Household inhalants exposure and nasopharyngeal carcinoma risk: a large-scale case-control study in Guangdong, China

Epidemiology of nasopharyngeal carcinoma: current insights and future outlook

Nasopharyngeal carcinoma (NPC) is characterised by its remarkable geographical and ethnic distribution. The interplay between genetic susceptibility, environmental exposures, and Epstein-Barr virus (EBV) infections is indicated in the development of NPC. Exposure to tobacco smoking, dietary factors, and inhalants has been associated with the risk of NPC. Genetic association studies have revealed NPC-associated susceptibility loci, including genes involved in immune responses, xenobiotic metabolism, genome maintenance, and cell cycle regulation. EBV exposure timing and strain variation might play a role in its carcinogenicity, although further investigations are required. Other factors including medical history and oral hygiene have been implicated in NPC. Prevention strategies, including primary prevention and secondary prevention through early detection, are vital in reducing mortality and morbidity of NPC. The current review discusses the global and regional distribution of NPC incidences, the risk factors associated with NPC, and the public health implications of these insights. Future investigations should consider international, large-scale prospective studies to elucidate the mechanisms underlying NPC pathogenesis and develop individualized interventions for NPC.

Nasopharyngeal cancer risk assessment by country or region worldwide from 1990 to 2019

BACKGROUND

Nasopharyngeal carcinoma (NPC) is 22nd most common cancer that occurs all over the world, but the prevalence rate can exhibit significant geographical differences. The Global Burden of Disease (GBD) database provides data related to the incidence, mortality, and disease burden of NPC worldwide from 1990 to 2019. We have designed this study in order to evaluate the potential effectiveness of health care policies and strategies for NPC prevention, diagnosis and treatment in different countries or regions around the world.

METHODS

We used for the first time two distinct indicators, EAPC-ASIR and EACP-ASDR, to perform cluster analysis on 200 countries or regions around the world.

RESULTS

200 countries or regions could be divided into five diverse groups. Group 1: The incidence rate showed an increasing trend whereas the mortality rate depicted a decreasing trend. Group 2: Morbidity as well as mortality showed a slight increase; Group 3: Morbidity as well as mortality increased significantly; Group 4: Morbidity and mortality decreased significantly; Group 5: Both morbidity as well as mortality decreased slightly. Moreover, in the context of a global decline in NPC incidence, mortality and disease burden, Group 3 countries, including: "Turkmenistan", "Bosnia and Herzegovina", "Dominican Republic", "Bulgaria", "Lesotho", "Cabo Verde", "Romania", "Cuba", "Jamaica", "Azerbaijan", "Uzbekistan", "Chad", "Belize" and "Ukraine" displayed a significant increase in morbidity, mortality, and disease burden, thus indicating a dangerous trend.

CONCLUSION

It is suggested that the medical and health policies formulated by the countries in Group 3 for NPC, as well as their capacity for conducting censuses, preventing, diagnosing, and treating diseases, need to be substantially strengthened.

Association between ambient exposure to PM2.5 and upper aerodigestive tract cancer in Los Angeles

Fine particulate matter (PM2.5 ) contains carcinogens similar to those generated by tobacco smoking, which may increase the risks of developing smoking-related cancers, such as upper aerodigestive track (UADT) cancers, for both smokers and never-smokers. Therefore, it is imperative to understand the relation between ambient PM2.5 exposure and risk of UADT cancers. A population-based case-control study involving 565 incident UADT cancer cases and 983 controls was conducted in Los Angeles County from 1999 to 2004. The average residential PM2.5 concentration 1 year before the diagnosis date for cases and the reference date for controls was assessed using a chemical transport model. The association between ambient PM2.5 and the UADT cancers was estimated by unconditional logistic regression, adjusting for confounders at the individual and block-group level. Stratified analyses were conducted by sex, tobacco smoking status and UADT subsites. We also assessed the interaction between PM2.5 and tobacco smoking on UADT cancers. PM2.5 concentrations were associated with an elevated odds of UADT cancers (adjusted odds ratio = 1.21 per interquartile range [4.5 μg/m3 ] increase; 95% confidence interval: 1.02, 1.44). The association between PM2.5 and UADT cancers was similar across UADT subsites, sex and tobacco smoking status. The interaction between PM2.5 and tobacco smoking on UADT cancers was approximately additive on the odds scale. The effect estimate for PM2.5 and UADT cancers was similar among never smokers. Our findings support the hypothesis that exposure to PM2.5 increases the risk of UADT cancers. Improvements in air quality may reduce the risk of UADT cancers.

