Emerging and established global life-style risk factors for cancer of the upper aero-digestive tract

A study of risk factors associated with the presence of oral potentially malignant disorders: a community-based study from Northeastern Thailand

BACKGROUND

The principal objective of this study is to ascertain the connections between well-known risk factors of oral cancer, including smoking (cigarette and tobacco), alcohol consumption, betel quid chewing, irritations in the oral cavity, history of head and neck cancer, and history of working outdoor more than 4 days/week, and the presence of OPMDs within the Thai population.

METHOD

349,318 subjects were recruited for initial screening, then 1,483 subjects who had at least 1 risk factor and a suspicious lesion underwent comprehensive oral examinations followed by a clinical diagnosis and then received initial treatment from either oral surgeons or oral medicine specialists. Among these subjects, individuals with at least 1 risk factor and with a clinical diagnosis of OPMDs were classified as cases, while those with at least 1 risk factor but without OPMDs were categorized as controls. The case group comprised a total of 487 subjects, whereas the control group consisted of 996 subjects. Exclusion criteria were known cases of currently having oral cancer or OPMDs.

RESULTS

The outcomes of the multivariate analysis revealed that among the variables assessed, betel quid (adjusted OR 5.12 [3.93-6.68], p < 0.001) and smoking (adjusted OR 1.46 [1.08-1.97], p = 0.013), there were an association with the presence of OPMDs. Conversely, alcohol drinking, having irritations in the oral cavity, a history of head and neck cancer, and a history of working outdoors more than 4 days/week were not associated with the presence of OPMDs. Furthermore, we also study the synergistic effect of alcohol drinking, irritations in the oral cavity, history of head and neck cancer, and history of working outdoors more than 4 days/week using subgroup analysis. The analysis showed that alcohol consumption combined with smoking or betel quid chewing expressed a significantly increased risk of OPMDs, from 1.46 to 2.03 (OR 2.03 [1.16-3.56], p = 0.014) and from 5.12 to 7.20 (OR 7.20 [3.96-13.09], p < 0.001).

CONCLUSION

Smoking and exposure to betel quid were a significant risk factors for the presence of OPMDs. The combination of alcohol with smoking or betel quid chewing was also found to increase the risk of OPMDs in this Thai northeastern population.

Breath biopsy, a novel technology to identify head and neck squamous cell carcinoma: A systematic review

Head and neck cancers are a heterogeneous group of neoplasms, which together comprise the sixth most common cancer globally. Breath biopsies are a non-invasive clinical investigation that detect volatile organic compounds (VOCs) in exhaled breath. This systematic review examines current applications of breath biopsy for the diagnosis of head and neck squamous cell carcinoma (HNSCC), including data on efficacy and utility, and speculates on the future uses of this non-invasive detection method. Medline, PubMed, Web of Science, Cochrane and Scopus, as well as the grey literature were searched using a search strategy developed to identify relevant studies on the role of breath biopsy in the diagnosis of HNSCC. All included studies were subject to a thorough methodological quality assessment. The initial search generated a total of 1443 articles, 20 of which were eligible for review. A total of 660 HNSCC samples were investigated across the included studies. 3,7-dimethylundecane and benzaldehyde were among several VOCs to be significantly correlated with the presence of HNSCC compared to healthy controls. We show that current breath biopsy methods have high accuracy, specificity and sensitivity for identifying HNSCC. However, further studies are needed given the reported poor quality of the included studies.

