Distinct Failure Patterns in Hypopharyngeal Cancer Patients Receiving Surgery-Based Versus Radiation-Based Treatment.

BACKGROUND: To cure advanced hypopharyngeal squamous cell carcinoma (HPSCC), primary operation followed by adjuvant (chemo-)radiotherapy (OP-CRT) or definitive chemoradiation (CCRT) are the two primary options. This study aimed to compare the failure patterns and long-term survival outcomes of HPSCC patients treated with these two strategies. PATIENTS AND METHODS: From 2007 to 2015, 198 pathologically confirmed HPSCC patients receiving either OP-CRT or CCRT were retrospectively reviewed. Failure patterns and survival outcomes stratified by the 7th American Joint Committee on Cancer staging system and treatment modalities were compared. RESULTS: One hundred and eighty-nine patients (95.4%) were stage III/IV and 62 patients (31.3%) received OP-CRT. Median follow-up duration was 4.9 years. Compared with CCRT, OP-CRT provided better 3-year local relapse-free survival for T3 (93 vs 48%, p < 0.0001), T4a (88 vs 37%, p = 0.0005) and better 3-year regional relapse-free survival for N2b+2c (93 vs 60%, p < 0.0001). Of note, for stage IVA subjects, OP-CRT provided better 3-year loco-regional relapse-free survival (85 vs 37%, p < 0.0001), marginal poor 3-year distant metastasis-free survival (62 vs 79%, p = 0.06), but comparable 3-year OS (52 vs 44%, p = 0.37) and 5-year OS (44 vs 31%, p = 0.15) compared with CCRT. CONCLUSIONS: For patients with advanced HPSCC, although OP-CRT and CCRT provided similar overall survival, failure patterns were distinct. OP-CRT provided better loco-regional control but was more likely to encounter distant metastases than CCRT. The detailed analysis of failure patterns will pave the way to improve this devastating disease.

Investigating the association between serum human papillomavirus type 16 E7 antibodies and risk of head and neck cancer.

Human papillomavirus (HPV) is recognized as a major cause of oropharyngeal cancer (OPC) in Western countries. Less is known regarding its contribution to the OPC occurring in Asia. The current study aimed to investigate the association between antibody responses to HPV16 E7 and head and neck cancer (HNC) risk in a hospital-based case-control study conducted in Taiwan with 693 HNC cases and 1,035 controls. A positive association was observed between seropositivity to HPV16 E7 and OPC risk, whereas no significant association was found in the non-OPC cases. The increased OPC risk associated with seropositivity to HPV16 E7 was more significant among nonbetel quid or noncigarette users. Seropositivity to HPV16 E7 showed moderate agreement with P16 expression in OPC. OPC patients that were seropositive to HPV16 E7 or p16 positive were more highly educated and less likely to use alcohol, betel quids, and cigarettes compared to HPV16 E7 seronegative or p16 negative OPC patients. Furthermore, patients with p16 positive OPC were more likely to be women compared to patients with p16 negative OPC, likely owing to the low prevalence of alcohol, betel quid, and cigarette users among women. Overall, this study suggested that similar to Western countries, HPV may also be an important risk factor of OPC in Taiwan. With the declining consumption of betel quids and cigarettes in Taiwan, a higher percentage of OPC cases in Taiwan will be attributed to HPV in the future. Public health measures, including HPV vaccination, need to be implemented to prevent the occurrence of HPV-positive OPC.

Investigating the health disparities in the association between lifestyle behaviors and the risk of head and neck cancer.

Many studies have reported a positive association between lower socioeconomic status (SES) and higher head and neck cancer (HNC) risk. Fewer studies have examined the impact of SES on the association between alcohol or cigarette use and HNC risk. The current case-control study (1104 HNC cases and 1363 controls) investigated the influence of education, a SES indicator, on the association between HNC and the use of alcohol, cigarettes, or betel quids in Taiwan, a country with universal health care. Our results showed a larger increase in HNC risk associated with alcohol among those with lower educational level (odds ratio [OR] = 2.07; 95% confidence interval [CI], 1.53-2.80) than those with higher educational level (OR = 1.38; 95% CI, 1.04-1.85) (heterogeneity-P = .03). Educational level had an influence on the association between alcohol use and HNC risk among those with genetic susceptibility (ALDH2-deficient) to the carcinogenic effect of alcohol. The association between cigarette or betel quid use and HNC risk was similar between the high and low educational groups. National policies and social interventions have led to the decline in the prevalence of cigarette and betel quid users in Taiwan. In contrast, due to the lack of adequate alcohol control policies, alcohol consumption in Taiwan has continued to rise. A higher impact of alcohol on HNC risk among lower SES individuals even with universal health care could be the result of insufficient alcohol control policies in Taiwan.