Independent and Joint Effects of Prenatal Incense-Burning Smoke Exposure and Children's Early Outdoor Activity on Preschoolers' Obesity

Incense burning is a significant source of indoor air pollution in many Asian regions. There is emerging evidence that maternal prenatal exposure to incense-burning smoke may be a risk factor for childhood obesity. We aimed to extend this new line of research by investigating the independent and joint effect of incense-burning smoke exposure, and children's outdoor activity in early life, on preschoolers' obesity. A total of 69,637 mother-child dyads were recruited from all kindergartens in the Longhua District of Shenzhen, China. Information on sociodemographic characteristics, maternal exposure to incense-burning smoke (IBS) during pregnancy, and frequency and duration of outdoor activity at the age of 1-3 years was collected by a self-administered questionnaire. In addition, the heights and weights of the children were measured by the research team. Logistic regression models and cross-over analyses were conducted to investigate the independent and combined effects of maternal exposure to incense-burning smoke during pregnancy and children's early outdoor activity on obesity in preschoolers. We found that prenatal exposure to incense-burning smoke increased the risk of the presence of obesity in preschoolers' (AOR = 1.13, 95% CI = 1.03-1.23). Additionally, lower frequencies (<3 times/week) or shorter durations (<60 min/time) of outdoor activity from the age of 1-3 years were significantly associated with the presence of obesity, with AORs of 1.24 (95% CI =1.18-1.32) and 1.11 (95% CI = 1.05-1.17), respectively. Furthermore, the cross-over analysis showed that prenatal exposure to IBS combined with a lower frequency of early outdoor activity (AOR = 1.47, 95% CI = 1.31-1.66) or a shorter duration of outdoor activity during ages of 1-3 years (AOR = 1.22, 95% CI = 1.07-1.39) increased the risk of obesity in preschoolers. Finally, additive interactions between prenatal exposure to IBS and postnatal outdoor activity on obesity were identified. Our study indicates that maternal exposure to incense-burning smoke during pregnancy and early lower postanal outdoor activity may independently and jointly increase the risk of obesity among preschoolers.

Particulate organic emissions from incense-burning smoke: Chemical compositions and emission characteristics

Incense burning is a common practice in Asian cultures, releasing hazardous particulate organics. Inhaling incense smoke can result in adverse health effects, yet the molecular compositions of incense-burning organics have not been well investigated due to the lack of measurement of intermediate-volatility and semi-volatile organic compounds (I/SVOCs). To elucidate the detailed emission profile of incense-burning particles, we conducted a non-target measurement of organics emitted from incense combustion. Quartz filters were utilized to trap particles, and organics were analyzed by a comprehensive two-dimensional gas chromatography-mass spectrometer (GC × GC-MS) coupled with a thermal desorption system (TDS). To deal with the complex data obtained by GC × GC-MS, homologs are identified mainly by the combination of selected ion chromatograms (SICs) and retention indexes. SICs of 58, 60, 74, 91, and 97 were utilized to identify 2-ketones, acids, fatty acid methyl esters, fatty acid phenylmethyl esters, and alcohols, respectively. Phenolic compounds contribute the most to emission factors (EFs) among all chemical classes, taking up 24.5 % ± 6.5 % of the total EF (96.1 ± 43.1 μg g-1). These compounds are largely derived from the thermal degradation of lignin. Biomarkers like sugars (mainly levoglucosan), hopanes, and sterols are extensively detected in incense combustion fumes. Incense materials play a more important role in shaping emission profiles than incense forms. Our study provides a detailed emission profile of particulate organics emitted from incense burning across the full-volatility range, which can be used in the health risk assessments. The data processing procedure in this work could also benefit those with less experience in non-target analysis, especially GC × GC-MS data processing.

Circular RNA SMARCA5 Modulates Epithelial-Mesenchymal Transformation, Proliferation, and Metastasis of Nasopharyngeal Carcinoma Cells via microRNA-582-3p/Phosphatase and Tensin Homolog Axis

The action mechanism in which circular RNA (circ) SMARCA5 targeted nasopharyngeal carcinoma (NPC) cell proliferation, migration, invasion, and apoptosis via microRNA (miR)-582-3p/phosphatase and tensin homolog (PTEN) axis was explored. The examination was performed via reverse transcription-quantitative polymerase chain reaction (RT-qPCR), discovering that circSMARCA5 was elevated while miR-582-3p was silenced in NPC tissues and cells. E-cadherin and N-cadherin were detected. The results illustrated transfection with si-circSMARCA5 or miR-582-3p-mimic was available to repress cancer cell advancement, and E-cadherin was augmented. Transfection with pcDNA 3.1-circSMARCA5 or miR-582-3p-inhibitor was available to accelerate cancer cell advancement, and N-cadherin was augmented. MiR-582-3p-inhibitor blocked the suppression of si-circSMARCA5 on NPC. The si-PTEN blocked the malignant behavior of pcDNA 3.1-circSMARCA5 against NPC. The binding sites between circSMARCA5 and miR-582-3p and between miR-582-3p and PTEN were verified. Linear analysis results illuminated the expression pattern of circSMARCA5 was opposite to miR-582-3p, while the expression pattern of circSMARCA5 was positively associated with PTEN. In brief, the results of the research clarified circSMARCA5 modulated NPC cells' vital movement via the miR-582-3p/PTEN molecular axis.