Detection of herpes simplex virus in oral tongue squamous cell carcinoma

Introduction: Oral tongue squamous cell carcinoma (OTSCC) is the most common cancer of the oral cavity. Contradictory results have been observed on the involvement of herpes simplex virus 1 (HSV-1) in oral squamous cell carcinomas. Here, we aimed to study the predominance of HSV-1 or HSV-2 in oral HSV infections and to investigate the presence of HSV-1 in OTSCC and its effect on carcinoma cell viability and invasion. Methods: The distribution of HSV types one and two in diagnostic samples taken from suspected oral HSV infections was determined from the Helsinki University Hospital Laboratory database. We then analysed 67 OTSCC samples for HSV-1 infection using immunohistochemical staining. We further tested the effects of HSV-1 using six concentrations (0.00001-1.0 multiplicity of infection [MOI]) on viability and two concentrations (0.001 and 0.1 MOI) on invasion of highly invasive metastatic HSC-3 and less invasive primary SCC-25 OTSCC cell lines using MTT and Myogel-coated Transwell invasion assays. Results: Altogether 321 oropharyngeal samples were diagnosed positive for HSV during the study period. HSV-1 was the predominant (97.8%) HSV type compared with HSV-2 (detected in 2.2% of samples). HSV-1 was also detected in 24% of the OTSCC samples and had no association with patient survival or recurrence. OTSCC cells were viable even after 6 days with low viral load (0.00001, 0.0001, 0.001 MOI) of HSV-1. In both cell lines, 0.001 MOI did not affect cell invasion. However, 0.1 MOI significantly reduced cell invasion in HSC-3 cells. Discussion: HSV-1 infection is predominant compared with HSV-2 in the oral cavity. HSV-1 is detected in OTSCC samples without clinical significance, and OTSCC cell survival or invasion was not affected at low doses of HSV-1.

Canned Fish Consumption and Upper Digestive Tract Cancers

Canned fish is a widely consumed and affordable food whose effect on cancer risk has been little investigated. We studied its effect on risk of upper digestive tract cancers using data from a network of hospital-based case-control studies from Northern Italy providing information about canned fish consumption as a separate item and including a total of 946 patients with oral cavity and pharynx cancer, 304 patients with esophageal cancer, 230 patients with gastric cancer and 3273 controls. Twenty-three percent of patients with cancer of the oral cavity or pharynx and 26% of those with cancer of the stomach consumed ≥1 serving per week of canned fish, compared to 40% and 49% of the respective control group. Among cases of esophageal cancer and controls 22% consumed ≥1 serving per week of canned fish. Odds ratios for ≥1 vs <1 portion per week were 0.79 (95% Confidence Interval, CI: 0.64-0.97) for cancer of the oral cavity and pharynx, and 0.59 (95% CI: 0.41-0.86) for stomach cancer, whereas there was no inverse association with esophageal cancer. These findings suggest a favorable role of canned fish for selected upper digestive tract cancers.

A roadmap of six different pathways to improve survival in laryngeal cancer patients

PURPOSE OF REVIEW

Laryngeal cancer continues to require improvement in earlier stage diagnosis and better imaging delineation of disease, and hence 'more evidence-based' selection of treatment, as recent evidence suggests that related mortality, in the last decades, has not significantly decreased worldwide. Even though the reasons are not fully understood, there persists an urgency for a review and development of future strategies to embrace such clinical and diagnostic challenges from a political, societal, as well as scientific and clinical points of view.

RECENT FINDINGS

This review of the published literature suggests that survival improvement in laryngeal cancer may be achieved by fuelling and combining at least some or all of six targeted agendas: documentation of disease global incidence and national burden monitoring; development and implementation of high-quality cancer registries; education on risk factors and hazardous habits associated with laryngeal cancer for the general population; active modification of proven at-risk population lifestyles; centralization of treatment; and use of machine learning of gathered 'big data' and their integration into approaches for the optimization of prevention and treatments strategies.

SUMMARY

Laryngeal cancer should be tackled on several fronts, commencing with disease monitoring and prevention, up to treatment optimisation. Available modern resources offer the possibility to generate significant advances in laryngeal cancer management. However, each nation needs to develop a comprehensive approach, which is an essential prerequisite to obtain meaningful improvement on results.

