Involuntary smoking and head and neck cancer risk: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

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

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

Exclusive use of different types of tobacco products, exposure to secondhand tobacco smoke and risk of subtypes of head and neck cancer among Indian males

Tobacco products are used in vary many forms in India. Although the risk of tobacco uses in developing head and neck cancer (HNC) is known, risk by exclusive use of different tobacco products on HNC and its subtypes is poorly understood. A case-control study was conducted at a tertiary cancer hospital, which receives cases from different geographical regions of India with use of different types of tobacco products. The study included 824 oral cavity (OC), 149 oropharynx (OPX) 104 hypopharyngeal (HPX) and 81 larynx (LX) cancer cases and 1206 visitor controls. Information on 11 different types of tobacco products and exposure to secondhand smoke was collected through structured questionnaires. Odds ratios (OR) and 95% confidence intervals (CI), for the association of various HNC subtypes with exclusive use of each tobacco product compared to nonusers of tobacco were estimated using logistic regression models, after adjusting for potential confounders. Exclusive use of any type of smokeless tobacco product was strongly associated with all subtypes of HNC. Gutka chewing (only) had highest risk (OR = 33.67; 95% CI = 19.8-57.0) while exclusive users of betel quid with tobacco (BQ + T), tobacco quid, Khaini, Mawa and Mishri users had a OR of 14.77, 24.20, 5.33, 2.96 and 3.32, respectively, for development of OC. Bidi smoking and secondhand smoke was independently associated with increased risk of HNC. Our study indicates that tobacco control policies should focus on product specific awareness messaging that switching between tobacco product types is not a safe alternative to complete cessation.

Differential characteristics of patients with squamous cell carcinoma of the head and neck with no history of tobacco or alcohol use

OBJECTIVE

The present study aims to analyse the differential characteristics of patients with head and neck squamous cell carcinoma (HNSCC) without a history of consumption of toxic substances such as tobacco and alcohol.

MATERIAL AND METHODS

We carried out a retrospective study of 4694 patients with HNSCC located in the oral cavity, oropharynx, hypopharynx or larynx treated in our centre during the period 1985-2019.

RESULT

7.7% of the patients (n = 363) did not report a history of consumption of toxic substances. The group of patients with no toxic history was older, had a higher proportion of women, a higher frequency of cases located in the oral cavity, a higher proportion of cases diagnosed in early stages, and a lower incidence of second neoplasms. The percentage of patients with no history of consumption of toxic substances increased significantly over the study period. The overall survival of patients with no history of consumption of toxic substances was significantly higher than that of patients with toxic substances use. Specific survival for patients with tumours located in the oral cavity without a history of consumption of toxic substances was significantly lower than that of patients with toxic substances use, whereas for patients with oropharyngeal carcinomas the absence of a history of consumption of toxic substances was associated with a better prognosis.

CONCLUSIONS

There were differences in the epidemiological and prognostic characteristics of patients with HNSCC according to the history of consumption of toxic substances such as tobacco and alcohol.

Reviewing the epidemiology of head and neck cancer: definitions, trends and risk factors

Introduction Head and neck cancer appears to be increasing in incidence, with potential changes in aetiology proposed. This paper aims to provide a narrative overview of the epidemiological literature to describe the disease burden and trends in terms of incidence and mortality both in the UK and globally and to review the evidence on current risk factors.

Methods A search was performed on multiple databases (PubMed and Epistemonikos), applying filters to identify systematic reviews and meta-analyses which investigated head and neck cancer incidence, mortality and risk factors. International and UK cancer registries and sources were searched for incidence and mortality data.

Results Multiple definitions of head and neck cancer are employed in epidemiology. Globally, incidence rates have increased in recent decades, largely driven by oropharyngeal cancer. Mortality rates over the last decade have also started to rise, reflecting the disease incidence and static survival rates. Major risk factors include tobacco smoking alone and in combination with alcohol consumption, betel chewing (particularly in Southeast Asian populations) and the human papillomavirus in oropharyngeal cancer.

Conclusions These epidemiological data can inform clinical and preventive service planning for head and neck cancer.

Head and neck cancer incidence is increasing and is projected to continue to rise, largely driven by increases in oropharyngeal cancer.

Mortality rates have started to increase within the last decade, reflecting a rising incidence and static survival rates.

Major risk factors that are associated with the risk of head and neck cancer are tobacco smoking and tobacco used in combination with alcohol consumption. Human papillomavirus is an additional major risk factor for oropharyngeal cancer. Cancers of the head and neck are clearly socioeconomically patterned but this socioeconomic risk is not entirely explained by smoking and alcohol behaviours.

Secondhand smoke exposure and oral cancer risk: a systematic review and meta-analysis

OBJECTIVES

Inhalation of secondhand smoke (SHS) causes several diseases, including lung cancer. Tobacco smoking is a known cause of oral cancer; however, it has not been established whether SHS also causes oral cancer . The aim of this study was to evaluate the potential association between SHS exposure and the risk of oral cancer.

METHODS

A systematic review and meta-analysis study (following the PRISMA guidelines) was developed to examine the studies reporting on the associations of SHS and the risk of oral cancer, employing a search strategy on electronic databases (PubMed, Web of Science, Scopus, Cochrane Library, Open Grey, and ProQuest databases for dissertations) until 10 May 2020. Meta-analyses and sensitivity analyses were performed using random-effect models. The protocol was registered in PROSPERO (CRD42020189970).

RESULTS

Following the application of eligibility criteria, five studies were included, comprising a total of 1179 cases and 5798 controls, with 3452 individuals exposed and 3525 individuals not exposed to SHS. An overall OR of 1.51 (95% CI 1.2o to 1.91, p=0.0004) for oral cancer was observed, without significant heterogeneity (I²=0%, p=0.41). The duration of exposure of more than 10 or 15 years increased the risk of oral cancer (OR 2.07, 95% CI 1.54 to 2.79, p<0.00001), compared with non-exposed individuals, without significant heterogeneity (I²=0%, p=0.76).

CONCLUSIONS

This systematic review and meta-analysis supports a causal association between SHS exposure and oral cancer. Our results could provide guidance to public health professionals, researchers, and policymakers to further support effective SHS exposure prevention programs worldwide.

Addictions Causing Head-and-Neck Cancers

Head-and-neck cancers pose a serious economic burden, with most countries investing significant resources to reduce the incidence, primarily focusing on understanding addictive etiologies. The traditional literature focused on tobacco and alcohol use, with few studies on contemporary factors such as e-cigarette, waterpipe smoking, and human papillomavirus. This article attempts to collate and present an update on the globally identified etiologic factors.

The aim of this study was to identify and review the addictive etiologic factors causing head-and-neck cancers.

An electronic search was performed on Medline, Embase, and Google Scholar to identify the etiologies causing head-and-neck cancers and narrowed down on those driven by addiction. Further, we identified their constituents, mechanism of action, and the risks attributable to various forms of products.

