The magnitude of tobacco smoking-betel quid chewing-alcohol drinking interaction effect on oral cancer in South-East Asia. A meta-analysis of observational studies

Novel prognostic nomograms for postoperative patients with oral cavity squamous cell carcinoma in the central region of China

BACKGROUND

Oral cavity squamous cell carcinoma (OCSCC) is the most common pathological type in oral tumors. This study intends to construct a novel prognostic nomogram model based on China populations for these resectable OCSCC patients, and then validate these nomograms.

METHODS

A total of 607 postoperative patients with OCSCC diagnosed between June 2012 and June 2018 were obtained from two tertiary medical institutions in Xinxiang and Zhengzhou. Then, 70% of all the cases were randomly assigned to the training group and the rest to the validation group. The endpoint time was defined as overall survival (OS) and disease-free survival (DFS). The nomograms for predicting the 3-, and 5-year OS and DFS in postoperative OCSCC patients were established based on the independent prognostic factors, which were identified by the univariate analysis and multivariate analysis. A series of indexes were utilized to assess the performance and net benefit of these two newly constructed nomograms. Finally, the discrimination capability of OS and DFS was compared between the new risk stratification and the American Joint Committee on Cancer (AJCC) stage by Kaplan-Meier curves.

RESULTS

607 postoperative patients with OCSCC were selected and randomly assigned to the training cohort (n = 425) and validation cohort (n = 182). The nomograms for predicting OS and DFS in postoperative OCSCC patients had been established based on the independent prognostic factors. Moreover, dynamic nomograms were also established for more convenient clinical application. The C-index for predicting OS and DFS were 0.691, 0.674 in the training group, and 0.722, 0.680 in the validation group, respectively. Besides, the calibration curve displayed good consistency between the predicted survival probability and actual observations. Finally, the excellent performance of these two nomograms was verified by the NRI, IDI, and DCA curves in comparison to the AJCC stage system.

CONCLUSION

The newly established and validated nomograms for predicting OS and DFS in postoperative patients with OCSCC perform well, which can be helpful for clinicians and contribute to clinical decision-making.

Alcohol and Periodontal Disease: A Narrative Review

The scientific literature dealing with alcohol and alcoholic beverages revealed that these drinks possess an adverse impact on periodontal tissues. Additionally, other principal risk factors include tobacco, smoking, poor oral hygiene, etc. It has been observed that among chronic alcoholics, there are further issues, such as mental, social, and physical effects, that promote alcoholism. These people may have weak immunity for defense against pathogenic organisms and bacteria. Thus, chances of gingival bleeding, swollen gums, bad breath, and increased bone loss are there. Different alcoholic beverages in the market cause less salivation; these beverages contain sugars that promote acid production in the oral cavity by pathogens that demineralize the enamel and damage gum and teeth. This chronic alcohol consumption can progress into different types of oral disorders, including cancer, halitosis, and caries, and is also associated with tobacco and smoking. Chronic alcohol consumption can cause alteration of the oral microbiome and increase oral pathogens, which lead to periodontal disease and an environment of inflammation created in the body due to malnutrition, diminished immunity, altered liver condition, brain damage, and gut microbiota alteration. Heavily colored alcoholic beverages produce staining on teeth and, due to less saliva, may cause other toxic effects on the periodontium. Over-dependency on alcohol leads to necrotizing lesions such as necrotizing gingivitis, necrotizing periodontitis, and necrotizing stomatitis. These pathological impairments instigate severe damage to oral structures. Therefore, proper counseling by the attending dental surgeon and related health professionals is urgently required for the patient on the basis that the individual case needs to go away from the regular heavy consumption of alcohol.

Evaluating Alterations of the Oral Microbiome and Its Link to Oral Cancer among Betel Quid Chewers: Prospecting Reversal through Probiotic Intervention

Areca nut and slaked lime, with or without tobacco wrapped in Piper betle leaf, prepared as betel quid, is extensively consumed as a masticatory product in many countries across the world. Betel Quid can promote the malignant transformation of oral lesions as well as trigger benign cellular and molecular changes. In the oral cavity, it causes changes at the compositional level in oral microbiota called dysbiosis. This dysbiosis may play an important role in Oral Cancer in betel quid chewers. The abnormal presence and increase of bacteria Fusobacterium nucleatum, Capnocytophaga gingivalis, Prevotella melaninogenica, Peptostreptococcus sp., Porphyromonas gingivalis, and Streptococcus mitis in saliva and/or other oral sites of the cancer patients has attracted frequent attention for its association with oral cancer development. In the present review, the authors have analysed the literature reports to revisit the oncogenic potential of betel quid and oral microbiome alterations, evaluating the potential of oral microbiota both as a driver and biomarker of oral cancer. The authors have also shared a perspective that the restoration of local microbiota can become a potentially therapeutic or prophylactic strategy for the delay or reversal of lip and oral cavity cancers, especially in high-risk population groups.

The Influence of the Oral Microbiome on Oral Cancer: A Literature Review and a New Approach

In our recent article (Smędra et al.: Oral form of auto-brewery syndrome. J Forensic Leg Med. 2022; 87: 102333), we showed that alcohol production can occur in the oral cavity (oral auto-brewery syndrome) due to a disruption in the microbiota (dysbiosis). An intermediate step on the path leading to the formation of alcohol is acetaldehyde. Typically, acetic aldehyde is transformed into acetate particles inside the human body via acetaldehyde dehydrogenase. Unfortunately, acetaldehyde dehydrogenase activity is low in the oral cavity, and acetaldehyde remains there for a long time. Since acetaldehyde is a recognised risk factor for squamous cell carcinoma arising from the oral cavity, we decided to analyse the relationship linking the oral microbiome, alcohol, and oral cancer using the narrative review method, based on browsing articles in the PubMed database. In conclusion, enough evidence supports the speculation that oral alcohol metabolism must be assessed as an independent carcinogenic risk. We also hypothesise that dysbiosis and the production of acetaldehyde from non-alcoholic food and drinks should be treated as a new factor for the development of cancer.

Machilin D Promotes Apoptosis and Autophagy, and Inhibits Necroptosis in Human Oral Squamous Cell Carcinoma Cells

Oral squamous cell carcinoma (OSCC) accounts for about 90% of all head and neck cancers, the prognosis is very poor, and there are no effective targeted therapies. Herein, we isolated Machilin D (Mach), a lignin, from the roots of Saururus chinensis (S. chinensis) and assessed its inhibitory effects on OSCC. Herein, Mach had significant cytotoxicity against human OSCC cells and showed inhibitory effects against cell adhesion, migration, and invasion by inhibiting adhesion molecules, including the FAK/Src pathway. Mach suppressed the PI3K/AKT/mTOR/p70S6K pathway and MAPKs, leading to apoptotic cell death. We investigated other modes of programmed cell death in these cells and found that Mach increased LC3I/II and Beclin1 and decreased p62, leading to autophagosomes, and suppressed the necroptosis-regulatory proteins RIP1 and MLKL. Our findings provide evidence that the inhibitory effects of Mach against human YD-10B OSCC cells are related to the promotion of apoptosis and autophagy and inhibition of necroptosis and are mediated via focal adhesion molecules.

A Genome-Wide Association Study Identified Novel Genetic Susceptibility Loci for Oral Cancer in Taiwan

Taiwan has the highest incidence rate of oral cancer in the world. Although oral cancer is mostly an environmentally induced cancer, genetic factors also play an important role in its etiology. Genome-wide association studies (GWAS) have identified nine susceptibility regions for oral cancers in populations of European descent. In this study, we performed the first GWAS of oral cancer in Taiwan with 1529 cases and 44,572 controls. We confirmed two previously reported loci on the 6p21.33 (HLA-B) and 6p21.32 (HLA-DQ gene cluster) loci, highlighting the importance of the human leukocyte antigen and, hence, the immunologic mechanisms in oral carcinogenesis. The TERT-CLMPT1L locus on 5p15.33, the 4q23 ADH1B locus, and the LAMC3 locus on 9q34.12 were also consistent in the Taiwanese. We found two new independent loci on 6p21.32, rs401775 in SKIV2L gene and rs9267798 in TNXB gene. We also found two suggestive novel Taiwanese-specific loci near the TPRS1 gene on 8q23.3 and in the TMED3 gene on 15q25.1. This study identified both common and unique oral cancer susceptibility loci in the Taiwanese as compared to populations of European descent and shed significant light on the etiology of oral cancer in Taiwan.

