Family history and the risk of oral and pharyngeal cancer

Tongue cancer in non-smoking and non-alcoholic mother and daughter

Tongue cancer is more prevalent in male smokers and alcoholics. Although an increased incidence of tongue cancer has been noted in non-smoking and non-alcoholic women, reports of its occurrence in mother and daughter are extremely rare. Here, we report a case of a non-smoking and non-alcoholic mother and her daughter diagnosed and treated surgically for tongue squamous cell carcinoma (SCC). The daughter is still being monitored and the mother died from complications from COVID-19 after 6 years of treatment. This report shows that OSCC should be considered in the differential diagnosis of oral ulcerated lesions in non-smoking and non-alcoholic women, especially if there is a family history of first-degree oral cancer.

Legume intake and cancer risk in a network of case-control studies

Evidence on the relationship between legume consumption and risk of specific cancer sites is inconclusive. We used data from a series of case-controls studies, conducted in Italy and in the Swiss Canton of Vaud between 1991 and 2009 to quantify the association between legume consumption and several cancer sites including oral cavity, esophagus, larynx, stomach, colorectum, breast, endometrium, ovary, prostate and kidney. Multiple logistic regression models controlled for sex, age, education, smoking, alcohol, body mass index, physical activity, comorbidities, and consumption of fruit, vegetables, processed meat and total calorie intake were used to estimate the odds ratios (OR) for different cancer sites and their corresponding 95% confidence intervals(CI). For female hormone-related cancers, the models also included adjustments for age at menarche, menopausal status and parity. Although most of the estimates were below unity, suggesting a protective effect, only colorectal cancer showed a significant association. Compared to no consumption, the OR for consuming at least one portion of legumes was 0.79 (95% CI: 0.68-0.91), the OR for consuming two or more portions was 0.68 (95% CI: 0.57-0.82) and the estimate for an increment of one portion per week was 0.87 (95% CI: 0.81-0.93). The inverse association between legume consumption and colorectal cancer suggests a possible role of legumes in preventing cancer risk.

Immunogenetic Determinants of Susceptibility to Head and Neck Cancer in the Million Veteran Program Cohort

Increasing rates of human papillomavirus (HPV)-driven oropharyngeal cancer (OPC) have largely offset declines in tobacco-associated head and neck squamous cell carcinoma (HNSCC) at non-OPC sites. Host immunity is an important modulator of HPV infection, persistence, and clearance, and also of immune evasion in both virally- and nonvirally-driven cancers. However, the association between collective known cancer-related immune gene variants and HNSCC susceptibility has not been fully characterized. Here, we conducted a genetic association study in the multiethnic Veterans Affairs Million Veteran Program cohort, evaluating 16,050 variants in 1,576 immune genes in 4,012 HNSCC cases (OPC = 1,823; non-OPC = 2,189) and 16,048 matched controls. Significant polymorphisms were further examined in a non-Hispanic white (NHW) validation cohort (OPC = 1,206; non-OPC = 955; controls = 4,507). For overall HNSCC susceptibility in NHWs, we discovered and validated a novel 9q31.1 SMC2 association and replicated the known 6p21.32 HLA-DQ-DR association. Six loci/genes for overall HNSCC susceptibility were selectively enriched in African-Americans (6p21.32 HLA-G, 9q21.33 GAS1, 11q12.2 CD6, 11q23.2 NCAM1/CD56, 17p13.1 CD68, 18q22.2 SOCS6); all 6 genes function in antigen-presenting regulation and T-cell activation. Two additional loci (10q26 DMBT1, 15q22.2 TPM1) were uncovered for non-OPC susceptibility, and three loci (11q24 CRTAM, 16q21 CDH5, 18q12.1 CDH2) were identified for HPV-positive OPC susceptibility. This study underscores the role of immune gene variants in modulating susceptibility for both HPV-driven and non-HPV-driven HNSCC. Additional large studies, particularly in racially diverse populations, are needed to further validate the associations and to help elucidate other potential immune factors and mechanisms that may underlie HNSCC risk.

SIGNIFICANCE

Several inherited variations in immune system genes are significantly associated with susceptibility to head and neck cancer, which could help improve personalized cancer risk estimates.

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

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

Explainable ensemble learning model improves identification of candidates for oral cancer screening

OBJECTIVES

Artificial intelligence could enhance the use of disparate risk factors (crude method) for better stratification of patients to be screened for oral cancer. This study aims to construct a meta-classifier that considers diverse risk factors to identify patients at risk of oral cancer and other suspicious oral diseases for targeted screening.

MATERIALS AND METHODS

A retrospective dataset from a community oral cancer screening program was used to construct and train the novel voting meta-classifier. Comprehensive risk factor information from this dataset was used as input features for eleven supervised learning algorithms which served as base learners and provided predicted probabilities that are weighted and aggregated by the meta-classifier. Training dataset was augmented using SMOTE-ENN. Additionally, Shapley additive explanations (SHAP) values were generated to implement the explainability of the model and display the important risk factors.

RESULTS

Our meta-classifier had an internal validation recall, specificity, and AUROC of 0.83, 0.86, and 0.85 for identifying the risk of oral cancer and 0.92, 0.60, and 0.76 for identifying suspicious oral mucosal disease respectively. Upon external validation, the meta-classifier had a significantly higher AUROC than the crude/current method used for identifying the risk of oral cancer (0.78 vs 0.46; p = 0.001) Also, the meta-classifier had better recall than the crude method for predicting the risk of suspicious oral mucosal diseases (0.78 vs 0.47).

CONCLUSION

Overall, these findings showcase that our approach optimizes the use of risk factors in identifying patients for oral screening which suggests potential clinical application.