Validation of Alcohol Flushing Questionnaire to Identify ALDH2 Status in a Case-Control Study of Head and Neck Cancer.

BACKGROUND: Carriers of the ALDH2*2 allele have impaired alcohol metabolism and are more susceptible to the development of alcohol-related cancers, including head and neck cancer (HNC). Screening for ALDH2*2 allele may identify high-risk individuals for alcohol health education. Although genotyping of ALDH2 is the most accurate way to identify ALDH2 deficiency, it may not be practical due to the cost and requirement for genotyping service. METHODS: This study evaluated the accuracy of the alcohol flushing questionnaire to identify ALDH2 deficiency in a case-control study of HNC conducted in Taiwan using data collected from 904 patients with HNC and 1,078 controls. RESULTS: Overall, alcohol flushing questionnaire had a high sensitivity (89%) of identifying ALDH2*2 carriers among the control subjects and a good sensitivity (79%) among the patients with HNC. The sensitivity of the alcohol flushing questionnaire in identifying ALDH2*2 carriers was affected by alcohol use, with a lower sensitivity among individuals who consumed alcohol, particularly among current regular (drinking alcohol once per week or more) alcohol drinkers. CONCLUSIONS: The current validation study showed that the alcohol flushing questionnaire may be a reasonable method to identify ALDH2-deficient individuals. However, current regular users of alcohol who reported no alcohol flushing may need to undergo genotyping of ALDH2 for a more accurate assessment of the ALDH2 status.

Oral hygiene and the overall survival of head and neck cancer patients.

Poor oral hygiene is an established risk factor of head and neck cancer (HNC); however, its role in the survival of HNC patients is unclear. This study evaluated the association between oral hygiene habits, including regular dental visits, frequency of tooth brushing, and use of dental floss, and the overall survival (OS) of HNC patients using interview data collected from 740 HNC patients. In addition, the interactions between oral hygiene and the polymorphisms of TLR2 and TLR4 on the OS of HNC patients were assessed. The analysis indicated that poor oral hygiene was significantly associated with poorer OS of HNC patients (hazard ratio (HR) = 1.38, 95% confidence interval (CI): 1.03-1.86). This association was modified by a single nucleotide polymorphism, rs11536889, of TLR4. A significant association between poor oral hygiene and worse survival of HNC was observed among those with the CG or CC genotype (HR = 2.32, 95% CI: 1.41-3.82) but not among those with the GG genotype (HR = 0.95, 95% CI: 0.65-1.40). Our results suggested that poor oral hygiene is not only a risk factor but may also be a prognostic factor of HNC.

The Influence of Prediagnosis Alcohol Consumption and the Polymorphisms of Ethanol-Metabolizing Genes on the Survival of Head and Neck Cancer Patients.

BACKGROUND: Although alcohol drinking is an established risk factor of head and neck cancer (HNC), less is known about its role in the prognosis of HNC. The current study investigated the association between pretreatment alcohol consumption and the overall survival (OS) of HNC patients. METHODS: Cox proportional hazards models were performed to evaluate the association between prediagnosis alcohol drinking and the OS of HNC patients. In addition, the influence of the polymorphisms of two ethanol-metabolizing genes, ADH1B and ALDH2, on this relationship was also evaluated. RESULTS: The results showed a significant positive dose-response relationship between prediagnosis alcohol use and worse OS of HNC patients. This association was more significant for oropharyngeal cancer, hypopharyngeal cancer, and laryngeal cancer than for oral cancer. The association between alcohol use and the poorer OS of HNC patients was mainly through its association with a higher stage of HNC at diagnosis. The worst OS associated with alcohol use was observed among HNC patients with the fast ADH1B and the slow/nonfunctional ALDH2 genotype combination. CONCLUSIONS: Our analysis showed a significant positive dose-response relationship between prediagnosis alcohol use and a worse OS of HNC. This association was mainly due to the higher stage of HNC among alcohol drinkers. In addition, the polymorphisms of the ethanol-metabolizing genes, ADH1B and ALDH2, modified the relationship between prediagnosis alcohol use and the OS of HNC patients. IMPACT: Prediagnosis alcohol use may be a prognostic indicator of HNC.