Statin Use Ameliorates Survival in Oral Squamous Cell Carcinoma-Data from a Population-Based Cohort Study Applying Propensity Score Matching

The anti-cancer properties of statins have attracted much attention recently, but little is known about the prognostic role of statins in oral squamous cell carcinoma (OSCC). In a retrospective approach, we analyzed a population-based cohort of 602 OSCC patients with primary curative tumor resection to negative margins and concomitant neck dissection between 2005-2017. Long-term medication with statins was correlated with overall survival (OAS) as well as recurrence-free survival (RFS) using uni- and multivariable Cox regression. Additionally, propensity score matching was applied to adjust for confounders. Statin use was present in 96 patients (15.9%) at a median age of 65.7 years. Statin treatment correlated with ameliorated survival in multivariable Cox regression in the complete cohort (OAS: HR 0.664; 95% CI 0.467-0.945, p = 0.023; RFS: HR 0.662; 95% CI 0.476-0.920, p = 0.014) as well as matched-pair cohort of OSCC patients (OAS: HR 0.691; 95% CI 0.479-0.997, p = 0.048; RFS: HR 0.694; 95% CI 0.493-0.976, p = 0.036) when compared to patients not taking statins at time of diagnosis. These findings were even more pronounced by sub-group analysis in the matched-pair cohort (age < 70 years). These data indicate that statin use might ameliorate the oncological outcome in primarily resected OSCC patients, but prospective clinical trials are highly recommended.

Prevalence and factors associated with oral potentially malignant disorders and oral squamous cell carcinoma: An institutional study

INTRODUCTION

Incidence & prevalence of OPMDs & OSCC is increasing day by day, thereby escalating the burden of oral cancer in India. Oral cancer ranks in the top three of all cancers in India and is quickly becoming a health priority. This study aims to assess prevalence and associated factors of OPMDs and OSCC in patients attending dental OPD and its association with age, gender, habit (type & duration), clinical presentation and site of involvement.

MATERIAL AND METHODS

A prospectively 12 months study was conducted in the outpatient department. Patient's data whether suspected or proven cases of OPMDs & OSCC and fits in clinical criteria were reviewed and analysed for demographic data, oral adverse habit, clinical presentation and site of involvement.

RESULTS

Overall 38,588 patient's data were analysed for 12 month time duration. Out of this 552 (1.43%) cases of OPMDs and 58 (0.15%) cases of OSCC were reported. Out of 552 maximum patients were reported with OSMF (34.4%), followed by other lesions and minimum with LP (7.9%). Age group most commonly affected was above 45 years (44.9%) of age. Males (81.1%) were affected more than females. OPMDs (92%) and OSCC (96.5%) were mostly associated with smokeless or smoking form of tobacco.

CONCLUSION

Present study evaluated the prevalence rates and associated factors of OPMDs & OSCC, which is beneficial for general practitioner in early diagnosis, formulating better treatment plan and to educate general population about risk factors, early signs and symptoms of these lesions.

Identifying oral microbiome alterations in adult betel quid chewing population of Delhi, India

The study targets to establish a factorial association of oral microbiome alterations (oral dysbiosis) with betel quid chewing habits through a comparison of the oral microbiome of Betel quid chewers and non-chewing individuals. Oral microbiome analysis of 22 adult individuals in the Delhi region of India through the 16S sequencing approach was carried out to observe the differences in taxonomic abundance and diversity. A significant difference in diversity and richness among Betel Quid Chewers (BQC) and Betel Quid Non-Chewers (BQNC) groups was observed. There were significant differences in alpha diversity among the BQC in comparison to BQNC. However, in the age group of 21-30 years old young BQC and BQNC there was no significant difference in alpha diversity. Similar result was obtained while comparing BQC and Smoker-alcoholic BQC. BQ smoker-chewers expressed significant variance in comparison to BQC, based on cluster pattern analysis. The OTU-based Venn Diagram Analysis revealed an altered microbiota, for BQ chewing group with 0-10 years exposure in comparison to those with 10 years and above. The change in the microbial niche in early chewers may be due to abrupt chemical component exposure affecting the oral cavity, and thereafter establishing a unique microenvironment in the long-term BQC. Linear discriminant analysis revealed, 55 significant features among BQC and Alcoholic-Smoker BQC; and 20 significant features among BQC and Smoker BQC respectively. The study shows the abundance of novel bacterial genera in the BQC oral cavity in addition to the commonly found ones. Since the oral microbiome plays a significant role in maintaining local homeostasis, investigating the link between its imbalance in such conditions that are known to have an association with oral diseases including cancers may lead to the identification of specific microbiome-based signatures for its early diagnosis.

Dentists Behavioral Factors Influencing Early Detection of Oral Cancer: Direct Clinical Observational Study

This study aimed to investigate the possible factors affecting dentists' behavior relating to performing oral cancer examinations as part of routine clinical examination. A total of 95 direct clinical observation sessions-utilizing an instrument consisting of 19 evidence-based observational criteria for oral cancer examinations-were observed by four calibrated dentists. Thirty-two final-year students, 32 interns, and 31 faculty members of Jazan Dental School were examined between April 9 and May 4, 2017. A descriptive analysis was conducted to investigate the frequencies/percentages of the performed observing criteria by all examiners. ANOVA and Tukey tests were carried out to investigate the difference between the examiner groups. A total number of 32 patients participated in the study, whereby each patient was examined by three different examiners from each group, as well as by the attending observer/s. Fewer than 50% of the examiners performed the clinical steps necessary for an oral cancer examination-for example, taking into account past medical history, as well as extra and intra-oral examinations. More than 90% of the examiners examined hard tissue, whereas fewer than 30% of them educated their patients about possible risk factors. A significant difference between examiner groups was found in favor of faculty members. A gap between knowledge and actual practice of oral cancer examinations was evident: majority of participants failed to perform the necessary steps for an oral cancer examination. Previous experience and confidence in performing oral cancer examination are possible explanations for the dentist's behavior toward oral cancer examination.

CircRNA has_circ_0069313 induced OSCC immunity escape by miR-325-3p-Foxp3 axes in both OSCC cells and Treg cells

Introduction: CircRNAs are engaged in the tumorigenesis and progression of oral squamous cancer cells (OSCC). However, the function and underlying mechanism of circRNAs on tumor-associated immunity escape are largely unknown.

Materials and methods: We analyzed the expression pattern of has_circ_0069313 in our in-house database and its correlation with OSCC prognosis. Immunohistochemistry was applied to detected PDL1 expression. RNA fluorescence in situ hybridization was applied to detect subcellular location of circRNA. A luciferase activity assay was used to detect the interaction of has_circ_0069313 and miR-325-3p and its downstream target, Foxp3. Exosomes were collected to detect the exosomal circRNAs and co-culture assays were performed to detect the function of exosomal circRNAs on Tregs.

Results: has_circ_0069313 was upregulated in OSCC tissues and predicts poor prognosis. has_circ_0069313 promotes immunity escape through inhibiting miR-325-3p-induced Foxp3 degradation. has_circ_0069313 is an exosomal circRNA and the transfer of has_circ_0069313 to Treg cells promotes the Treg function through maintaining Foxp3 levels.

Conclusion: Our results indicate that has_circ_0069313 induces OSCC immunity escape via the miR-325-3p-Foxp3 axis in both OSCC cells and Treg cells.