Epidemiological, Clinical, and Genomic Profile in Head and Neck Cancer Patients and Their Families

Inherited cancer predisposition genes are described as risk factors in head and neck cancer (HNC) families. To explore the clinical and epidemiological data and their association with a family history of cancer, we recruited 74 patients and 164 relatives affected by cancer. The germline copy number alterations were evaluated in 18 patients using array comparative genomic hybridization. Two or more first-degree relatives with HNC, tobacco-associated tumor sites (lung, esophagus, and pancreas), or other related tumors (breast, colon, kidney, bladder, cervix, stomach carcinomas, and melanoma) were reported in 74 families. Ten index patients had no exposure to any known risk factors. Family members presented tumors of 19 topographies (30 head and neck, 26 breast, 21 colon). In first-degree relatives, siblings were frequently affected by cancer (n = 58, 13 had HNC). Breast cancer (n = 21), HNC (n = 19), and uterine carcinoma (n = 15) were commonly found in first-degree relatives and HNC in second-degree relatives (n = 11). Nineteen germline genomic imbalances were detected in 13 patients; three presented gains of WRD genes. The number of HNC patients, the degree of kinship, and the tumor types detected in each relative support the role of heredity in these families. Germline alterations may potentially contribute to cancer development.

Knowledge of Oral Cancer Amongst Dental Patients Attending Public Clinics in South East Queensland, Australia

Patient knowledge of risk factors, signs and symptoms associated with oral cancers is crucial for increasing the likelihood of patient presentation for opportunistic screening and reducing delay in patient appraisal for early detection. This study aimed to assess the knowledge of oral cancer and to ascertain socio-demographic factors that influence knowledge amongst adult dental patients attending public clinics in Brisbane, Australia. A convenience sample of 213 adult dental patients who attended the Herston and Stafford public health clinics in Brisbane, Australia, between July and August 2019 participated in the self-administered questionnaire. Multivariate analyses were performed to identify predictors for oral cancer knowledge. Patients were well informed of smoking as a risk factor (n = 135; 84.4%), whereas only 53.8% (n = 82) of participants agreed that heavy alcohol consumption was a risk factor. A larger proportion of participants identified difficulty of moving the tongue (n = 79; 49.4%) and pain on swallowing (n = 72; 45.0%) compared to the proportion who identified fixed red patches (n = 61; 38.1%) and fixed white patches (n = 57; 35.6%) as a sign or symptom. Education level and gender were significant knowledge predictors for alcohol (p = 0.01), old age (p = 0.008) and family history (p = 0.004) as a risk factors for oral cancer. Those with a family history of cancer were more likely to identify a red patch (p = 0.02), bleeding gums (p = 0.001) and altered sensation (p = 0.023) as a sign or symptom of oral cancer. Overall, patient knowledge was greater for risk factors than for signs and symptoms for oral cancer. Symptoms associated with later stages of cancer were recognised by a greater proportion of patients compared to early stages of oral cancer. These results indicate the need for targeted public health initiatives to improve patient knowledge.

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

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

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

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

The role of family history of Cancer in Oral Cavity Cancer

Objectives

Oral and oropharyngeal squamous cell carcinoma (SCC) is the 10th most common cancer in the United States (8th in males, 13th in females), with an estimated 54,010 new cases expected in 2021, and is primarily associated with smoked tobacco, heavy alcohol consumption, areca nut use and persistent high-risk human papillomavirus (HPV). Family history of cancer (FHC) and family history of head and neck cancer (FHHNC) have been reported to play an important role in the development of OSCC. We aimed to investigate the role of FHC, FHHNC and personal history of cancer in first/second degree-relatives as co-risk factors for oral cancer.

Methods

This was a retrospective study of patients diagnosed with OSCC at the Division of Oral Medicine and Dentistry at Brigham and Women’s Hospital and at the Division of Head and Neck Oncology at Dana Farber Cancer Institute. Conditional logistic regressions were performed to examine whether OSCC was associated with FHC and FHHNC of FDRs and SDRs, personal history of cancer and secondary risk factors.

Results

Overall, we did not find an association between FHC, FHHNC and OSCC risk, whereas patients with a cancer history in one of their siblings were 1.6-times more likely to present with an OSCC. When secondary risk factors were considered, patients with a history of oral leukoplakia and dysplasia had a 16-times higher risk of having an OSCC.

Conclusions

Our study confirmed that a previous history of oral leukoplakia or dysplasia was an independent risk factor for OSCC. A positive family history of cancer in one or more siblings may be an additional risk factor for OSCC.

Family History of Head and Neck Cancers

Simple Summary

Head and neck cancers are cancers that arise between the mouth and larynx. Risk factors for these include smoking, alcohol, human papilloma virus (HPV) infection and family history. Because families can be identified for the whole Swedish population, we wanted to analyzed familial risks for HNC with same and different cancers among first-degree relatives. When a parent or sibling was diagnosed with HNC, other family members had a two-fold risk of being diagnosed with HNC, but the risk was higher when specific types of HNC, such as oral or nasopharyngeal cancers, were analyzed. Husbands of wives with cervical cancer had an increased risk of oropharyngeal cancer which may be related to shared HPV infection. In the Swedish population with low smoking levels, HPV is becoming a dominant risk factor, emphasizing the need for sexual hygiene and HPV vaccination.

Abstract

Background: Head and neck cancers (HNCs) encompass a heterogeneous group of cancers between the mouth and larynx. Familial clustering in HNCs has been described, but how it influences individual sites and to which extent known risk factors, such as human papilloma virus (HPV) infection, may contribute is not well established. Patients/methods: We employed standardized incidence ratios (SIRs) to estimate familial risks for HNC with same (concordant) and different (discordant) cancers among first-degree relatives using data from the Swedish Cancer Registry from 1958 to 2018. Results: Incidence for male and female oropharyngeal cancer increased close to four-fold in the past 39 years. Familial HNC was found in 3.4% of the study population, with an overall familial SIR of 1.78. Patients with concordant nasopharyngeal cancer showed a high risk of 23.97, followed by hypopharyngeal cancer (5.43). The husbands of wives with cervical cancer had an increased risk of oropharyngeal cancer. Discussion/Conclusion: Nasopharyngeal cancers lacked associations with lifestyle or HPV associated cancers, suggesting a role for germline genetics, which was also true for the high-risk families of three HNC patients. In the Swedish population with low smoking levels, HPV is becoming a dominant risk factor, emphasizing the need for sexual hygiene and HPV vaccination.