Regional Homogeneity and Multivariate Pattern Analysis of Cervical Spondylosis Neck Pain and the Modulation Effect of Treatment.

Objects: We investigated brain functional alteration in patients with chronic cervical spondylosis neck pain (CSNP) compared to healthy controls (HCs) and the effect of intervention. Methods: 104 CSNP patients and 96 matched HCs were recruited. Patients received 4 weeks of treatment. Resting-state fMRI and Northwick Park Neck Pain Questionnaire (NPQ) were collected before and after treatment. Resting state regional homogeneity (rs-ReHo) and multivariate pattern analysis (MVPA) were applied to (1) investigate rs-ReHo differences between CSNP patients and controls and the effect of longitudinal treatment and (2) classify CSNP patients from HCs and predict clinical outcomes before treatment using MVPA. Results: We found that (1) CSNP patients showed decreased rs-ReHo in the left sensorimotor cortex and right temporo-parietal junction (rTPJ), and rs-ReHo at the rTPJ significantly increased after treatment; (2) rs-ReHo at rTPJ was associated with NPQ at baseline, and pre- and post-treatment rs-ReHo changes at rTPJ were associated with NPQ changes in CSNP patients; and (3) MVPA could discriminate CSNP patients from HCs with 72% accuracy and predict clinical outcomes with a mean absolute error of 19.6%. Conclusion: CSNP patients are associated with dysfunction of the rTPJ and sensorimotor area. Significance: rTPJ plays on important role in the pathophysiology and development of CSNP.

The interplay between oral microbiome, lifestyle factors and genetic polymorphisms in the risk of oral squamous cell carcinoma.

Poor oral hygiene may lead to overgrowth of pathogenic oral bacteria, which may induce chronic inflammation to promote the oncogenesis of oral squamous cell carcinoma (OSCC). This study investigated the association between oral bacterial profile and OSCC risk in a case-control study of 138 OSCC cases and 151 controls (88 cases and 90 controls for the discovery group and 50 cases and 61 controls for the validation group). Oral bacterial profiles were characterized by targeted sequencing of the 16S rRNA gene. Three species of periodontopathogenic bacteria, Prevotella tannerae, Fusobacterium nucleatum, and Prevotella intermedia, were associated with an increased OSCC risk. This association was modified by the genetic polymorphisms of TLR2 and TLR4. Use of alcohol, betel quids and cigarettes and poor oral hygiene were associated with a higher percentage of oral periodontopathogenic bacteria. The association between alcohol and periodontopathogenic bacteria was modified by the genetic polymorphism of ALDH2, with a stronger positive association observed among the ALDH2-deficient individuals. The percentage of periodontopathogenic bacteria was positively correlated with the level of salivary IL1ß, an inflammatory cytokine. Overall, our results showed a positive association between periodontopathogenic bacteria and OSCC risk and this relationship may be influenced by lifestyle and genetic factors. Our results provided further biological support for the established association between poor oral hygiene and OSCC risk. This suggested that improving oral hygiene may reduce OSCC risk and should be part of a public health campaign to prevent the occurrence of OSCC.

Investigating the association between diet and risk of head and neck cancer in Taiwan.

