10⁸ CFU mL^-1 LGG and lactic-acidified milk (placebo), followed by five glasses of beer (0.4 g ethanol per kg body weight), with a one-week wash-out. Consuming LGG fermented milk before alcohol reduced areas under the response curves of blood and salivary acetaldehyde in wild-type and heterozygous mutant ALDH2 individuals (p < 0.05 and p < 0.01, respectively). Interestingly, participants with mutant ALDH2 responded better than wild-type participants for salivary acetaldehyde (90% vs. 70%, p < 0.001). Their durations of flushing were reduced when consuming LGG milk. Regardless of ALDH2 status, 10⁵ CFU mL^-1 LGG was retained in saliva at least 3.5 h after milk consumption. In conclusion, intake of LGG fermented milk before drinking alcohol reduces blood and salivary acetaldehyde levels and duration of flushing in drinkers with wild-type and heterozygous mutant ALDH2. The addition of exogenous capacity to detoxify acetaldehyde using the probiotic product could be a potential strategy to promote the alleviation of exposure to reactive and carcinogenic acetaldehyde associated with alcohol drinking in individuals with defective ALDH2 enzyme.

The Relationship of Tobacco, Alcohol, and Betel Quid with the Formation of Oral Potentially Malignant Disorders: A Community-Based Study from Northeastern Thailand

This study's objective was to describe the relationship between the main risk factors for oral cancer, including tobacco (in the form of cigarettes, smokeless tobacco (SLT), secondhand smoking (SS)), alcohol, and betel quid (BQ), and the occurrence of oral potentially malignant disorders (OPMDs). A community-based case-control study was conducted with a population of 1448 adults aged 40 years or above in northeastern Thailand. Patients aged 60 years or above (OR 1.79, p < 0.001) and female patients (OR 2.17, p < 0.001) had a significant chance of having OPMDs. Our multivariate analysis showed that the most potent risk factor for OPMDs occurrence was betel quid (BQ) (adjusted OR 4.65, p < 0.001), followed by alcohol (OR 3.40, p < 0.001). Even former users were at risk of developing OPMDs. The synergistic effect between these main risk factors was significantly shown in the group exposed to SLT, SS, BQ, and alcohol. The most potent synergistic effect was found in the group exposed to SLT, BQ and alcohol with the OR = 20.96.

Ethanol-Induced Cell Damage Can Result in the Development of Oral Tumors

Simple Summary

Alcohol consumption is linked to 26.4% of all lip and oral cavity cancer cases worldwide. Despite this clear causal relationship, the exact molecular mechanisms by which ethanol damages cells are still under investigation. It is well-established that the metabolism of ethanol plays an important role. Ethanol metabolism yields reactive metabolites that can directly damage the DNA. If the damage is repaired incorrectly, mutations can be fixed in the DNA sequence. Whenever mutations affect key regulatory genes, for instance cell cycle regulating genes, uncontrolled cell growth can be the consequence. Recently, global patterns of mutations have been identified. These so-called mutational signatures represent a fingerprint of the different mutational processes over time. Interestingly, there were ethanol-related signatures discovered that did not associate with ethanol metabolism. This finding highlights there might be other molecular effects of ethanol that are yet to be discovered.

Abstract

Alcohol consumption is an underestimated risk factor for the development of precancerous lesions in the oral cavity. Although alcohol is a well-accepted recreational drug, 26.4% of all lip and oral cavity cancers worldwide are related to heavy drinking. Molecular mechanisms underlying this carcinogenic effect of ethanol are still under investigation. An important damaging effect comes from the first metabolite of ethanol, being acetaldehyde. Concentrations of acetaldehyde detected in the oral cavity are relatively high due to the metabolization of ethanol by oral microbes. Acetaldehyde can directly damage the DNA by the formation of mutagenic DNA adducts and interstrand crosslinks. Additionally, ethanol is known to affect epigenetic methylation and acetylation patterns, which are important regulators of gene expression. Ethanol-induced hypomethylation can activate the expression of oncogenes which subsequently can result in malignant transformation. The recent identification of ethanol-related mutational signatures emphasizes the role of acetaldehyde in alcohol-associated carcinogenesis. However, not all signatures associated with alcohol intake also relate to acetaldehyde. This finding highlights that there might be other effects of ethanol yet to be discovered.

A multivariable Mendelian randomization analysis investigating smoking and alcohol consumption in oral and oropharyngeal cancer

The independent effects of smoking and alcohol in head and neck cancer are not clear, given the strong association between these risk factors. Their apparent synergistic effect reported in previous observational studies may also underestimate independent effects. Here we report multivariable Mendelian randomization performed in a two-sample approach using summary data on 6,034 oral/oropharyngeal cases and 6,585 controls from a recent genome-wide association study. Our results demonstrate strong evidence for an independent causal effect of smoking on oral/oropharyngeal cancer (IVW OR 2.6, 95% CI = 1.7, 3.9 per standard deviation increase in lifetime smoking behaviour) and an independent causal effect of alcohol consumption when controlling for smoking (IVW OR 2.1, 95% CI = 1.1, 3.8 per standard deviation increase in drinks consumed per week). This suggests the possibility that the causal effect of alcohol may have been underestimated. However, the extent to which alcohol is modified by smoking requires further investigation.

Recognition of oral potentially malignant disorders and transformation to oral cancer

Oral potentially malignant disorders refer to oral mucosal disorders with increased risk for malignant transformation, primarily to oral squamous cell carcinoma (SCC). Leukoplakia and erythroplakia are the most common of these disorders, but others have been identified. Transformation rates to oral cancer vary based on multiple factors. Healthcare providers should be aware of risk factors and clinical manifestations of these disorders and should intervene early to monitor and/or treat them to reduce the potential for malignant transformation.