Frequencies of Porphyromonas gingivalis Detection in Oral-Digestive Tract Tumors

Mounting evidence suggests a causal relationship between specific bacterial infections and the development of certain malignancies. In this study, we examined the presence of Porphyromonas gingivalis (P. gingivalis) in oral-digestive tract tumors by immunohistochemistry (IHC) and PCR and analyzed the correlation between P. gingivalis detection and clinicopathological characteristics and prognosis of oral and esophageal carcinoma. The IHC results showed that the positive rates of P. gingivalis were 60.00, 46.00, 20.00, 6.67, and 2.86% in oral, esophagus, cardiac, stomach, and colorectal cancer tissues, respectively. Likewise, PCR results showed rates of 56.00, 42.00, 16.67, 3.33, and 2.86%, respectively. The two methods were consistent, and the kappa value was 0.806, P < 0.001. In addition, P. gingivalis expression was significantly correlated with lymph node metastasis and the clinical stages of oral and esophageal cancer (P < 0.05). The overall survival rate of the P. gingivalis undetected group (86, 50%) was significantly higher than that of the P. gingivalis detected group (57, 14%) for oral and esophageal cancer, respectively. In conclusion, the detection rate of P. gingivalis showed a decreasing trend in oral-digestive tract tumors. Detection with P. gingivalis was associated with poor prognosis for oral and esophageal cancer.

Differences in the bacteriome of swab, saliva, and tissue biopsies in oral cancer

Microbial dysbiosis has been implicated in the pathogenesis of oral cancer. We analyzed the compositional and metabolic profile of the bacteriome in three specific niches in oral cancer patients along with controls using 16SrRNA sequencing (Illumina Miseq) and DADA2 software. We found major differences between patients and control subjects. Bacterial communities associated with the tumor surface and deep paired tumor tissue differed significantly. Tumor surfaces carried elevated abundances of taxa belonging to genera Porphyromonas, Enterobacteriae, Neisseria, Streptococcus and Fusobacteria, whereas Prevotella, Treponema, Sphingomonas, Meiothermus and Mycoplasma genera were significantly more abundant in deep tissue. The most abundant microbial metabolic pathways were those related to fatty-acid biosynthesis, carbon metabolism and amino-acid metabolism on the tumor surface: carbohydrate metabolism and organic polymer degradation were elevated in tumor tissues. The bacteriome of saliva from patients with oral cancer differed significantly from paired tumor tissue in terms of community structure, however remained similar at taxonomic and metabolic levels except for elevated abundances of Streptococcus, Lactobacillus and Bacteroides, and acetoin-biosynthesis, respectively. These shifts to a pro-inflammatory profile are consistent with other studies suggesting oncogenic properties. Importantly, selection of the principal source of microbial DNA is key to ensure reliable, reproducible and comparable results in microbiome studies.

Mortality from Selected Cancers among Brazilian Mechanics

Introduction:

Mechanics are exposed to known human carcinogens. This study aimed to compare mortality from selected cancers between male mechanics and the general population of the South and Southeast regions of Brazil.

Methods:

Data on deaths, occurred between 2006-2017, among male mechanics and the general population, were obtained from the Mortality Information System. Occupations were classified using the Brazilian Classification of Occupations. Mortality Odds Ratio (MOR) and confidence intervals (95%) for selected cancers among mechanics, stratified by age (30-49, 50-69 years), race, and education compared to the general population, were estimated using logistic regression models.

Results:

In general, mechanics showed higher mortality from oropharynx, hypopharynx, larynx, lung and bladder cancers, but lower mortality for all leukemias. Oropharynx and larynx cancer mortality risk was slightly higher among older mechanics, while hypopharynx cancer mortality was more noticeable among the youngest. Lower mortality from all leukemias was observed only among younger mechanics. Mortality by oropharynx and larynx cancers were higher among white mechanics. They were also the only ones to experience higher mortality by hypopharynx cancer, while lung cancer mortality were increased only among non-white ones. Mechanics of all educational levels were more likely to die by the oropharynx cancer. Those with 1-7 and 8 or more years of schooling also showed excess of death by the cancers of larynx and all leukemias. Significantly higher mortality by pancreas cancer was only observed among mechanics with no education, while those with 1-7 years of schooling showed higher risk to die by lung and bladder cancers. Those with 8 or more years of schooling show increased mortality risk for hypopharynx cancer. Increased mortality risk for myeloid leukemia was only observed when stratified by region of residence.

Conclusion:

Results of our study suggest a positive association between mechanic occupation and some specific cancers.

Smokeless Tobacco Use, Cigarette Smoking, and Upper Aerodigestive Tract Cancers: A Case-Control Study in the Batna Region, Algeria, 2008-2011

BACKGROUND

A significant proportion of the Algerian population uses tobacco products and is at risk of developing tobacco-associated cancers.