Evidence of areca nut consumption in the United States mainland: a cross-sectional study

BACKGROUND

Areca nut (AN) is an addictive substance consumed in the Southeast region and is highly associated with oral premalignant lesions and oral cancer. The impact of AN use in the United States (US) is largely unknown, but the products are readily available and probably used by a significant fraction of Asian immigrants or descendants living in the US. We aimed at assessing AN use prevalence among the Asian community in Houston, Texas.

METHODS

A cross-sectional questionnaire was used to interview adult individuals (≥ 18 years of age) who self-identified as Asian immigrants or descendants residing in Houston. Means, frequencies, and proportions were reported. Factors associated with AN use were evaluated using logistic regression.

RESULTS

We surveyed 275 individuals (58% women, 43% between 35-54 years old, 67% born outside of the US, and 6% concurrent smokers). Among respondents, 91% were familiar with AN products, 17% self-reported ever use of AN products in the US, and 31% had friends/family members who were AN ever users. AN use was significantly associated with being Indian Subcontinent immigrants or descendants (ISID) (OR = 3·9; CI: 1·10,13·81; p = 0·035) and having friends/family members using AN products (OR = 6·2; CI: 1·69, 22·69; p = 0·006).

CONCLUSIONS

Our findings provide quantitative data on the prevalence of AN ever use and context for future AN prevention and cessation interventions specific to the Southeast Asian groups living in the US mainland. This is crucial for the prevention and control of oral cancer and other detrimental conditions related to AN consumption.

Global, regional, and national cancer deaths and disability-adjusted life-years (DALYs) attributable to alcohol consumption in 204 countries and territories, 1990-2019

BACKGROUND

Alcohol consumption is a risk factor for a number of communicable and non-communicable diseases, including several types of cancer. This article reports the burden of cancers attributable to alcohol consumption by age, sex, location, sociodemographic index (SDI), and cancer type from 1990 to 2019.

METHODS

The Comparative Risk Assessment approach was used in the 2019 Global Burden of Disease study to report the burden of cancers attributable to alcohol consumption between 1990 and 2019.

RESULTS

In 2019, there were globally an estimated 494.7 thousand cancer deaths (95% uncertainty interval [UI], 439.7 to 554.1) and 13.0 million cancer disability-adjusted life-years (DALYs; 95% UI, 11.6 to 14.5) that were attributable to alcohol consumption. The alcohol-attributable DALYs were much higher in men (10.5 million; 95% UI, 9.2 to 11.8) than women (2.5 million; 95% UI, 2.2 to 2.9). The global age-standardized death and DALY rates of cancers attributable to alcohol decreased by 14.7% (95% UI, 6.4% to 23%) and 18.1% (95% UI, 9.2% to 26.5%), respectively, over the study period. Central Europe had the highest age-standardized death rates that were attributable to alcohol consumption(10.3; 95% UI, 8.7 to12.0). Moreover, there was an overall positive association between SDI and the regional age-standardized DALY rate for alcohol-attributable cancers.

CONCLUSIONS

Despite decreases in age-standardized deaths and DALYs, substantial numbers of cancer deaths and DALYs are still attributable to alcohol consumption. Because there is a higher burden in males, the elderly, and developed regions (based on SDI), these groups and regions should be prioritized in any prevention programs.

Paeoniflorigenone regulates apoptosis, autophagy, and necroptosis to induce anti-cancer bioactivities in human head and neck squamous cell carcinomas

ETHNOPHARMACOLOGICAL RELEVANCE

Paonia suffruticosa Andr. belonging to the family Paeoniaceae and has been used as a medicinal plant in Asian countries including China, Korea, and Japan. The roots of P. suffruticosa has been used in traditional medicine in various diseases including cancer and cardiovascular, female genital, and inflammatory diseases.

AIM OF THE STUDY

Head and neck squamous cell carcinomas (HNSCCs) pathologically account for 90% of all head and neck cancers. However, effective targeted therapies for HNSCCs are insufficient and the prognosis is very poor, especially in patients with metastatic HNSCCs. To overcome the current limitations of available therapies for HNSCCs, pathological approaches using natural compounds are attracting attention. Our study aimed to demonstrate the anti-cancer effects of paeoniflorigenone (Paeo, 98.9% purity) isolated from the root bark of P. suffruticosa.

MATERIALS AND METHODS

Our scientific methodology was performed as follows: cytotoxicity, morphological changes, and apototic DNA fragmentation were analyzed using MTT, light microscopy, and TUNEL assays. Protein expression, apoptosis, necroptosis, and autophagy were analyzed using Western blot and immunofluorescence assays. Cell migration and invasion were analyzed using wound healing and Boyden chamber assays.

RESULTS

We demonstrated that Paeo significantly reduced cell proliferation and cell division, leading to caspase-dependent apoptotic cell death in human YD-10B HNSCC cells. This result was associated with PI3K/AKT/mTOR/p70S6K signaling in these cells. In addition, we investigated other programmed cell death mechanisms associated with apoptosis and found that Paeo inhibited necroptosis via dephosphorylation of key necroptotic proteins (RIP and MLKL), whereas Paeo induced autophagy via increased LC3I/II expression and autophagosome formation in human YD-10B HNSCC cells. The anti-metastatic effects of Paeo significantly suppressed cell migration and invasion in human YD-10B HNSCC cells.

CONCLUSION

Overall, our results demonstrated that the bioactive compound, Paeo, exhibited anti-cancer bioactivities in human YD-10B HNSCC cells, suggesting that Paeo may be an attractive pathological approach for patients with human HNSCCs.

Areca Nut and Oral Cancer: Evidence from Studies Conducted in Humans

Areca nut chewing is one of the major risk factors for oral cancer, with large-magnitude risks reported in studies comparing betel quid chewers and never users, and it has been evaluated as a group 1 carcinogen by the International Agency for Research on Cancer. Data from a high-quality meta-analysis examining risk estimates are presented in summary form with additional information from more recent studies (pooled adjusted relative risk, 7.9; 95% CI, 7.1 to 8.7). The risk of oral cancer increases in a dose-response manner with the daily number of quids consumed and the number of years chewing. In the Indian subcontinent and in Taiwan, approximately half of oral cancers reported are attributed to betel quid chewing (population attributable fraction, 53.7% for residents in Taiwan and 49.5% for the Indian population), a disease burden that could be prevented. Oral leukoplakia and oral submucous fibrosis are 2 main oral potentially malignant disorders caused by areca nut chewing that can progress to oral cancer with continued use. Ex-chewers seem to demonstrate lower risks than current chewers, but the impact of areca nut cessation on oral cancer risk has not been scientifically evaluated on the basis of randomized controlled studies. These data strongly reconfirm that betel quid chewing, primarily areca nut use, should be taken into account in assessing the cancer risk of South Asian, East Asian populations and Pacific Islanders for the development of oral cancer.

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.

Simultaneous determination of areca nut- and tobacco-specific alkaloids in saliva by LC-MS/MS: Distribution and transformation of alkaloids in oral cavity

Areca nut and tobacco are frequently used in combination. Cigarette smoking and betel quid (BQ) chewing habits impose greater oral cancer risk than either habit alone. Saliva is a better noninvasive diagnostic material as it is in direct contact with oral mucosa and cancerous lesions. This study describes the application of isotope-dilution LC-MS/MS for simultaneous quantitation of five areca nut-specific alkaloids (ASAs) and three tobacco-specific alkaloids (TSAs) in human saliva. With this method, we demonstrate that the distribution of ASAs vary significantly in smokers who chew BQ habitually, due to the hydrolysis of ASAs and metabolic activity in the oral cavity. The alkaline condition formed due to slaked lime in BQ, plays an important role in the distribution of ASAs and TSAs, by catalyzing the hydrolysis of ester forms of ASAs to their respective carboxylic acid forms besides facilitating the TSA (i.e., nicotine) absorption in the oral cavity. Moreover, our results reveal that oral mucosa rather than saliva contributes to the metabolism of ASAs at oral cavity. Less than 2.1% of ASAs were metabolized by saliva, as determined by in vitro test. Our findings may provide a better insight into the pathobiology of oral carcinogenesis due to BQ chewing.