Wine Consumption and Oral Cavity Cancer: Friend or Foe, Two Faces of Janus

The health benefits of moderate wine consumption have been extensively studied during the last few decades. Some studies have demonstrated protective associations between moderate drinking and several diseases including oral cavity cancer (OCC). However, due to the various adverse effects related to ethanol content, the recommendation of moderate wine consumption has been controversial. The polyphenolic components of wine contribute to its beneficial effects with different biological pathways, including antioxidant, lipid regulating and anti-inflammatory effects. On the other hand, in the oral cavity, ethanol is oxidized to form acetaldehyde, a metabolite with genotoxic properties. This review is a critical compilation of both the beneficial and the detrimental effects of wine consumption on OCC.

Pineal gland protects against chemically induced oral carcinogenesis and inhibits tumor progression in rats

Clinical investigations suggest that melatonin suppression and circadian dysfunction may be related to cancer development in shift workers. Studies also show that melatonin suppression after pinealectomy increases cancer incidence in preclinical models. However, no study evaluated the influence of pinealectomy on oral cancer development. In the current study, we investigated the effects of pinealectomy on oral squamous cell carcinoma (OSCC) occurrence and progression in rats. Rats submitted to sham surgery were used as control. Pinealectomy promoted an increase of 140% in OSCC occurrence when compared to sham animals. Tumors from pinealectomized rats displayed a higher volume and thickness than the tumors from sham-operated animals. Pinealectomy induced atrophy of the epithelium adjacent to the oral lesions. Pinealectomized rats showed higher mean number of tumor-associated macrophages and eosinophils in the invasive front of OSCC. In addition, nuclear overexpression of ERK1/2 and p53 was also observed in the front of carcinomas from pinealectomized rats. These results reveal that pineal gland plays a protective role against oral carcinogenesis. The melatonin suppression caused by the pinealectomy might contribute to oral cancer development by acting on ERK1/2 and p53 pathways and regulating tumor inflammation.

Different Expression of Aldehyde Dehydrogenases 1A1 and 2 in Oral Leukoplakia With Epithelial Dysplasia and in Oral Squamous Cell Carcinoma

Oral potentially malignant disorders (OPMD) may develop malignant characteristics and transform into oral squamous cell carcinoma (OSCC) in a range of 1% to 2% of cases. Chronic alcohol consumption is associated with carcinogenesis, but its mechanism has not yet been fully elucidated. ALDH1A1 and 2, isoenzymes responsible for aldehyde oxidation involved in ethanol metabolism may be associated with the development of malignant head and neck neoplasms. The aim of this study was to analyze the expression of ALDH1A1 and ALDH2 in oral leukoplakia with epithelial dysplasia (OLP) and OSCC. A retrospective study was conducted on 27 cases of OLP and 30 cases of OSCC. Clinical data were obtained from medical records, and all cases were classified as mild, moderate, and severe for OLP, and well-differentiated, moderately differentiated, or poorly differentiated for OSCC cases. The ALDH1A1 and ALDH2 expression in OLP and OSCC was evaluated by the immunohistochemical technique. There was predominance of the male sex, in both OLP and OSCC cases. Oral tongue was the most affected site in both groups. OLP showed positive protein expression of ALDH1A1 in all cases, both basal and suprabasal epithelial layers, whereas ALDH2 showed less protein expression. In OSCC, the immunohistochemical reaction for ALDH1A1 expression was negative in 70%, whereas ALDH2 expression was positive in all cases. This study demonstrated the gradual loss of ALDH1A1 expression in OSCC in comparison with OLP, and the increased ALDH2 expression in OSCC.

Risk factors for primary lung cancer among never-smoking women in South Korea: a retrospective nationwide population-based cohort study

BACKGROUND/AIMS

We performed a large-scale, retrospective, nationwide, cohort study to investigate the risk factors for lung cancer among never-smoking Korean females.

METHODS

The study data were collected from a general health examination and questionnaire survey of eligible populations conducted between January 1, 2003 and December 31, 2004; the data were acquired from the tailored big data distribution service of the National Health Insurance Service. After a 1-year clearance period, 5,860,922 of 6,318,878 never-smoking female participants with no previous history of lung cancer were investigated. After a median follow-up of 11.4 years, 43,473 (0.74%) participants were defined as "newly diagnosed lung cancer".

RESULTS

After adjusting for all variables at baseline, the variables older age, lower body mass index (BMI), less exercise, frequent alcohol drinking, meat-based diet, rural residence, and previous history of cancer were associated with a higher incidence of lung cancer. Low BMI (< 18.5 kg/m2: hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.27 to 1.40) was a significant independent risk factor; as BMI decreased, HR increased. Negative associations between BMI and lung-cancer development were also observed after controlling for age (p for trend < 0.001). Drinking alcohol one to two times a week (HR, 1.25; 95% CI, 1.21 to 1.28) and eating a meat-based diet (HR, 1.08; 95% CI, 1.01 to 1.15) were associated with lung-cancer incidence.

CONCLUSION

Modifiable baseline characteristics, such as BMI, exercise, alcohol consumption, and diet, are risk factors for lung-cancer development among never- smoking females. Thus, lifestyle modifications may help prevent lung cancer.