AIMS

This case-control study reports on the association between tobacco use and the occurrence of upper aerodigestive tract (UADT) cancers in Batna, Algeria.

METHODS

Incident primary UADT cancer cases in residents of Batna in 2008-2011 were identified using the regional tumor registry. One hospital and 1 population control were matched to each case by sex, year of birth, and residence. Information on tobacco use was collected, and odds ratios (ORs) were obtained using conditional logistic regression also after sex stratification.

RESULTS

The study included 192 cases (80%) of the 241 primary UADT cancer cases identified and 384 controls. Males represented 76.6% of cancer cases. Cancers of the nasopharynx (48%) and the larynx (26%) were the most common types. Ever use of smokeless tobacco (ST) (OR = 1.0; 95% confidence interval [CI]: 0.6-1.5) or current ST use (OR = 1.1; 95% CI: 0.6-1.7) was not associated with overall risk of UADT cancers. Associations with cancers of the nasopharynx (OR = 1.5; 95% CI: 0.5-4.6) and oral cavity/oropharynx (OR = 3.0; 95% CI: 0.8-11.8) were found when comparing use of ST only to no consumption of any tobacco. Cigarette smoking was associated with an increase in the overall risk of UADT cancers, with a 3-fold increase in the risk of laryngeal cancer when comparing smoking only to no consumption of any tobacco (OR = 3.3; 95% CI: 1.0-11.5). Associations for smokers who also consumed ST differed by cancer site.

CONCLUSION

In this study from Algeria dominated by male cases and by cancer in the nasopharynx, cigarette smoking but not ST was associated with UADT cancer. Analyses by anatomical site and using as reference never use of any type of tobacco suggested few associations with ST but of lower precision.

Association between polymorphisms in the CYP1A1, CYP2E1 and GSTM1 genes, and smoking, alcohol and upper digestive tract carcinomas in a high-incidence area of northern China

Metabolic gene variants, smoking, and alcohol consumption are important upper digestive tract cancer (UDTC) risk factors. However, the gene-gene and gene-environment interactions remain unclear. A case-control study in a high incidence area for upper digestive tract cancer was conducted in China. DNA was extracted from buffy coat samples for PCR or PCR-restriction fragment length polymorphism. Smoking and alcohol drinking status was determined by questionnaires. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the associations. After adjusting for confounding factors, smoking increased esophageal cancer (EC), gastric cardia cancer (GCC) and gastric antral carcinoma (GAC) risk by 3.594, 4.658, and 3.999-fold, respectively. Alcohol consumption increased EC, GCC and GAC risk by 1.953, 2.442 and 1.765-fold, respectively. The cytochrome P4501A1 (CYP1A1) rs4646903 T>C polymorphism increased GCC risk, the cytochrome P4502E1 (CYP2E1) rs2031920 C>T polymorphism increased EC risk, while the GSTM1 null genotype decreased EC risk. An association existed between the following: CYP1A1 rs4646903 and smoking in EC, GCC and GAC; CYP1A1 rs4646903 and alcohol consumption in EC and GCC; CYP2E1 rs2031920 and smoking in EC, GCC and GAC and CYP2E1 rs2031920 and alcohol consumption in EC and GCC. No association was observed between CYP1A1 and CYP2E1. The glutathione S-transferase mu 1 (GSTM1) null genotype decreased EC risk (OR=0.510). Smoking/drinking are upper digestive tract cancer risk factors. The CYP1A1 rs4646903 and CYP2E1 rs2031920 polymorphisms were risk factors of GCC or EC, and the GSTM1 null genotype may serve a protective role against EC. The results of the present study indicated that gene-environment interactions increase the risk of UDTC.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

Role of Poor Oral Hygiene in Causation of Oral Cancer-a Review of Literature

Oral squamous cell carcinomas (OSCC) are among the commonest cancers in South East Asia and more so in the Indian subcontinent. The role of tobacco and alcohol in the causation of these cancers is well-documented. Poor oral hygiene (POH) is often seen to co-exist in patients with OSCC. However, the role of poor oral hygiene in the etio-pathogenesis of these cancers is controversial. We decided to evaluate the available literature for evaluating the association of POH with OSCC. A thorough literature search of English-language articles in MEDLINE, PubMed, Cochrane Database of Systematic Reviews, and Web of Science databases was conducted, and 93 relevant articles were short-listed. We found that POH was strongly associated with oral cancers. It aids the carcinogenic potential of other known carcinogens like tobacco and alcohol. Even on adjusting for known confounding factors like tobacco, alcohol use, education, and socio-economic strata, presence of POH exhibits higher odds of developing oral cancer.

