Quantitative association of tobacco smoking with the risk of nasopharyngeal carcinoma: a comprehensive meta-analysis of studies conducted between 1979 and 2011

Metabolic Phase I (CYPs) and Phase II (GSTs) Gene Polymorphisms and Their Interaction with Environmental Factors in Nasopharyngeal Cancer from the Ethnic Population of Northeast India

Multiple genetic and environmental factors and their interaction are believed to contribute in the pathogenesis of Nasopharyngeal Cancer (NPC). We investigate the role of Metabolic Phase I (CYPs) and Phase II (GSTs) gene polymorphisms, gene-gene and gene-environmental interaction in modulating the susceptibility to NPC in Northeast India. To determine the association of metabolic gene polymorphisms and environmental habits, 123 cases and 189 controls blood/swab samples were used for PCR and confirmed by Sanger sequencing. Analysis for GSTM1 and GSTT1 gene polymorphism was done by multiplex PCR. The T3801C in the 3'- flanking region of CYP1A1 gene was detected by PCR-RFLP method. The Logistic regression analysis was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). The GSTM1 null genotype alone (OR = 2.76) was significantly associated with NPC risk (P < 0.0001). The combinations of GSTM1 null and GSTT1 null genotypes also higher, 3.77 fold (P < 0.0001), risk of NPC, while GSTM1 null genotype along with CYP1A1 T3801C TC + CC genotype had 3.22 (P = 0.001) fold risk. The most remarkable risk was seen among individual carrying GSTM1 null, GSTT1 null genotypes and CYP1A1 T3801C TC + CC genotypes (OR = 5.71, P = 0.001). Further; analyses demonstrate an enhanced risk of NPC in smoked meat (OR = 5.56, P < 0.0001) and fermented fish consumers (OR = 5.73, P < 0.0001) carrying GSTM1 null genotype. An elevated risk of NPC was noted in smokers (OR = 12.67, P < 0.0001) and chewers (OR = 5.68, P < 0.0001) with GSTM1 null genotype. However, smokers had the highest risk of NPC among individuals carrying GSTT1 null genotype (OR = 4.46, P = 0.001) or CYP1A1 T3801C TC + CC genotype (OR = 7.13, P < 0.0001). The association of null genotypes and mutations of metabolic neutralizing genes along with the environmental habits (tobacco smokers and chewers, smoke meat, fermented fishes) can be used as a possible biomarker for early detection and preventive measure of NPC.

Evaluation of seven recombinant VCA-IgA ELISA kits for the diagnosis of nasopharyngeal carcinoma in China: a case-control trial

OBJECTIVE

Seven recombinant viral capsid antigen-IgA (VCA-IgA) ELISA kits are widely used in China, but their diagnostic effects have not been evaluated. In this study, we evaluated whether the diagnostic effects of these kits are similar to those of the standard kit (EUROIMMUN, Lübeck, Germany).

METHODS

A diagnostic case-control trial was conducted with 200 cases of nasopharyngeal carcinoma (NPC) and 200 controls from NPC-endemic areas in southern China. The areas under the curve (AUCs), the sensitivities and the specificities of testing kits were compared with those of the standard kit. The test-retest reliability of each kit was determined by intraclass correlation coefficient (ICC). Their diagnostic accuracy in combination with Epstein-Barr virus nuclear antigen 1-IgA (EBNA1-IgA) was also evaluated in logistic models.

RESULTS

Three testing kits-BB, HA and KSB-showed diagnostic accuracy equal to that of the standard kit, with good performance in the AUCs (0.926-0.945), and no significant differences in sensitivity were found between early-stage and advanced-stage NPCs. ICCs exceeded 0.8. Three logistic regression models were built, and the AUCs of these models (0.961-0.977) were better than those of the individual VCA-IgA kits. All new models had diagnostic accuracy equal to that of the standard kit. New cut-off values of these three kits and their corresponding combinations for researchers to replicate and use in NPC early detection and screening in the future were provided.

CONCLUSIONS

Three recombinant VCA-IgA kits-BB,HA and KSB-had diagnostic effects equal to those of the standard kit, and, in combination with EBNA1-IgA in logistic regression models, can be used in future screening for NPC.

Active and Passive Smoking and Risk of Nasopharyngeal Carcinoma: A Population-Based Case-Control Study in Southern China

The magnitude and patterns of associations between smoking and risk of nasopharyngeal carcinoma (NPC) in high-incidence regions remain uncertain. Associations with active and passive tobacco smoking were estimated using multivariate logistic regression in a population-based case-control study of 2,530 NPC cases and 2,595 controls in Guangdong and Guangxi, southern China, in 2010-2014. Among men, risk of NPC was significantly higher in current smokers compared with never smokers (odds ratio (OR) = 1.32, 95% confidence interval (CI): 1.14, 1.53) but not in former smokers (OR = 0.92, 95% CI: 0.73, 1.17). Risk increased with smoking intensity (per 10 cigarettes/day, OR = 1.09, 95% CI: 1.03, 1.16), smoking duration (per 10 years, OR = 1.11, 95% CI: 1.06, 1.16), and cumulative smoking (per 10 pack-years, OR = 1.08, 95% CI: 1.04, 1.12). Risk decreased with later age at smoking initiation (per year, OR = 0.97, 95% CI: 0.96, 0.98) but not greater time since smoking cessation. Exposures to passive smoking during childhood (OR = 1.24, 95% CI: 1.03, 1.48) and from a spouse during adulthood (OR = 1.30, 95% CI: 1.03, 1.63) were independently associated with increased NPC risk in never-smoking men and women, but exposure-response trends were not observed. In conclusion, active and passive tobacco smoking are associated with modestly increased risk of NPC in southern China; risk is highest among long-term smokers.