Mouthwash With Alcohol and Oral Carcinogenesis: Systematic Review and Meta-analysis

BACKGROUND

It has been shown that the risk of developing oral cancer is closely related to the intensity and duration of exposure to alcohol and tobacco. Even so, the use of mouthwashes with alcohol in their compositions and the increased risk of oral cancer has been a source of controversy for decades.

OBJECTIVE

This study proposes a systematic review and a meta-analysis of the literature, to assess the possible relationship between the use of mouthwashes with alcohol and the development of oral and pharyngeal cancers.

MATERIALS AND METHODS

A systematic search was done using the Medline and PubMed databases. Exclusion criteria were as follows: articles published in languages other than English or Spanish, systematic reviews, and expert opinions. No limitations were used for publication date.

RESULTS

A total of 14 articles were obtained, 11 case-control studies and 3 clinical trials. Three case-control studies found no statistically significant evidence between the relationship of mouthwash use and oral cancer and the remaining 8 case-control studies found statistically significant evidence. The 3 clinical trials observed a relationship between the use of mouthwashes with alcohol and the possibility of developing cancer due to the genotoxicity and mutagenic capacity of alcohol in chronic contact with oral tissues and mucous membranes. The meta-analysis resulted in an OR = 1.480 and a P-value = .161 (95% CI: 0.855; P-value = 2.561) for the analysis of studies of cancer risk and consumption of mouthwashes with alcohol and OR = 1.057 0.364 (95% CI: 0.951; P-value = 1.174) for studies that related the risk of cancer and mouthwash use without taking into account the presence of alcohol.

CONCLUSIONS

There is no sufficient evidence to accept the proposition that the use of mouthwashes containing alcohol can influence the development of oral cancer.

Amplification of the EGFR and CCND1 Are Coordinated and Play Important Roles in the Progression of Oral Squamous Cell Carcinomas

Oral squamous cell carcinoma (OSCC) is a common cancer in Taiwan and worldwide. To provide some clues for clinical management of OSCC, 72 advanced-stage OSCCs were analyzed using two microarray platforms (26 cases with Affymetrix 500 K and 46 cases with Affymetrix SNP 6.0). Genomic identification of significant targets in cancer analyses were used to identify significant copy number alterations (CNAs) using a q-value cutoff of 0.25. Among the several significant regions, 12 CNAs were common between these two platforms. Two gain regions contained the well-known oncogenes EGFR (7p11.2) and CCND1 (11q13.3) and several known cancer suppressor genes, such as FHIT (3p14.2-p12.1), FAT1 (4q35.1), CDKN2A (9p21.3), and ATM (11q22.3-q24.3), reside within the 10 deletion regions. Copy number gains of EGFR and CCND1 were further confirmed by fluorescence in situ hybridization and TaqMan CN assay, respectively, in 257 OSCC cases. Our results indicate that EGFR and CCND1 CNAs are significantly associated with clinical stage, tumor differentiation, and lymph node metastasis. Furthermore, EGFR and CCND1 CNAs have an additive effect on OSCC tumor progression. Thus, current genome-wide CNA analysis provides clues for future characterization of important oncogenes and tumor suppressor genes associated with the behaviors of the disease.

Disulfiram (Antabuse) Activates ROS-Dependent ER Stress and Apoptosis in Oral Cavity Squamous Cell Carcinoma

A paucity of advances in the development of novel therapeutic agents for squamous cell carcinomas of the head and neck, oral cavity (OSCC) and oropharynx, has stagnated disease free survival rates over the past two decades. Although immunotherapies targeted against checkpoint inhibitors such as PD-1 or CTLA-4 are just now entering the clinic for late stage disease with regularity the median improvement in overall survival is only about three months. There is an urgent unmet clinical need to identify new therapies that can be used alone or in combination with current approaches to increase survival by more than a few months. Activation of the apoptotic arm of the unfolded response (UPR) with small molecules and natural products has recently been demonstrated to be a productive approach in pre-clinical models of OSCC and several other cancers. The aim of current study was to perform a high throughput screen (HTS) with a diverse chemical library to identify compounds that could induce CHOP, a component of the apoptotic arm of the UPR. Disulfiram (DSF, also known as Antabuse) the well-known aversion therapy used to treat chronic alcoholism emerged as a hit that could generate reactive oxygen species, activate the UPR and apoptosis and reduce proliferation in OSCC cell cultures and xenografts. A panel of murine embryonic fibroblasts null for key UPR intermediates (e.g., Chop and Atf4) was resistant to DSF suggesting that an intact UPR is a key element of the mechanism regulating the antiproliferative effects of DSF.

The oral microbiota - a mechanistic role for systemic diseases

Human oral microbiota is the ecological community of commensal, symbiotic, and pathogenic microorganisms found in the oral cavity. Oral microbiota generally exists in the form of a biofilm and plays a crucial role in maintaining oral homeostasis, protecting the oral cavity and preventing disease development. Human oral microbiota has recently become a new focus research for promoting the progress of disease diagnosis, assisting disease treatment, and developing personalised medicines. In this review, the scientific evidence supporting the association that endogenous and exogenous factors (diet, smoking, drinking, socioeconomic status, antibiotics use and pregnancy) modulate oral microbiota. It provides insights into the mechanistic role in which oral microbiota may influence systemic diseases, and summarises the challenges of clinical diagnosis and treatment based on the microbial community information. It provides information for noninvasive diagnosis and helps develop a new paradigm of personalised medicine. All these benefit human health in the post-metagenomics era.