Substances identified included smoked and chewed tobacco, alcohol, mate, marijuana, areca nut and betel quid, and viruses. An alarming majority of youth are now utilizing these substances. Furthermore, migrant movements have led to the spread of traditional practices across the regions, especially from the Asian subcontinent.

Ironically, despite modern advances and technology, we still see that a large proportion of population succumb to these cancers, emphasizing the need for more effective and targeted policies to combat this menace at the grassroots level.

Risk Prediction Models for Head and Neck Cancer in the US Population From the INHANCE Consortium

Head and neck cancer (HNC) risk prediction models based on risk factor profiles have not yet been developed. We took advantage of the large database of the International Head and Neck Cancer Epidemiology (INHANCE) Consortium, including 14 US studies from 1981-2010, to develop HNC risk prediction models. Seventy percent of the data were used to develop the risk prediction models; the remaining 30% were used to validate the models. We used competing-risk models to calculate absolute risks. The predictors included age, sex, education, race/ethnicity, alcohol drinking intensity, cigarette smoking duration and intensity, and/or family history of HNC. The 20-year absolute risk of HNC was 7.61% for a 60-year-old woman who smoked more than 20 cigarettes per day for over 20 years, consumed 3 or more alcoholic drinks per day, was a high school graduate, had a family history of HNC, and was non-Hispanic white. The 20-year risk for men with a similar profile was 6.85%. The absolute risks of oropharyngeal and hypopharyngeal cancers were generally lower than those of oral cavity and laryngeal cancers. Statistics for the area under the receiver operating characteristic curve (AUC) were 0.70 or higher, except for oropharyngeal cancer in men. This HNC risk prediction model may be useful in promoting healthier behaviors such as smoking cessation or in aiding persons with a family history of HNC to evaluate their risks.

Gender-related incidence, risk factors exposure and survival rates of laryngeal cancers - the 10-years analysis of trends from one institution

OBJECTIVES

The aim of the study was the analysis of the epidemiology of laryngeal cancer over 10 years in relation to known risk factors and to assess the current survival rates in this group of patients.

METHODS

The data were retrospectively collected from patients' medical records, then entered in the database using dedicated software and a statistical analysis was performed.

RESULTS

512 subjects - 443 men (86.5%) and 69 women (13.5%) were enrolled into the study. The male-to-female ratio was 6.4:1. There were 97.1% smoking women and 98% smoking men, however the history of more than 20 cigarettes per day smoking admitted 81.1 % of women and 94.6% of men. Heavy alcohol consumption was the case in 14 (20.3%) women and in 307 (69.3%) men. For both the size of heavy alcohol consumption and the size of excessive tobacco use, there was found statistically significant difference between women and men with laryngeal cancer (p&lt;0.05). In the majority of male and female subjects, the tumour was located in the supraglottis/glottis area. Apparently this tumour location was much more common among women, accounting for 60.9% of cases , while in men was confirmed in 39.3% of cases. The stages of the laryngeal cancer were similarly of high advancement for both the men and women - stages III and IV were confirmed in 82.6% of women and in 77.6% of men. The over 5-year survival rate was 39.1% among women and 37.2% among men. Conclusions Contradictory to decreased exposure to risk factors and the shorter period for diagnosis, the higher stages of cancer were observed in women. Although in women the advancement was higher and the majority of cases were located in unfavourable supraglottic area, the survival rates were higher. Key words: laryngeal cancer, epidemiology, men and women, risk factors.

The effect of second hand smoke in patients with squamous cell carcinoma of the head and neck

Background

Active tobacco smoking is a well-known risk factor for head and neck malignancy, and strong evidence has associated tobacco as the main carcinogenic factor in squamous cell cancers of this region. Evidence supporting a carcinogenic effect of second-hand smoke (SHS) on head and neck organs in non-smokers was also demonstrated with results consistent with those for active smokers. There is little data on the effects of SHS in patients previously treated for squamous cell carcinomas of the head and neck.

Objective

The purpose of this study was to prospectively evaluate the role of SHS on recurrence and survival in treated head and neck cancer patients.

Methods

We conducted a prospective cohort study to examine the association between self-reported SHS exposure and the risk of recurrence and mortality in patients treated for squamous cell cancers of the head and neck in a longitudinal fashion. Patients filled out an exhaustive smoking questionnaire on presentation and abbreviated questionnaires at each follow-up visit, which occurred every 6 months. Primary outcome measures were recurrence, development of a second primary malignancy, and recurrence-free survival. Chi square analysis was used to assess the association between SHS and the primary outcomes. A multivariate binary logistic regression analysis was applied to determine the independent predictors of recurrence. Cox proportional hazards and Kaplan Meier modeling were employed to assess the possible relationships between SHS exposure and time to develop the primary outcomes.

Results

Untreated new patients with a histologically confirmed diagnosis of first primary SCC of the UADT (defined as cancer of the oral cavity, the oropharynx, the hypopharynx, and the larynx) were recruited. Patients seen at The University of Texas Medical Branch (UTMB) Head and Neck oncology clinic from 1988 to 1996 were considered as cases in this study. One hundred and thirty-five patients were enrolled in the study. The median follow-up time for the sample was 54 months (3.92 years). Complete records were achieved for 92% of patients, thus 124 patients were included in the final analysis. SHS significantly correlated with recurrence and recurrence-free survival. The rate of recurrence was 46% in the group exposed to SHS and 22% in the non-exposed group. Based on multivariate binary logistic regression analysis, SHS exposure was detected as a significant independent predictor for recurrence (HR = 3.00 [95% CI 1.18–7.63]). Kaplan-Meier analysis demonstrated that patients who were not exposed to SHS had a statistically significant longer recurrence-free survival (log-rank P = 0.029). The mean survival for non SHS-exposed patients was 76 [63–89] months versus 54 [45–63] months for those exposed to SHS.

Conclusions

SHS exposure is an independent predictor of recurrence and survival after head and neck cancer treatment. These results support the importance and efforts of reducing smoking at home in in the work-place.

Occupations and the Risk of Head and Neck Cancer: A Pooled Analysis of the International Head and Neck Cancer Epidemiology (INHANCE) Consortium

OBJECTIVE

To investigate the associations between head and neck cancer (HNC) risk and occupations.

METHODS

We harmonized data on occupations in a pooled analysis of 8839 HNC cases and 13,730 controls in International Head and Neck Cancer Epidemiology (INHANCE) consortium. Logistic regression was used to estimate odds ratios (ORs) for associations of occupations and HNC risk. Population attributable fraction (PAF) for occupations was calculated using the formula PEC × (OR - 1)/OR.

RESULTS

Trend of increasing HNC risk was found with increasing duration of employment for many occupations, including cooks (OR = 1.36; 95% confidence interval [CI] 1.09 to 1.68), cleaners (OR = 1.38; 95% CI 1.13 to 1.69), painters (OR = 1.82; 95% CI 1.42 to 2.35). The PAF for a priori occupations was 14.5% (95% CI 7.1% to 21.9%) for HNC.