Lifestyle, Epstein-Barr virus infection, and other factors could impede nasopharyngeal cancer survivorship: a five-year cross-sectional study in North Eastern India

Nasopharyngeal Carcinoma (NPC) is one of the leading cancers in India's north-eastern (NE) region affecting a section of the population each year. A proportion of the NPC cases are observed to recur even after therapy, indicating the involvement of other factors. We aimed to explore the NPC and Epstein-Barr virus (EBV) burden in the NE region and investigate the prognostic factors for the NPC patients' poor survival and recurrence. NPC patients' information was obtained from different state hospitals between 2014 and 2019. PCR and Sanger sequencing were performed to detect EBV types. Statistical analysis, including forest plot analysis, Kaplan-Mayer survival plot, Log-rank test, cox hazard regression, and Aalen's additive regression model, were performed to determine prognostic factors for the NPC patients' lower survival and recurrence. We observed an increased incidence of NPC and EBV infection in the past five years. Step-wise statistical analyses pointed out that variable such as non-professionals (B = 1.02, HR = 2.8, 95%CI = 1.5,4.9) workers (B = 0.92, HR = 2.5, 95%CI = 1.4,4.4), kitchen cum bedroom (B = 0.61, HR = 1.8, 95%CI = 1.2,2.8), mosquito repellent (B = 0.60, HR = 1.7, 95%CI = 1.1,2.7), nasal congestion (B = 0.60, HR = 1.8, 95%CI = 1.2,2.8), lower haemoglobin level (B = 0.92, HR = 2.5, 95%CI = 1.3,4.9), tumor stage IV (B = 2.8, HR = 1.8, 95%CI = 1.6,14.3), N2 (B = 1.4, HR = 4.0, 95%CI = 1.8,9.1), N3 (B = 1.9, HR = 6.4, 95%CI = 2.8,15.3), and M+ (B = 2.02, HR = 7.5, 95%CI = 4.1,13.7) revealed significant correlation with NPC patients' poor prognosis (p < 0.05). The presence of viral factors also showed a significant association with NPC patients' decreased survival. We concluded that factors related to day-to-day life with EBV infection could be the individual predictor for NPC incidence, lower survival, and disease recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-022-00789-5.

Occupational risk variation of nasopharyngeal cancer in the Nordic countries

Background

The aim of this study was to estimate occupational risk variation in the incidence of nasopharyngeal cancer (NPC) in a large population-based cohort of the Nordic Occupational Cancer (NOCCA) study.

Methods

This study is based on a cohort of almost 15 million persons from Denmark, Finland, Iceland, Norway and Sweden, with 2898 nasopharyngeal cancer cases diagnosed in 1961–2005. The data on occupations were gathered from population censuses and cancer data from the national cancer registries. Standardized incidence ratios (SIR) with 95% confidence intervals (CI) were estimated using the national NPC incidence rates as the reference.

Results

There were 1980 male and 918 female NPC patients. The highest SIRs of NPC were observed among male waiters (SIR 3.69, 95% CI 1.91–6.45) and cooks and stewards (SIR 2.24, 95% CI 1.16–3.91). Among women, launderers had the highest SIR of NPC (2.04, 95% CI 1.02–3.65). Significantly decreased SIRs were found among male farmers (SIR 0.79, 95% CI 0.68–0.92) and male textile workers (SIR 0.49, 95% CI 0.22–0.93).

Conclusions

This study suggests that NPC may be associated with several work-related exposure agents such as smoking, kitchen air pollution and solvents. In future, occupational exposure-risk relations should be studied to understand more about causality and to assess effective prevention strategies.

The Adverse Impact of Incense Smoke on Human Health: From Mechanisms to Implications

Incense burning is a very popular activity in daily life among many parts all over the world. A growing body of both epidemiological and experimental evidences has reported the negative effects of incense use on human well-being, posing a potential threat at public significance. This work is a comprehensive review that covers the latest findings regarding the adverse impact of incense smoke on our health, providing a panoramic visualization ranging from mechanisms to implications. The toxicities of incense smoke come directly from its harmful constituents and deposition capacity in the body. Besides, reactive oxygen species-driven oxidative stress and associated inflammation seem to be plausible underlying mechanisms, eliciting various unfavorable responses. Although our current knowledge remains many gaps, this issue still has some important implications.

Incidence and Demographics of Nasopharyngeal Carcinoma in Cheung Chau Island of Hong Kong-A Distinct Geographical Area With Minimal Residential Mobility and Restricted Public Healthcare Referral Network

Background

Nasopharyngeal carcinoma (NPC) is endemic in Hong Kong with a skewed geographical and ethnic distribution. We performed an epidemiological study of NPC in Cheung Chau Island, a fishing village with very minimal residential mobility, and compared its demographics and survival with the rest of Hong Kong.