Alcohol consumption and lung cancer risk in never smokers: a pooled analysis of case-control studies

Background

Lung cancer is the deadliest cancer in developed countries but the etiology of lung cancer risk in never smokers (LCRINS) is largely unknown. We aim to assess the effects of alcohol consumption, in its different forms, on LCRINS.

Methods

We pooled six multi-center case-control studies developed in the northwest of Spain. Cases and controls groups were composed of never smokers. We selected incident cases with anatomopathologically confirmed lung cancer diagnoses. All participants were personally interviewed. We performed two groups of statistical models, applying unconditional logistic regression with generalized additive models. One considered the effect of alcohol type consumption and the other considered the quantity of each alcoholic beverage consumed.

Results

A total of 438 cases and 863 controls were included. Median age was 71 and 66, years, respectively. Adenocarcinoma was the predominant histological type, comprising 66% of all cases. We found that any type of wine consumption posed an OR of 2.20 OR 95%CI 1.12-4.35), and spirits consumption had an OR of 1.90 (95%CI 1.13-3.23). Beer consumption had an OR of 1.33 (95%CI 0.82-2.14). These results were similar when women were analyzed separately, but for men there was no apparent risk for any alcoholic beverage. The dose-response analysis for each alcoholic beverage revealed no clear pattern.

Conclusions

Wine and spirits consumption might increase the risk of LCRINSs, particularly in females. These results have to be taken with caution given the limitations of the present study.

Alcohol consumption and lung cancer risk in never smokers

OBJECTIVE

The main objective of this study is to analyse the role of alcohol consumption on lung cancer risk in people who have never smoked.

METHODS

We conducted a systematic review of the scientific literature following the PRISMA statement. We searched Medline, EMBASE and CINAHL using different combinations of MeSH terms and free text. We included cohort studies, pooled cohort studies and case-control studies comprising at least 25 anatomopathologically-confirmed diagnoses of lung cancer cases, a sample size larger than 100 individuals and more than five years of follow-up for cohort studies. We excluded studies that did not specifically report results for never smokers. We developed a quality score to assess the quality of the included papers and we ultimately included 14 investigations with a heterogeneous design and methodology.

RESULTS

Results for alcohol consumption and lung cancer risk in never smokers are inconclusive; however, several studies showed a dose-response pattern for total alcohol consumption and for spirits. Heterogeneous results were found for wine and beer.

CONCLUSION

No clear effect is observed for alcohol consumption. Due to the limited evidence, no conclusion can be drawn for beer or wine consumption. There is little research available on the effect of alcohol on lung cancer risk for people who have never smoked, and more studies are urgently needed on this topic.

Alcohol-dysregulated miR-30a and miR-934 in head and neck squamous cell carcinoma

BACKGROUND

Alcohol consumption is a well-established risk factor for head and neck squamous cell carcinoma (HNSCC); however, the molecular mechanisms by which alcohol promotes HNSCC pathogenesis and progression remain poorly understood. Our study sought to identify microRNAs that are dysregulated in alcohol-associated HNSCC and investigate their contribution to the malignant phenotype.

METHOD

Using RNA-sequencing data from 136 HNSCC patients, we compared the expression levels of 1,046 microRNAs between drinking and non-drinking cohorts. Dysregulated microRNAs were verified by qRT-PCR in normal oral keratinocytes treated with biologically relevant doses of ethanol and acetaldehyde. The most promising microRNA candidates were investigated for their effects on cellular proliferation and invasion, sensitivity to cisplatin, and expression of cancer stem cell genes. Finally, putative target genes were identified and evaluated in vitro to further establish roles for these miRNAs in alcohol-associated HNSCC.

RESULTS

From RNA-sequencing analysis we identified 8 miRNAs to be significantly upregulated in alcohol-associated HNSCCs. qRT-PCR experiments determined that among these candidates, miR-30a and miR-934 were the most highly upregulated in vitro by alcohol and acetaldehyde. Overexpression of miR-30a and miR-934 in normal and HNSCC cell lines produced up to a 2-fold increase in cellular proliferation, as well as induction of the anti-apoptotic gene BCL-2. Upon inhibition of these miRNAs, HNSCC cell lines exhibited increased sensitivity to cisplatin and reduced matrigel invasion. miRNA knockdown also indicated direct targeting of several tumor suppressor genes by miR-30a and miR-934.

CONCLUSIONS

Alcohol induces the dysregulation of miR-30a and miR-934, which may play crucial roles in HNSCC pathogenesis and progression. Future investigation of the alcohol-mediated pathways effecting these transformations will prove valuable for furthering the understanding and treatment of alcohol-associated HNSCC.

Incidence, risk factors and outcome of de novo tumors in liver transplant recipients focusing on alcoholic cirrhosis

Orthotopic liver transplantation (OLT) is an established life-saving procedure for alcoholic cirrhotic (AC) patients, but the incidence of de novo tumors ranges between 2.6% and 15.7% and is significantly increased in comparison with patients who undergo OLT for other etiologies. Tobacco, a known carcinogen, has been reported to be between 52% and 83.3% in AC patients before OLT. Other risk factors that contribute to the development of malignancies are dose-dependent immunosuppression, advanced age, viral infections, sun exposure, and premalignant lesions (inflammatory bowel disease, Barrett’s esophagus). A significantly more frequent incidence of upper aerodigestive (UAD) tract, lung, skin, and kidney-bladder tumors has been found in OLT recipients for AC in comparison with other etiologies. Liver transplant recipients who develop de novo non-skin tumors have a decreased long-term survival rate compared with controls. This significantly lower survival rate is more evident in AC recipients who develop UAD tract or lung tumors after OLT mainly because the diagnosis is usually performed at an advanced stage. All transplant candidates, especially AC patients, should be encouraged to cease smoking and alcohol consumption in the pre- and post-OLT periods, use skin protection, avoid sun exposure and over-immunosuppression, and have a yearly otopharyngolaryngeal exploration and chest computed tomography scan in order to prevent or reduce the incidence of de novo malignancies. Although still under investigation, substitution of calcineurin inhibitors for sirolimus or everolimus may reduce the incidence of de novo tumors after OLT.