CONCLUSIONS

We found associations between certain occupations and HNC risks, including for subsites, with a duration-response relationship.

Head and neck cancer prevention: from primary prevention to impact of clinicians on reducing burden

Survival from head and neck cancers (HNCs) of the lip, oral cavity, pharynx, and larynx has increased by 10% over the past few decades. Little over half of patients who develop HNCs will survive beyond 5 years. Survival is lower for individuals in many countries where traditional risk factors such as tobacco smoking, alcohol drinking, and betel quid chewing are highly prevalent but tertiary health care center access is limited or unavailable. Early diagnosis of HNC is the most important prognostic factor for each tumor site. Molecular-based research on HNC tumors holds promise for early stage detection, screening, vaccination, disease follow-up, and progression. Future investments for HNC control must consider both effectiveness and sustainability for both high- and low-resource countries alike, with priority toward risk factor prevention and earlier diagnosis.

Comparative assessment of HPV, alcohol and tobacco etiological fractions in Algerian patients with laryngeal squamous cell carcinoma

Background

Despite the increasing incidence of laryngeal squamous cell carcinoma (LSCC) in Algeria, scarce information is available on the importance of the preventable etiological factors which may drive the disease. Remarkably, a significant number of cases occur in nonsmoker and nondrinker patients; hence, suggesting that alternative risk factors, like Human papillomavirus (HPV), might be etiologically involved. To gain more insight on the risk factors associated with the disease in the country, we evaluated the etiological fraction of HPV in comparison to tobacco and alcohol intake in LSCC patients.

Methods

To evaluate the etiopathologic fraction (EF) for HPV compared to history of tobacco and alcohol in LSCC, HPV DNA presence in 46 invasive and 3 non-invasive formalin-fixed paraffin-embedded laryngeal tumors was screened using the SPF10-DEIA-LiPA25 Assay. Demographic data and information related to exposure to the risk factors were gathered through interviewer-assisted questionnaires.

Results

We observed that 40.8% of all LSCC cases were associated with smoking, 40.8% had combined tobacco and alcohol exposure history, and 14.3% did not show prior exposure to either risk factor. 1 out of 3 in-situ carcinoma cases was positive for HPV-6. HPV prevalence was null in the invasive tumors. HPV DNA was detected in 2.38% for all studied cases. 10.2% of LSCC patients did not associate with any of the studied risk factors.

Conclusion

Here we show that HPV etiological fraction in LSCC Algerian patients is low and smoking and alcohol remain the principal etiopathologic risk for LSCC burden in Algeria.

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

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

Genetic Contributions to The Association Between Adult Height and Head and Neck Cancer: A Mendelian Randomization Analysis

With the aim to dissect the effect of adult height on head and neck cancer (HNC), we use the Mendelian randomization (MR) approach to test the association between genetic instruments for height and the risk of HNC. 599 single nucleotide polymorphisms (SNPs) were identified as genetic instruments for height, accounting for 16% of the phenotypic variation. Genetic data concerning HNC cases and controls were obtained from a genome-wide association study. Summary statistics for genetic association were used in complementary MR approaches: the weighted genetic risk score (GRS) and the inverse-variance weighted (IVW). MR-Egger regression was used for sensitivity analysis and pleiotropy evaluation. From the GRS analysis, one standard deviation (SD) higher height (6.9 cm; due to genetic predisposition across 599 SNPs) raised the risk for HNC (Odds ratio (OR), 1.14; 95% Confidence Interval (95%CI), 0.99-1.32). The association analyses with potential confounders revealed that the GRS was associated with tobacco smoking (OR = 0.80, 95% CI (0.69-0.93)). MR-Egger regression did not provide evidence of overall directional pleiotropy. Our study indicates that height is potentially associated with HNC risk. However, the reported risk could be underestimated since, at the genetic level, height emerged to be inversely associated with smoking.

Cumulative meta-analysis and trial sequential analysis of correlation between hOGG1 Ser326Cys polymorphism and the risk of head and neck squamous cell carcinoma

Background

The human 8-oxoguanine glycosylase 1 (hOGG1) Ser326Cys polymorphism has been involved in the risk of head and neck squamous cell carcinoma (HNSCC), but the results of published studies on this topic still inconsistent.

Results

Finally 11 qualified publications with 13 independent case-control studies were yielded. Overall, we observed significant differences in CysCys vs. SerSer [odds ratio (OR) = 1.55, 95% confidence interval (95% CI) = 1.01–2.38] and CysCys vs. SerCys+SerSer (OR = 1.42, 95% CI = 1.005–1.99) genetic models. Sensitivity analyses showed the results were not robust, cumulative meta-analyses and trial sequential analysis indicated the results didn't not need more studies to identification. Subgroup analyses showed there was a significant association in Caucasian, laryngeal squamous cell carcinoma, studies agreement with Hardy-Weinberg equilibrium, and alcohol drinkers subgroups under the corresponding contrasts. In addition, the results of Egger’s test were contradictory.

Materials and Methods

All eligible studies were searched from the online databases including PubMed, Web of Science, China Knowledge Resource Integrated Database, and Wanfang databases up to February 10, 2017. After study selection and data extraction, the meta-analysis was performed using STATA 12.0 software and TSA software version 0.9 Beta.

Conclusions

Our meta-analysis results indicated that hOGG1 Ser326Cys polymorphism may be associated with increased risk of HNSCC, especially in Caucasians, alcohol drinkers and the patients with laryngeal squamous cell carcinoma.

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.

Apoptotic capacity and risk of squamous cell carcinoma of the head and neck

BACKGROUND

Tobacco smoke and alcohol drinking are the major risk factors for squamous cell carcinoma of the head and neck (SCCHN). Smoking and drinking cause DNA damage leading to apoptosis, and insufficient apoptotic capacity may favour development of cancer because of the dysfunction of removing damaged cells. In the present study, we investigated the association between camptothecin (CPT)-induced apoptotic capacity and risk of SCCHN in a North American population.

METHODS

In a case-control study of 708 SCCHN patients and 685 matched cancer-free controls, we measured apoptotic capacity in cultured peripheral blood lymphocytes in response to in vitro exposure to CPT by using the flow cytometry-based method.

RESULTS

We found that the mean level of apoptotic capacity in the cases (45.9 ± 23.3%) was significantly lower than that in the controls (49.0 ± 23.1%) (P = 0.002). When we used the median level of apoptotic capacity in the controls as the cutoff value for calculating adjusted odds ratios, subjects with a reduced apoptotic capacity had an increased risk (adjusted odds ratio = 1.42, 95% confidence interval = 1.13-1.78, P = 0.002), especially for those who were age ≥57 (1.73, 1.25-2.38, 0.0009), men (1.76, 1.36-2.27, <0.0001) and ever drinkers (1.67, 1.27-2.21, 0.0003), and these variables significantly interacted with apoptotic capacity (Pinteraction = 0.015, 0.005 and 0.009, respectively). A further fitted prediction model suggested that the inclusion of apoptotic capacity significantly improved in the prediction of SCCHN risk.