A cross-sectional survey of awareness of human papillomavirus-associated oropharyngeal cancers among general practitioners in the UK

OBJECTIVES

To examine the level of awareness of the link between human papillomavirus (HPV) and oropharyngeal cancer (OPC) and epidemiological trends in HPV-related OPC among general practitioners (GPs) in the UK.

DESIGN

Cross-sectional survey.

PARTICIPANTS

384 GPs from England, Scotland, Wales and Northern Ireland.

SETTING

The survey was administered at GP training courses and via email to lists of training course attendees.

PRIMARY AND SECONDARY OUTCOME MEASURES

Proportion of respondents aware of the link between HPV and OPC; respondents' self-rated knowledge of OPC; proportion of participants aware of the epidemiological trends in HPV-associated OPC.

RESULTS

384 questionnaires were completed with an overall response rate of 72.9%. 74.0% of participants recognised HPV as a risk factor for OPC, which was lower than knowledge about the role of smoking, chewing tobacco and alcohol consumption (all >90% recognition). Overall, 19.4% rated their knowledge of OPC as very good or good, 62.7% as average and 17.7% as poor or very poor. The majority (71.9%) were aware that rates of HPV-associated OPC have increased over the last two decades. Fewer than half (41.5%) of the participants correctly identified being male as a risk factor of HPV-associated OPC, while 58.8% were aware that patients with HPV-associated OPC tend to be younger than those with non-HPV-associated disease.

CONCLUSIONS

The association of HPV infection with OPC is a relatively recent discovery. Although the level of awareness of HPV and OPC among GPs was high, the characteristics of HPV-associated OPC were less well recognised, indicating the need for further education.

Oral cancer associated with chronic mechanical irritation of the oral mucosa

Background

Most of the studies dealing with Chronic Mechanical Irritation (CMI) and Oral Cancer (OC) only considered prosthetic and dental variables separately, and CMI functional factors are not registered. Thus, the aim of this study was to assess OC risk in individuals with dental, prosthetic and functional CMI. Also, we examined CMI presence in relation to tumor size.

Material and Methods

A case-control study was carried out from 2009 to 2013. Study group were squamous cell carcinoma cases; control group was patients seeking dental treatment in the same institution.

Results

153 patients were studied (Study group n=53, Control group n=100). CMI reproducibility displayed a correlation coefficient of 1 (p<0.0001). Bivariate analysis showed statistically significant associations for all variables (age, gender, tobacco and alcohol consumption and CMI). Multivariate analysis exhibited statistical significance for age, alcohol, and CMI, but not for gender or tobacco. Relationship of CMI with tumor size showed no statistically significant differences.

Conclusions

CMI could be regarded as a risk factor for oral cancer. In individuals with other OC risk factors, proper treatment of the mechanical injuring factors (dental, prosthetic and functional) could be an important measure to reduce the risk of oral cancer.

Key words:Oral cancer, risk factors, chronic mechanical irritation, tumor size, case-control study.

Associations between oral hygiene habits, diet, tobacco and alcohol and risk of oral cancer: A case-control study from India

OBJECTIVE

This study examines the association between the incidence of oral cancer in India and oral hygiene habits, diet, chewing and smoking tobacco, and drinking alcohol. We also assessed the effects of oral hygiene habits with oral cancer risk among chewers versus never chewers.

METHODS

A hospital-based case-control study was conducted in Pune, India, based on face-to-face interviews, anthropometry, and intra-oral examinations conducted for 187 oral cancer cases and 240 controls.