Most studies reporting an inverse association between the consumption of vegetables and fruits and head and neck cancer (HNC) risk were conducted in Western populations and only a few included East Asians. The current case-control study investigated the association between diet and HNC risk using data of 838 HNC cases and 998 controls from a case-control study of HNC conducted in Taiwan. Each participant was asked about their consumption of fresh vegetables, pickled vegetables, fresh fruits, citrus fruits, meat, processed meat, fish, egg, and dairy products. Unconditional logistic regression was performed to estimate the odds ratio (OR) and 95% confidence interval (CI) of HNC risk associated with each food category, adjusted for sex, age, education, and use of alcohol, betel quid and cigarette. An inverse association was observed between HNC risk and daily intake of fresh vegetables (OR = 0.44, 95% CI: 0.20-0.95, p-trend = 0.002) or fruits (OR = 0.55, 95% CI: 0.43-0.72, p-trend = 0.00001). Individuals who did not consume fresh fruits and vegetables daily had more than double the risk of HNC compared to those with daily intake of vegetables and fruits (OR= 2.24, 95% CI: 1.54-3.25). The results of the current study supported an inverse association between the consumption of fresh vegetables and fruits and HNC risk. In addition to cessation of cigarette smoking and betel quid chewing and reduction of alcohol drinking, a public health campaign for preventing the occurrence of HNC should promote a healthy diet that contains plenty of fresh vegetables and fruits.

Investigating the Association between Alcohol and Risk of Head and Neck Cancer in Taiwan.

Although alcohol is an established risk factor of head and neck cancer (HNC), insufficiencies exist in the literature in several aspects. We analyzed detailed alcohol consumption data (amount and type of alcoholic beverage) of 811 HNC patients and 940 controls to evaluate the association between alcohol and HNC by HNC sites and by genotypes of ADH1B and ALDH2. Alcohol was associated with an increased HNC risk in a dose-response relationship, with the highest risk observed for hypopharyngeal cancer, followed by oropharyngeal and laryngeal cancers. Liquor showed a stronger positive association with HNC than beer and wine. The highest HNC risk occurred in individuals with the slow ADH1B and slow/non-functional ALDH2 genotype combination. In our study population, 21.8% of HNCs, 55.7% of oropharyngeal cancers, and 89.1% of hypopharyngeal cancers could be attributed to alcohol. Alcohol accounted for 47.3% of HNCs among individuals with the slow ADH1B and slow/non-functional ALDH2 genotype combination. The HNC risk associated with alcohol became comparable to that of never/occasional drinkers after ten or more years of cessation from regular alcohol drinking. In conclusion, alcohol use is associated with an increased HNC risk, particularly for individuals with slow ethanol metabolism. HNC incidence may be reduced by alcohol cessation.

Regular recreational physical activity and risk of head and neck cancer.

BACKGROUND: Although substantial evidence supports a 20-30% risk reduction of colon cancer, breast cancer, and endometrial cancer by physical activity (PA), the evidence for head and neck cancer (HNC) is limited. Three published studies on the association between PA and HNC have generated inconsistent results. The current study examined the association between recreational PA (RPA) and HNC risk with a more detailed assessment on the intensity, frequency, duration, and total years of RPA. METHODS: Data on RPA were collected from 623 HNC cases and 731 controls by in-person interview using a standardized questionnaire. The association between RPA and HNC risk was assessed using unconditional logistic regression, adjusted for sex, age, educational level, use of alcohol, betel quid, and cigarette, and consumption of vegetables and fruits. RESULTS: A significant inverse association between RPA and HNC risk was observed in a logistic regression model that adjusted for sex, age, and education (odds ratio (OR) = 0.65, 95% confidence interval (CI): 0.51-0.82). However, after further adjustment for the use of alcohol, betel quid, and cigarette, and consumption of vegetables and fruits, RPA was no longer associated with HNC risk (OR =0.97, 95% CI: 0.73-1.28). No significant inverse association between RPA and HNC risk was observed in the analysis stratified by HNC sites or by the use of alcohol, betel quid, or cigarette. CONCLUSION: Results from our study did not support an inverse association between RPA and HNC risk. The major focus of HNC prevention should be on cessation of cigarette smoking and betel chewing, reduction of alcohol drinking, and promotion of healthy diet that contains plenty of fruits and vegetables.

A Comprehensive Analysis on the Association between Tobacco-Free Betel Quid and Risk of Head and Neck Cancer in Taiwanese Men.