Genetic variants associated with expression of TCF19 contribute to the risk of head and neck cancer in Chinese population

BACKGROUND

Squamous cell carcinoma of the head and neck (SCCHN) is one of the most common cancers worldwide and includes cancers arising from the oral cavity, pharynx and larynx. Genome-wide association studies have found several genetic variants related to the risk of SCCHN; however, they could only explain a small fraction of the heritability. Thus, more susceptibility loci associated with SCCHN need to be identified.

METHODS

An association study was conducted by genotyping 555 patients with SCCHN and 1367 controls in a Chinese population. Single-variant association analysis was conducted on 63 373 SNPs, and the promising variants were then confirmed by a two-stage validation with 1875 SCCHN cases and 4637 controls. Bioinformatics analysis and functional assays were applied to uncover the potential pathogenic mechanism of the promising variants and genes associated with SCCHN.

RESULTS

We first identified three novel genetic variants significantly associated with the risk of SCCHN (p=7.45×10^-7 for rs2517611 at 6p22.1, p=1.76×10^-9 for rs2524182 at 6p21.33 and p=2.17×10^-10 for rs3131018 at 6p21.33). Further analysis and biochemical assays showed that rs3094187, which was in a region in high linkage disequilibrium with rs3131018, could modify TCF19 expression by regulating the binding affinity of the transcription factor SREBF1 to the promoter of TCF19. In addition, experiments revealed that the inhibition of TCF19 may affect several important pathways involved in tumourigenesis and attenuate the cell proliferation and migration of SCCHN.

CONCLUSION

These findings offer important evidence that functional genetic variants could contribute to development of SCCHN and that TCF19 may function as a putative susceptibility gene for SCCHN.

Polymorphic variants of drug-metabolizing enzymes alter the risk and survival of oral cancer patients

The present study investigated the prevalence of CYP2D6*4, CYP3A5*3 and SULT1A1*2, using PCR-RFLP, in normal and oral cancer (OC) patients that were stratified by OC subtype and gender. The risk of cancer, 5-year cumulative survival and hazard's ratio (HR) with respect to risk factors and clinical factors were estimated using Fisher's exact test, Kaplan-Meier analysis, and Cox proportional hazards models. CYP2D6*4 'GA' lowered the risk of buccal mucosa cancer (BMC) in males (OR = 0.37), whereas, 'G' allele of CYP3A5*3 increased risk of tongue cancer (TC) (OR = 1.67). SULT1A1*2 'GA' increased the risk of TC (OR = 2.36) and BMC (OR = 3.25) in females. The 5-year survival of the patients depended on factors like age, lymphovascular spread (LVS), perinodal spread (PNS), recurrence, tobacco, and alcohol. CYP3A5*3 'AG' and 'GG' had decreased the hazard ratio (HR) for BMC females when inflammatory infiltrate alone or along with other covariates, LVS, PNI, PNS, metastasis, recurrence, and relapse was adjusted. Similarly, CYP3A5*3 'AG' decreased the risk of death (HR = 0.05) when the grade was adjusted. SULT1A1*2 'GA' had decreased HR for TC males (HR = 0.08) after adjusting for inflammatory infiltrate, LVS, perineural invasion (PNI), PNS, metastasis, recurrence, and relapse. Further, our bioinformatics study revealed the presence of a CpG island within the CYP2D6 and a CTCF binding site upstream of CYP2D6. Interestingly, three CpG islands and two CTCF binding sites were also identified near the SULT1A1. In conclusion, the SNPs altered risk and survival of BMC and TC differentially in a gender specified manner, that varied with clinical and risk factors.

Tobacco, Alcohol and Family History of Cancer as Risk Factors of Oral Squamous Cell Carcinoma: Case-Control Retrospective Study

The aim of the study is to observe retrospectively the correlation between Oral Squamous Cell Carcinoma (OSCC) and risk factors; including tobacco, alcohol and Family History of Cancer (FHC). A total of 478 patients were included retrospectively from the database of the Department of Oral Sciences and Maxillofacial Surgery, Sapienza University of Rome. A Test Group (TG) consisted of 239 patients with a confirmed diagnosis of OSCC. A Control Group (CG) consisted of 239 patients without history and/or diagnosis of oral cancer. The logistic regression models were used to calculate the adjusted Odd Ratios (ORs) associated with alcohol, tobacco and FHC; including the General Family History of Cancer (GFHC) and Family History of Head and Neck Cancer (FHHNC) and their 95% Confidence Intervals (CI). The high rate of tobacco consumption was associated with an OR of 1.035 (95% CI 1.001–1.070) and a statistical significance (p = 0.041). Drinker patients showed a significant risk of developing OSCC (p = 0.05) and the OR was 1.035 (95% CI 1.010–1.061). The GFHC was associated with a marginal risk of OSCC with an OR of 1.095 (95% CI 0.953–1.259), without significance (p = 0.199). The FHHNC showed a notable risk increase with an OR of 1.871 (95% CI 0.902–3.882), without significance (p = 0.092). Alcohol and tobacco may be associated with an increase in the risk of OSCC.

Familial cancer risk in family members and spouses of patients with early-onset head and neck cancer

BACKGROUND

Reported patterns of familial aggregation of head and neck cancer (HNC) vary greatly, with many studies hampered by the limited number of subjects.

METHODS

Altogether 923 early-onset (≤40 years old) HNC probands, their first-degree relatives, spouses, and siblings' offspring were ascertained. Cumulative risk and standardized incidence ratios (SIRs) were estimated.

RESULTS

Of all early-onset HNC families, only 21 (2.3%) had familial HNC cancers at any age and less than five familial early onset HNC cancers among first-degree relatives. The cumulative risk of HNC for siblings by age 60 (0.52%) was at population level (0.33%). No increased familial risk of early-onset HNC could be discerned in family members (SIR 2.68, 95% CI 0.32-9.68 for first-degree relatives).

CONCLUSIONS

Our study indicates that the cumulative and relative familial risk of early-onset HNC is modest in the Finnish population and, at most, only a minor proportion of early-onset HNCs are due solely to inherited genetic mutations.