Differential prevalence and correlates of whole blood Epstein-Barr virus DNA between HIV-positive and HIV-negative men who have sex with men in Shanghai, China

This cross-sectional study aimed to examine and compare prevalence and correlates of whole blood Epstein-Barr virus (EBV) DNA between HIV-positive and HIV-negative men who have sex with men (MSM). Five hundred and four HIV-positive MSM and 504 age-matched HIV-negative MSM were recruited from an HIV counseling and testing clinic in Shanghai, China from November 2014 to November 2015 and were administered with a face-to-face questionnaire interview. Whole blood EBV DNA was tested by nested polymerase chain reaction assays on EBNA-1, EBNA-2, and LMP-1 genes. The prevalence of whole blood EBV DNA was 56·0% (95% CI 51·7-60·3%) among HIV-positive MSM and 26·0% (95% CI 22·4-30·0%) among HIV-negative MSM. Whole blood EBV DNA positivity was significantly associated with HIV infection (adjusted odds ratio (aOR) 3·43, 95% CI 2·58-4·57) and frequent intake of pickled, smoked, or salty food (aOR 1·71, 95% CI 1·02-2·86) in the whole sample, and with <200 cells/μl CD4 cell counts (aOR 1·79, 95% CI 1·05-3·05) and pickled, smoked, or salty food intake (aOR 3·14, 95% CI 1·39-7·08) in HIV-positive group. HIV-infected MSM are at higher risk of active EBV replication than HIV-uninfected MSM, underscoring needs of surveillance and research on EBV-related carcinogenesis in this population.

Prevalence-based, disease-specific estimate of the social cost of smoking in Singapore

OBJECTIVE

To estimate the cost of smoking in Singapore in 2014 from the societal perspective.

METHODS

A prevalence-based, disease-specific approach was undertaken to estimate the smoking-attributable costs. These include direct and indirect costs of inpatient treatment, premature mortality, loss of productivity due to medical leaves and smoking breaks.

RESULTS

In 2014, the social cost of smoking in Singapore was conservatively estimated to be at least US$479.8 million, ∼0.2% of the 2014 gross domestic product. Most of this cost was attributable to productivity losses (US$464.9 million) and largely concentrated in the male population (US$434.9 million). Direct healthcare costs amounted to US$14.9 million where ischaemic heart disease and lung cancer had the highest cost burden.

CONCLUSIONS

The social cost of smoking is smaller in Singapore than in other Asian countries. However, there is still cause for concern. A recently observed increase in smoking prevalence, particularly among adolescent men, is likely to result in rising total cost. Most significantly, our results suggest that a large share of the overall cost burden lies outside the healthcare system or may not be highly salient to the relevant decision makers. This is partly because of the nature of such costs (indirect or intangible costs such as productivity losses are often not salient) or data limitations (a potentially significant fraction of direct healthcare expenditure may be in private primary care where costs are not systematically captured and reported). The case of Singapore thus illustrates that even in countries perceived as success stories, strong multisectoral anti-tobacco strategies and a supporting research agenda continue to be needed.

Associations of lifestyle and diet with the risk of nasopharyngeal carcinoma in Singapore: a case-control study

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a commonly diagnosed cancer in Southeast Asia. Many studies have examined the risk factors for NPC, yet the roles of some risk factors remain inconclusive. The purpose of this study was to examine associations between modifiable lifestyle factors and the risk of NPC in the Singaporean population.

METHODS

We conducted a case-control study in Singapore with 300 patients and 310 controls who were recruited between 2008 and 2012. Each control was selected and individually matched to each patient based on sex, ethnicity, and age (±5 years). A total of 290 pairs of cases and controls were matched successfully. We examined lifestyle factors such as tobacco smoking, alcohol drinking, various salted and preserved food consumption, and weaning practices.

RESULTS

After adjusting for covariates, multivariate analysis showed that those participants who were current smokers and had ever smoked tobacco had a higher risk of NPC than participants who had never smoked, with odds ratios (ORs) of 4.50 (95% confidence interval [CI] 2.58-7.86; P < 0.001) and 2.52 (95% CI 1.54-4.12; P < 0.001), respectively. Those who consumed salted vegetables at least once a week also showed a significantly increased risk of NPC than those who never or rarely consumed salted vegetables, with an OR of 4.18 (95% CI 1.69-10.38; P = 0.002).

CONCLUSION

Smoking (currently and ever-smoked) and consuming salted vegetables once a week or more were lifestyle risk factors for NPC, and changes of these factors for the better may reduce the risk of NPC.