Análise de hábitos nocivos à saúde entre pacientes com lesões bucais

Objetivo Propõe-se identificar a prevalência dos hábitos tabagistas e etilistas entre pacientes diagnosticados com lesões bucais, assim como possíveis fatores associados. Material e método Estudo analítico, de caráter retrospectivo, entre pacientes assistidos por clínica odontológica universitária na área de Diagnóstico Bucal. Foram analisados os prontuários odontológicos e laudos histopatológicos dos pacientes que realizaram o procedimento de biópsia entre fevereiro de 2010 e julho de 2012. As variáveis dependentes – hábitos nocivos à saúde – foram construídas pelas informações referentes aos hábitos tabagistas e etilistas então atuais ou passados. Utilizou-se o software SPSS 19.0. Foram conduzidas análises descritivas e univariada pelo teste qui-quadrado de Pearson (p≤0,05). A normalidade da amostra foi investigada pelo teste Kolmogorov-Smirnov e Shapiro-Wilk (p<0,05). Resultado Dos 125 pacientes atendidos no período de avaliação, 110 foram incluídos. A presença de hábitos tabagistas e etilistas – então atuais ou passados – foi identificada em 42 (38,2%) e 21 (19,1%) pacientes, respectivamente. Na análise univariada, as variáveis estatisticamente significantes (p≤0,05) associadas ao hábito tabagista foram: sexo, faixa etária, tipo de biópsia e diagnóstico histopatológico. Quanto ao hábito etilista, as variáveis foram: sexo e tipo de biópsia. Conclusão Os hábitos tabagistas e etilistas estiveram ou permaneceram presentes na vida de uma parcela significativa dos indivíduos investigados, que desenvolveram lesões bucais. Nota-se, ainda, quão relevante é o sinergismo de ambos no desenvolvimento de tais lesões.

Salivary alcohol dehydrogenase in non-smoking and smoking alcohol-dependent persons

Increasing attention to the importance of saliva testing is not surprising because smoking and alcohol drinking act synergistically on oral tissues, and their metabolite levels, e.g., acetaldehyde, are much higher in saliva than in blood. The activity of salivary alcohol dehydrogenase (ADH) comes from oral microbiota, mucosa, and salivary glands. The purpose of this study was to investigate the involvement of ADH in the oral health pathology of smoking (AS) and non-smoking (ANS) alcohol-dependent males. The results indicated that the AS group had a more significant and longer duration (until the 30th day of alcohol abstinence) decrease in ADH activity and output than the ANS group (until the 15th day of alcohol abstinence) compared to controls (social drinkers; C). The decreased salivary flow (SF) in alcoholics was observed longer in the ANS group (until the 30th day of alcohol abstinence), whereas in the AS group SF normalized at the 15th day, probably due to the irritating effect of tobacco smoke on the oral mucosa. Because saliva was centrifuged to remove cells and debris (including microbial cells), the detected salivary ADH activity was derived from salivary glands and/or oral mucosa. A more profound and longer decrease in ADH activity/output in smoking than non-smoking alcoholics was likely due to the damaged salivary glands and/or oral mucosa, caused by the synergistic effect of alcohol drinking and smoking. The lower values of salivary ADH in smoking than non-smoking alcoholics might also be partly due to the reversed/inhibited ADH reaction by high levels of accumulated acetaldehyde.

Cytotoxicity and metabolic stress induced by acetaldehyde in human intestinal LS174T goblet-like cells

There is compelling evidence indicating that ethanol and its oxidative metabolite acetaldehyde can disrupt intestinal barrier function. Apart from the tight junctions, mucins secreted by goblet cells provide an effective barrier. Ethanol has been shown to induce goblet cell injury associated with alterations in mucin glycosylation. However, effects of its most injurious metabolite acetaldehyde remain largely unknown. This study aimed to assess short-term effects of acetaldehyde (0, 25, 50, 75, 100 μM) on functional characteristics of intestinal goblet-like cells (LS174T). Oxidative stress, mitochondrial function, ATP, and intramitochondrial calcium (Ca(2+)) were assessed by dichlorofluorescein, methyltetrazolium, and bioluminescence, MitoTracker green and rhod-2 double-labeling. Membrane integrity and apoptosis were evaluated by measuring lactate dehydrogenase (LDH), caspase 3/7, and cleavage of cytokeratin 18 (CK18). Expression of mucin 2 (MUC2) was determined by cell-based ELISA. Acetaldehyde significantly increased reactive oxygen species generation and decreased mitochondrial function compared with negative controls (P < 0.05). In addition, acetaldehyde dose-dependently decreased ATP levels and induced intramitochondrial Ca(2+) accumulation compared with negative controls (P < 0.05). Furthermore, acetaldehyde induced LDH release and increased caspase3/7 activity and percentage of cells expressing cleaved CK18 and increased MUC2 protein expression compared with negative controls (P < 0.0001). ATP depletion and LDH release could be largely prevented by the antioxidant N-acetylcysteine, suggesting a pivotal role for oxidative stress. Our data demonstrate that acetaldehyde has distinct oxidant-dependent metabolic and cytotoxic effects on LS174T cells that can lead to induction of cellular apoptosis. These effects may contribute to acetaldehyde-induced intestinal barrier dysfunction and subsequently to liver injury.