CONCLUSION

Individuals with a reduced CPT-induced apoptotic capacity may be at an increased risk of developing SCCHN, and apoptotic capacity may be a biomarker for susceptibility to SCCHN.

Racial differences in head and neck squamous cell carcinomas among non-Hispanic black and white males identified through the National Cancer Database (1998-2012)

PURPOSE

Head and neck squamous cell carcinoma (HNSCC) incidence is increasing, and evidence suggests survival disparities between non-Hispanic (nH) black and white males. However, temporal changes in HNSCCs and factors contributing to survival differences have not been examined at the national level.

METHODS

National Cancer Database (NCDB) cases were used to evaluate temporal trends in HNSCC anatomical sites and site groupings (i.e., oral cavity, oropharyngeal, non-oropharyngeal), and to estimate incidence ratios (IRs) comparing nH black and white males in demographic and clinical characteristics.

RESULTS

Between 1998 and 2012, 18,443 (11 %) nH black males and 145,611 (89 %) nH white males were diagnosed with HNSCCs. Cases rose from 9094 diagnosed in 1998 to 13,838 in 2012, driven by increases in oropharyngeal tumors, particularly tumors of the tonsil and tongue. Annual percent changes in nH black males and nH white males were 1.93 and 3.17, respectively. Additionally, nH black males had higher incidence of the more aggressive non-oropharyngeal tumors (p < .0001) and distant-stage tumors (76 vs. 64 %, p < .0001). However, nH white males had higher incidence of high-risk HPV types (IRs range from 1.68, 95 % CI 1.50-1.88 in oropharyngeal tumors to 3.03, 95 % CI 1.11-8.25 in non-oropharyngeal tumors).

CONCLUSIONS

Incidence of oropharyngeal tumors has risen in both nH black and white males. However, nH white males have higher incidence of HPV, and nH black males have higher incidence of more aggressive and advanced HNSCCs. Racial differences in clinical characteristics associated with poorer survival exist, and future studies should determine factors associated with these differences.

Epidemiological evidence on environmental tobacco smoke and cancers other than lung or breast

We reviewed 87 epidemiological studies relating environmental tobacco smoke (ETS) exposure to risk of cancer other than lung or breast in never smoking adults. This updates a 2002 review which also considered breast cancer. Meta-analysis showed no significant relationship with ETS for nasopharynx cancer, head and neck cancer, various digestive cancers (stomach, rectum, colorectal, liver, pancreas), or cancers of endometrium, ovary, bladder and brain. For some cancers (including oesophagus, colon, gall bladder and lymphoma) more limited data did not suggest a relationship. An increased cervix cancer risk (RR 1.58, 95%CI 1.29-1.93, n = 17 independent estimates), reducing to 1.29 (95%CI 1.01-1.65) after restriction to five estimates adjusting for HPV infection or sexual activity suggests a causal relationship, as do associations with nasosinus cancer observed in 2002 (no new studies since), and less so kidney cancer (RR 1.33, 95%CI 1.04-1.70, n = 6). A weaker association with total cancer (RR 1.13, 95%CI 1.03-1.35, n = 19) based on heterogeneous data is inconclusive. Inadequate confounder control, recall bias, publication bias, and occasional reports of implausibly large RRs in individual studies contribute to our conclusion that the epidemiological evidence does not convincingly demonstrate that ETS exposure causes any of the cancers studied.

Low frequency of cigarette smoking and the risk of head and neck cancer in the INHANCE consortium pooled analysis

BACKGROUND

Cigarette smoking is a major risk factor for head and neck cancer (HNC). To our knowledge, low cigarette smoking (<10 cigarettes per day) has not been extensively investigated in fine categories or among never alcohol drinkers.

METHODS

We conducted a pooled analysis of individual participant data from 23 independent case-control studies including 19 660 HNC cases and 25 566 controls. After exclusion of subjects using other tobacco products including cigars, pipes, snuffed or chewed tobacco and straw cigarettes (tobacco product used in Brazil), as well as subjects smoking more than 10 cigarettes per day, 4093 HNC cases and 13 416 controls were included in the analysis. The lifetime average frequency of cigarette consumption was categorized as follows: never cigarette users, >0-3, >3-5, >5-10 cigarettes per day.

RESULTS

Smoking >0-3 cigarettes per day was associated with a 50% increased risk of HNC in the study population [odds ratio (OR) = 1.52, 95% confidence interval (CI): (1.21, 1.90). Smoking >3-5 cigarettes per day was associated in each subgroup from OR = 2.01 (95% CI: 1.22, 3.31) among never alcohol drinkers to OR = 2.74 (95% CI: 2.01, 3.74) among women and in each cancer site, particularly laryngeal cancer (OR = 3.48, 95% CI: 2.40, 5.05). However, the observed increased risk of HNC for low smoking frequency was not found among smokers with smoking duration shorter than 20 years.

CONCLUSION

Our results suggest a public health message that low frequency of cigarette consumption contributes to the development of HNC. However, smoking duration seems to play at least an equal or a stronger role in the development of HNC.

Reduced DNA double-strand break repair capacity and risk of squamous cell carcinoma of the head and neck--A case-control study

Tobacco smoke and alcohol use play important roles in the etiology of squamous cell carcinoma of the head and neck (SCCHN). Smoking causes DNA damage, including double-strand DNA breaks (DSBs), that leads to carcinogenesis. To test the hypothesis that suboptimal DSB repair capacity is associated with risk of SCCHN, we applied a flow cytometry-based method to detect the DSB repair phenotype first in four EBV-immortalized human lymphoblastoid cell lines and then in human peripheral blood T-lymphocytes (PBTLs). With this blood-based laboratory assay, we conducted a pilot case-control study of 100 patients with newly diagnosed, previously untreated SCCHN and 124 cancer-free controls of non-Hispanic whites. We found that the mean DSB repair capacity level was significantly lower in cases (42.1%) than that in controls (54.4%) (P<0.001). When we used the median DSB repair capacity level in the controls as the cutoff value for calculating the odds ratios (ORs) with adjustment for age, sex, smoking and drinking status, the cases were more likely than the controls to have a reduced DSB repair capacity (adjusted OR=1.93; 95% confidence interval, CI=1.04-3.56, P=0.037), especially for those subjects who were ever drinkers (adjusted OR=2.73; 95% CI=1.17-6.35, P=0.020) and had oropharyngeal tumors (adjusted OR=2.17; 95% CI=1.06-4.45, P=0.035). In conclusion, these findings suggest that individuals with a reduced DSB repair capacity may be at an increased risk of developing SCCHN. Larger studies are warranted to confirm these preliminary findings.