[Radiotherapy for nasopharyngeal carcinoma]

Nasapharyngeal carcinoma is a rare disease. Oftenly, the diagnostic is made for advanced disease. Localized tumors, T1 or T2 NO observed a good prognosis and are locally controlled in more than 90 % of the cases by radiotherapy alone. The standard treatment of locally advanced disease is combined chemoradiation. A special vigilance of fast decrease of the volume of the pathological lymph nodes, sometimes associated to loss of weight might indicate an adaptive dosimetric revision. The treatment of recurrent disease is of great importance. Surgical indications are limited but should be discussed in multidisciplinary tumor board when possible. Surgical nodal sampling has to be proposed for nodal recurrence as well as reirradiation, which could be indicated according to the technical issues.

HPV Associated Head and Neck Cancer

Head and neck cancers (HNCs) are a highly heterogeneous group of tumours that are associated with diverse clinical outcomes. Recent evidence has demonstrated that human papillomavirus (HPV) is involved in up to 25% of HNCs; particularly in the oropharyngeal carcinoma (OPC) subtype where it can account for up to 60% of such cases. HPVs are double-stranded DNA viruses that infect epithelial cells; numerous HPV subtypes, including 16, 18, 31, 33, and 35, drive epithelial cell transformation and tumourigenesis. HPV positive (HPV+) HNC represents a distinct molecular and clinical entity from HPV negative (HPV-) disease; the biological basis for which remains to be fully elucidated. HPV positivity is strongly correlated with a significantly superior outcome; indicating that such tumours should have a distinct management approach. This review focuses on the recent scientific and clinical investigation of HPV+ HNC. In particular, we discuss the importance of molecular and clinical evidence for defining the role of HPV in HNC, and the clinical impact of HPV status as a biomarker for HNC.

The HLA-DRB1 allele polymorphisms and nasopharyngeal carcinoma

Human leukocyte antigen (HLA)-DRB1 has been reported to influence individual's susceptibility to nasopharyngeal carcinoma (NPC) by many studies in recent years; however, these studies provided controversial results. The meta-analysis was thus conducted here to estimate the relationship between HLA-DRB1 polymorphisms and NPC. After an extensive review of journals from various databases (PubMed, the Web of Science, Embase, China National Knowledge Internet (CNKI), and Wanfang Database), 8 out of 69 case-control studies, including 778 cases and 1148 controls, were extracted. The results showed that 4 of 13 polymorphisms allele are statistically significantly associated with NPC, among them, HLA-DRB1*3, HLA-DRB1*9, and HLA-DRB1*10 may increase the risk of NPC while HLA-DRB1*01 has the opposite effect. The pooled odds ratio and 95 % confidence interval (CI) were 1.702 [95 % CI (1.047, 2.765)], 1.363 [95 % CI (1.029, 1.806)], 1.989 [95 % CI (1.042, 3.799)], and 0.461 [95 % CI (0.315, 0.676)], respectively. In a further ethnicity-based subgroup analysis, HLA-DRB1*08, HLA-DRB1*11, and HLA-DRB1*16 were found to be linked with NPC in Asian, Tunisian, and Caucasian, respectively. In Asian, HLA-DRB1*03, 08, and 10 may elevate the risk whereas HLA-DRB1*09 could lower it. In Tunisian, HLA-DRB1*01 and 11 are the protective factors while HLA-DRB1*03 is the only risk factor. In Caucasian, HLA-DRB1*01 and 03 increase the risk and HLA-DRB1*16 lowers it. The most frequent statistically associated gene is found to be HLA-DRB1*03 which has protective influence on Asian and Tunisian. In conclusion, HLA-DRB1*01, DRB1*03, DRB1*09, and DRB1*10 are related with NPC susceptibility, and the association of HLA-DRB1*08, DRB1*11, and DRB1*16 with NPC risk are significantly different in different ethnicities.

Effectiveness of a multicentre nasopharyngeal carcinoma awareness programme in Indonesia

OBJECTIVE

To evaluate the effectiveness of a nasopharyngeal carcinoma (NPC) awareness programme on the short-term and long-term improvement of knowledge and referral of patients with NPC by primary healthcare centres (PHCCs) staff in Indonesia.

DESIGN

The NPC awareness programme consisted of 12 symposia including a Train-The-Trainer component, containing lectures about early symptoms and risk factors of NPC, practical examination and the referral system for NPC suspects. Before and after training participants completed a questionnaire. The Indonesian Doctors Association accredited all activities.

PARTICIPANTS

1 representative general practitioner (GP) from each PHCC attended an NPC awareness symposium. On the basis of the Train-The-Trainer principle, GPs received training material and were obligated to train their colleagues in the PHCC.

RESULTS

703 GPs attended the symposia and trained 1349 staff members: 314 other GPs, 685 nurses and 350 midwives. After the training, respondents' average score regarding the knowledge of NPC symptoms increased from 47 points (of the 100) to 74 points (p<0.001); this increase was similar between symposium and Train-The-Trainer component (p=0.88). At 1½ years after the training, this knowledge remained significantly increased at 59 points (p<0.001).

CONCLUSIONS

The initial results of this NPC awareness programme indicate that the programme effectively increases NPC knowledge in the short and long term and therefore should be continued. Effects of the improved knowledge on the stage at diagnoses of the patients with NPC will still need to be scrutinised. This awareness programme can serve as a blueprint for other cancer types in Indonesia and for other developing countries.