Methods

NPC data in Cheung Chau and non–Cheung Chau residents between 2006 and 2017 treated in our tertiary center were collected. The incidence, stage distribution, and mortality of Cheung Chau NPC residents were compared with those of their counterparts in the whole Hong Kong obtained from the Hong Kong Cancer Registry. Propensity score matching (PSM) was performed between Cheung Chau and non–Cheung Chau cases in a 1:4 ratio. Overall survival (OS), progression-free survival (PFS), and cancer-specific survival (CSS) were compared between these two cohorts by product limit estimation and log-rank tests.

Results

Sixty-one patients residing in Cheung Chau were identified between 2006 and 2017. There was a significantly higher NPC incidence (P < .001) but an insignificant difference in the mortality rate in Cheung Chau compared to the whole Hong Kong data. After PSM with 237 non–Cheung Chau patients, the Cheung Chau cohort revealed a stronger NPC family history (P < .001). However, there were no significant differences in OS (P = .170), PFS (P = .053), and CSS (P = .160) between these two cohorts.

Conclusion

Our results revealed that Cheung Chau had a higher NPC incidence but similar survival outcomes compared to the whole of Hong Kong. Further prospective studies are warranted to verify this finding and to explore the possible underlying mechanisms.

Research Progress on the Functions and Mechanism of circRNA in Cisplatin Resistance in Tumors

Cisplatin is a common chemotherapeutic drug that has been used to treat of numerous tumors, including testicular, lung, bladder, ovarian, liver and head and neck cancers. Although clinical chemotherapy based on cisplatin has shown a remarkable therapeutic effect, the resistance to cisplatin becomes increasingly obvious as a patient uses it for a prolonged period. It not only affects the prognosis of these tumors, but also causes the recurrence of cancer and decreases the overall survival rate. The development of cisplatin resistance involves several mechanisms, including DNA damage repair, ATP-binding cassette (ABC) transporter, autophagy, cancer stem cells (CSCs), epithelial-mesenchymal transition (EMT), and other related signaling pathways. Interestingly, these mechanisms have been found to be influenced by circular RNAs (circRNAs) to regulate tumor proliferation, invasion, chemosensitivity, and other biological behaviors in the tumor microenvironment (TME). In recent years, circRNAs in cisplatin resistance in tumors, especially lung cancer and gastric cancer, have gradually drawn peoples' attention. This review summarizes recent studies on the functions and mechanisms of circRNAs in cisplatin resistance. We emphasize that circRNA can be used as a promising target gene to improve drug resistance and therapeutic efficacy.

Human health-risk assessment based on chronic exposure to the carbonyl compounds and metals emitted by burning incense at temples

Health effects resulting from the smoke of carbonyl compounds (aldehydes and ketones) and metal-containing incense particles at temples during incense burning periods were evaluated at temple A (without incense reduction activities) and B (with incense reduction activities), Nantou County, in 2018. The predominant size fractions of particles were PM₁, PM_1-2.5, and PM_2.5-10 at both temples. The total particle mass at temple A was approximately 1.1 times that of temple B due to incense reduction at temple B. The most abundant metal elements in all particle size fractions at both temples were Fe, Al, and Zn. Metal species of incense smoke are divided into three groups by hierarchical cluster analysis and heatmaps, showing higher metal contents in groups PM₁, PM_18-10, and PM_18-2.5 at temple A. In contrast, higher metal contents were observed in PM_18-10 and PM_2.5-1 at temple B. Most of the carbonyl species were formaldehyde and acetaldehyde, released during incense burning periods, with concentrations ranging from 6.20 to 13.05 μg/m³ at both temples. The total deposited fluxes of particle-bound metals at temples A and B were determined to be 83.00% and 84.82% using the International Commission on Radiological Protection (ICRP) model. Health-risk assessments revealed that the risk values of metals and carbonyls were above recommended guidelines (10^-6) at temple A. Since worshippers and staff are exposed to incense burning environments with poor ventilation over a long period, these toxic organic compounds and metals increase health risks in the respiratory tract. Therefore, incense reduction is important to achieve healthy temple environments.

Residence characteristics and risk of nasopharyngeal carcinoma in southern China: A population-based case-control study

OBJECTIVES

Given the role of exposures related to residence in the development of nasopharyngeal carcinoma (NPC) has not been well explored, present study aims to investigate the magnitude and pattern of associations for NPC with lifelong residential exposures.

MATERIALS AND METHODS

We carried out a multi-center, population-based case-control study with 2533 incident NPC cases and 2597 randomly selected population controls in southern China between 2010 and 2014. We performed multivariate logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the risk of NPC associated with residential exposures.

RESULTS

Compared with those living in a building over lifetime, risk of NPC was higher for individuals living in a cottage (OR: 1.56; 95% CI: 1.34-1.81) or in a boat (3.87; 2.07-7.21). NPC risk was also increased in individuals using wood (1.34; 1.03-1.75), coal (1.70; 1.17-2.47), or kerosene (3.58; 1.75-7.36) vs. using gas/electricity as cooking fuel; using well water (1.57; 1.34-1.83), river water (1.80; 1.47-2.21), or spring/pond/stream water (2.03; 1.70-2.41) vs. tap water for source of drinking water; living in houses with smaller-sized vs. larger windows in the bedroom (3.08; 2.46-3.86), hall (1.89; 1.55-2.31) or kitchen (1.67; 1.34-2.08); and increasing exposure to cooking smoke [(1.53; 1.20-1.94) for high exposure)] or burned incense [(1.59; 1.31-1.95) for daily use)]. Weighted Cox regression analysis corroborated these results.