Association between socioeconomic status and severity of oral epithelial dysplasia using a Taiwanese Nationwide Oral Mucosal Screening Program: a retrospective analysis

BACKGROUND

The study aimed to investigate the association between socioeconomic status and severity of oral epithelial dysplasia (OED) using current data from the Taiwanese Nationwide Oral Mucosal Screening Program (TNOMSP).

METHODS

This retrospective analysis was conducted in the Department of Oral and Maxillofacial Surgery at a general hospital in Taipei, Taiwan. A total of 134 participants were analysed from a previous study database of 150 patients. The inclusion criteria included age > 20 years and a history of either tobacco or betel nut use. Background information, including para-habits such as betel and tobacco use, was analysed using the Pearson chi-square (χ2) test; furthermore, the correlation of background information with OED severity was investigated using logistic regression (mild or moderate/severe).

RESULTS

High school education level (P < 0.001), poor self-awareness (P = 0.002), current betel use (P < 0.001), and tobacco use (P = 0.003) were highly correlated with moderate- and severe OED (P < 0.05). The odds ratio (OR) of education status above senior high school was 0.03 (95% confidence interval [CI] 0.01-0.15, P < 0.001), while that of junior high school was 1. Current betel chewing (OR 6.57 [95% CI 1.17-37.0], P = 0.033) was significantly associated with OED severity compared with never or ex-use of betel.

CONCLUSIONS

We found a strong correlation between the severity of OED and current betel use and low education status. The current study revealed that the socioeconomic status, poor self-awareness, and para-habit history of the patients with OED should be evaluated to identify high-risk individuals using TNOMSP.

Falcarindiol Stimulates Apoptotic and Autophagic Cell Death to Attenuate Cell Proliferation, Cell Division, and Metastasis through the PI3K/AKT/mTOR/p70S6K Pathway in Human Oral Squamous Cell Carcinomas

Human oral squamous cell carcinomas (OSCCs) have high cancer mortality and a 5-year survival rate lower than that of most other carcinomas. New therapeutic strategies are required for the treatment and prevention against OSCCs. An approach to cancer therapy using plant-derived natural compounds has been actively in progress as a trend. Falcarindiol (FALC), or its isolated form Ostericum koreanum Kitagawa (O. koreanum), is present in many food and dietary plants, especially in carrots, and this compound has a variety of beneficial effects. However, biological activity of FALC has not been reported in OSCCs yet. This study aimed to demonstrate the antitumor effects of FALC against OSCCs, YD-10B cells. In this study, FALC was selected as a result of screening for compounds isolated from various natural products in YD-10B cells. FALC suppressed cell growth, and FALC-induced apoptotic cell death was mainly accompanied by the dephosphorylation of PI3K, AKT, mTOR, and p70S6K. The apoptotic cell death was also associated with autophagy as evidenced by the expression of Beclin-1, the conversion of LC3-II, and the formation of autophagosome. FALC-induced autophagy was accompanied by MAPKs including ERK1/2 and p38. Furthermore, FALC caused the antimetastatic effects by inhibiting the migration and invasion of YD-10B cells. Taken together, the findings suggest the potential value of FALC as a novel candidate for therapeutic strategy against OSCCs.

Betel Quid Dependence Effects on Working Memory and Remote Memory in Chewers with Concurrent Use of Cigarette and Alcohol

OBJECTIVE

The current study asked whether BQ dependence level could affect working memory (WM) and remote memory for the chewers with concurrent use of cigarettes and alcohol, a common phenomenon in Taiwan.

METHODS

The standardized neuropsychological tests (Wechsler Memory Scale III (WMS-III) and Remote Memory Test) were adopted to address the BQ chewers' verbal WM, spatial WM and remote memory. The Spatial Span Test and the Digit Span Test from WMS-III and the Remote Memory Test were adopted. The Betel Nut Dependency Scale (BNDS), the Fagerstrom Test for Nicotine Dependence (FTND), and the Alcohol Use Disorders Identification Test (AUDIT) were adopted to measure the dependence levels.

RESULTS

The BQ dependence level and Last BQ did not affect spatial WM, verbal WM, and remote memory. Last Cigarette is critical in affecting WM; namely, longer interval led to worse performance. Finally, higher alcohol dependence level could lead to better remote memory.

CONCLUSIONS

To our knowledge, there are no BQ studies addressing the effects of concurrent use of cigarettes and alcohol on memory. The current results suggest that cigarette smoking and alcohol drinking, rather than BQ chewing, are critical for memory performance.

Molecular and Cellular Mechanisms of Perineural Invasion in Oral Squamous Cell Carcinoma: Potential Targets for Therapeutic Intervention

Simple Summary

Squamous cell carcinoma is the most common type of oral cavity cancer. It can spread along and invade nerves in a process called perineural invasion. Perineural invasion can increase the chances of tumor recurrence and reduce survival in patients with oral cancer. Understanding how oral cancer interacts with nerves to facilitate perineural invasion is an important area of research. Targeting key events that contribute to perineural invasion in oral cavity cancer may reduce tumor recurrence and improve survival. In this review, we describe the impact of perineural invasion in oral cancer and the mechanisms that contribute to perineural invasion. Highlighting the key events of perineural invasion is important for the identification and testing of novel therapies for oral cancer with perineural invasion.

Abstract

The most common oral cavity cancer is squamous cell carcinoma (SCC), of which perineural invasion (PNI) is a significant prognostic factor associated with decreased survival and an increased rate of locoregional recurrence. In the classical theory of PNI, cancer was believed to invade nerves directly through the path of least resistance in the perineural space; however, more recent evidence suggests that PNI requires reciprocal signaling interactions between tumor cells and nerve components, particularly Schwann cells. Specifically, head and neck SCC can express neurotrophins and neurotrophin receptors that may contribute to cancer migration towards nerves, PNI, and neuritogenesis towards cancer. Through reciprocal signaling, recent studies also suggest that Schwann cells may play an important role in promoting PNI by migrating toward cancer cells, intercalating, and dispersing cancer, and facilitating cancer migration toward nerves. The interactions of neurotrophins with their high affinity receptors is a new area of interest in the development of pharmaceutical therapies for many types of cancer. In this comprehensive review, we discuss diagnosis and treatment of oral cavity SCC, how PNI affects locoregional recurrence and survival, and the impact of adjuvant therapies on tumors with PNI. We also describe the molecular and cellular mechanisms associated with PNI, including the expression of neurotrophins and their receptors, and highlight potential targets for therapeutic intervention for PNI in oral SCC.

Malignancies and Biosensors: A Focus on Oral Cancer Detection through Salivary Biomarkers

Oral cancer is among the deadliest types of malignancy due to the late stage at which it is usually diagnosed, leaving the patient with an average five-year survival rate of less than 50%. The booming field of biosensing and point of care diagnostics can, in this regard, play a major role in the early detection of oral cancer. Saliva is gaining interest as an alternative biofluid for non-invasive diagnostics, and many salivary biomarkers of oral cancer have been proposed. While these findings are promising for the application of salivaomics tools in routine practice, studies on larger cohorts are still needed for clinical validation. This review aims to summarize the most recent development in the field of biosensing related to the detection of salivary biomarkers commonly associated with oral cancer. An introduction to oral cancer diagnosis, prognosis and treatment is given to define the clinical problem clearly, then saliva as an alternative biofluid is presented, along with its advantages, disadvantages, and collection procedures. Finally, a brief paragraph on the most promising salivary biomarkers introduces the sensing technologies commonly exploited to detect oral cancer markers in saliva. Hence this review provides a comprehensive overview of both the clinical and technological advantages and challenges associated with oral cancer detection through salivary biomarkers.