Assessing Oral Cancer Awareness Among Dentists

The aim of this study was to assess oral cancer awareness among dentists who attended 101st FDI World Dental Congress, İstanbul, Turkey. Among 170 dentists who agreed to participate, there were 13 oral surgeons, 6 restorative dentists, 4 endodontists, 4 orthodontists, 6 periodontists, 5 pedodontists, and 14 prosthodontists. Knowledge of oral cancer risk factors and diagnosis procedures, dentists' attitude towards oral cancers, management practice regarding oral cancer, and oral cancer information sources were assessed using 25 questions. The data were analyzed with IBM SPSS Statistics 22.0 program. Among 170 participant dentists, there were 69 (40.6%) male dentists and 101 (59.4%) female dentists. Largest number of them identified tobacco (98.8%) and alcohol usage (91.2%), prior oral cancer lesions (95.3%), viral infections (90.0%), UV exposure (86.5%), and betel quid chewing (80.6%), and lower numbers reported older age (56.5%) and low consumption of fruit and vegetables (52.4%). Oral medicine specialists scored marginally higher in indicating erythroplakia and leukoplakia most likely to be precancerous and squamous cell carcinoma as the most common form of oral cancer (p < 0.01). This study highlighted the importance of improved educational methods for dentists on oral cancer detection and prevention.

Prevalence of Oral Premalignant Lesions and Its Risk Factors among the Adult Population in Udupi Taluk of Coastal Karnataka, India

Objective:

Globally oral cancer is one of the ten most common cancers with prevalence being high in Central and South East Asian countries. This survey was conducted to estimate the prevalence of oral pre-malignant lesions (OPML) and to identify their risk factors.

Methods:

A community based cross-sectional study was carried out among 2033 individuals aged ≥18 years. A questionnaire was administered to collect socio-demographic characteristics, various risk factors for oral cancer and presence of its symptoms. Oral cavity of all the participants was examined in detail by the study investigator as per WHO guidelines for the early diagnosis of oral neoplasia.

Result:

The prevalence of OPML was found to be 3.73%. Among those with OPML, all were ever tobacco consumers and had poor oral hygiene. A significant association was observed between OPML and younger age group (OR=2.56, 95% CI 1.08-6.02), males (OR=26.76, 95% CI 8.40-85.19) and low socio-economic status (OR = 1.91, 95% CI 1.20-3.02). Tobacco (p<0.001), alcohol (OR= 7.92, 95% CI 4.77-13.14) and areca nut consumption (OR = 5.48, 95% CI 3.42-8.77) were strongly associated with OPML. On multivariate analysis among ever tobacco users, OPML was associated with younger individuals, males and those using smokeless forms of tobacco (p <0.05). The study showed that the participants with OPML were more likely to be never married (OR=1.6, 95% CI 0.92-2.96), to be unskilled workers (OR= 1.45, 95% CI 0.61-3.43), to have suffered from oral trauma (OR =1.30, 95% CI 0.75-2.26), to have consumed hot and spicy food frequently (OR=1.53, 95% CI 0.96-2.24), to have consumed fruits infrequently (OR=1.53, 95% CI 0.90-2.59) and to report family history of any cancer (OR = 1.29, 95% CI 0.58-2.87). However, these associations were statistically insignificant.

Conclusion:

The study reinforces that use of substances such as tobacco, alcohol and areca nut are the modifiable risk factors for OPML.

Impact of age at diagnosis on clinicopathological outcomes of oral squamous cell carcinoma patients

Objective

A recent trend in diagnosis of oral cancer in young age is observed, however its impact on various clinicopathological parameters needs to be explored. The aim of the current study was to compare and analyze impact of age at diagnosis with clinicopathological parameters of oral squamous cell carcinoma patients.

Methods

In this cross sectional study conducted at Department of Oncology Ziauddin Hospital Karachi, we included histologically confirmed cases of oral squamous cell carcinoma. The patients were categorized as young age group (40yrs and younger) and old age group (41 yrs and above). A total of 115 patients diagnosed between 2013 and 2016 were enrolled in the study. The variables considered were age at diagnosis, sex, site of lesion, positive family history, tumor grade, stage, uric acid level and survival.

Results

A statistically significant difference was observed between two age groups in overall survival, uric acid level and positive family history of cancer. No significant difference was observed in tumor location, grade and stage.

Conclusion

Majority of oral cancer patients present at an advanced stage irrespective of age at diagnosis but young age has an overall improved survival. Moreover, a positive family history of cancer in young age group mandates further exploration of possible role of genetic polymorphisms which might be responsible for early onset of the disease.

[Cancer of the oral cavity in three brothers of the whole blood in Mauritania]

Les facteurs de risque majeurs pour les cancers de la cavité orale sont la consommation d'alcool et le tabac mais une composante héréditaire a également été évoquée. L’observation que nous vous présentons ci-dessous a pour objectif d’illustrer cette composante parmi les autres facteurs de risque plus connus. C’est l’histoire de trois frères germains ayant présenté chacun un cancer de la cavité orale avec une évolution très rapide en moins d’une année pour chacun d’entre eux. En plus du facteur familial, les facteurs de risque retrouvés chez ces patients étaient: le tabagisme, une mauvaise hygiène bucco-dentaire, une alimentation pauvre en légumes et en fruits. Le risque familial des cancers de la cavité orale était pendant très longtemps un sujet controversé mais plusieurs études récentes ont suggérées l’existence de ce risque ce qui concorde avec notre observation chez ces trois frères. Ces études ont montré aussi que bien que la composante héréditaire pour les carcinomes des voies aéro-digestives supérieures semble probable, il est important que les membres de la famille à risque comprennent que leur vulnérabilité à ces tumeurs peut être considérablement réduite par l'arrêt du tabac, la modération de la consommation d'alcool et la consommation fréquente de fruits et légumes crus. Des études plus poussées devront être réalisées dans notre pays pour préciser la place respective de ces différents facteurs de risque pour ce cancer. En attendant, la prévention et le diagnostic précoce restent les moyens les plus appropriées pour la lutte contre ce type de cancers.