CONCLUSION

Poorer residential conditions and household air pollution are associated with an increased risk of NPC. Large-scale studies in other populations or longitudinal studies are warranted to further corroborate these findings.

The Evolving Epidemiology of Nasopharyngeal Carcinoma

BACKGROUND

The epidemiology of nasopharyngeal carcinoma (NPC) has long been a source of fascination due to the malignancy's striking geographic distribution, the involvement of the oncogenic Epstein-Barr virus (EBV), the unique association with intake of Chinese-style salt-preserved fish, and etiologic heterogeneity by histologic subtype.

METHODS

This review summarizes the current epidemiologic literature on NPC, highlighting recent results from our population-based case-control study in southern China.

RESULTS

Findings from our case-control study provide new insight into the epidemiology of NPC, including a diminished role of Chinese-style salt-preserved fish, a profound impact of EBV genetic sequence variation, modest positive associations with passive smoking and household air pollution, and possible effects of oral health and the oral microbiome. Recent findings from other studies include a protective association with infectious mononucleosis, suggesting a causal role of early EBV infection; familial risk conferred by shared genetic variation in the host antibody-mediated immune response to EBV infection; and an unclear association with occupational exposure to formaldehyde.

CONCLUSIONS

To shed further light on the interplay of environmental, genetic, and viral causes of NPC, large pooled studies must accumulate sufficient cases with detailed exposure data.

IMPACT

New epidemiologic findings have reshaped the causal model for NPC.

Occupational exposures and risk of nasopharyngeal carcinoma in a high-risk area: A population-based case-control study

BACKGROUND

The potential role of occupational exposures in the development of nasopharyngeal carcinoma (NPC) remains unclear, particularly in high-incidence areas.

METHODS

The authors conducted a population-based case-control study, consisting of 2514 incident NPC cases and 2586 randomly selected population controls, in southern China from 2010 to 2014. Occupational history and other covariates were self-reported using a questionnaire. Multivariate logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the risk of NPC associated with occupational exposures. Restricted cubic splines were used to evaluate potentially nonlinear duration-response relations.

RESULTS

Individuals who had exposure to occupational dusts (OR, 1.45; 95% CI, 1.26-1.68), chemical vapors (OR, 1.37; 95% CI, 1.17-1.61), exhausts/smokes (OR, 1.42; 95% CI, 1.25-1.60), or acids/alkalis (OR, 1.56; 95% CI, 1.30-1.89) in the workplace had an increased NPC risk compared with those who were unexposed. Risk estimates for all 4 categories of occupational exposures appeared to linearly increase with increasing duration. Within these categories, occupational exposure to 14 subtypes of agents conferred significantly higher risks of NPC, with ORs ranging from 1.30 to 2.29, including dust from metals, textiles, cement, or coal; vapor from formaldehyde, organic solvents, or dyes; exhaust or smoke from diesel, firewood, asphalt/tar, vehicles, or welding; and sulfuric acid, hydrochloric acid, nitric acid, and concentrated alkali/ammonia.

CONCLUSIONS

Occupational exposures to dusts, chemical vapors, exhausts/smokes, or acids/alkalis are associated with an excess risk of NPC. If the current results are causal, then the amelioration of workplace conditions might alleviate the burden of NPC in endemic areas.

LAY SUMMARY

The role of occupational exposures in the development of nasopharyngeal carcinoma (NPC) remains unclear, particularly in high-incidence areas. The authors conducted a population-based study with 2514 incident NPC cases and 2586 population controls in southern China and observed that occupational exposures were associated with an increased risk of NPC. Duration-response trends were observed with increasing duration of exposure. These findings provide new evidence supporting an etiologic role of occupational exposures for NPC in a high-incidence region.

Risk of two common glandular cell-type cancers (breast and colorectal cancers) in Chinese occupational chefs: a nationwide ecological study in Taiwan

OBJECTIVES

Cooking oil fumes (COFs) contain many carcinogens. We investigated the association between COFs and incidence risk of colorectal cancer and female breast in chefs.

METHODS

We identified Chinese food chefs and non-Chinese food chefs from Taiwan's national database of certified chefs in 1984-2007. In total, 379,275 overall and 259,450 females had not been diagnosed as having any cancer before chef certification. We followed these chefs in Taiwan's Cancer Registry Database (1979-2010) and Taiwan's National Death Statistics Database (1985-2011) for newly diagnosed colorectal cancer and female breast cancer.