Low concentration of formononetin stimulates the proliferation of nasopharyngeal carcinoma cell line CNE2 by upregulating bcl-2 and p-ERK1/2 expression

Context Formononetin is a typical phytoestrogen, which is a bioactive component found in red clover plants. Previous studies have shown that formononetin inhibits the proliferation of several types of cancer cells, including prostate cancer and osteosarcoma. However, how formononetin affects the proliferation of CNE2 is not clear. Objective The objective of this study is to investigate the effects of formononetin on nasopharyngeal carcinoma cells in vitro, along with the underlying mechanism. Materials and methods CNE2 cells were incubated with various concentrations of formononetin (0, 0.1, 0.2, 0.3 and 1 μM) for 48 h. Cell proliferation was measured by [3-(4,5-dimethylthiazol-2-yl)]-2,5-diphenyltetrazolium bromide (MTT) assay, while the rate of apoptosis was measured by flow cytometry. Bcl-2 and bax mRNA expression levels were determined by real time polymerase chain reaction (RT-PCR), while p-ERK1/2 and bcl-2 protein expression levels were quantified by Western blotting. Results Formononetin promoted the proliferation of CNE2 cells at low concentrations (0, 0.05, 0.1, 0.2, 0.5, 1, 2 and 5 μM), OD values increased from 0.27 ± 0.01 to 0.30 ± 0.01, 0.30 ± 0.01,0.36 ± 0.01, 0.35 ± 0.01, 0.34 ± 0.01, 0.34 ± 0.01 and 0.32 ± 0.01, respectively. The percentage of late apoptosis declined from 6.77% ± 0.73% (0 μM group) to 6.2% ± 0.4% (0.1 μM group), 3.83% ± 0.71% (0.3 μM group) and 5.1% ± 0.52% (1M group). The mRNA levels of bax and bcl-2 were down- and upregulated, respectively, by formononetin. Bcl-2 and p-ERK1/2 protein levels were also upregulated. Conclusions Formononetin stimulates CNE2 cell proliferation and has an inhibitory effect on CNE2 cells apoptosis, which is mediated by the activation of the ERK1/2 signaling pathways.

Global trends in incidence and mortality of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a rare malignancy with an extraordinarily skewed geographic distribution worldwide. Although decreasing trends in incidence and mortality of NPC have been sporadically reported in some high-risk areas, no comprehensive description of the global trends has ever been made. We accessed incidence (1970-2007) and mortality (1970-2013) data from multiple sources, with the main ones being the Cancer Incidence in Five Continents (CI5) series and the World Health Organization (WHO) cancer mortality database. During the entire period studied, age-standardized incidence rates (ASIRs) of NPC decreased significantly in southern and eastern Asia, north America and Nordic countries with average annual percent changes (AAPCs) of -0.9% to -5.4% in males and -1.1% to -4.1% in females. Declines in age-standardized mortality rates (ASMRs) are even more remarkable and extensive, with AAPCs varying from -0.9% and -0.8% to -3.7% and -6.5% in males and females, respectively. Decreasing trends in NPC incidence are probably due to tobacco control, changes in diets and economic development. Declines in mortality rates are the results of advancements in diagnostic and radiotherapy techniques, as well as decreased incidence rates.

Evaluation of Body Mass Index and Survival of Nasopharyngeal Carcinoma by Propensity-Matched Analysis: An Observational Case-Control Study

The effect of pretreatment body mass index on survival of nasopharyngeal carcinoma remains contradictory.All patients (N = 1778) underwent intensity-modulated radiotherapy with or without chemotherapy. Body mass index was categorized as underweight (<18.5 kg/m2), normal weight (18.5-22.9 kg/m2), overweight (22.9-27.5 kg/m2), and obesity (≥27.5 kg/m2). Propensity score matching method was used to identify patients with balanced characteristics and treatment regimen. Disease-specific survival (DSS), overall survival (OS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival were estimated by Kaplan-Meier method and Cox regression.Following propensity matching, 115 (underweight vs normal), 399 (overweight vs normal), and 93 (obese vs normal) pairs of patients were selected, respectively. In univariate analysis, underweight patients had inferior DSS/OS (P = 0.042) and DMFS (P = 0.025) while both overweight and obese patients showed similar survival across all the endpoints (P ≥ 0.098) to those with normal weight. In multivariate analysis, underweight remained predictive of poor DSS/OS (P = 0.044) and DMFS (P = 0.040), whereas overweight (P ≥ 0.124) or obesity (P ≥ 0.179) was not associated with any type of survival.Underweight increased the risk of death and distant metastasis, whereas overweight or obese did not affect the survival of nasopharyngeal carcinoma. This provides support for early nutritional intervention during the long waiting time before treatment.

Smoking and nasopharyngeal carcinoma mortality: a cohort study of 101,823 adults in Guangzhou, China

Background

Nasopharyngeal carcinoma (NPC), also known as Cantonese cancer, is rare worldwide, but has particularly high incidence in North Africa and Southeast Asia, especially in Guangdong, China, such as Guangzhou. Tobacco causes head and neck cancers, but nasopharyngeal carcinoma is not included as causally related to smoking in the 2014 United States Surgeon General’s report. Prospective evidence remains limited. We used Guangzhou Occupational Cohort data to conduct the first and robust prospective study on smoking and NPC mortality in an NPC high-risk region.