Mouth Cancer for Clinicians Part 5: Risk Factors (Other)

A MEDLINE search early in 2015 revealed more than 250,000 papers on head and neck cancer; over 100,000 on oral cancer; and over 60,000 on mouth cancer. Not all publications contain robust evidence. We endeavour to encapsulate the most important of the latest information and advances now employed in practice, in a form comprehensible to healthcare workers, patients and their carers. This series offers the primary care dental team, in particular, an overview of the aetiopathogenesis, prevention, diagnosis and multidisciplinary care of mouth cancer, the functional and psychosocial implications, and minimization of the impact on the quality of life of patient and family. Clinical Relevance: This article offers the dental team an overview of other cancer risk factors agents, such as human papilloma viruses (HPV) and irradiation.

Mouth Cancer for Clinicians Part 4: Risk Factors (Traditional: Alcohol, Betel and Others)

A MEDLINE search early in 2015 revealed more than 250,000 papers on head and neck cancer; over 100,000 on oral cancer; and over 60,000 on mouth cancer. Not all publications contain robust evidence. We endeavour to encapsulate the most important of the latest information and advances now employed in practice, in a form comprehensible to healthcare workers, patients and their carers. This series offers the primary care dental team, in particular, an overview of the aetiopathogenesis, prevention, diagnosis and multidisciplinary care of mouth cancer, the functional and psychosocial implications, and minimization of the impact on the quality of life of patient and family.

CLINICAL RELEVANCE

This article offers the dental team an overview of the main cancer risk factors, namely tobacco and alcohol, betel and other chewing habits, and environmental factors.

Clinical features and prognostic factors in patients with head and neck cancer: Results from a multicentric study

BACKGROUND

The purpose of this study is to evaluate whether demographics, lifestyle habits, clinical data and alcohol dehydrogenase polymorphisms rs1229984 and rs1573496 associated with first primary head and neck (HNC) are associated with overall survival, recurrence, and second primary cancer (SPC).

METHODS

We conducted a follow-up study in five centres including 801 cases. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for overall survival, recurrence and SPC.

RESULTS

Five-years overall survival was 62% for HNC cases, 55% for oral cavity, 53% for oropharynx, 41% for hypopharynx, and 71% for larynx. Predictors of survival were older ages (HR=1.18 for 5 years increase; CI: 1.07-1.30), higher tumour stage (HR=4.16; CI: 2.49-6.96), and high alcohol consumption (HR=3.93; CI: 1.79-8.63). A combined therapy (HR=3.29; CI: 1.18-9.13) was associated with a worst prognosis for oral cavity cancer. The only predictor was higher tumour stage (HR=2.25; CI: 1.26-4.03) for recurrence, and duration of smoking (HR=1.91; CI: 1.00-3.68) for SPC. ADH1B rs1229984 polymorphism HRs for HNC and oesophageal cancer death and for alcohol related cancer death were 0.67 (95% CI: 0.42-1.08), and 0.64 (95% CI: 0.40-1.03), respectively.

CONCLUSIONS

The survival expectation differs among HNC sites. Increasing age and stage, and high alcohol consumption were unfavourable predictors of HNC survival overall. Duration of tobacco consumption before the first primary tumour was a risk factor for SPC.

PHF21B as a candidate tumor suppressor gene in head and neck squamous cell carcinomas

A significant association between DNA losses on 22q13.31 and head and neck squamous cell carcinomas (HNSCC) was previously reported by our group. Our data indicated that PHF21B gene, mapped on 22q13.31 and encoding a protein with function of chromatin-mediated transcriptional regulation, might be a putative tumor suppressor gene. To test this hypothesis, gene copy number was assessed in 75 HNSCC and 49 matched peripheral blood samples. PHF21B losses were detected in 43 tumors and were significantly associated with patients with familial history of cancer (P < 0.0001); i.e., 36/43 cases showed a positive family history of cancer and 22/36 had first-degree relatives with cancer (P = 0.049). In attempt to investigate other mechanisms for PHF21B loss of function, DNA sequencing was performed and no mutations were detected. We next evaluated the gene expression levels after inhibition of DNA methylation in nine HNSCC and breast carcinoma cell lines. Additionally, PHF21B expression levels were evaluated in colon cancer HCT116 cells as well as in its counterpart DKO (double knockout of DNMT1 and DNMT3B). The higher expression levels of PHF21B gene detected in DKO cells were inversely correlated with the DNA methylation. Further, DNA methylation in the specific promoter-associated CpG Island was investigated. Interestingly, gene hypermethylation was detected in 13/37 tumors: 5/13 HNSCC cases had family history of cancer in first-degree relatives and 8/13 showed both, DNA methylation and PHF21B losses in the tumor sample. One patient had PHF21B loss in the peripheral blood cells and PHF21B methylation in the tumor sample. Additionally, overexpression of PHF21B in cell lines drastically reduces clonogenic and migratory abilities. These data suggest that PHF21B is a novel tumor suppressor gene that can be inactivated by genetic and epigenetic mechanisms in the human cancer.

Mouth cancer awareness and beliefs among dental patients

OBJECTIVES

The aim of the present study was to assess the levels of awareness, knowledge about signs and risk factors of mouth (oral) cancer, and attitudes towards early diagnosis and treatment among dental outpatients.

MATERIAL AND METHODS

A total of 1,200 adult outpatients attending dental clinics at the University of Jordan Hospital for dental examination and treatment were randomly selected to participate in the study. An 18-item pretested close-ended questionnaire was used for the study. Descriptive statistics were generated and chi-square tests, t-tests, one-way analysis of variance (ANOVA), and Spearman's rho test were used to examine differences between groups.

RESULTS

Only 45.6% of the subjects had heard about oral cancer. Some 66.9% and 33.8%, respectively, were able to correctly identify tobacco and alcohol as risk factors. Some 24.1% had no knowledge about any signs of oral cancer. Male subjects, smokers, alcohol drinkers, older participants (>40 years), and participants with less than a university education were significantly less aware, and had much less knowledge, of the signs and risk factors of oral cancer (P<0.05).

CONCLUSION

Awareness about oral cancer among Jordanian dental outpatients is low. These dental patients, especially those in high-risk groups for mouth cancer and those of lower socio-economic status (SES), are less well informed about the signs and risk factors of oral cancer. Interventions to improve public knowledge about oral cancer and attitudes towards early diagnosis and treatment are urgently indicated.