Alcoholic beverages and carbonated soft drinks: consumption and gastrointestinal cancer risks

Alcoholic beverages (ABs) and carbonated soft drinks (CSDs) are widely consumed worldwide. Given the high consumption of these beverages, the scientific community has increased its focus on their health impact. There is epidemiological evidence of a causal association between AB intake and digestive cancer, but the role of alcohol in determining cancer is not fully defined. Experimental studies have so far identified multiple mechanisms involved in carcinogenesis; ethanol itself is not carcinogenic but available data suggest that acetaldehyde (AA) and reactive oxygen species-both products of ethanol metabolism-have a genotoxic effect promoting carcinogenesis. Other carcinogenetic mechanisms include nutritional deficits, changes in DNA methylation, and impaired immune surveillance. As CSDs are often suspected to cause certain gastrointestinal disorders, consequently, some researchers have hypothesized their involvement in gastrointestinal cancers. Of all the ingredients, carbon dioxide is prevalently involved in the alteration of gastrointestinal physiology by a direct mucosal effect and indirect effects mediated by the mechanical pressure determined by gas. The role of sugar or artificial sweeteners is also debated as factors involved in the carcinogenic processes. However, several surveys have failed to show any associations between CSDs and esophageal, gastric, or colon cancers. On the other hand, a slight correlation between risk of pancreatic cancer and CSD consumption has been found.

Effects of alcohol on the morphological and structural changes in oral mucosa

Objective: To investigate the morphological and structural changes of oral mucosa under the influence of alcohol.

Methods: Sixty male and female specimens (42 males and 18 females) who died of chronic alcoholism were selected in this study. The specimens (5-7 mm) were sliced by the morphological-histological detection method, and stained by the HE and Spielmeyer (myelin staining) protocols respectively. Then five immune peroxidase chemical reaction tests were performed.

Results: 10% of the tissue sections had epithelial hyperplasia points with hyperkeratosis and acanthosis. 90% of the sections had epithelial atrophy points with different degrees of damage, and had moderate infiltration of lymphocytes-macrophages in the basal oral mucosa simultaneously. For the tissue sections of patients who died of cardiovascular diseases with a history of alcoholism, about a half showed that extensive necrotic points were observed in different parts of oral mucosa, accompanied by a secondary infection. Approximately 15% of the sections had more dense and homogeneous necrotic tissues with microbial colonization, and the necrotic focus of 5% of the sections was located above the epithelial tissue, which was not distinctively different from other tissues. 48% of the sections were subjected to small nerve bundles with jeopardized deep oral mucosa, accompanied by necrosis of neuron axon and its myelin membrane.

Conclusion: The findings of this study show that drinking alcohol over an extended time may lead to carcinogenic changes in oral mucosa.

Oral and pharyngeal cancer in women

Although in the United States the incidence of oral and pharyngeal cancer (OPC) has been significantly higher in men than in women, the identification of human papilloma virus as a risk factor for OPC has focused new scrutiny on who may develop OPC. One surprising element is that non-Hispanic white women have a higher incidence of OPC than of cervical cancer. OPC is thus a woman's disease, and diligence is needed to ensure that the occurrence of OPC in women does not go undetected by their oral health care providers.

Polymorphisms in the human cytochrome P450 and arylamine N-acetyltransferase: susceptibility to head and neck cancers

The occurrence of head and neck cancer (HNC) is associated with smoking and alcohol drinking. Tobacco smoking exposes smokers to a series of carcinogenic chemicals. Cytochrome P450 enzymes (CYP450s), such as CYP1A1, CYP1B1, and CYP2D6, usually metabolize carcinogens to their inactive derivatives, but they occasionally convert the chemicals to more potent carcinogens. In addition, via CYP450 (CYP2E1) oxidase, alcohol is metabolized to acetaldehyde, a highly toxic compound, which plays an important role in carcinogenesis. Furthermore, two N-acetyltransferase isozymes (NATs), NAT1 and NAT2, are polymorphic and catalyze both N-acetylation and O-acetylation of aromatic and heterocyclic amine carcinogens. Genetic polymorphisms are associated with a number of enzymes involved in the metabolism of carcinogens important in the induction of HNC. It has been suggested that such polymorphisms may be linked to cancer susceptibility. In this paper, we select four cytochrome P450 enzymes (CYP1A1, CYP1BA1, CYP2D6, and CYP2E1), and two N-acetyltransferase isozymes (NAT1 and NAT2) in order to summarize and analyze findings from the literature related to HNC risk by focusing on (i) the interaction between these genes and the environment, (ii) the impact of genetic defect on protein activity and/or expression, and (iii) the eventual involvement of race in such associations.