RESULTS

A total of 4,218,135 and 2,873,515 person-years were included in our analysis of colorectal cancer and female breast cancer incidence, respectively. Compared to non-Chinese food chefs, the Chinese food chefs had an adjusted IRR for colorectal cancer of 1.65 (95% CI  1.17-2.33). The risk of colorectal cancer was even higher among female Chinese food chefs certified for more than 5 years (adjusted incident rate ratio (IRR) = 2.39, 95% CI   1.38-4.12). For female breast cancer, the risk was also significant (adjusted IRR = 1.40, 95% CI 1.10-1.78) and the risks were even higher in female Chinese food chefs certified for more than 5 years (adjusted IRR = 1.74, 95% CI 1.37-2.22).

CONCLUSIONS

This study found that Chinese food chefs had an increased risk of colorectal cancer and female breast cancer, particularly female chefs who had worked for more than 5 years. Future human and animal studies are necessary to re-confirm these findings.

Genetic Polymorphisms Along with Dietary and Environmental Factors Enhance the Susceptibility to Nasopharyngeal Carcinoma in Nagaland of Northeast India

This study investigated the association of seven widely known DNA repair gene polymorphisms (hOGG1 Ser326Cys, XRCC1 Arg194Trp, XRCC1 Arg280His, XRCC1 Arg399Gln, XPC Val499Ala, XPD Lys751Gln and ERCC1 Cys8092Ala) with dietary and environmental factors for Nasopharyngeal Carcinoma (NPC) susceptibility in Nagaland of Northeast India. The genotypes were determined in 128 NPC patients and 180 healthy controls by PCR-RFLP. XRCC1 Arg280His, XPC Val499Ala and ERCC1 Cys8092Ala were found to be associated with NPC risk. Tobacco smoking and burning of firewood for cooking were also found to be a risk factor for NPC. The haplotype analysis of five single-nucleotide polymorphisms (SNPs) XRCC1 Arg194Trp, XRCC1 Arg280His, XRCC1 Arg399Gln, XPD Lys751Gln and ERCC1 Cys8092Ala identified haplotype TGAAC to be significantly associated with NPC. Multifactor dimensionality reduction (MDR) analysis suggested ERCC1 Cys8092Ala to be the best one-factor model that could predict NPC risk. From this study, we conclude that examining the synergistic interactions of various gene-environmental factors together is a better approach to understand NPC susceptibility, instead of their individual effects.

Implication of hsa_circ_0028007 in reinforcing migration, invasion, and chemo-tolerance of nasopharyngeal carcinoma cells

Background

Given the reliability of circRNAs in symbolizing cancer progression, this investigation was designed to expound the involvement of hsa_circ_0028007 in regulating chemosensitivity of nasopharyngeal carcinoma (NPC) cells.

Methods

Altogether, 241 pairs of NPC tissues and para‐cancerous normal tissues were collected to identify NPC‐symbolic circRNAs, which have been screened by circRNA microarray in advance. Expressions of the circRNAs were determined by means of real‐time polymerase chain reaction (PCR). Besides, human NPC cell lines (ie, CNE2 and HONE1) were transfected by si‐hsa_circ_0028007 and si‐NC. Scratch assay, transwell assay, and MTT assay were performed to assess migration, invasion, and paclitaxel/cisplatin‐resistance of NPC cell lines.

Results

Hsa_circ_0028007 expression was abnormally heightened within NPC tissues in comparison with matched non‐tumor tissues (P < .05). Over‐expressed hsa_circ_0028007 was strongly associated with advanced (III‐IV) tumor stage, aggressive infiltration, and metastatic lymph nodes of NPC patients (P < .05). Regarding in vitro experiments, hsa_circ_0028007 expression was elevated in CNE2 and HONE1 cell lines as compared with HENE cell line (P < .05). Silencing of hsa_circ_0028007 not merely sensitized CNE2 and HONE1 cells against paclitaxel and cisplatin (P < .05), but also significantly repressed migration and invasion of the cell lines (P < .05).

Conclusion

Hsa_circ_0028007 was involved in facilitating progression and chemo‐resistance of NPC, which might offer an alternative for NPC treatment.

Association of Ambient Air Pollution with Nasopharyngeal Carcinoma Incidence in Ten Large Chinese Cities, 2006-2013

Large cities in China are experiencing severe ambient air pollution. Although China accounts for more than 45% of new cases of nasopharyngeal carcinoma worldwide in 2018, few studies have examined the association between ambient air pollution and the high nasopharyngeal carcinoma (NPC) incidence in China. Thus, we aim to investigate whether exposure to ambient air pollution (including nitrogen dioxide, sulfur dioxide, and PM10) would significantly affect NPC incidence in large Chinese cities. We collected panel data of ten Chinese provincial cities about local NPC incidence, air pollution level, meteorology, and city profiles during 2006 to 2013 to construct a two-way fixed-effects model to explore the association between ambient air pollution and NPC incidence, as well as possible regional and gender differences behind the association. We found that NO2 had the strongest association with NPC incidence, and the relative risks were 2.2995 (95% CI, 1.2567-4.2075) for males and 1.3010 (95% CI, 0.8212-2.0620) for females, respectively. Under cumulative exposure, it was still NO2 that had the strongest association with NPC incidence, with a relative risk of 1.8836 (95% CI, 1.2416-2.8577), compared to 1.0857 (95% CI, 0.9474-1.2450) and 1.0547 (95% CI, 0.8790-1.2663) for SO2 and PM10, respectively. In addition, males were found more sensitive to ambient air pollution than females. We also found that southern Chinese cities were more sensitive to NO2 than northern cities, which might be related to a higher humidity there. Our study reveals that exposure to ambient air pollutants like SO2, PM10, and particularly NO2, is significantly positively associated with NPC incidence in China.