OBJECTIVES: Although betel quid (BQ) is an established risk factor of head and neck cancer (HNC), insufficiencies exist in the literature regarding the dose-response, BQ types, HNC sites, and BQ cessation. The current study was conducted to fill these insufficiencies. MATERIALS AND METHODS: A hospital-based case-control study was conducted to evaluate the association between BQ and HNC. In-person interview was conducted to collect data on BQ chewing. The current analysis included 487 men newly diagnosed with HNC and 617 male controls who were frequency-matched to the cases by age. The association between BQ and HNC was assessed using multivariable unconditional logistic regression. RESULTS: Ever BQ chewing was associated with an increased HNC risk regardless of the BQ types. A non-linear positive association between BQ and HNC was observed, with a steep rise in HNC risk for the first 5 pack-years or 200,000 minutes of BQ consumption. Every year of BQ cessation was associated with a 2.9% reduction in HNC risk; however, the risk did not reduce to the level of non-BQ chewers even after 20 years of BQ cessation. Eliminating BQ chewing may prevent 51.6% of HNCs, 62.6% of oral cancers, and 41.3% of pharyngeal cancers in Taiwan. CONCLUSION: Our results supported the positive association between BQ and HNC. BQ cessation is effective in reducing HNC risk and should be encouraged. Because BQ cessation may not reduce the HNC risk to the level of non-BQ chewers, it is important to prevent the initiation of BQ chewing.

Allergy symptoms, serum total immunoglobulin E, and risk of head and neck cancer.

PURPOSE: Allergy symptoms have been associated with a reduced head and neck cancer (HNC) risk, while elevated blood immunoglobulin E (IgE) levels have been associated with an increased HNC risk. According to the "prophylaxis hypothesis," allergic reaction is the body's way of expelling carcinogens. IgE level may be increased by exposure to environmental carcinogens, including alcohol and cigarette smoke. We hypothesized that individuals with elevated serum IgE without allergy symptoms (i.e., asymptomatic atopic) would have the highest HNC risk. METHODS: A case-control study of HNC (576 cases and 740 controls) was conducted to evaluate the association between allergy symptoms or serum total IgE and HNC risk and the effect modification of allergy symptoms on the association between serum total IgE and HNC risk. RESULTS: Elevated serum total IgE was associated with a significantly increased HNC risk [odds ratio (OR) 1.71, 95 % confidence interval (CI) 1.21-2.42]. Having allergy symptoms was associated with a significantly reduced HNC risk (OR 0.56, 95 % CI 0.43-0.73). Compared to subjects with normal serum total IgE and no allergy symptoms, asymptomatic atopic individuals had a significantly increased HNC risk (OR 2.12, 95 % CI 1.33-3.35). CONCLUSIONS: Our results provided further evidence to support the "prophylaxis hypothesis." Further investigations regarding the immune profiles of asymptomatic atopic individuals may provide additional clues for the biological mechanisms underlying the association between allergy symptoms, IgE, and HNC risk.

Alcohol Drinking Obliterates the Inverse Association Between Serum Retinol and Risk of Head and Neck Cancer.

This analysis evaluated the association between serum retinol levels and risk of head and neck cancer (HNC) and whether the association is modulated by the use of alcohol, betel quid, or cigarette. In addition, we also examined the association between HNC risk and 2 single nucleotide polymorphisms, TTR rs1667255 and RBP4 rs10882272, that have been associated with serum retinol levels. Unconditional logistic regression was performed to evaluate the association between serum retinol levels and HNC risk among 160 HNC cases and 198 controls. The associations between TTR rs1667255 and RBP4 rs10882272 and serum retinol levels or HNC risk were evaluated by linear regression and unconditional logistic regression, respectively, for 418 HNC cases and 497 controls. The results showed that HNC cases had a lower mean serum retinol level compared with controls (845.3 µg/L vs 914.8 µg/L, P = 0.03). An inverse association between serum retinol levels and HNC risk occurred among never/occasional alcohol drinkers but not among regular drinkers. TTR rs1667255 was associated with serum retinol levels; however, neither TTR rs1667255 nor RBP4 rs10882272 was associated with HNC risk. In summary, this study showed an inverse association between serum retinol levels and HNC risk, specifically among never/occasional alcohol drinkers. More studies are needed to establish the underlying biologic mechanisms for the inverse association between serum retinol levels and HNC risk and the modulation of this relationship by alcohol drinking.