A variant at a potentially functional microRNA-binding site in BRIP1 was associated with risk of squamous cell carcinoma of the head and neck

DNA double-strand breaks (DSBs) are one of the most serious forms of DNA damage to the cell, causing genomic instability and ultimately carcinogenesis. In this study, we hypothesized that single nucleotide polymorphisms (SNPs) at the micro RNA (miRNA)-binding sites of DSB repair genes may influence cancer risk by dysregulating target gene expression. To test our hypothesis, we firstly performed functional prediction for common SNPs in DSB genes and found 12 potentially functional SNPs located at the miRNA-binding sites. We then investigated their associations with risk of squamous cell carcinoma of the head and neck (SCCHN) in 1087 patients and 1090 cancer-free controls in a non-Hispanic white population. As a result, SNP rs7213430 in BRIP1 was found to be significantly associated with cancer risk (P trend = 0.021). Compared with the AA homozygotes, the G allele carriers had an increased risk of SCCHN (adjusted OR 1.16, 95 % CI 1.02-1.31). Marginal significance was found for another SNP rs15869 in BRCA2 (P = 0.053). Further, functional analyses showed that SNP rs7213430 is within the miR-101 seed-binding region, and the variant G allele could lead to significantly lower luciferase activity and BRIP1 mRNA expression, compared to the A allele with the presence of miR-101. Our results suggested that SNP rs7213430 in the 3'-UTR of BRIP1 might contribute to SCCHN susceptibility by affecting the binding activity of miR-101 and resulting in a decreased BRIP1 expression. Additional larger population and functional studies are warranted to confirm our findings.

An epidemiological evaluation of salivary gland cancer in the Netherlands (1989-2010)

BACKGROUND

The relative 5-year survival rate of salivary gland cancer is moderate at best. This study was set up to evaluate whether the improvements in diagnosis and treatment in the last decades impacted the incidence, mortality and survival of salivary gland cancer.

METHODS

Data on patients with salivary gland cancer from 1989 through 2010 were extracted from the Netherlands Cancer Registry (NCR); we examined incidence, mortality and relative survival. Furthermore, information on sex, age, tumor stage, histology, and treatment was taken into account.

RESULTS

A total of 2737 patients were included. Fifty-three percent (53%) were males and 47% were females with a significant higher proportion of early stages in women. In 2010, the incidence rate (European Standardized Rate (ESR)) of salivary gland cancer was 0.9 per 100,000 per year. The estimated annual percentage change in incidence rate since 1989 equaled 0.6% (95%CI: -0.2-1.4). Mortality rates (ESR) decreased in men until 1997 and increased thereafter. Mortality in women remained stable at 1.5 per 100,000. Over time more patients were treated by surgery and radiotherapy (p<0.001). The relative five-year survival rate equaled 69% and did not change in time.

CONCLUSION

We observed no relevant changes in incidence or mortality rates in the last two decades. Despite the increased combined treatment by surgery and radiotherapy, survival did not improve. This implies an urgent need for the development of new effective treatment modalities.

Genetic polymorphisms in the Cytochrome P450 family and squamous cell carcinoma of the oral cavity, pharynx and larynx

Objective:To analyze the genetic polymorphisms of the cytochrome P450 family and their relationship with squamous cell carcinoma of the oral cavity, pharynx and larynx.Methods: We present a narrative literature review, conducted in Pubmed, Lilacs and Cochrane Databases of articles published in the last five years correlating genetic polymorphisms of the cytochrome P450 family and cancer risk in different populations worldwide.Results: We initially found 65 articles and, after selection criteria, 20 case-control studies with various populations worldwide were eligible. The most studied polymorphisms were those of CYP2E1 and CYP1A1 subfamilies. There is little about the other subfamilies. The association found between polymorphisms and cancer risk amounted to a countless number of variables, amongst them: population, selection methods, racial factors and different modes of exposure to carcinogens, genotyping methods, and nomenclature of the polymorphisms.Conclusion: so far, there is no proven link between genetic polymorphisms of cytochrome P450 family and squamous cell carcinoma of the oral cavity, pharynx and larynx relationship.

Laryngeal cancer in Kazakhstan - ethnic, age and gender differences over time

The purpose of the present study was to provide an assessment of the incidence of cancer of the larynx in Kazakhstan with especial attention to ethnicity and gender, as well as age. The retrospective design covered all new cases of laryngeal cancer in 11 years (1999-2009). The total number was 4,967 cases, 4,535 (91.3%) in males and 432 (8.7%) in women, with a gender ratio of 10.5:1. Patients of Kazakh (31.2%) and Russian (51.4%) ethnicity accounted for the vast majority (82.6%), with Russians predominating in both sexes, but particularly in females. Age peak in Kazakhs was 70 years and older (14.6 ± 0.70/0000), and in Russians was 60-69 years (21.6 ± 1.30/0000). In the dynamics, the rates had the tendency to decrease more markedly in Russian than Kazakh men, especially in the younger groups, while increase was noted in the youngest females of both ethnicities, but again greater in Russians, presumably reflecting change in underlying lifestyle factors.

Changes in cancer incidence attributable to tobacco smoking in Germany, 1999-2008

Tobacco smoking, a major cancer risk factor, is very common in Germany as in many other high-income countries. Few studies have assessed the burden of tobacco-associated cancer incidence in the German population. We calculated the proportion of cancers attributable to tobacco smoking to estimate the burden of tobacco-associated cancer in 1999 and 2008. Smoking prevalence was determined from national surveys of a representative sample of the German population in 1998 and 2008-2011, and data on relative risks were obtained from meta-analyses. Cancer incidence for the years 1999 and 2008 was estimated by the German Centre for Cancer Registry Data at the Robert Koch Institute. We estimate that 72,208 incident cancer cases were attributable to tobacco smoking in Germany in 2008, an increase of >6,200 cases over 1999 levels. Among the cases in 2008 were 55,057 cases among men (22.8% (95% CI, 21.3-24.1) of all new cases) and 17,151 cases among women (7.9% (95% CI, 7.21-8.68) of all new cases). The highest proportions attributable to smoking were estimated for cancer of the lung, larynx, pharynx and the lower urinary tract. Tobacco smoking is currently responsible for more than one in five cancer cases among men and nearly 1 in 12 among women. Considering the increasing trends in cancer incidence and, until very recently, rising prevalence of smoking among women, it can be expected that the number of tobacco-attributable cancer cases will rise further.

Adult height and head and neck cancer: a pooled analysis within the INHANCE Consortium

Several epidemiological studies have shown a positive association between adult height and cancer incidence. The only study conducted among women on mouth and pharynx cancer risk, however, reported an inverse association. This study aims to investigate the association between height and the risk of head and neck cancer (HNC) within a large international consortium of HNC. We analyzed pooled individual-level data from 24 case-control studies participating in the International Head and Neck Cancer Epidemiology Consortium. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated separately for men and women for associations between height and HNC risk. Educational level, tobacco smoking, and alcohol consumption were included in all regression models. Stratified analyses by HNC subsites were performed. This project included 17,666 cases and 28,198 controls. We found an inverse association between height and HNC (adjusted OR per 10 cm height = 0.91, 95% CI 0.86-0.95 for men; adjusted OR = 0.86, 95% CI 0.79-0.93 for women). In men, the estimated OR did vary by educational level, smoking status, geographic area, and control source. No differences by subsites were detected. Adult height is inversely associated with HNC risk. As height can be considered a marker of childhood illness and low energy intake, the inverse association is consistent with prior studies showing that HNC occur more frequently among deprived individuals. Further studies designed to elucidate the mechanism of such association would be warranted.