Methods

Information on demographic characteristics and smoking status was collected through occupational health examinations in factories and driver examination stations from March 1988 to December 1992. Vital status and causes of deaths were retrieved until the end of 1999. Cox proportional hazard model was used to assess the association of smoking with NPC mortality.

Results

Of 101,823 subjects included for the present analysis, 34 NPC deaths occurred during the average 7.3 years of follow up. The mean age (standard deviation) of the subjects was 41 (5.7) years. Compared with never smokers, the hazard ratio (HR) of NPC mortality was 2.95 (95 % confidence interval 1.01–8.68; p = 0.048) for daily smokers and 4.03 (1.29–12.58; p = 0.016) for smokers with more than 10 pack-years of cumulative consumption, after adjusting for age, sex, education, drinking status, occupation and cohort status and accounting for smoking-drinking interaction. The risk of NPC mortality increased significantly with cigarettes per day (p for trend = 0.01) and number of pack-years (p for trend = 0.02).

Conclusions

In this first and largest cohort in a high NPC risk region, smoking was associated with higher NPC mortality. The findings have shown statistically significant dose–response trend between smoking amount and smoking cumulative consumption and the risk of NPC mortality, but due to the small event number, further studies with larger sample size are needed to confirm the findings in the present study. Our results support that smoking is one of the risk factors likely to be causally associated with NPC mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1902-9) contains supplementary material, which is available to authorized users.

Nasopharyngeal Cancer: Molecular Landscape

Nasopharyngeal carcinoma (NPC) is a unique epithelial malignancy arising from the superior aspect of the pharyngeal mucosal space, associated with latent Epstein-Barr virus infection in most cases. The capacity to characterize cancer genomes in unprecedented detail is now providing insights into the genesis and molecular underpinnings of this disease. Herein, we provide an overview of the molecular aberrations that likely drive nasopharyngeal tumor development and progression. The contributions of major Epstein-Barr virus–encoded factors, including proteins, small RNAs, and microRNAs, along with their interactions with pathways regulating cell proliferation and survival are highlighted. We review recent analyses that clearly define the role of genetic and epigenetic variations affecting the human genome in NPC. These findings point to the impact of DNA methylation and histone modifications on gene expression programs that promote this malignancy. The molecular interactions that allow NPC cells to evade immune recognition and elimination, which is crucial for the survival of cells expressing potentially immunogenic viral proteins, are also described. Finally, the potential utility of detecting host and viral factors for the diagnosis and prognosis of NPC is discussed. Altogether, the studies summarized herein have greatly expanded our knowledge of the molecular biology of NPC, yet much remains to be uncovered. Emerging techniques for using and analyzing well-annotated biospecimens from patients with NPC will ultimately lead to a greater level of understanding, and enable improvements in precision therapies and clinical outcomes.

Incidence trend of nasopharyngeal carcinoma from 1987 to 2011 in Sihui County, Guangdong Province, South China: an age-period-cohort analysis

Introduction

In the past several decades, declining incidences of nasopharyngeal carcinoma (NPC) have been observed in Chinese populations in Hong Kong, Taiwan, Los Angeles, and Singapore. A previous study indicated that the incidence of NPC in Sihui County, South China remained stable until 2002, but whether age, diagnosis period, and birth cohort affect the incidence of NPC remains unknown.

Methods

Age-standardized rates (ASRs) of NPC incidence based on the world standard population were examined in both males and females in Sihui County from 1987 to 2011. Joinpoint regression analysis was conducted to quantify the changes in incidence trends. A Poisson regression age-period-cohort model was used to assess the effects of age, diagnosis period, and birth cohort on the risk of NPC.

Results

The ASRs of NPC incidence during the study period were 30.29/100,000 for males and 13.09/100,000 for females. The incidence of NPC remained stable at a non-significant average annual percent change of 0.2% for males and −1.6% for females throughout the entire period. A significantly increased estimated annual percent change of 6.8% (95% confidence interval, 0.1%–14.0%) was observed from 2003 to 2009 for males. The relative risk of NPC increased with advancing age up to 50–59 and decreased at ages >60 years. The period effect curves on NPC were nearly flat for males and females. The birth cohort effect curve for males showed an increase from the 1922 cohort to the 1957 cohort and a decrease thereafter. In females, there was an undulating increase in the relative risk from the 1922 cohort to the 1972 cohort.

Conclusions

The incidence trends for NPC remained generally stable in Sihui from 1987 to 2011, with an increase from 2003 to 2009. The relative risks of NPC increased in younger females.

The Epstein-Barr virus latent membrane protein-1 (LMP1) 30-bp deletion and XhoI-polymorphism in nasopharyngeal carcinoma: a meta-analysis of observational studies

BACKGROUND

Epstein-Barr virus (EBV) is considered to be closely associated with nasopharyngeal carcinoma (NPC), in which EBV-encoded latent membrane protein 1 (LMP1) was found to have an oncogenic role. However, the results published on the LMP1 polymorphism are inconsistent. In the present study, we performed a meta-analysis to determine the frequency of the associations and a more precise association between NPC and EBV LMP1 gene variants (30-bp deletion (del)/XhoI-loss).