Lack of Salivary Long Non-Coding RNA XIST Expression Is Associated with Increased Risk of Oral Squamous Cell Carcinoma: A Cross-Sectional Study

Studies have shown that there is a disparity between males and females in south-east Asia with regard to oral cancer morbidity. A previous study found that oral cancer tissue showed loss of heterozygosity of the X-linked lncRNA XIST gene. We suggest that XIST may play an important role in oral cancer morbidity when associated with sex. Saliva contains proteins and RNAs that are potential biomarkers for the diagnosis of diseases. This study investigated salivary XIST expression and the correlation to clinical-pathological data among oral squamous cell carcinoma patients. Salivary XIST expression was only observed in females, and a high proportion of females with OSCC lack salivary lncRNA XIST expression (88%). The expression showed no correlation with alcohol consumption, betel quid chewing, or cigarette smoking habits. People lacking salivary lncRNA XIST expression had a significantly increased odds ratio of suffering from OSCC (OR = 19.556, p < 0.001), particularly females (OR = 33.733, p < 0.001). The ROC curve showed that salivary lncRNA XIST expression has acceptable discrimination accuracy to predict the risk of OSCC (AUC = 0.73, p < 0.01). Lack of salivary lncRNA XIST expression was associated with an increased risk of OSCC. We provided an insight into the role of salivary lncRNA XIST as a biomarker to predict the morbidity of OSCC.

Mouthwash Use and the Risk of Oral, Pharyngeal, and Laryngeal Cancer. A Meta-Analysis

Objective: The main aim of this study was to test whether the use of mouthwash is associated with subtypes of squamous cell carcinoma of the head and neck (SCCHN) and to test the potential risk of SCCHN depending on the mouthwash use duration, frequency, or alcoholic content. Materials and methods: We performed a meta-analysis using Web of Science and Scopus databases to detect the risk change associated with mouthwash use depending on the alcohol content, duration and frequency of use, and anatomical location. We used a random-effects model with the Sidik–Jonkman estimator for effect size model measures. Results: We included 17 studies in the meta-analysis containing 17,085 cases and 20,032 controls. The risk difference for SCCHN between mouthwash users and non-users was minimal, with a value of −0.02 [−0.05, 0.01]. Alcoholic mouthwash use was associated with a minimal decrease in risk (of −0.01 [−0.07, 0.05]). Frequent usage of mouthwash was associated with a statistically significant risk increase for SCCHN but the risk increase was marginal (0.04, [0.01, 0.06]). Conclusions: Overall, our study failed to show a statistically significant correlation between mouthwash use and the risk of SCCHN. The only statistically significant correlation that we could identify was between frequent usage and SCCHN, potentially caused by prolonged contact between some constituents of mouthwash (possibly alcohol) and the oral epithelium.

Bimodal multispectral imaging system with cloud-based machine learning algorithm for real-time screening and detection of oral potentially malignant lesions and biopsy guidance

SIGNIFICANCE

Screening and early detection of oral potentially malignant lesions (OPMLs) are of great significance in reducing the mortality rates associated with head and neck malignancies. Intra-oral multispectral optical imaging of tissues in conjunction with cloud-based machine learning (CBML) can be used to detect oral precancers at the point-of-care (POC) and guide the clinician to the most malignant site for biopsy.

AIM

Develop a bimodal multispectral imaging system (BMIS) combining tissue autofluorescence and diffuse reflectance (DR) for mapping changes in oxygenated hemoglobin (HbO2) absorption in the oral mucosa, quantifying tissue abnormalities, and guiding biopsies.

APPROACH

The hand-held widefield BMIS consisting of LEDs emitting at 405, 545, 575, and 610 nm, 5MPx monochrome camera, and proprietary Windows-based software was developed for image capture, processing, and analytics. The DR image ratio (R610/R545) was compared with pathologic classification to develop a CBML algorithm for real-time assessment of tissue status at the POC.

RESULTS

Sensitivity of 97.5% and specificity of 92.5% were achieved for discrimination of OPML from patient normal in 40 sites, whereas 82% sensitivity and 96.6% specificity were obtained for discrimination of abnormal (OPML + SCC) in 89 sites. Site-specific algorithms derived for buccal mucosa (27 sites) showed improved sensitivity and specificity of 96.3% for discrimination of OPML from normal.

CONCLUSIONS

Assessment of oral cancer risk is possible by mapping of HbO2 absorption in tissues, and the BMIS system developed appears to be suitable for biopsy guidance and early detection of oral cancers.

Invasive oral squamous cell carcinoma induced by concurrent smokeless tobacco and creamy snuff use: A case report

Oral squamous cell carcinomas (OSCC) are caused by chronic tobacco abuse. In this regard, the carcinogenic potential of smoking and smokeless forms of tobacco, including chewing tobacco and moist/dry snuff, has been widely documented. However, the effects of tobacco-containing products such as creamy snuff on oral health have not been widely reported. Here, we report on the clinical presentation of a patient with OSCC induced by concurrent chewing tobacco and creamy snuff use. The development and progression of mucosal carcinogenesis in the context of mixed tobacco use habits is discussed. With the increased availability of newer tobacco-containing products, it is important for clinicians to be aware of these products in the marketplace, including dentifrices and nicotine pouches, and counsel their patients regarding their health risks.

Alcohol consumption and risk of cardiovascular disease, cancer and mortality: a prospective cohort study

Background

Studies regarding whether light to moderate alcohol consumption is associated with a lower risk of cardiovascular diseases (CVD) have generated mixed results. Further, few studies have examined the potential impact of alcohol consumption on diverse disease outcomes simultaneously. We aimed to prospectively study the dose-response association between alcohol consumption and risk of CVD, cancer, and mortality.

Methods

This study included 83,732 adult Chinese participants, free of CVD and cancer at baseline. Participants were categorized into 6 groups based on self-report alcohol consumption: 0, 1–25, 26–150, 151–350, 351–750, and > 750 g alcohol/wk. Incident cases of CVD, cancers, and mortality were confirmed by medical records. Hazard ratios (HRs) for the composite risk of these three outcomes, and each individual outcome, were calculated using Cox proportional hazard model.

Results

During a median follow-up of 10.0 years, there were 6411 incident cases of CVD, 2947 cancers and 6646 deaths. We observed a J-shaped relation between alcohol intake and risk of CVD, cancer, and mortality, with the lowest risk at 25 g/wk., which is equivalent to ~ 2 servings/wk. Compared to consuming 1–25 g/wk., the adjusted HR for composite outcomes was 1.38 (95% confidence interval (CI):1.29–1.49) for non-drinker, 1.15 (95% CI: 1.04–1.27) for 26–150 g/wk., 1.22 (95% CI: 1.10–1.34) for 151–350 g/wk., 1.33 (95% CI: 1.21–1.46) for 351–750 g/wk., and 1.57 (95% CI: 1.30–1.90) for > 750 g/wk., after adjusting for age, sex, lifestyle, social economic status, and medication use.

Conclusions

Light alcohol consumption at ~ 25 g/wk was associated with lower risk of CVD, cancer, and mortality than none or higher consumption in Chinese adults.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00671-y.

Evaluation of density of tumor-associated macrophages using CD163 in histological grades of oral squamous cell carcinoma, an immunohistochemical study

Background:

Macrophages account for 30%–50% of the total inflammatory cell population of ''tumor microenvironment'' that plays an important role in cancer metastasis. M2 macrophages are designated as tumor-associated macrophages (TAMs). They are known to orchestrate all the stages of tumor progression. CD163 is TAMs–M2-specific marker.

Aims:

The aim of the study was to evaluate the role of TAMs using CD163 in different histological grades of oral squamous cell carcinoma (OSCC).

Setting and Design:

Expression of CD 163 was investigated in 30 histopthologically diagnosed cases of OSCC.