RESULTS

Poor oral hygiene score was associated with a significant risk of oral cancer (adjusted OR=6.98; 95%CI 3.72-13.05). When stratified by tobacco-chewing habit, the poor oral hygiene score was a significant risk factor only among ever tobacco chewers (adjusted OR=14.74; 95%CI 6.49-33.46) compared with never chewers (adjusted OR=0.71; 95%CI 0.14-3.63). Dental check-ups only at the time of pain by ever-chewers with poor oral hygiene was associated with an elevated risk (adjusted OR=4.22; 95%CI 2.44-7.29), while consumption of green, yellow, and cruciferous vegetables and citrus fruits was protective. A linear dose-response association was observed between oral cancer and chewing tobacco in terms of age at initiation, duration, and frequency of chewing per day (P<0.001). Smoking more than 10 bidis/cigarettes per day (adjusted OR=2.74; 95%CI 1.28-5.89) and for a duration >25 years (adjusted OR=2.31; 95%CI 1.14-4.71) elevated the risk of oral cancer.

CONCLUSION

Good oral hygiene habits - as characterized by healthy gums, brushing more than once daily, use of toothpaste, annual dental check-ups, and a minimal number of missing teeth - can reduce the risk of oral cancer significantly. In addition to refraining from chewing/smoking tobacco, a diet adequate in fruits and vegetables may protect against the disease.

Predictors affecting quality of life in patients with upper aerodigestive tract cancers: a case-control study from India

OBJECTIVE

The aim of this study was to measure quality of life (QOL) in patients with upper aerodigestive tract (UADT) cancer in comparison with hospital-based controls. We also assessed the impact of various clinical predictors at time of diagnosis of disease/cancer on QOL in these patients.

STUDY DESIGN

A case-control study was conducted (N = 480) with 240 UADT cancer cases and 240 controls matched by gender and age (≥5 years) from 2 different hospitals in Pune, India. The University of Washington Quality of Life Questionnaire was used to measure QOL and was administered through face-to-face interviews. Various QOL domains were analyzed by using one-way analysis of variance and Bonferroni adjustments for post hoc comparisons.

RESULTS

Cases had significantly lower scores across all domains of QOL compared with controls. Overall, the most affected domains were anxiety and mood. Cancer site significantly influenced QOL, with patients with cancers of the oropharynx and hypopharynx having the worst mean scores across all domains. Patients with stage IV cancer had the worst mean scores across the majority of the QOL domains. Our findings highlight the complex interactions between individual and clinical predictors that have an impact on QOL.

CONCLUSIONS

QOL needs to be incorporated as an important outcome measure in an individualized approach to therapeutic and palliative care planning to enable a better quality of survival of patients with UADT cancers.

Relationship of Lifetime Exposure to Tobacco, Alcohol and Second Hand Tobacco Smoke with Upper aero-digestive tract cancers in India: a Case-Control Study with a Life-Course Perspective

Background:

Squamous cell carcinomas of the upper aero-digestive tract (UADTSCC) are a multifaceted public health problem. Effects of lifestyle risk factors, including tobacco (chewing and smoking), alcohol drinking and exposure to second hand tobacco smoke (SHS) at home and their association with UADT cancers was assessed in a case-control study with a life-course perspective. The study was conducted at two different hospitals in Pune, India.

Material and methods:

The total sample size (N=480) included 240 histopathologically confirmed cases of UADT cancers and an equal number of controls frequency matched with cases by gender and age distribution (+5 years). All the patients were interviewed face-face using structured questionnaires. Self-reported information on socio-demographic and lifestyle risk factors from childhood to the date of diagnosis of disease/cancer was obtained. Frequency, duration and age of initiation of habits were also recorded to study dose-response relationships. Odds ratios and their 95% confidence intervals were calculated through unconditional logistic regression, adjusting for relevant potential confounders.

Results:

Chewing tobacco emerged as the strongest predictor for UADT cancers (OR=7.61; 95% CI 4.65-12.45) in comparison to smoking and drinking alcohol. Exposure to SHS during childhood (<16 years) rather than ≥16 years increased the risk (OR=4.05; 95% CI 2.06-7.95). Combined effects of tobacco and alcohol consumption habits elevated the risk by twelve fold (OR=12.05; 95% 4.61-31.49) in comparison to never users of these habits. Furthermore, the combination of these lifestyle risk factors accounted for 86.8% of population attributable risk.