Ethanol metabolism and its effects on the intestinal epithelial barrier

Ethanol is widely consumed and is associated with an increasing global health burden. Several reviews have addressed the effects of ethanol and its oxidative metabolite, acetaldehyde, on the gastrointestinal (GI) tract, focusing on carcinogenic effects or alcoholic liver disease. However, both the oxidative and the nonoxidative metabolites of ethanol can affect the epithelial barrier of the small and large intestines, thereby contributing to GI and liver diseases. This review outlines the possible mechanisms of ethanol metabolism as well as the effects of ethanol and its metabolites on the intestinal barrier. Limited studies in humans and supporting in vitro data have indicated that ethanol as well as mainly acetaldehyde can increase small intestinal permeability. Limited evidence also points to increased colon permeability following exposure to ethanol or acetaldehyde. In vitro studies have provided several mechanisms for disruption of the epithelial barrier, including activation of different cell-signaling pathways, oxidative stress, and remodeling of the cytoskeleton. Modulation via intestinal microbiota, however, should also be considered. In conclusion, ethanol and its metabolites may act additively or even synergistically in vivo. Therefore, in vivo studies investigating the effects of ethanol and its byproducts on permeability of the small and large intestines are warranted.

Exploring the mechanisms of alcohol-related damage in oral mucosa - is oxidative stress associated with the increase in cell proliferation in rat tongue epithelium?

CONTEXT

Alcohol consumption has been related to a cell proliferation increase in oral epithelium but its mechanism remains unclear.

OBJECTIVE

The aim of this study was to investigate whether oxidative stress parameters are implicated in the induction of cell proliferation in rat tongue epithelium after different times of chronic alcohol consumption.

MATERIALS AND METHODS

Cell proliferation was assessed in tongue epithelium using AgNOR (argyrophilic proteins related to active nucleolar organizer regions) quantification. Oxidative stress parameters [lipid peroxidation, protein carbonyls, superoxide dismutase activity and catalase (CAT) activity and immunocontent] and Nrf2 immunocontent were quantified in tongue homogenates.

RESULTS AND DISCUSSION

Mean AgNOR numbers (mAgNOR) per nucleus was 2.22 ± 0.30 in ventral tongue epithelium after 120 days of alcohol consumption (vs. 1.87 ± 0.18 for control animals and 1.91 ± 0.23 for animals treated with alcohol for 60 days) indicating cell proliferation increase (p < 0.05, ANOVA followed by Tukey post hoc). Interestingly, 60 days of alcohol consumption induced changes in oxidative stress parameters, but no alteration in cell proliferation. Vitamin E co-treatment was conduced in order to evaluate its possible protective effects. The 120 day Tween + vitamin E + alcohol treatment induced an increase in mAgNORs when compared to the Tween + vitamin E treated group (respectively 2.10 ± 0.30 vs. 1.77 ± 0.11, p < 0.05, ANOVA followed by Tukey post hoc), showing that vitamin E co-treatment had no protective effects. In addition, an inverse association was observed between CAT activity and AgNORs quantity (R = -0.32; p < 0.05, Person's correlation) as well as the possible involvement of Nrf2 in alcohol-related damage.

CONCLUSIONS

Our findings suggest that the increase in cell proliferation associated with alcohol-related damage has no direct relation with an imbalance in oxidative parameters. In contrast, our results indicate that hydrogen peroxide may be implicated in cellular signaling during proliferation in the oral mucosa.

Detection of Cytomorphological Changes in Oral Mucosa among Alcoholics and Cigarette Smokers

OBJECTIVE

This study aimed to detect the cytomorphological changes in buccal mucosa among alcoholics and cigarette smokers.

METHODS

Buccal smears were collected from 200 volunteers; 50 were alcoholics, 50 were cigarette smokers, 50 were alcoholic and cigarette smokers, and another 50 were treated as a control group (neither drinkers nor smokers). The smokers and alcoholics included in this study had been continuously exposed for more than 5 years. Smears were stained using the Papanicolaou technique.

RESULTS

The cytological assessment in the alcoholics group revealed; atypical cellular changes detected in four individuals, bacteria was found in smears of 16 individuals; 18% cocci and 14% actinomyces species were also detected. Hyperkeratosis was detected in five individuals, while 25 individuals showed no oral changes. In the smokers group; atypical cellular changes were seen in six individuals and bacteria were detected in the smears of 15 individuals; 18% cocci and 12% Actinomyces species. Hyperkeratosis was observed in 14% of the individuals, but 44% showed no oral cytological changes. In the cigarette smoking and alcoholics group; atypical cellular changes were detected in only 14%, while bacteria were detected in 54% of smears; 32% were cocci and 16% were Actinomyces species. Changes in cells infected by human papilloma virus were detected in 4% and monilia in 2% of the cases. Also, 20% of the individuals showed hyperkeratosis and 12% showed no lesions.

CONCLUSION

The study proved that alcohol and cigarette smoking are risk factors for oral atypical cellular changes and possibly of oral infection. The degree of change depends on the duration of alcohol consumption and cigarette smoking.

Assessing the oral microbiota of healthy and alcohol-treated rats using whole-genome DNA probes from human bacteria

OBJECTIVE

This study aimed to evaluate the capacity of whole-genome DNA probes prepared from human oral bacteria to cross-react with bacteria from the oral cavity of rats, and to assess the influence of alcohol ingestion on the animals' oral biofilm.

DESIGN

Twenty four mature Wistar rats were equally divided in two groups. One group (control) was fed balanced diet of rat pellets and water. The alcohol-treated group (AT) received the same diet and 20% ethanol solution. Upon euthanasia after 30 days, bacterial samples from the oral biofilm covering the animals' teeth were collected using microbrushes. Bacteria identification and quantification were performed using the DNA checkerboard hybridization method with 33 probes prepared from human oral bacteria. Signals corresponding to bacterial genome counts and percentages were compared using a Mann-Whitney U test with a significance level <0.05.