Functional single nucleotide polymorphisms of the RASSF3 gene and susceptibility to squamous cell carcinoma of the head and neck

BACKGROUND

RASSF3 suppresses tumour formation through uncertain mechanisms, but it is an important gene of p53-dependent apoptosis. RASSF3 depletion impairs DNA repair after DNA damage, leading to polyploidy. The authors hypothesised that potential functional single-nucleotide polymorphisms (SNPs) of RASSF3 are associated with risk of squamous cell carcinoma of the head and neck (SCCHN).

METHODS

The authors used a functional SNP approach to evaluate the associations between common (minor allele frequency⩾0.05), putative functional variants in RASSF3 and risk of SCCHN. Four selected such functional SNPs (rs6581580 T>G, rs7313765 G>A, rs12311754 G>C and rs1147098 T>C) in RASSF3 were identified and genotyped in 1087 patients and 1090 cancer-free controls in a non-Hispanic white population.

RESULTS

The authors found that two SNPs were significantly associated with SCCHN risk. Carriers of the variant rs6581580G and rs7313765A alleles were at a reduced SCCHN risk, compared with the corresponding common homozygotes [adjusted odds ratio (OR)=0.75 and 0.73 and 95% confidence interval (CI)=0.62-0.91 and 0.60-0.88, respectively, for dominant models; and Ptrend=0.012 and 0.041, respectively, for additive models], particularly for non-oropharyngeal tumours (adjusted OR=0.68 and 0.60 and 95% CI=0.53-0.86 and 0.47-0.77, respectively, for dominant models). In the genotype-phenotype correlation analysis of peripheral blood mononuclear cells from 102 cancer-free controls, the rs6581580 GG genotype was associated with significantly increased expression levels of RASSF3 mRNA (P=0.038), compared with the TT genotype. Additional functional experiments further showed that variant G allele of rs6581580 had a significantly stronger binding affinity to the nuclear protein extracts than the T allele.

CONCLUSION

Taken together, these findings indicate that the RASSF3 promoter rs6581580 T>G SNP is potentially functional, modulating susceptibility to SCCHN among non-Hispanic whites. Larger replication studies are needed to confirm our findings.

Childhood passive smoke exposure is associated with adult head and neck cancer

INTRODUCTION

Passive smoke is carcinogenic but its association with head and neck squamous cell carcinoma (HNSCC) is uncertain.

METHODS

We conducted a case-control study of childhood passive smoke exposure (CPSE) and HNSCC in 858 cases and 806 frequency-matched controls using an interviewer-administered questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were estimated with logistic regression controlling for adult smoking in the total study population, and in never-smokers only (184 cases and 415 controls). CPSE was also studied in oropharyngeal separately from other HNSCC using polytomous logistic regression.

RESULTS

CPSE was associated with HNSCC (OR, 1.28; 95% CI, 1.01-1.63) after controlling for adult smoking and other factors. This association was similar in magnitude, although not statistically significant, among subjects who never smoked as adults (OR, 1.19, 95% CI, 0.80-1.76). CPSE was associated more strongly with oropharyngeal cancer (a HNSCC subtype commonly associated with human papillomavirus (HPV) infection) than with HNSCC at non-oropharyngeal sites (OR, 2.02; 95% CI, 1.01-4.06, N=52 cases vs. OR, 1.04; 95% CI, 0.68-1.60, N=132 cases; P-for-heterogeneity=0.08).

CONCLUSIONS

Data from this large US-based case control study suggest a role for CPSE in HNSCC etiology.

Epidemiological evaluation of laryngeal cancer incidence in Kazakhstan for the years 1999-2009

The purpose was to provide a descriptive epidemiological assessment of the incidence of cancer of the larynx in Kazakhstan and spatial evaluation with gender characteristics. This retrospective study covered all new cases of laryngeal cancer in 11 years (1999-2009). The total number was 4,967 cases, 4,535 (91.3%) in males and 432 (8.7%) in women, with a ratio of 10.5:1. The higher incidence in men compared to women was evident in all age groups, the differences being statistically significant (p<0.05). At the same time revealed a unimodal growth with age, peaking at 70 years and older both sexes. In the dynamics, incidence rates of laryngeal cancer demonstrated a tendency to decrease, in women (T=-6.7%) this being more pronounced than in men (T=-3.3%). Levels were determined to produce cartograms of cancer of the larynx for male and female populations, clear geographical variation being evidenced. The data are discussed with reference to possible risk factors.

Pre-treatment gelatinases' serum levels and post-treatment changes in laryngeal cancer patients

INTRODUCTION

Laryngeal cancer, especially in the advanced stages, is a highly devastating disease, characterized by increased invasiveness and high rates of metastasis. Gelatinases A and B (MMP-2 and -9 respectively) are of particular interest due to their contribution to various stages of carcinogenesis. There is a growing body of evidence with regard to the prognostic value of certain MMPs and their possible role as tumour markers.

AIM

To identify the pattern of alteration of serum gelatinases A and B in patients with laryngeal cancer following treatment, and a possible correlation with various clinicopathological parameters.

MATERIALS AND METHODS

Forty nine patients were included in this study. Pre-treatment and post-treatment serum samples were collected and processed by gelatin zymography and western blotting.

RESULTS

Only the latent forms of MMP-2 and -9 were identified. Both gelatinases were increased in the serum of laryngeal cancer patients compared to healthy individuals. Patients with supraglottic tumours and active smokers had significantly higher pre-treatment levels of proMMP-2 than patients with glottic tumours (p < 0.05) and ex-smokers (p < 0.05), respectively. Patients with primary disease and patients with lymph node involvement showed lower serum proMMP-9 pre-treatment levels than patients with recurrence (p < 0.05) and patients without neck disease (p < 0.1), respectively. During the follow-up period the proMMP-2 serum levels increased significantly in the first ten to fifteen days after treatment, gradually decreasing over the following months. The proMMP-9 serum levels showed a gradual decrease after treatment, which was statistically significant (p<0.05).

CONCLUSIONS

The post-treatment alteration pattern of proMMP-9 serum levels shows a possible role of this molecule as a tumour marker in laryngeal cancer. Further research is necessary to clarify the contribution of both gelatinases to the disease progress and determine their role as prognostic factors and tumour markers.