[MRI pain matrix regional homogeneity in cervical spondylosis of neck type treated with acupuncture at multiple acupoints].

OBJECTIVE: To observe the impacts on pain matrix (PM) brain area in the patients of cervical spondylosis of neck type treated with acupuncture at single point and the multiple points. METHODS: Forty-nine patients of cervical spondylosis of neck type were randomized into a single-point group (25 cases) and a multiple-point group (24 cases), and treated with acupuncture at Bailao (EX-HN 15) singly or Bailao (EX-HN 15) and Hegu (LI 4) in combination correspondingly. At the same time, 19 healthy people were selected as a control group. The resting state functional magnetic resonance imaging (fMRI) was conducted in each group before and after treatment. The changes in the regional homogeneity (ReHo) of brain area PM were analyzed in terms of the different therapeutic programs. The relevant analysis was on the scores of the Northwick Park neck pain questionnaire (NPQ) and short form 36 questionnaire (SF-36) for life quality. RESULTS: Compared with the control group, ReHo value was increased in supplementary motor area (SMA) of PM in the patients, of cervical spondylosis of neck type. In the single-point group, after treatment, ReHo value was reduced in the bilateral medial superior frontal gyri of patients. In the multiple-point group, ReHo values were reduced in the left medial superior frontal gyrus and right SMA in PM area after treatment. In the single-point group, ReHo value in each brain area of PM was not significantly correlated with NPQ and SF-36 scores. In the multiple-point group, the changes of ReHo value in superior frontal gyrus were positively correlated with those of NPQ scores. CONCLUSION: Considering the clinical efficacy of acupunctrue for cervical spondylosis of neck type, the overall result in the multiple-point group is better than that in the single-point group. It is deduced that the advantages of the therapeutic program in the multiple-point group is relevant with the cooperative integration of the stimulation at multiple points in cerebral analgesic center.

Tea consumption and risk of head and neck cancer.

BACKGROUND: The current study evaluated the association between tea consumption and head and neck cancer (HNC) in Taiwan, where tea is a major agricultural product and a popular beverage. METHODS: Interviews regarding tea consumption (frequency, duration, and types) were conducted with 396 HNC cases and 413 controls. Unconditional logistic regression was performed to estimate the odds ratio (OR) and 95% confidence interval (CI) of HNC risk associated with tea drinking, adjusted for sex, age, education, cigarette smoking, betel quid chewing, and alcohol drinking. RESULTS: A reduced HNC risk associated with tea drinking (OR for every cup per day = 0.96, 95% CI: 0.93-0.99; OR for ≧5 cups per day = 0.60, 95% CI: 0.39-0.94) was observed. The association was especially significant for pharyngeal cancer (OR for every cup per day = 0.93, 95% CI: 0.88-0.98; OR for ≧5 cups per day = 0.32, 95% CI: 0.16-0.66). A significant inverse association between HNC and tea consumption was observed particularly for green tea. CONCLUSIONS: This study suggests that tea drinking may reduce the risk of HNC. The anticancer property of tea, if proven, may offer a natural chemopreventive measure to reduce the occurrence of HNC.

The interplay between alcohol consumption, oral hygiene, ALDH2 and ADH1B in the risk of head and neck cancer.