Conclusions:

Early exposure to various modifiable lifestyle risk factors has a strong positive association with UADT cancer incidence. Effective future public health interventions with focus on vital time points in life targeting these risk factors could possibly be a major step in primary prevention and control of this cancer at the population level.

A risk factor-based model for upper aerodigestive tract cancers in India: predicting and validating the receiver operating characteristic curve

BACKGROUND

A study was conducted to develop and validate a screening model using risk scores to identify individuals at high risk for developing upper aerodigestive tract (UADT) cancers in an Indian population.

METHODS

A hospital-based case-control study (n = 480) was conducted in Pune, India. We assessed risk factors for UADT cancers by administering a questionnaire through face-to-face interviews. We developed a risk factor model based on the statistically significant risk factors in multiple logistic regression. A total, single risk score was calculated per individual based on the adjusted odds ratio for each of their risk factors. Standard receiver operator characteristic curve was plotted for the total score and the presence of UADT cancers. The stratification ability of the model was determined using the c-statistic. The optimal criterion value was determined at the point on curve at which the Youden's index was maximal. Confidence intervals were calculated by bootstrapping.

RESULTS

Total risk score for each individual ranged from 0 to 26. Area under the receiver operating characteristic curve (95.8; P < 0.001) suggests strong predictive ability. A risk score criterion value of ≤10 produced optimal sensitivity (93.5%), specificity (71.1%), false-positive rate (28.8%), false-negative rate (6.4%), positive predictive value (74.8%), and negative predictive value (96.6%).

CONCLUSION

This risk factor-based model has the potential of satisfactorily screening and detection of UADT cancers at its early stage in a high-risk population like India. The identified at-risk individuals can then be targeted for clinical examination and for focused preventive/treatment measures at the hospital.

Epidemiological Study of Laryngeal Carcinoma in Western Nepal

BACKGROUND

Laryngeal malignancy is a common malignancy of the head and neck region. Affected patients usually present with features that are characteristic of certain subsites. The larynx is oncologically divided into three: supraglottis, glottis and subglottis. Studies from Western countries have shown that the glottis is the commonest subsite to harbour laryngeal malignancy. However, the supraglottis has been reported to be the commonest subsite in developing countries, including examples in the Indian subcontinent. To our knowledge, no study has been carried out in western Nepal about the epidemiology of laryngeal cancer to date. The purpose of this study was to analyse the epidemiology of laryngeal cancer in relation to its risk factors, age distribution,and preferred subsites and to see if there is any recent change in the subsite wise distribution of laryngeal malignancy in western Nepal.

MATERIALS AND METHODS

Patients of all ages and both sexes with suspected laryngeal malignancy were enrolled in the initial study. Detailed history taking and clinical examination was performed to find out the involved subsite in relation to the clinical features. Direct laryngoscopy was performed to further confirm the subsite and to take biopsy from the growth under general anesthesia. After confirmation of malignancy from the biopsy report, patients were finally included in the study. Data were analysed and observations were made to find out the distribution of laryngeal malignancy in different subsites.

RESULTS

The supraglottic larynx was the commonest subsite to harbor laryngeal malignancy. Smoking and alcohol were found to be the common risk factors. The mean age of the patients was in their sixties.

CONCLUSIONS

Laryngeal malignancy is common in elderly individuals. Supraglottic laryngeal malignancy is the commonest laryngeal malignancy in people who smoke and drink alcohol in Nepal. Avoidance of alcohol use and smoking will be a milestone to reduce the incidence of laryngeal cancers and associated mortality.