METHODS

Eligible articles met the inclusion/exclusion criteria and were identified in the following electronic databases: PubMed, ScienceDirect, and SciELO. Consequently, the data of interest were extracted and plotted in a table to calculate the frequency and odds ratio (OR) of the outcomes of interest (30-bp del-LMP1/XhoI-loss) in patients with NPC. Study quality (Newcastle-Ottawa Scale (NOS)), publication bias, and heterogeneity were assessed.

RESULTS

Thirty-one observational studies were included with a total of 2,846 individuals (NPC, n = 1,855; control, n = 991). The risk of bias in relation to study quality evaluated by NOS was considered low. The pooled estimate of the frequency of 30-bp del-LMP1 and XhoI-loss in patients with NPC was 77% (95% confidence interval (CI): 72 to 82) and 82% (95% CI: 71 to 92), respectively. There was an association between 30-bp del-LMP1 and NPC susceptibility (OR = 2.86, 95% CI: 1.35 to 6.07, P = 0.00). Similarly, there was an association between XhoI-loss and NPC (OR = 8.5, 95% CI: 1.7 to 41, P = 0.00). However, when we analyze the co-existence of the 30-bp del-LMP1 and XhoI-loss in patients with NPC, there was no association (OR = 1.09, 95% CI: 0.06 to 18.79, P = 0.002).

CONCLUSIONS

Our results suggest an association between the 30-bp del-LMP1 and XhoI-loss with NPC susceptibility. However, our data should be interpreted with caution because the sample size was small, and there was heterogeneity between the studies. Thus, future studies are needed with adjusted estimates to simultaneously evaluate multiple factors involved in the development of NPC.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014013496 .

Tobacco smoking, family history, and the risk of nasopharyngeal carcinoma: a case-referent study in Hong Kong Chinese

PURPOSE

This study aimed to investigate the associations of tobacco smoking and family history of nasopharyngeal carcinoma (NPC) with the risk of NPC in Hong Kong Chinese.

METHODS

Between June 2010 and December 2012, we conducted a case-referent study with 352 incident cases and 410 referents in Hong Kong. We collected information on tobacco smoking and family history of NPC via face-to-face interviews.

RESULTS

There were 174 (49.4%) and 131 (32.0%) ever-smokers among cases and referents, respectively. The adjusted odds ratio (OR) for NPC related to current smoking was 1.67 [95% confidence interval (CI) 1.06, 2.61]. Exposure-response relationships were observed between years and total pack-years of smoking, and NPC risk (p = 0.001 and p = 0.018, respectively). History of NPC in first-degree relatives was associated with an increased NPC risk (adjusted OR = 4.52, 95% CI 2.39, 8.55). The increased NPC risk associated with sibling history (adjusted OR = 6.80, 95% CI 2.63, 17.56) was higher than that for parental history (adjusted OR = 3.04, 95% CI 1.27, 7.25). The adjusted OR for ever-smokers with family history using never-smokers without family history as the reference was 4.54 (95% CI 1.67, 12.34).

CONCLUSIONS

This study verified the important roles of tobacco smoking and family history on NPC risk among Hong Kong Chinese. The provided evidence supported the knowledge that both environmental exposures and inherited susceptibility contributed to the risk of NPC.

Incidence Trends and Geographical Distribution of Nasopharyngeal Carcinoma in Iran

BACKGROUND

Nasopharyngeal carcinoma (NPC) has known as a highly distinct kind of head and neck cancer. This distinction has been due to its clinical presentation, epidemiology, outcome, and treatment. There have not been any reports of epidemiological analysis of NPC in Iran. This study has evaluated the incidence rates and trends of nasopharyngeal carcinoma in the Iranian population during 2004 to 2009.

METHODS

The data have collected from the Iranian national cancer data system registry. All the cases of nasopharyngeal carcinoma (with the topography code 11 and histology of carcinoma) have retrieved and analyzed from an overall cancer database during a 6-year period. The data have analyzed by using the SPSS, version 16.

RESULTS

To determine the current incidence of NPC in Iran, we have examined the NPC cases from 2004 to 2009. A total of 1431 cases (981 male and 450 female NPC patients) have analyzed epidemiologically in this study. The mean age of the patients was 47.1 years. The incidence was 0.33 per 100000 persons. The overall incidence rate have increased annually (p<0.05). The incidence of NPC gradually increased with age. Prefectures that bordering the Caspian Sea have proved to have a higher incidence than the other studied areas.

CONCLUSION

Our study has indicated an increasing trend in the incidence of nasopharyngeal carcinoma. Therefore; attempts should be precipitated for prevention.

Dosimetric Evaluation of a Simple Planning Technique for Improving Intensity-Modulated Radiotherapy for Nasopharyngeal Cancer

PURPOSE

To evaluate the dosimetric outcomes of a simple planning technique for improving intensity-modulated radiotherapy (IMRT) for nasopharyngeal cancer (NPC).