Significant differences in demographic, clinical, and pathological features in relation to smoking and alcohol consumption among 1,633 head and neck cancer patients

OBJECTIVE

As a lifestyle-related disease, social and cultural disparities may influence the features of squamous cell carcinoma of the head and neck in different geographic regions. We describe demographic, clinical, and pathological aspects of squamous cell carcinoma of the head and neck according to the smoking and alcohol consumption habits of patients in a Brazilian cohort.

METHODS

We prospectively analyzed the smoking and alcohol consumption habits of 1,633 patients enrolled in five São Paulo hospitals that participated in the Brazilian Head and Neck Genome Project - Gencapo.

RESULTS

The patients who smoked and drank were younger, and those who smoked were leaner than the other patients, regardless of alcohol consumption. The non-smokers/non-drinkers were typically elderly white females who had more differentiated oral cavity cancers and fewer first-degree relatives who smoked. The patients who drank presented significantly more frequent nodal metastasis, and those who smoked presented less-differentiated tumors.

CONCLUSIONS

The patients with squamous cell carcinoma of the head and neck demonstrated demographic, clinical, and pathological features that were markedly different according to their smoking and drinking habits. A subset of elderly females who had oral cavity cancer and had never smoked or consumed alcohol was notable. Alcohol consumption seemed to be related to nodal metastasis, whereas smoking correlated with the degree of differentiation.

Racial differences in the relationship between tobacco, alcohol, and squamous cell carcinoma of the head and neck

PURPOSE

Tobacco and alcohol use are well-known risk factors for squamous cell carcinoma of the head and neck (SCCHN), but there has been little examination of disparities in SCCHN and racial patterns of tobacco and alcohol use, especially for African-Americans. The Carolina Head and Neck Cancer Study, a population-based case-control study, was utilized to determine whether relationships between tobacco and alcohol use and SCCHN differed by race.

METHODS

Using a rapid case ascertainment system, cases were recruited from 46 contiguous counties in North Carolina from 2002 to 2006. Controls, selected from motor vehicle records, were frequency-matched to cases on age, sex, and race. This analysis was based on 989 white and 351 African-American cases and 1,114 white and 264 African-American controls. Analyses were performed using unconditional logistic regression, adjusting for age, sex, race, education, and fruit and vegetable consumption.

RESULTS

The association between SCCHN and ever tobacco use among African-Americans (odds ratio (OR), 9.68; 95 % confidence interval (CI), 4.70, 19.9) was much greater than that observed in whites (OR, 1.94; 95 % CI, 1.51, 2.50). Smaller differences were observed when examining ever alcohol use (African-Americans: OR, 3.71; CI, 1.65, 8.30, and Whites: OR, 1.31: CI 0.96, 1.78). African-Americans consistently had greater effect measure estimates when examining common levels of duration and intensity metrics of tobacco and alcohol use, both independently and jointly. No racial differences in the effects of environmental (passive) tobacco smoke were observed.

CONCLUSIONS

These findings suggest racial differences in SCCHN are not solely explained by differences in consumption patterns, and tobacco and alcohol may have greater impact in African-Americans.

A review of risk factors for oral cavity cancer: the importance of a standardized case definition

The aim of this work is to review the literature on risk factors of oral cavity cancer with a special attention to the definition of the cases, in order to highlight special features of these cancers and of their subsites. PubMed database was systematically searched to access relevant articles published between 1980 and 2010. Reference lists of selected papers were examined to identify further articles. One hundred and two studies met the inclusion criteria. Their results were difficult to compare because of the lack of uniformity in defining oral cavity. In addition, few studies examined risk factors other than alcohol and tobacco, and studies differentiating between subsites were rare. Despite these limitations, some characteristics of oral cavity cancers may be emphasized: smoked tobacco seems to be a stronger risk factor for oral cavity cancer than alcohol, and the floor of the mouth seems to be more sensitive to the harmful effects of alcohol and smoked tobacco. Studies limited strictly to oral cavity cancers and distinguishing between subsites are needed to better understand the aetiology of these cancers, and better define risk groups to target prevention efforts and screening.

Seroreactivity against Epstein-Barr virus (EBV) among first-degree relatives of sporadic EBV-associated nasopharyngeal carcinoma in Indonesia

Epstein-Barr virus (EBV) infection and family history are significant risk factors associated with undifferentiated nasopharyngeal carcinoma. The presence of aberrant immunoglobulin A (IgA) antibodies against specific EBV antigens in healthy individuals can be predictive of the disease. Very limited reports explored the EBV IgA antibody presence within families of sporadic cases of nasopharyngeal carcinoma. This study aimed to determine whether EBV IgA was observed more frequently among family members of sporadic cases of nasopharyngeal carcinoma compared to community controls and evaluated the non-viral factors as determinants of antibody level. First-degree relatives of nasopharyngeal carcinoma patients (n = 520) and case-matched community controls (n = 86) were recruited. Sera from all individuals were tested in standardized peptide-based EBV IgA ELISA. Data on demographic variables and other exogenous factors were collected using a questionnaire through face-to-face interviews. A similar frequency of EBV IgA (cut-off value/CoV 0.354) was observed in the first-degree relatives of cases and in community controls (41.2% vs. 39.5%, P = 0.770). However, with a higher antibody level (OD(450)  = 1.000; about three times standard CoV), the relatives showed significantly higher frequency (36.9% vs. 14.7%, P = 0.011). When adjusted for all exogenous factors, the strongest factors associated with seropositivity are being a father (odds ratio/OR = 4.36; 95% confidence interval/CI = 1.56-12.21) or a sibling (OR = 1.89; 95% CI = 1.06-3.38) of a case of nasopharyngeal carcinoma. The higher level of EBV IgA seroreactivity in first-degree relatives of sporadic cases of nasopharyngeal carcinoma compared to the general population supports the use of EBV IgA ELISA for screening among family members.

Combined effects of E2F1 and E2F2 polymorphisms on risk and early onset of squamous cell carcinoma of the head and neck

Deregulated expression of most members of the E2F family has been detected in many human cancers. We examined the association of common single nucleotide polymorphisms (SNPs) of E2F transcription factors 1 and 2 (E2F1 and E2F2) with risk of squamous cell carcinoma of the head and neck (SCCHN) in 1,096 SCCHN patients and 1,090 cancer-free controls. We genotyped 10 selected SNPs in E2F1 and E2F2, including those at the near 5'-untranslated region (UTR), microRNA (miRNA)-binding sites at the near 3'-UTR and tagSNPs according to bioinformatics analysis. Although none of the selected SNPs alone was significantly associated with risk of SCCHN, there was a statistically significantly increased risk of SCCHN associated with the combined risk genotypes (i.e., rs3213182 AA, rs3213183 GG, rs3213180 GG, rs321318121 GG, rs2742976 GT+TT, rs6667575 GA+AA, rs3218203 CC, rs3218148 AA, rs3218211 CC, and rs3218123 GT+TT). Compared with those with 0-4 risk genotypes, an increased risk was observed for those who carried 5-8 risk genotypes (adjusted OR = 1.04; 95% CI = 0.86-1.26) and 9-10 risk genotypes (adjusted OR = 1.62; 95% CI = 1.14-2.30) in a dose-response manner (P = 0.045). Furthermore, the joint effect was more pronounced among patients with oropharyngeal cancer, younger adults (≤57 yr old), men, non-smokers, non-drinkers, and individuals with family history of cancer in first-degree relatives. Additionally, we also observed that those with 5-10 risk genotypes had an earlier SCCHN onset than those with 0-4 risk genotypes, particularly for non-smokers and/or non-drinkers. We concluded that E2F1 and E2F2 genetic variants may jointly play important roles in head and neck carcinogenesis.