Materials and Methods:

Two sections of 4-μ thickness were stained with hematoxylin and eosin, CD163 (Cell Marque, USA). The expression of TAMs with CD163-positive cells was done by counting the number of macrophages in three high-power fields (×400), and the mean number of macrophages per HPF was evaluated.

Statistical Analysis:

The statistical analysis was performed using Statistical Software SPSS version 20.0.

Results:

CD163 TAMs score increasing in higher tumor, node, metastasis stages with significant positive correlation.

Conclusion:

With higher histological grades, CD163 TAMs score increased. Thus, TAMs may be considered as an independent factor for determining the progression of the tumor. The immunotherapeutic approaches to control M2 TAM numbers could protect against progression to malignancy.

Biological information and functional analysis reveal the role of discoidin domain receptor 1 in oral squamous cell carcinoma

OBJECTIVES

This study aimed to establish a framework for the role of discoidin domain receptor 1 (DDR1) in oral squamous cell carcinoma (OSCC) through biological data and functional analysis.

STUDY DESIGN

The GSE31056 series of the Gene Expression Omnibus database and UALCAN website were used to assess DDR1 expression in head and neck squamous cell carcinoma (HNSCC) and OSCC. DDR1 RNA sequencing data for 260 HNSCC samples from The Cancer Genome Atlas were overlaid to evaluate its association with tumor progression and prognosis. To identify the function of DDR1 in OSCC, 38 patients with OSCC were followed for 8 years and immunohistochemical analysis, western blotting, Cell Counting Kit-8, and colony formation assays were conducted on OSCC cell lines to reveal DDR1 expression and function.

RESULTS

DDR1 was overexpressed in HNSCC and OSCC tumor specimens and its expression correlated with overall survival and T-stage classification (P = .049, P = .0316). Furthermore, DDR1 was related to OSCC tumor growth because its expression increased with the T-stage level (P = .0071) but not N-stage level, histologic stage, or recurrence (P > .05). DDR1 was highly expressed in OSCC cell lines and promoted cell proliferation, which was repressed by nilotinib (P < .05).

CONCLUSIONS

DDR1 has an oncogenic role in OSCC and might be a novel target for anti-OSCC therapy.

Moving from two- to multi-way interactions among binary risk factors on the additive scale

Many studies have focused on investigating deviations from additive interaction of two dichotomous risk factors on a binary outcome. There is, however, a gap in the literature with respect to interactions on the additive scale of >2 risk factors. In this paper, we present an approach for examining deviations from additive interaction among three or more binary exposures. The relative excess risk due to interaction (RERI) is used as measure of additive interaction. First, we concentrate on three risk factors – we propose to decompose the total RERI to: the RERI owned to the joint presence of all three risk factors and the RERI of any two risk factors, given that the third is absent. We then extend this approach, to >3 binary risk factors. For illustration, we use a sample from data from the Greek EPIC cohort and we investigate the association with overall mortality of Mediterranean diet, body mass index , and smoking. Our formulae enable better interpretability of any evidence for deviations from additivity owned to more than two risk factors and provide simple ways of communicating such results from a public health perspective by attributing any excess relative risk to specific combinations of these factors.

Abbreviations: BMI: Body Mass Index; ERR: excess relative risk; EPIC: European Prospective Investigation into Cancer and nutrition; MD: Mediterranean diet; RERI: relative excess risk due to interaction; RR: relative risk; TotRERI: total relative excess risk due to interaction

Simultaneous identification to monitor consortia strain dynamics of four biofuel yeast species during fermentation

Mixed strain dynamics are still not well or easily monitored although recently molecular identification methods have improved our knowledge. This study used a chromogenic differential plating medium that allows the discrimination of four of the main selected biofuel strains that are currently under development for ethanol production from cellulosic hydrolysates. Complete fermentation of hexoses and xylose was obtained with a yeast consortium composed of Spathaspora passalidarum, Scheffersomyces stipitis, Candida akabanensis and Saccharomyces cerevisiae. The results showed that C.akabanensis excessively dominated consortium balance. Reducing its inoculum from 33 to 4.8% improved population strain balance and fermentation efficiency. Comparison of the consortia with single strain fermentations showed that it optimize sugar consumption and ethanol yields. This simple and cheap method also has advantages compared with molecular methods, as the yeast strains do not need to be genetically marked and identified cell proportions are probably active in the fermentation system as compared to DNA determination methods.

Joint effect of tobacco, alcohol, and oral HPV infection on head and neck cancer risk in the French West Indies

We investigated the role of tobacco and alcohol consumption on the occurrence of head and neck squamous cell carcinomas (HNSCC), and the joint effects of these factors with oral human papillomavirus (HPV) infection in the French West Indies, in the Caribbean. We conducted a population‐based case‐control study (145 cases and 405 controls). We used logistic regression models to estimate adjusted odds ratios (OR) and their 95% confidence intervals (CI). Two‐way interactions were assessed on both multiplicative and additive scales. Current smoking (OR = 11.6, 95% CI = 6.7‐20.1), drinking more than five glasses of alcohol per day (OR = 2.7, 95% CI = 1.2‐4.7), and oral infection with High‐risk HPV (OR = 2.4, 95% CI = 1.1‐5.0) were significantly associated with HNSCC. The combined exposure to tobacco and alcohol produced a significant synergistic effect on the incidence of HNSCC. Oral infection with High‐risk HPV increased the risk of HNSCC in never smokers and nondrinkers. The effects of tobacco, alcohol, and of the combined exposure of tobacco and alcohol were substantially lower in HPV‐positive than in HPV‐negative HNSCC. This is the first case‐control study to investigate the role of tobacco smoking, alcohol drinking and oral HPV infection in an Afro‐Caribbean population. Although each of these risk factors has a significant effect, our findings indicate that tobacco and alcohol play a less important role in Hr‐HPV‐positive HNSCC. Further investigations are warranted notably on the interaction of these three risk factors by cancer site.

Anti-Proliferative Effect of Statins Is Mediated by DNMT1 Inhibition and p21 Expression in OSCC Cells

Statins, also known as HMG-CoA reductase inhibitors, are a class of cholesterol-lowering drugs and their anti-cancer effects have been studied in different types of malignant diseases. In the present study, we investigated the anti-proliferative effects of statins, including cerivastatin and simvastatin, on oral squamous cell carcinoma (OSCC) cells. Our data showed that statins inhibited the proliferation of three OSCC cell lines in a dose-dependent manner and this growth inhibition was confirmed through G0/G1 cell cycle arrest. Accordingly, we found the upregulation of p21 and downregulation of cyclin-dependent kinases, including CDK2, CDK4, and CDK6, in the statin-treated cells. Importantly, we clearly showed that statins were able to inhibit the expression of DNA methyltransferase 1 (DNMT1) and further promote the expression of p21. Taken together, our data demonstrated that the anti-proliferative effect of statins is mediated by suppressing DNMT1 expression, thus promoting p21 expression and leading to G0/G1 cell cycle arrest in OSCC cells.

Tongue microbiome of smokeless tobacco users

Background

The possibility that smokeless tobacco may contribute to oral carcinogenesis by influencing the oral microbiome has not been explored. This preliminary cross-sectional study sought to assess the effect of using shammah, a form of smokeless tobacco prevalent in Arabia, on the tongue microbiome. Tongue scarping samples were obtained from 29 shammah users (SU; 27.34 ± 6.9 years) and 23 shammah non-users (SNU; 27.7 ± 7.19 years) and analyzed with 16S rRNA gene sequencing (V1-V3). Species-level taxonomy assignment of the high-quality, merged reads was obtained using a previously described BLASTn-based algorithm. Downstream analyses were performed with QIIME, LEfSe, and R.