Alcohol consumption is an established risk factor for head and neck cancer (HNC). The major carcinogen from alcohol is acetaldehyde, which may be produced by humans or by oral microorganisms through the metabolism of ethanol. To account for the different sources of acetaldehyde production, the current study examined the interplay between alcohol consumption, oral hygiene (as a proxy measure for the growth of oral microorganisms), and alcohol-metabolizing genes (ADH1B and ALDH2) in the risk of HNC. We found that both the fast (*2/*2) and the slow (*1/*1+ *1/*2) ADH1B genotypes increased the risk of HNC due to alcohol consumption, and this association differed according to the slow/non-functional ALDH2 genotypes (*1/*2+ *2/*2) or poor oral hygiene. In persons with the fast ADH1B genotype, the HNC risk associated with alcohol drinking was increased for those with the slow/non-functional ALDH2 genotypes. For those with the slow ADH1B genotypes, oral hygiene appeared to play an important role; the highest magnitude of an increased HNC risk in alcohol drinkers occurred among those with the worst oral hygiene. This is the first study to show that the association between alcohol drinking and HNC risk may be modified by the interplay between genetic polymorphisms of ADH1B and ALDH2 and oral hygiene. Although it is important to promote abstinence from or reduction of alcohol drinking to decrease the occurrence of HNC, improving oral hygiene practices may provide additional benefit.

Investigating the association between oral hygiene and head and neck cancer.

OBJECTIVES: This analysis examined the association between oral hygiene and head and neck cancer (HNC) and whether this association differed by the consumption of alcohol, betel quid, or cigarette and by the genetic polymorphisms of inflammation-related genes. MATERIALS AND METHODS: Interviews regarding dental care and oral health were conducted with 317 HNC cases and 296 controls. Genotyping was performed for 6 single nucleotide polymorphisms in IL6, IL10 and PTGS2. RESULTS: A positive association was observed between HNC and no regular dental visits (odds ratio (OR)=2.86, 95% confidence interval (CI): 1.47-5.57), brushing teeth <2times/day (OR=1.51, 95% CI: 1.02-2.23), frequent gum bleeding (OR=3.15, 95% CI: 1.36-7.28), and loss of >20 teeth (OR=2.31, 95% CI: 1.05-5.07). Analysis with dental care score (range: 0-4, 4=worst dental care), which combined regular dental visits, toothbrushing, and use of dental floss and mouthwash, showed a positive trend with HNC risk, particularly among alcohol drinkers and cigarette smokers. Multifactor dimensionality reduction analysis divided the study subjects into high- and low-risk group based on combinations of dental care score and IL6 rs1800796 genotypes. Compared to the low-risk group, the high-risk group had an OR of HNC=2.16 (95% CI: 1.44-3.25). CONCLUSIONS: This study observed a positive association between poor oral hygiene and HNC, which appeared to differ by alcohol or cigarette consumption and the genotypes of IL6 rs1800796. Further investigations are needed to determine whether poor oral hygiene is a cause for HNC or a surrogatemarker of an unhealthy lifestyle that increases the risk of HNC.

Allergies and risk of head and neck cancer: an original study plus meta-analysis.

BACKGROUND: Although the relationship between allergy and cancer has been investigated extensively, the role of allergy in head and neck cancer (HNC) appears less consistent. It is not clear whether allergies can independently influence the risk of HNC in the presence of known strong environmental risk factors, including consumption of alcohol, betel quid, and cigarette. METHODS: THE CURRENT PAPER REPORTS RESULTS FROM: 1) an original hospital-based case-control study, which included 252 incident cases of HNC and 236 controls frequency-matched to cases on sex and age; and 2) a meta-analysis combining the results of the current case-control study and 13 previously published studies (9 cohort studies with 727,569 subjects and 550 HNC outcomes and 5 case-control studies with 4,017 HNC cases and 10,928 controls). RESULTS: In the original case-control study, we observed a strong inverse association between allergies and HNC [odds ratio = 0.41, 95% confidence interval (CI): 0.27-0.62]. The meta-analysis also indicated a statistically significant inverse association between HNC and allergies [meta-relative risk (RR) = 0.76, 95% CI: 0.63-0.91], particularly strong for allergic rhinitis (meta-RR = 0.55, 95% CI: 0.40-0.76). In addition, the inverse association between allergies and HNC was observed only among men (meta-RR = 0.67, 95% CI: 0.54-0.84) but not among women (meta-RR = 0.98, 95% CI: 0.81-1.18). CONCLUSIONS: These findings suggest that immunity plays an influential role in the risk of HNC. Future studies investigating immune biomarkers, including cytokine profiles and genetic polymorphisms, are warranted to further delineate the relationship between allergies and HNC. Understanding the relationship between allergies and HNC may help devise effective strategies to reduce and treat HNC.