Clinical and epidemiological characteristics of patients in the head and neck surgery department of a university hospital

CONTEXT AND OBJECTIVES

Head and neck cancer is the fifth most common type of cancer worldwide. The objective of this study was to evaluate the clinical and epidemiological parameters in a head and neck surgery service.

DESIGN AND SETTING

Cross-sectional study using patients' records, developed in otolaryngology and head and neck department of a university hospital in the northwest of the state of São Paulo.

METHODS

A total of 995 patients in the head and neck surgery service between January 2000 and May 2010 were evaluated. The variables analyzed included: age, gender, skin color, tobacco and alcohol consumption, primary site, staging and histological tumor type, treatment and number of deaths.

RESULTS

The disease was more frequent among men (79.70%), smokers (75.15%) and alcohol abusers (58.25%). The most representative sites were oral cavity (29.65%) and larynx (24.12%) for the primary site; squamous cell carcinoma (84.92%) was the most frequent histological type, and surgery (29.04%) and radiotherapy (14.19%) were the most common treatments.

CONCLUSION

The cancer that affects patients assisted by the head and neck surgery service occurs mainly men, smokers and alcohol abusers, and the oral cavity and larynx are the sites with the highest incidence. The high rate of patients with stages III and IV indicates late diagnosis by the treatment centers, which reflects the need for prevention education campaigns for early diagnosis of the disease.

Diet and the risk of head and neck cancer: a pooled analysis in the INHANCE consortium

We investigated the association between diet and head and neck cancer (HNC) risk using data from the International Head and Neck Cancer Epidemiology (INHANCE) consortium. The INHANCE pooled data included 22 case-control studies with 14,520 cases and 22,737 controls. Center-specific quartiles among the controls were used for food groups, and frequencies per week were used for single food items. A dietary pattern score combining high fruit and vegetable intake and low red meat intake was created. Odds ratios (OR) and 95% confidence intervals (CI) for the dietary items on the risk of HNC were estimated with a two-stage random-effects logistic regression model. An inverse association was observed for higher-frequency intake of fruit (4th vs. 1st quartile OR = 0.52, 95% CI = 0.43-0.62, p (trend) < 0.01) and vegetables (OR = 0.66, 95% CI = 0.49-0.90, p (trend) = 0.01). Intake of red meat (OR = 1.40, 95% CI = 1.13-1.74, p (trend) = 0.13) and processed meat (OR = 1.37, 95% CI = 1.14-1.65, p (trend) < 0.01) was positively associated with HNC risk. Higher dietary pattern scores, reflecting high fruit/vegetable and low red meat intake, were associated with reduced HNC risk (per score increment OR = 0.90, 95% CI = 0.84-0.97).

Sequence Variants and the Risk of Head and Neck Cancer: Pooled Analysis in the INHANCE Consortium

Previous molecular epidemiological studies on head and neck cancer have examined various single nucleotide polymorphisms (SNPs), but there are very few documented associations. In the International head and neck cancer epidemiology (INHANCE) consortium, we evaluated associations between SNPs in the metabolism, cell cycle, and DNA repair pathways and the risk of head and neck cancer. We analyzed individual-level pooled data from 14 European, North American, Central American, and Asia case-control studies (5,915 head and neck cancer cases and 10,644 controls) participating in the INHANCE consortium. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for SNP effects, adjusting for age, sex, race, and country. We observed an association between head and neck cancer risk and MGMT Leu84Phe heterozygotes (OR = 0.79, 95% CI = 0.68-0.93), XRCC1 Arg194Trp homozygotes Arg/Arg (OR = 2.3, 95% CI = 1.1-4.7), ADH1B Arg48His homozygotes Arg/Arg (OR = 2.7, 95% CI = 1.9-4.0), ADH1C Ile350Val homozygotes Ile/Ile (OR = 1.2, 95% CI = 1.1-1.4), and the GSTM1 null genotype (OR = 1.1, 95% CI = 1.0-1.2). Among these results, MGMT Leu84Phe, ADH1B Arg48His, ADH1C Ile350Arg, and the GSTM1 null genotype had fairly low false positive report probabilities (<20%). We observed associations between ADH1B Arg48His, ADH1C Ile350Arg, and GSTM1 null genotype and head and neck cancer risk. No functional study currently supports the observed association for MGMT Leu84Phe, and the association with XRCC1 Arg194Trp may be a chance finding.

Inverse association between toothbrushing and upper aerodigestive tract cancer risk in a Japanese population

BACKGROUND

Oral hygiene is attracting increasing attention as a potential risk factor for cancers. To investigate the association between toothbrushing frequency and upper aerodigestive tract (UADT) cancer, the authors conducted a large-scale case-control study.

METHODS

A total of 856 UADT cancer case participants and 2696 age- and sex-matched control subjects without cancer were included. Edentulous or participants with unknown frequency of toothbrushing or number of remaining teeth were excluded. Associations were assessed by odds ratios and 95% confidence intervals in logistic regression models with adjustment for potential confounders.

RESULTS

Compared with toothbrushing once per day, the adjusted odds ratio for brushing twice or more was 0.82 (95% confidence interval: 0.68, 0.99) whereas that for not brushing was 1.79 (0.79, 4.05). This association was observed especially in subjects who had a history of heavy smoking or drinking.

CONCLUSIONS

The authors suggest that toothbrushing could have a protective effect for UADT cancer.

Laryngeal cancer and passive smoking: the neglected factor?

In the present paper we investigate the relationship of environmental tobacco smoke (ETS) exposure to laryngeal cancer. 209 patients who were diagnosed with laryngeal cancer from 2000 to 2009 at the University Hospital of Patras, Western Greece, were reviewed with regard to patient age, disease stage at presentation, tumor differentiation, tobacco product use, alcohol consumption, occupation, and ETS exposure in the working environment. Pearson Chi-square method was used to determine the effect of ETS exposure on cancer stage, TNM classification and tumor differentiation in the dichotomized population (exposed vs. not exposed) and in groups of low, medium and high ETS exposure. ETS exposure in the working environment was found to significantly affect overall disease stage and T stage (p < 0.01) both in the dichotomic analysis and the group analysis. Minor significance was also noted for N stage (p = 0.047) in the exposure group analysis. Our data suggest that occupational ETS exposure presents a contributing risk factor for laryngeal cancer that requires further research to determine its significance.