Polymorphisms in human DNA repair genes and head and neck squamous cell carcinoma

Genetic polymorphisms in some DNA repair proteins are associated with a number of malignant transformations like head and neck squamous cell carcinoma (HNSCC). Xeroderma pigmentosum group D (XPD) and X-ray repair cross-complementing proteins 1 (XRCC1) and 3 (XRCC3) genes are involved in DNA repair and were found to be associated with HNSCC in numerous studies. To establish our overall understanding of possible relationships between DNA repair gene polymorphisms and development of HNSCC, we surveyed the literature on epidemiological studies that assessed potential associations with HNSCC risk in terms of gene-environment interactions, genotype-induced functional defects in enzyme activity and/or protein expression, and the influence of ethnic origin on these associations.We conclude that large, well-designed studies of common polymorphisms in DNA repair genes are needed. Such studies may benefit from analysis of multiple genes or polymorphisms and from the consideration of relevant exposures that may influence the likelihood of HNSCC when DNA repair capacity is reduced.

Family history of cancer, personal history of medical conditions and risk of oral cavity cancer in France: the ICARE study

BACKGROUND

The aim of this study was to evaluate the role of family history of cancer and personal history of other medical conditions in the aetiology of the oral cavity cancer in France.

METHODS

We used data from 689 cases of oral cavity squamous cell carcinoma and 3481 controls included in a population-based case-control study, the ICARE study. Odds-ratios (ORs) associated with family history of cancer and personal medical conditions and their 95% confidence intervals (95% CI) were estimated by unconditional logistic regression and were adjusted for age, gender, area of residence, education, body mass index, tobacco smoking and alcohol drinking.

RESULTS

Personal history of oral candidiasis was related to a significantly increased risk of oral cavity cancer (OR 5.0, 95% CI 2.1-12.1). History of head and neck cancers among the first-degree relatives was associated with an OR of 1.9 (95% CI 1.2-2.8). The risk increased with the number of first-degree relatives with head and neck cancer.

CONCLUSION

A family history of head and neck cancer is a marker of an increased risk of oral cavity cancer and should be taken into account to target prevention efforts and screening. Further studies are needed to clarify the association between oral cavity cancer and personal history of candidiasis.

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

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

Family history of cancer and the risk of cancer: a network of case-control studies

BACKGROUND

The risk of many cancers is higher in subjects with a family history (FH) of cancer at a concordant site. However, few studies investigated FH of cancer at discordant sites.

PATIENTS AND METHODS

This study is based on a network of Italian and Swiss case-control studies on 13 cancer sites conducted between 1991 and 2009, and including more than 12 000 cases and 11 000 controls. We collected information on history of any cancer in first degree relatives, and age at diagnosis. Odds ratios (ORs) for FH were calculated by multiple logistic regression models, adjusted for major confounding factors.

RESULTS

All sites showed an excess risk in relation to FH of cancer at the same site. Increased risks were also found for oral and pharyngeal cancer and FH of laryngeal cancer (OR = 3.3), esophageal cancer and FH of oral and pharyngeal cancer (OR = 4.1), breast cancer and FH of colorectal cancer (OR = 1.5) and of hemolymphopoietic cancers (OR = 1.7), ovarian cancer and FH of breast cancer (OR = 2.3), and prostate cancer and FH of bladder cancer (OR = 3.4). For most cancer sites, the association with FH was stronger when the proband was affected at age <60 years.

CONCLUSIONS

Our results point to several potential cancer syndromes that appear among close relatives and may indicate the presence of genetic factors influencing multiple cancer sites.

Dietary folates and cancer risk in a network of case-control studies

BACKGROUND

Folate deficiency leads to DNA damage and inadequate repair, caused by a decreased synthesis of thymidylate and purines. We analyzed the relationship between dietary folate intake and the risk of several cancers.

PATIENTS AND METHODS

The study is based on a network of case-control studies conducted in Italy and Switzerland in 1991-2009. The odds ratios (ORs) for dietary folate intake were estimated by multiple logistic regression models, adjusted for major identified confounding factors.

RESULTS

For a few cancer sites, we found a significant inverse relation, with ORs for an increment of 100 μg/day of dietary folate of 0.65 for oropharyngeal (1467 cases), 0.58 for esophageal (505 cases), 0.83 for colorectal (2390 cases), 0.72 for pancreatic (326 cases), 0.67 for laryngeal (851 cases) and 0.87 for breast (3034 cases) cancers. The risk estimates were below unity, although not significantly, for cancers of the endometrium (OR = 0.87, 454 cases), ovary (OR = 0.86, 1031 cases), prostate (OR = 0.91, 1468 cases) and kidney (OR = 0.88, 767 cases), and was 1.00 for stomach cancer (230 cases). No material heterogeneity was found in strata of sex, age, smoking and alcohol drinking.

CONCLUSIONS

Our data support a real inverse association of dietary folate intake with the risk of several common cancers.

Current aspects on oral squamous cell carcinoma

Oral squamous cell carcinoma is the most common malignant epithelial neoplasm affecting the oral cavity. This article overviews the essential points of oral squamous cell carcinoma, highlighting its risk and genomic factors, the potential malignant disorders and the therapeutic approaches. It also emphasizes the importance of the early diagnosis.

History of cholelithiasis and cancer risk in a network of case-control studies

BACKGROUND

We analyzed the relationship between cholelithiasis and cancer risk in a network of case-control studies conducted in Italy and Switzerland in 1982-2009.

METHODS

The analyses included 1997 oropharyngeal, 917 esophageal, 999 gastric, 23 small intestinal, 3726 colorectal, 684 liver, 688 pancreatic, 1240 laryngeal, 6447 breast, 1458 endometrial, 2002 ovarian, 1582 prostate, 1125 renal cell, 741 bladder cancers, and 21 284 controls. The odds ratios (ORs) were estimated by multiple logistic regression models.