Results

A total of 178 species, belonging to 62 genera and 8 phyla were identified. Genera Streptococcus, Leptotrichia, Actinomyces, Veillonella, Haemophilus, Prevotella and Neisseria accounted for more than 60% of the average microbiome. There were no differences between the two groups in species richness and alpha-diversity, but PCoA showed significant separation (P = 0.015, ANOSIM). LEfSe analysis identified 22 species to be differentially abundant between the SU and SNU. However, only 7 species maintained a false discovery rate of ≤0.2 and could cluster the two groups separately: Rothia mucilaginosa, Streptococcus sp. oral taxon 66, Actinomyces meyeri, Streptococcus vestibularis Streptococcus sanguinis and a potentially novel Veillonella species in association with SU, and Oribacterium asaccharolyticum with SNU.

Conclusion

These preliminary results indicate that shammah use induces tongue microbiome changes including enrichment of several species with high acetaldehyde production potential, which warrants further investigation.

Association of Smokeless Tobacco Use and Oral Cancer: A Systematic Global Review and Meta-Analysis

INTRODUCTION

Smokeless tobacco products have been linked to precancerous and cancers of oral cavity for long. Evidence was available on the association between smokeless tobacco (SLT) products and oral cancers at regional but not at global level. Present meta-analysis is aimed to evaluate the risk of oral cancer with the use of SLT products among "ever" versus "never" users.

METHOD

Studies published for the period (1960-2016) are retrieved using Pubmed, Indmed, EMBASE, and Google Scholar search engines for the subject "ever" versus "never" users of SLT products and estimated the risk association with oral cancer. Summary odds ratios (relative risk) are estimated and meta-analysis was performed using random-effects model.

RESULTS

Thirty-seven studies from four of six WHO regions, Southeast Asia region (SEAR), the Eastern Mediterranean Region (EMR), Europe, and region of Americas (North and South) are included in the analysis. Significant risk with SLT products with oral cancer was found for SEAR (4.44, 95% CI = 3.51 to 5.61) and for EMR (1.28, 95% CI = 1.04 to 1.56). Significantly higher risk (p < .001) was found for females (5.83, 95% CI = 2.93 to 11.58). Product wise analysis for different SLT products revealed various levels of risk viz. gutkha (8.67, 95% CI = 3.59 to 20.93), pan tobacco / betel liquid (7.18, 95% CI = 5.48 to 9.41), oral snuff (4.18, 50% CI = 2.37 to 7.38), Mainpuri tobacco (3.32, 95% CI = 1.32 to 8.36), and snus (0.86, 95% CI = 0.58 to 1.29).

CONCLUSION

A significant positive association was observed between SLT use and the risk of oral cancer, in SEAR, EMRs, and among women users.

IMPLICATIONS

The present meta-analysis demonstrates SLT product use and the risk of oral cancer at global level. Moreover, the present analysis provided data on the risk associated with individual SLT product. The results fulfil the gap in the data on independent effect of individual SLT product use on the outcome of oral cancer at global level, conclusively. Chewing SLT products was associated with higher risk of oral cancer than other types of SLT. This can serve as a useful tool for policy makers in forming strict policies in controlling SLT menace. Hence, we propose that in addition to smoking, efforts should be directed towards SLT product cessation as well in reducing oral cancer incidence.

Effects of Betel Quid, Smoking and Alcohol on Oral Cancer Risk: A Case-Control Study in Hunan Province, China

Background: The high prevalence of betel quid chewing is associated with a serious burden of oral diseases. However, there is limitertd research on the effects of betel quid, smoking, and alcohol on oral cancer in the Hunan province, China. Objectives: We investigated the relationship between oral cancer and betel quid chewing, smoking, and alcohol consumption in the betel quid endemic area of Hunan province. Methods: A paired case-control study from January 2014 to September 2015 was conducted in the Hunan province, China. We recruited 304 oral cancer patients and 304 controls as subjects, and both groups were treated in the same provincial cancer hospital. Control subjects and cancer patients were matched by sex, age (3-year groups), education level, and residential district. Conditional logistic regression analyses were used to examine the associations between oral cancer and betel quid, smoking, and alcohol consumption. Results: A significantly increased risk of oral cancer was associated with smoking, alcohol consumption, and betel quid chewing (odds ratio [OR] of 1.49, 1.56, and 5.80, respectively; p < .05). The risk of cancer was significantly elevated at high levels of intake and prolonged duration of consumption of betel quid, smoking, and alcohol. After adjusting for confounders, betel quid chewers were found to have almost 5 times increased risk for oral cancer (OR = 5.41, 95% confidence interval: 3.32-8.80, p < .001). Conclusions: There was a positive correlation between betel quid chewing and risk of oral cancer in the Hunan Province.

Prevalence and Correlates of Betel Quid Chewing among Bhutanese Adults

Background: Chewing of betel quid, popularly known as doma khamdo, is prevalent in Bhutan and is associated with Bhutanese customs and traditions. The objective of this paper was to determine the prevalence and explore the correlates of current betel quid use in Bhutan. Materials and methods: This is a retrospective study of secondary data from the National Health Survey 2012 (NHS 2012) of Bhutan. The outcome variable of interest was current betel quid use. The self-reported demographic characteristics were obtained using a questionnaire developed following the WHO STEPwise approach to the surveillance of non-communicable diseases (STEP). Univariate and multivariate logistic regression were performed to identify correlates for betel quid use. Results: The prevalence of current betel quid use in this study was 45.0%. The correlates associated with current betel quid use were: being female; having a primary, high school or a monastic education; being professionals in the armed forces, managers, technicians, service and sales workers, and machine operators; being current smokers; alcohol consumption; and intake of drugs. Correlates associated with decreased betel quid use were: having a diploma/certificate-level and non-formal education, and living in urban areas. Conclusion: The findings indicate that betel quid was consumed by nearly half of the Bhutanese population. Bhutan should immediately initiate national prevention programs targeting these correlates of betel quid use.

Assessing oral cancer awareness among dental and medical students of a Malaysian private university

OBJECTIVE

Dental and medical practitioners play a pivotal role in detecting early stages of oral cancers. Hence, future dental and medical practitioners need to have adequate knowledge of oral cancer. This study was conducted to assess the current level of knowledge, attitude and practices regarding oral cancer among dental and medical students of a Malaysian private university.

METHODS

A cross-sectional study was conducted on third-, fourth- and final-year students of the dental and medical courses of MAHSA University, Malaysia. A total of 557 students participated in the survey. Oral cancer awareness, knowledge about risk factors, signs and symptoms of oral cancer, attitude and practices towards oral cancer were assessed using 43 questions. The questionnaire was pretested, and internal consistency, assessed using Cronbach's alpha, was acceptable (α > 0.7). The data were analysed using IBM SPSS version 21. The chi-square test was used to analyse the difference in oral cancer awareness between medical and dental students.

RESULTS

Among 557 participants, there were 351 (63%) medical students and 206 (37%) dental students. Based on the results obtained, dental students had a higher level of knowledge than medical students regarding oral cancer (P < 0.05). More than 90% of the dental students were able to identify smoking, alcohol consumption, betel quid chewing, human papilloma virus infection and exposure to radiation as risk factors associated with oral cancer compared to more than 50% of medical students (P < 0.05).

CONCLUSIONS

Through education and training, awareness amongst medical students can be reinforced, which will promote early detection of precancerous lesions and oral cancers.

Association of smokeless tobacco with oral cancer: A review of systematic reviews

INTRODUCTION

Various primary studies and systematic reviews have been conducted to explain the association between smokeless tobacco and oral cancer. This study aims to consolidate and summarize the risk estimates from various systematic reviews with or without meta-analysis to provide the spectrum of estimates on the association between smokeless tobacco use and oral cancer.

METHODS

A comprehensive literature search was done on various databases (PubMed, Google Scholar, IndMED, and TOXLINE) by two of the authors independently. Both qualitative and quantitative data extraction and analysis were performed for the included systematic reviews. Range of risk estimates was obtained and analyzed as quantitative findings due to the limitation of an overview of reviews for the pooled estimates. CASP (Critical Appraisals Skills Programme) and AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) tools were used for the quality assessment of the studies included.