Nasopharyngeal Carcinoma (NPC) Risk Factors: A Systematic Review and Meta-Analysis of the Association with Lifestyle, Diets, Socioeconomic and Sociodemographic in Asian Region

Objective:

Risk factors of nasopharyngeal carcinoma (NPC) have been linked with diets, life style and viral infections. NPC is more rampant in Asian populations than non-Asian countries. Our study aims to assess the validity of the suggestions provided by multiple case control studies demonstrating that salted fish consumption, smoking and alcohol consumption are associated with the risk of NPC in Asia.

Methods:

Search for related literature on salted fish, smoking and alcohol consumption were performed via Science Direct, PubMed databases and Google Scholar. Articles included in this study were from 2009 to 2017, with specific focus on salted fish, smoking and alcohol consumption as risk factors of NPC. This study excluded all articles published prior to 2009 and articles involving other cancers. Data were extracted independently by two different researchers and harmonized. Meta-analysis was conducted on the obtained data, by using R package Meta to create funnel and forest plots.

Results:

The meta-analysis revealed that salted fish, smoking and alcohol consumption were significantly associated to NPC risk with random effect model score showing OR of 1.41 at 95% confidence interval (CI) of 1.13-1.75 (P<0.01), OR of 1.89 at 95 % CI of 1.49 – 2.38, and OR: 1.42 at 95 % CI of 1.23 – 1.65 respectively. Our results also revealed significant association of salted meat, salted vegetables, house type, wood dust exposure associated with NPC risk with p values less than 0.05.

Conclusion:

This study proposes that salted fish intake, smoking and alcohol consumption might be linked to NPC risk in Asians. Further studies are necessary to ascertain the molecular mechanisms and clarify if the associated path that could function as therapeutic target.

Association between prenatal exposure to household inhalants exposure and ADHD-like behaviors at around 3 years of age: Findings from Shenzhen Longhua Child Cohort Study

BACKGROUND

Prenatal exposure to air pollutants has been suggested as a possible etiologic factor for the occurrence of ADHD or ADHD-like behaviors. But we still lack a comprehensive assessment of household air pollutants exposure on the development of ADHD-like behaviors during childhood.

OBJECT

We aimed to assess whether prenatal household inhalants exposure is associated with preschoolers' ADHD-like behaviors in a nonclinical population.

METHODS

This study used the baseline data of the Longhua Child Cohort Study. During 2015-2017, we recruited 42,983 mothers and their kindergarten-aged children who enrolled at kindergarten in the Longhua district of Shenzhen, to obtain the demographic data and relevant exposure information through self-administrated questionnaire survey. The source of prenatal household inhalants exposure include cooking fumes, environmental tobacco smoke, mosqutio coils, home renovated and indoor burning incense. Logistic and censored least absolute deviations (CLAD) models were used to reveal the association between prenatal exposure to household air pollutants and hyperactive behaviors in child.

RESULTS

We found that exposure to five types of household inhalants during pregnancy were independently associated with an increased risk of child hyperactive behaviors. Moreover, we observed a significant interaction between exposure to environmental tobacco smoke and cooking fumes during gestation on child hyperactive behaviors in CLAD models. We also found a significant joint effect between burning mosquito coils and incense during gestation for child hyperactive behaviors risk both in CLAD and Logistic models. Furthermore, a household inhalants exposure index was used to demonstrate a dose-response relationship between the cumulative effect of exposure to the five household air pollutants and child hyperactivity.

CONCLUSIONS

Our results suggest that prenatal exposure to different household inhalants might increase the risk of children's hyperactive behaviors at around 3 years of age with the presence of interaction effects between some inhalants.

Environmental and Life-Style Related Risk Factors for Sinonasal and Nasopharyngeal Malignancies among a Prospective Cohort in Jos, Nigeria

Background

Worldwide evidence indicates that environmental and life-style related factors are associated with increased risk for cancers in the head and neck region. We aim to study the association between these risk factors and cancers in the sinonasal and nasopharyngeal regions in our environment.

Methods

Longitudinal prospective cohort study at the Jos University Teaching Hospital, Jos, Nigeria. Risk exposures were classified based on the International Agency for the Research on Cancer (IARC) classification of suspected carcinogens. Associations between variables were analyzed using logistic regression.