RESULTS

The ORs for subjects with history of cholelithiasis compared with those without were significantly elevated for small intestinal (OR=3.96), prostate (OR=1.36), and kidney cancers (OR=1.57). These positive associations were observed ≥10 years after diagnosis of cholelithiasis and were consistent across strata of age, sex, and body mass index. No relation was found with the other selected cancers. A meta-analysis including this and three other studies on the relation of cholelithiasis with small intestinal cancer gave a pooled relative risk of 2.35 [95% confidence interval (CI) 1.82-3.03].

CONCLUSION

In subjects with cholelithiasis, we showed an appreciably increased risk of small intestinal cancer and suggested a moderate increased risk of prostate and kidney cancers. We found no material association with the other cancers considered.

Using prior information from the medical literature in GWAS of oral cancer identifies novel susceptibility variant on chromosome 4--the AdAPT method

Background

Genome-wide association studies (GWAS) require large sample sizes to obtain adequate statistical power, but it may be possible to increase the power by incorporating complementary data. In this study we investigated the feasibility of automatically retrieving information from the medical literature and leveraging this information in GWAS.

Methods

We developed a method that searches through PubMed abstracts for pre-assigned keywords and key concepts, and uses this information to assign prior probabilities of association for each single nucleotide polymorphism (SNP) with the phenotype of interest - the Adjusting Association Priors with Text (AdAPT) method. Association results from a GWAS can subsequently be ranked in the context of these priors using the Bayes False Discovery Probability (BFDP) framework. We initially tested AdAPT by comparing rankings of known susceptibility alleles in a previous lung cancer GWAS, and subsequently applied it in a two-phase GWAS of oral cancer.

Results

Known lung cancer susceptibility SNPs were consistently ranked higher by AdAPT BFDPs than by p-values. In the oral cancer GWAS, we sought to replicate the top five SNPs as ranked by AdAPT BFDPs, of which rs991316, located in the ADH gene region of 4q23, displayed a statistically significant association with oral cancer risk in the replication phase (per-rare-allele log additive p-value [p_trend] = 2.5×10⁻³). The combined OR for having one additional rare allele was 0.83 (95% CI: 0.76–0.90), and this association was independent of previously identified susceptibility SNPs that are associated with overall UADT cancer in this gene region. We also investigated if rs991316 was associated with other cancers of the upper aerodigestive tract (UADT), but no additional association signal was found.

Conclusion

This study highlights the potential utility of systematically incorporating prior knowledge from the medical literature in genome-wide analyses using the AdAPT methodology. AdAPT is available online (url: http://services.gate.ac.uk/lld/gwas/service/config).

Family history and oral health: findings from the Dunedin Study

CONTEXT

The effects of the oral health status of one generation on that of the next within families are unclear.

OBJECTIVES

  To determine whether parental oral health history is a risk factor for oral disease.

METHODS

Oral examination and interview data were collected during the age-32 assessments in the Dunedin Study. Parental data were also collected on this occasion. The sample was divided into two familial-risk groups for caries/tooth loss (high risk and low risk) based on parents' self-reported history of tooth loss at the age-32 assessment interview.

MAIN OUTCOME MEASURES

Probands' dental caries and tooth loss status at age 32, together with lifelong dental caries trajectory (age 5-32).

RESULTS

Caries/tooth loss risk analysis was conducted for 640 proband-parent groups. Reference groups were the low-familial-risk groups. After controlling for confounding factors (sex, episodic use of dental services, socio-economic status and plaque trajectory), the prevalence ratio (PR) for having lost 1+ teeth by age 32 for the high-familial-risk group was 1.41 [95% confidence interval (CI) 1.05, 1.88] and the rate ratio for DMFS at age 32 was 1.41 (95% CI 1.24, 1.60). In the high-familial-risk group, the PR of following a high caries trajectory was 2.05 (95% CI 1.37, 3.06). Associations were strongest when information was available about both parents' oral health. Nonetheless, when information was available for one parent only, associations were significant for some outcomes.

CONCLUSIONS

People with poor oral health tend to have parents with poor oral health. Family/parental history of oral health is a valid representation of the intricacies of the shared genetic and environmental factors that contribute to an individual's oral health status. Associations are strongest when data from both parents can be obtained.

History of cancer in first degree relatives of Barrett's esophagus patients: a case-control study

BACKGROUND AND OBJECTIVE

Familial clusters of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) have been reported. This study evaluates the history of cancer in BE patients families.

METHODS

In two years, patients with BE (272), esophagitis (456) and controls (517) were recruited in 12 Italian Endoscopy Units. Cancer family history in first-degree (FD) relatives was determined by a questionnaire.

RESULTS

Approximately 53% of BE, 51% of esophagitis, and 48% of controls had at least one relative affected by any type of malignancy. Probands with at least one esophageal or gastric (E/G) cancer-affected relative showed a BE risk which was at least eighty-five percent higher than that of probands without affected relatives. The relative risk of BE was 4.18, 95% CL=0.76-23.04 if a FD relative had early (mean age ≤ 50 years) onset E/G cancer compared to late onset E/G cancer.

CONCLUSION

In this sample there was no evidence that a family history of cancer was associated with the diagnosis of BE. An intriguing result was the association between the occurrence of E/G cancers at earlier ages (< 50 years) among BE relatives with respect the control group. This could suggest a genetic contribution in onset of these tumors, but the sample was too small to demonstrate a significant association. Further exploration of family history of E/G cancer and a diagnosis of BE in larger samples is warranted.

Epidemiology of cancer from the oral cavity and oropharynx

The classification of sites in tumors of the oral cavity, oropharynx, pharynx, and hypopharynx varies in the literature. More than 90% of these tumors of the mucosal lining are classified as squamous cell carcinoma developed from premalignant lesions such as leukoplakia and erythroleukoplakia. These carcinomas are associated to environmental and lifestyle risk factors, among which tobacco and alcohol play a major role. In addition to tobacco smoking, tobacco chewing is another risk factor as well as chewing betel quid and areca nut in Asia. Certain strains of virus, such as the sexually transmitted human papilloma virus, also play a carcinogenetic role. The temporal trends in incidence of these tumors relate to environmental factors; there is an increase in tendency in countries without prevention and a decrease in countries having an active policy of prevention of alcohol and tobacco consumption. In contrast, an increased incidence occurs in the world at tumor sites related to human papilloma virus infection in relation to changes in sexual habits.