RESULTS

Cross-reaction for all targeted species, except Streptococcus mutans and Streptococcus mitis-like species, occurred in the control group. Escherichia coli, Pseudomonas aeruginosa, Porphyromonas endodontalis, and Veillonella parvula-like species only produced detectable signals in the AT group. Significantly more signals were detected in the control group compared to the AT group (p=0.001). The percentage of E. coli-like species was highest in both groups.

CONCLUSIONS

Whole-genome DNA probes prepared from human oral bacteria can cross-react with rats' oral bacterial species. Alcohol consumption is associated with lower levels and diversity of bacterial species in the oral cavity of rats.

Ethanol elicits inhibitory effect on the growth and proliferation of tongue carcinoma cells by inducing cell cycle arrest

Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.

Concomitant consumption of marijuana, alcohol and tobacco in oral squamous cell carcinoma development and progression: recent advances and challenges

Oral squamous cell carcinoma (OSCC) corresponds to 95% of all malignant tumours of the mouth. The association between alcohol and tobacco is the major risk factor for this disease, increasing the chances for the development of OSCC by 35-fold. The plant, Cannabis sativa is smoked as cigarettes or blunts and is commonly used in association with tobacco and alcohol. Any type of smoking habit exposes individuals to a wide range of carcinogens or pro-carcinogens, such as polycyclic aromatic hydrocarbons, as well as some ethanol derived substances such as acetaldehyde (AA), and all are genotoxic in the same way. In addition, ethanol acts in the oral mucosa as a solvent and therefore increases the cellular membrane permeability to carcinogens. Carcinogens found in tobacco are also concentrated in marijuana, but the latter also contains high levels of cannabinoids, bioactive compounds responsible for several effects such as euphoria and analgesia. However, Δ(9)-tetrahydrocannabinol (Δ(9)-THC), the major psychotropic cannabinoid found in plants, causes a reduction of cellular metabolism and induction of apoptosis, both of which are anti-neoplastic properties. Apart from limited epidemiologic and experimental data, the effects of concomitant chronic exposure to marijuana (or Δ(9)-THC), tobacco and alcohol in OSCC development and progression is poorly known. This paper reviews the most recent findings on the effects of marijuana over cellular proliferation, as well as in the risk for OSCC, with emphasis on its interaction with tobacco and ethanol consumption.

Effects to exposure of tobacco smoke and alcohol on the tongue and pharynx of rats

AIM

To study in rats the effects of exposure to tobacco and alcohol on the mucosa of the tongue and pharynx.

MATERIAL AND METHODS

Forty adult Wistar rats were allocated into four groups of 10 animals each: GI (control), food and water "ad libitum"; GII (alcohol), 30% of ethanol diluted in drinking water and food "ad libitum"; GIII (tobacco), exposure to the smoke of 10 cigarettes/day, food and water "ad libitum"; GIV (alcohol and tobacco), simultaneous exposure to both agents. After 260 days, the animals were sacrificed. Tongue and pharynx were removed for histopathological analysis.

RESULTS

GI had the lowest tongue and pharynx histological scores. In GII, GIII, and GIV tongue samples revealed: apical cell hyperplasia (GII: 60%, GIII: 30%, GIV: 20%), basal cell hyperplasia (GII: 60%, GIII: 40%), hyperkeratosis (GII: 70%, GIII: 30%, GIV: 30%), dysplasia (GII: 60%, GIII: 60%, GIV: 50%), and apoptosis (GII: 60%, GIII: 40%, GIV: 60%). Pharynx samples revealed: apical cell hyperplasia (GII: 40%, GIII: 30%, GIV: 70%), basal cell hyperplasia (GII: 30%, GIII: 40%, GIV: 40%), hyperkeratosis (GII: 50%, GIII: 80%, GIV: 40%), and dysplasia (GII: 50%, GIII: 80%, GIV: 50%). Carcinoma in situ was detected in both sites.

CONCLUSIONS

Alcohol and tobacco led to significant tongue and pharyngeal lesions that ranged from benign events to severe dysplasia. These findings confirm the deleterious effects of alcohol and tobacco on the airway mucosa.

Outcome of oral tongue squamous cell carcinoma in patients with and without known risk factors

BACKGROUND

Tobacco smoking and high alcohol consumption are considered major risk factors of oral tongue squamous cell carcinoma. This study compared disease outcome between patients with and without known risk factors.

METHODS

Patients with oral tongue squamous cell carcinoma treated at two major medical centers from 1994 to 2008 were identified by cancer registry search. The medical files were reviewed for background-and-disease-related data, risk factors, and outcome.

RESULTS

The study sample consisted of 291 patients: 175 had a history of heavy tobacco smoking and alcohol abuse and 116 did not. Comparison of the patients without risk factors between the two centers yielded no differences in background features. Men accounted for 74% of the total patients with risk factors and comprised 77% of the risk-factor group. The risk-factor group was characterized by a significantly higher mean tumor grade (p=0.0001) and greater tumor depth of invasion (p=0.022) than the non-risk-factor group. The 5-year local and regional control rates were 85.3% and 74%, respectively, with no significant difference between the groups. The 5-year overall survival rate was 68% in the risk-factor group and 64% in the non-risk-factor group (p=NS). Separate analysis of patients aged <40 years at diagnosis revealed a worse overall (p=0.015) and disease-free survival (p=0.038) in those without risk factors.

CONCLUSIONS

The outcome of oral tongue carcinoma is similar in patients with and without risk factors. The worse prognosis in younger patients (<40 years) without risk factors suggests that the pathogenesis in these cases involves factors other than smoking and alcohol.