Ethnic Variation in Consumption of Traditional Tobacco Products and Lung Cancer Risk in Nepal

Lung cancer is the leading contributor to cancer deaths in the developing world. Within countries, significant variability exists in the prevalence of lung cancer risk, yet limited information is available whether some of the observed variability is associated with differences in the consumption pattern of local tobacco products with differing potency. We recruited 606 lung cancer cases and 606 controls from the B.P. Koirala Memorial Cancer Hospital in Nepal from 2009-2012. We estimated odds ratios (ORs) and 95% confidence intervals (CI) for lung cancer risk associated with different tobacco products, using unconditional logistic regression. Unfiltered cigarettes tended to be the most frequently used products across ethnic subgroup with about 53.7% of Brahmins, 60.1% of Chettris, and 52.3% of Rai/Limbu/Magar/others. In contrast, about 39.9% of Madishe/Tharu smokers reported using bidi compared with only 27.7% who smoked unfiltered cigarettes. Among those who only smoked one type of product, choor/kankat smokers had the highest lung cancer risk (OR 10.2; 95% CI 6.2-16.6), followed by bidi smokers (OR 5.6; 95% CI 3.6-8.7), unfiltered cigarettes (OR 4.9; 95% CI 3.4-7.2), and filtered cigarettes (OR 3.4; 95% CI 2.2-5.3). A clear dose-response relationship was observed between increased frequency of smoking and lung cancer risk across all ethnic subgroups. These results highlight the important role of traditional tobacco products on lung cancer risk in the low income countries.

Village Voices: Lessons about Processes for Disease Prevention from a Qualitative Study of Family Health Leaders in a Community in Northeastern Thailand

BACKGROUND

Cancer is a primary source of concern in Thailand and other countries around the world, including the Asian-Pacific region. Evidence supports that an important contributing cause of cancer and other chronic illnesses such as stroke, diabetes, and hypertension is excessive alcohol consumption. Studies conducted in Thailand reveal a worrisome rise in the number of new and regular drinkers in communities. Therefore, actions for primary, secondary and tertiary prevention of problem drinking are necessary. In recent years nurses in North East Thailand have been developing and implementing the Khon Kaen Family Health Nursing model to embed disease prevention in communities through the actions of family health nurses and local family health leaders.

AIM

The aim of this qualitative research was to better understand the experiences of the local family health leaders using this model and to synthesize lessons learned.

MATERIALS AND METHODS

As part of a participatory action research approach involving analysis of focus group discussions and individual interviews, the experiences of 45 family health leaders were synthesized.

RESULTS

Four main themes were identified, namely: i) Family first: role modeling beginning at the personal and family level. ii) Local leverage: using village community forums to reduce alcohol drinking. iii) Gentle growth: making the first step and treading gently; and iv) Respect, Redemption, Rehabilitation: valuing the person to re-integrate them in the village society.

CONCLUSIONS

As alcohol consumption in the village declined significantly following the prevention program, these findings illuminate how low-tech integrated prevention approaches may be very useful, particularly in rural communities. The lessons learned may have relevance not only in Thailand but in other countries seeking to prevent and mitigate behavior that conduces to diseases such as cancer.

Life course models for upper aero-digestive tract cancer

Upper aero-digestive tract (UADT) cancers are collectively cancers of various human body sites, such as the oral cavity, pharynx, oesophagus and larynx. Worldwide, they are the fourth most frequent cancer type and the fourth most common cause of mortality from cancer. Many studies have shown that several chronic diseases, such as cancer, which occur more commonly in later adulthood, are influenced by social and psychological circumstances during birth, childhood, adolescence and early adult life. It is suggested that the build up of problematic circumstances throughout life is the cause of disease, rather than circumstances that happen at one point in time. UADT cancer is a chronic disease of complex multifactorial origin and most of the underlying exposures/risks cannot be considered as individual factors or in isolation, as they act at different levels, which differ from time to time. Thus, life-course epidemiology, rather than drawing false dichotomies between different risk factors of the underlying disease, attempts to integrate biological and social risk processes that cause the chronic disease. It studies how socially patterned exposures during all stages of life--childhood, adolescence and early adult--influence disease risk in adulthood and socio-economic position and hence may account for social inequalities in adult health and mortality. Furthermore, varying health effects, according to the timing or duration of exposure to socio-economic circumstances, may indicate important traces to the causes of cancer. In this paper, we have attempted to draw a conceptual framework on the relationships between socio-economic inequalities, oral health risk factors along the life-course of an individual and incidence of UADT cancer.