METHODS

For 39 NPC cases, generally acceptable original plans were generated and were improved by the two planning techniques, respectively: (1) a basal-dose-compensation (BDC) technique, in which the treatment plans were re-optimized based on the original plans; (2) a local-dose-control (LDC) technique, in which the original plans were re-optimized with constraints for hot and cold spots. The BDC, original, and LDC plans were then compared regarding homogeneity index (HI) and conformity index (CI) of planning target volumes (PTVs), organ-at-risk (OAR) sparing and monitor units (MUs) per fraction. The whole planning times were also compared between the BDC and LDC plans.

RESULTS

The BDC plans had superior HIs / CIs, by 13-24% / 3-243%, respectively, over the original plans. Compared to the LDC plans, the BDC plans provided better HIs only for PTVnx (the PTV of nasopharyngeal primary tumor) by 11% and better CIs for all PTVs by 2-134%. The BDC technique spared most OARs, by 1-9%. The average MUs of the BDC, original, and LDC plans were 2149, 2068 and 2179, respectively. The average whole planning times were 48 and 69 minutes for the BDC and LDC plans, respectively.

CONCLUSIONS

For the IMRT of nasopharyngeal cancer, the BDC planning technique can improve target dose homogeneity, conformity and OAR sparing, with better planning efficiency.

The impact of smoking on the clinical outcome of locoregionally advanced nasopharyngeal carcinoma after chemoradiotherapy

Background

Cigarette smoking is a common risk factor for developing nasopharyngeal carcinoma. However, the relationship between smoking and clinical outcomes remains uncertain.

Methods

The patients who participated in this study were drawn from a randomized clinical trial, for which the purpose was to compare the efficacy of induction chemotherapy plus concurrent chemoradiotherapy with that of induction chemotherapy plus radiotherapy in patients with locoregionally advanced nasopharyngeal carcinoma. The patients who ever smoked were divided into the following categories of cumulative smoking exposure based on the duration of smoking and the quantity of cigarettes smoked: light, short-term smokers; light, long-term smokers; heavy, short-term smokers; and heavy, long-term smokers. A log-rank test and Cox models were used to assess the association between smoking and the clinical outcomes of overall survival (OS), failure-free survival (FFS), locoregional recurrence failure-free survival (LRFFS) and distant failure-free survival (DFFS).

Results

We found that ever-smokers experienced significantly shorter LRFFS times than never-smokers (5-year LRFFS rates: 85.8% vs. 88.5%, P = 0.022). The amount of smoking was significantly associated with FFS (P = 0.046) and LRFFS (P = 0.001) in the different ever-smoker groups. The amount of smoking was associated with LRFFS [P = 0.002, HR = 2.069 (95% confident interval (CI), 1.298-3.299)] even after a multivariable adjustment.

Conclusions

Smoking increases the risk of locoregional recurrence. Furthermore, the amount of smoking influences the prognosis of smokers, and these effects are dose-dependent.

Prognoses and long-term outcomes of nasopharyngeal carcinoma in Han and Uyghur patients treated with intensity-modulated radiotherapy in the Xinjiang Autonomous Region of China

Objectives

The objective of this study was to investigate the long-term outcomes and prognostic factors for nasopharyngeal carcinoma (NPC) in Han and Uyghur patients treated with intensity-modulated radiotherapy (IMRT) in the Xinjiang region of China.

Materials and Methods

One hundred twenty-one Han and 60 Uyghur patients with newly diagnosed NPC without distant metastasis received IMRT at the Affiliated Tumor Hospital of Xinjiang Medical University between 2005 and 2008. The Kaplan-Meier method was used to estimate survival rates, and the log-rank test was used to evaluate differences in survival.

Results

Comparing Han and Uyghur patients, the 5-year overall survival (OS), disease-free survival (DFS), local control (LC), regional control (RC), and distant metastasis-free survival (DMFS) rates were 81.9% vs 77.6% (P = 0.297), 72.1% vs 65.6% (P = 0.493), 88.3% vs 86.5% (P = 0.759), 95.0% vs 94.6% (P = 0.929), and 79.1% vs 75.2% (P = 0.613), respectively. Multivariate Cox proportional hazards regression identified the following independent prognostic factors in Han patients: N stage (P = 0.007) and age (P = 0.028) for OS, and age (P = 0.028) for DFS. OS differed significantly between Han and Uyghur patients >60 years old group (P = 0.036). Among Uyghur patients, the independent prognostic factors were age for OS (P = 0.033), as well as N stage (P = 0.037) and age (P = 0.021) for DFS. Additionally, Uyghur patients were less likely to experience mucositis and dermatitis than Han patients.

Conclusion

Han and Uyghur patients with NPC had statistically significant differences in age, smoking history, and N staging. There was no significant difference in overall treatment outcomes with IMRT between these 2 ethnic populations in Xinjiang, China.