RESULTS

In total, 12 systematic reviews with or without meta-analysis were included in the review. There was a positive and strong association of Smokeless Tobacco (SLT) use with oral cancer irrespective of gender, region, and type of smokeless tobacco. The risk estimate for the South–East Asia Region (SEAR) ranged 4.44–7.90, for Gutkha it was 8.67, while for Paan it ranged 6.3–7.90 and for overall SLT it ranged 1.36–7.90. Risk estimate for females ranged 5.83–14.56.

CONCLUSIONS

The study confirmed the association between SLT use and oral cancer. These findings are of high importance, especially to the South-East Asia Region.

A novel seven‑miRNA prognostic model to predict overall survival in head and neck squamous cell carcinoma patients

Head and neck squamous cell carcinoma (HNSCC) is highly prevalent worldwide, and the outcome of HNSCC is still difficult to predict due to the lack of appropriate prognostic markers. In the present study, a prognostic model based on a miRNA panel was established to better predict the survival of HNSCC patients. miRNA expression data and clinical information regarding HNSCC patients were acquired from The Cancer Genome Atlas (TCGA) database. Accompanying clinical data was obtained from the University of California, Santa Cruz (UCSC) Xena browser. Using this data, 140 differentially expressed miRNAs (DEMs) were identified between HNSCC tissue samples (n=525) and adjacent normal tissue samples (n=44). The present prognostic model included seven miRNAs (i.e. hsa‑miR‑499a, hsa‑miR‑548k, hsa‑miR‑3619, hsa‑miR‑99a, hsa‑miR‑137, hsa‑miR‑3170, and hsa‑miR‑654), which were identified using least absolute shrinkage and selection operator (LASSO) and Cox regression analyses. The independence of the predictive power of this model was validated by further analyses using clinical information. The outstanding performance of the seven‑miRNA prognostic model was confirmed by time‑dependent receiver operating characteristic curve (ROC) analysis. These results indicated that combining the miRNA panel with pathological characteristics may provide a more accurate prognosis for HNSCC. Functional identification of the target genes of the focal miRNAs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were also performed. The present study demonstrated that the novel miRNA panel reported here may be useful in making different prognoses and may improve the clinical management of patients with HNSCC.

Low C6orf141 Expression is Significantly Associated with a Poor Prognosis in Patients with Oral Cancer

C6orf141 (Chromosome 6 open reading frame 141) is a novel gene, and its role in oral cancer progression remains unclear. C6orf141 expression in oral squamous cell carcinoma (OSCC) and adjacent normal tissues from 428 patients was examined through immunohistochemistry (IHC). Our results revealed that C6orf141 expression was significantly reduced in OSCC compared with adjacent normal tissues. Low C6orf141 expression was significantly associated with a poor American Joint Committee on Cancer pathological stage (P < 0.001), T classification (P = 0.002), and pN stage (P = 0.032). Kaplan-Meier curves revealed that low C6orf141 expression was significantly associated with shorter disease-specific survival (DSS) in patients with OSCC (log-rank P = 0.007). Multivariate analysis indicated that low C6orf141 expression was an independent prognostic biomarker for DSS (adjusted hazard ratio = 1.34; 95% confidence interval = 1.10-1.81; P = 0.05). Additionally, ectopic C6orf141 expression could significantly suppress oral cancer cell proliferation, colony formation, and migratory and invasive abilities. Xenograft tumor growth assay revealed that C6orf141 could significantly suppress oral tumor growth in vivo. Our results suggest that C6orf141 plays a novel tumor-suppressive role in oral cancer cell growth and motility. Furthermore, C6orf141 dysfunction could be a potential prognostic biomarker for OSCC and provide new therapeutic strategies in the future.

Early Adolescent Patterns of Alcohol and Tobacco Use in Eight Association of South-East Asian Nations (ASEAN) Member States

BACKGROUND

Though alcohol and tobacco are the most commonly used substances among adolescents, little is known about the patterning of early adolescent substance use in Association of South-East Asian Nations (ASEAN) member states.

OBJECTIVES

This study examined past month patterns of substances use and its gender difference among adolescents.

METHODS

Cross-sectional samples among adolescents aged 13-16 years who completed the Global School-based Student Health Survey (GSHS) from eight ASEAN countries were included in the analysis (n = 40,212).

RESULTS

Prevalence of past month any tobacco use was relatively high in Brunei, Indonesia, Malaysia, Thailand, and the Philippines (11-15%), but prevalence of dual cigarette and other forms of tobacco use was about 2-5% in the five countries. Past month alcohol consumption prevalence was also high in Thailand, Viet Nam, and the Philippines (16-24%), compared to the rest countries (1.4-8.2%). Moreover, prevalence of the concurrent alcohol and tobacco use was higher in Thailand and the Philippines (7 and 10%, respectively), particularly in boys (13 and 15%, respectively). Conclusions/importance: Almost 30-40% of the boys and 10-20% of girls in Malaysia, Philippines, Thailand, and Viet Nam are engaged in at least one of the two risk behaviors, and the concurrent alcohol and tobacco use was also relatively high among boys in those countries (5-15%). This study may provide some valuable insights on alcohol and tobacco policy in the region and requires to begin prevention and treatment programs in ASEAN member states.

Reviewing the role of human papillomavirus in oral cancer using the Bradford Hill criteria of causation

Human papillomavirus is a well-established risk factor for oropharyngeal cancer, although its role in oral cancer is still debated. Inconclusive evidence of its role in oral cancer is due to conflicting data arising from methodological differences, mostly due to the use of diagnostic tests with varying sensitivity and specificity. In addition, there is a lack of experimental data linking HPV to oral cancer. Recent epidemiological studies provide data on HPV prevalence in oral squamous cell carcinoma and other potentially malignant oral disorders. Further, molecular data from in vivo and in vitro models have led to new insights into the role of human papillomavirus in oral cancer. The clinical significance of identifying HPV as an etiology for oral squamous cell carcinoma is that if proven, vaccination could be an effective prevention tool. Further, like oropharyngeal squamous cell carcinoma, prognostic differences may exist between human papillomavirus positive and negative oral squamous cell carcinoma. This manuscript reviews data from the published literature using Bradford Hill criteria of causation to assess the role of human papillomavirus in oral cancer. Due to the advancement in molecular biology, the requirements of each of the Bradford Hill criteria of causation are modified to include integrated data from both epidemiological studies and experimental studies exploring molecular carcinogenesis.

Treatment outcomes of unknown primary squamous cell carcinoma of the head and neck

Background

Treatment modality of unknown primary squamous cell carcinoma of the head and neck (SCCHN) remains controversial.

Objectives

To evaluate the treatment outcomes and prognostic factors of unknown primary SCCHN.

Materials and methods

Patients with unknown primary SCCHN from April 1995 to March 2013 were recruited retrospectively.

Results

Sixty-nine patients were enrolled. The median time of follow-up was 55.5 months. The 2-year loco-regional control rate of all the patients was 60.4%. Multivariate Cox regression analysis revealed that N3 stage, extracapsular spread, distant metastasis, and treatment modality were significantly associated with neck recurrence. The actuarial 5-year disease-specific survival rates of neck dissection, neck dissection plus adjuvant therapy, radiotherapy alone, and combined therapy were 80.0%, 61.7%, 33.3%, and 68.8%, respectively (p = 0.046). The 5-year disease-specific survival rates of N1/N2a, N2b/N2c, and N3 stage were 83.9%, 64.3%, and 36.7%, respectively (p = 0.013). Univariate regression analysis revealed that neck recurrence, supraclavicular node involvement, distant metastasis, N3 stage, and unhealthy lifestyle habits were correlated with disease-specific mortality, especially the first three parameters. Patient’s occupation and comorbidity were not significantly correlated with survival.

Conclusions

Composite therapy is mandatory for advanced unknown primary SCCHN. Supraclavicular node involvement and unhealthy lifestyle habits, such as betel nut chewing, indicate a poor prognosis.