Advances and applications of oral cancer basic research

Cancer of the oral cavity accounts for almost 3% of cancer cases in the world. The incidence varies widely reflecting geographic differences in exposure to risk factors. The recent rise in younger age groups and females seen in many countries is of particular concern. Treatment and management of complications, locoregional recurrence and further primary tumors result in high morbidity and mortality especially when the disease is advanced stage at initial diagnosis. Progress in cancer research has provided abundant new knowledge about cellular processes and molecular biology underlying oral carcinogenesis and tumor progression. The present review attempts to summarize the current most widely-used research approaches and their application in the prevention, diagnosis, effective treatment, and improved outcome of oral cancer.

A genome-wide association study of upper aerodigestive tract cancers conducted within the INHANCE consortium

Genome-wide association studies (GWAS) have been successful in identifying common genetic variation involved in susceptibility to etiologically complex disease. We conducted a GWAS to identify common genetic variation involved in susceptibility to upper aero-digestive tract (UADT) cancers. Genome-wide genotyping was carried out using the Illumina HumanHap300 beadchips in 2,091 UADT cancer cases and 3,513 controls from two large European multi-centre UADT cancer studies, as well as 4,821 generic controls. The 19 top-ranked variants were investigated further in an additional 6,514 UADT cancer cases and 7,892 controls of European descent from an additional 13 UADT cancer studies participating in the INHANCE consortium. Five common variants presented evidence for significant association in the combined analysis (p ≤ 5 × 10⁻⁷). Two novel variants were identified, a 4q21 variant (rs1494961, p = 1×10⁻⁸) located near DNA repair related genes HEL308 and FAM175A (or Abraxas) and a 12q24 variant (rs4767364, p =2 × 10⁻⁸) located in an extended linkage disequilibrium region that contains multiple genes including the aldehyde dehydrogenase 2 (ALDH2) gene. Three remaining variants are located in the ADH gene cluster and were identified previously in a candidate gene study involving some of these samples. The association between these three variants and UADT cancers was independently replicated in 5,092 UADT cancer cases and 6,794 controls non-overlapping samples presented here (rs1573496-ADH7, p = 5 × 10⁻⁸); rs1229984-ADH1B, p = 7 × 10⁻⁹; and rs698-ADH1C, p = 0.02). These results implicate two variants at 4q21 and 12q24 and further highlight three ADH variants in UADT cancer susceptibility.

CYP1A2*1C, CYP2E1*5B, and GSTM1 polymorphisms are predictors of risk and poor outcome in head and neck squamous cell carcinoma patients

Head and neck squamous cell carcinoma (HNSCC) is associated with environmental factors, especially tobacco and alcohol consumption. Most of the carcinogens present in tobacco smoke are converted into DNA-reactive metabolites by cytochrome P450 (CYPs) enzymes and detoxification of these substances is performed by glutathione S-transferases (GSTs). It has been suggested that genetic alterations, such as polymorphisms, play an important role in tumorigenesis and HNSCC progression. The aim of this study was to investigate CYP1A1, CYP1A2, CYP2E1, GSTM1, and GSTT1 polymorphisms as risk factors in HNSCC and their association with clinicopathologic data. The patients comprised 153 individuals with HNSCC (cases) and 145 with no current or previous diagnosis of cancer (controls). Genotyping of the single nucleotide polymorphisms (SNPs) of the CYP1A1, CYP1A2, and CYP2E1 genes was performed by PCR-RFLP and the GSTM1 and GSTT1 copy number polymorphisms (CNPs) were analyzed by PCR-multiplex. As expected, a significant difference was detected for tobacco and alcohol consumption between cases and controls (P<0.001). It was observed that the CYP1A2*1D (OR=16.24) variant and GSTM1 null alleles (OR=0.02) confer increased risk of HNSCC development (P<0.001). In addition, head and neck cancer alcohol consumers were more frequently associated with the CYP2E1*5B variant allele than control alcohol users (P<0.0001, OR=190.6). The CYP1A2*1C polymorphism was associated with tumor recurrence (log-rank test, P=0.0161). The CYP2E1*5B and GSTM1 null alleles were significantly associated with advanced clinical stages (T3+T4; P=0.022 and P=0.028, respectively). Overall, the findings suggested that the genetic polymorphisms studied are predictors of risk and are also associated with tumor recurrence, since they are important for determining the parameters associated with tumor progression and poor outcomes in HNSCC.

Family history of cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

Alcohol and tobacco consumption are well-recognized risk factors for head and neck cancer (HNC). Evidence suggests that genetic predisposition may also play a role. Only a few epidemiologic studies, however, have considered the relation between HNC risk and family history of HNC and other cancers. We pooled individual-level data across 12 case-control studies including 8,967 HNC cases and 13,627 controls. We obtained pooled odds ratios (OR) using fixed and random effect models and adjusting for potential confounding factors. All statistical tests were two-sided. A family history of HNC in first-degree relatives increased the risk of HNC (OR=1.7, 95% confidence interval, CI, 1.2-2.3). The risk was higher when the affected relative was a sibling (OR=2.2, 95% CI 1.6-3.1) rather than a parent (OR=1.5, 95% CI 1.1-1.8) and for more distal HNC anatomic sites (hypopharynx and larynx). The risk was also higher, or limited to, in subjects exposed to tobacco. The OR rose to 7.2 (95% CI 5.5-9.5) among subjects with family history, who were alcohol and tobacco users. A weak but significant association (OR=1.1, 95% CI 1.0-1.2) emerged for family history of other tobacco-related neoplasms, particularly with laryngeal cancer (OR=1.3, 95% CI 1.1-1.5). No association was observed for family history of nontobacco-related neoplasms and the risk of HNC (OR=1.0, 95% CI 0.9-1.1). Familial factors play a role in the etiology of HNC. In both subjects with and without family history of HNC, avoidance of tobacco and alcohol exposure may be the best way to avoid HNC.