Therapeutic implications of Epstein-Barr virus infection for the treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is highly endemic in certain regions including the People’s Republic of China and Southeast Asia. Its etiology is unique and multifactorial, involving genetic background, epigenetic, and environment factors, including Epstein–Barr virus (EBV) infection. The presence of EBV in all tumor cells, aberrant pattern of antibodies against EBV antigens in patient sera, and elevated viral DNA in patient circulation as well as nasopharyngeal site underline the role of EBV during NPC development. In NPC tumors, EBV expresses latency type II, where three EBV-encoded proteins, Epstein–Barr nuclear antigen 1, latent membrane protein 1 and 2 (LMP1, 2), are expressed along with BamH1-A rightward reading frame 1, Epstein–Barr virus-encoded small nuclear RNAs, and BamH1-A rightward transcripts. Among all encoded proteins, LMP1 plays a central role in the propagation of NPC. Standard treatment of NPC consists of radiotherapy with or without chemotherapy for early stage, concurrent chemoradiotherapy in locally advanced tumors, and palliative systemic chemotherapy in metastatic disease. However, this standard care has limitations, allowing recurrences and disease progression in a certain proportion of cases. Although the pathophysiological link and molecular process of EBV-induced oncogenesis are not fully understood, therapeutic approaches targeting the virus may increase the cure rate and add clinical benefit. The promising results of early phase clinical trials on EBV-specific immunotherapy, epigenetic therapy, and treatment with viral lytic induction offer new options for treating NPC.

Lower expressions of the human bitter taste receptor TAS2R in smokers: reverse transcriptase-polymerase chain reaction analysis

Background

Despite the fact that smokers have deficit in detecting taste, particularly bitter taste, no study has investigated its biological correlate.

Methods

In this context, we compared the expression of the bitter taste receptor gene, taste 2 receptor (TAS2R) in the tongues of smokers and non-smokers. Tissue samples were collected from the lateral portion of the tongues of 22 smokers and 22 age- and gender-matched healthy volunteers (19 males and three females) with no history of smoking. Reverse transcriptase-polymerase chain reaction was used to examine the expression of TAS2R in the two groups, and the effect of aging on TAS2R expression was also assessed.

Results

TAS2R expression was significantly lower among smokers than non-smokers (t = 6.525, P < .0001, 11.36 ± 6.0 vs. 2.09 ± 2.8, mean ± SD, non-smokers vs. smokers). Further, a positive correlation between age and expression of TAS2R was observed in non-smokers (r = .642, P = .001), but not smokers (r = .124, P = .584). This correlation difference was significant (Z = 1.96, P = .0496).

Conclusions

Smokers showed a significantly lower expression of the bitter taste receptor gene than non-smokers, which is potentially caused by their inability to acquire such receptors with age because of cigarette smoking, in contrast to non-smokers.

[Nasopharyngeal cancers, an overview]

Cancer of the nasopharynx is an uncommon malignancy in France (incidence  =  0.5/year/100,000 men) but is endemic in areas like in South-East Asia. Exclusive radiation therapy used to be the standard and results in local control rates for T3-T4 tumors around 50-75 %. Intensity-modulated radiotherapy (IMRT) improves tumor coverage with a sparing of organs at risk and has to be privileged. Concurrent chemotherapy with IMRT achieved significant survival benefice with 5-year overall survival above 75 %. Concurrent radiochemotherapy with platinum is the most frequent scheme but induction and adjuvant chemotherapies are discussed to reduce distant failure: studies are currently ongoing. Follow-up aims to detect early local failures with a chance of cure and to manage long-term toxicities.

Tobacco and otorhinolaryngology: epic and disaster

More than 500 papers are retrieved from the PubMed database by the keywords "Tobacco" and "Otorhinolaryngology", none of which, however, is devoted to the history of a plant that has a major impact on our specialty and practice. The present report describes and analyzes how tobacco conquered the world, the conflicts it triggered and the impact it has had in our field over the past centuries.

Cytochrome b5 reductase 2 is a novel candidate tumor suppressor gene frequently inactivated by promoter hypermethylation in human nasopharyngeal carcinoma

Cytochrome b5 reductase 2 (CYB5R2), a member of the flavoprotein pyridine nucleotide cytochrome reductase family, is associated with a number of physiological reactions. However, its role in cancer, especially nasopharyngeal carcinoma (NPC), has not been addressed. Here, we investigate the transcript levels and promoter methylation status of CYB5R2 in NPC derived cell lines and tumor biopsies and experimentally address its role as a tumor suppressor gene. We find that CYB5R2 transcript levels are decreased in NPC cell lines and tumor biopsies. Promoter hypermethylation of CYB5R2 was detected in all six tested NPC cell lines and in 84 % of primary NPC tumor biopsies but not in normal nasopharyngeal epithelium. Clinically, CYB5R2 methylation was associated with lymph node metastasis in NPC patients (P < 0.05). The endogenous expression of CYB5R2 could be restored in vitro by the methyltransferase inhibitor 5-aza-2′-deoxycytidine in NPC cell lines. Ectopic expression of CYB5R2 had an inhibitory effect on proliferation, clonogenicity and migration of NPC cells. Moreover, in vivo tests in nude mice indicated that ectopic expression of CYB5R2 reduces the tumorigenicity of CYB5R2-negative NPC cells. Collectively, these findings suggest that CYB5R2 may be a functional tumor suppressor gene, frequently inactivated by hypermethylation of its promoter in NPC. We report here the first instance of epigenetic downregulation in NPC tumor biopsies of a key enzyme, CYB5R2, which is responsible for the detoxification of environmental carcinogens. We propose the possibility of utilizing CYB5R2 promoter methylation as a diagnostic biomarker of NPC in the future.