Results

We studied 44 patients with malignancies in nasopharynx (n= 24; 54.5%) and sinonasal regions (n= 20; 45.5%). Male to female ratio is 1.9:1 and mean age is 45.2 years. Alcohol was the commonest risk factor in males (n= 19; 43.2%) while cooking wood fumes were the commonest in females (n= 14; 31.8%) which was associated with increased risk for malignancies for all sites, showing ten times risk in nasal cancers (OR= 9.67; 95% CI 1.87- 9.88; p= 0.01). Tobacco was associated with elevated risk of malignancies in the nasomaxillary and nasal regions. Other risks were herbicides, pesticides, and chemical fertilizers in farmers.

Conclusion

The significant risk exposures in females were cooking wood fumes and alcohol, tobacco, and exposure to agricultural chemicals in males. Life-style modification and environmental changes to ensure clean air in Nigeria are essential to reduce risks.

Anti-oncogenic activity of Chibby in the development of human nasopharyngeal carcinoma

The Wnt/β-catenin pathway serves important roles in cancer development. The expression and function of Chibby (Cby), as a direct antagonist of β-catenin, in nasopharyngeal carcinoma (NPC) has not been fully investigated. The present study revealed that the mRNA and protein expression of Cby was significantly lower in NPC tissue than in the adjacent normal tissue. Low expression of Cby was significantly associated with the tumor and the clinical staging. Furthermore, Cby overexpression inhibited the proliferation of human NPC SUNE1 cells and induced cell cycle arrest. In addition, Cby overexpression also significantly enhanced the susceptibility of SUNE1 cells to apoptosis. These results indicated that Cby might serve as an anti-oncogenic gene in the development of NPC and could represent a potential therapeutic target for the human NPC therapy.

The Relationship Between Environmental Factors and the Profile of Epstein-Barr Virus Antibodies in the Lytic and Latent Infection Periods in Healthy Populations from Endemic and Non-Endemic Nasopharyngeal Carcinoma Areas in China

Our previous study found that smoking was associated with an elevated level of the antibody against VCA in the Epstein-Barr virus (EBV) lytic phase, which was an important predictive marker of the risk of nasopharyngeal carcinoma (NPC). It remained unknown whether environmental factors were associated with the levels of other EBV antibodies, such as Zta-IgA, EA-IgA, EBNA1-IgA, and LMP1-IgA, in the lytic and latent infection periods. We aimed to investigate the possible environmental inducers that could affect EBV antibody levels in two independent healthy male populations from endemic NPC areas in South China (N=1498) and non-endemic NPC areas in North China (N=1961). We performed ELISA and immunoenzymatic assays to test the levels of antibodies specific to the EBV antigens. The seropositive rates of antibodies against the antigens expressed in both the EBV latent and lytic infection periods, namely, LMP1-IgA, EBNA1-IgA, and Zta-IgA, in endemic areas (28.65%, 5.43% and 14.49%, respectively) were significantly higher than those in non-endemic areas (14.43%, 1.07% and 6.32%, respectively). Smoking was associated with higher seropositivity for EBNA1-IgA (OR=1.47, 95% CI=1.12-1.93) and Zta-IgA (OR=1.28, 95% CI=0.99-1.66), with dose-response effects, while not associated with the levels of LMP1-IgA. In conclusion, smoking was an important environmental factor, which associated with increased levels of EBNA1-IgA, and Zta-IgA.

Nasopharyngeal carcinoma: A review of current updates

Nasopharyngeal carcinoma (NPC) is a rare malignancy worldwide, but it is endemic in a few areas including Southern China, Southeast Asia, North Africa and the Arctic. The underlying mechanisms behind this remarkable geographic distribution remain unclear. Although Epstein-Barr virus (EBV) infection has been suggested as a necessary cause of undifferentiated NPC, EBV itself is not sufficient to cause this malignancy. Other co-factors, such as environmental risk factors, and/or genetic susceptibility, may interact with EBV to play a role in the carcinogenesis of NPC. Survival rates differ significantly between NPC patients in early stages and late stages. Due to the close associations between EBV infection and NPC risk, EBV-related biomarkers have been used for early detection and screening for NPC in a few high-incidence areas. In the present review article the latest updates are discussed.

Lack of association between cigarette smoking and Epstein Barr virus reactivation in the nasopharynx in people with elevated EBV IgA antibody titres

BACKGROUND

Subjects with elevated Epstein-Barr virus (EBV) immunoglobulin A (IgA) titers have a higher risk of developing nasopharyngeal carcinoma (NPC), indicating that reactivation of EBV in the local mucosa might be important for NPC carcinogenesis. Cigarette smoking appears to be one of the environmental risk factors for NPC. However, it remains unclear whether smoking-induced nasopharyngeal carcinogenesis acts through reactivating EBV in the nasopharyngeal mucosa. Therefore, this study aims to investigate the association between cigarette smoking and nasopharyngeal EBV reactivation in a NPC high-risk population.

METHODS

A NPC high-risk cohort study, established from a population-based NPC screening program of 22,816 subjects, consisted of 1045 subjects with elevated serum IgA antibodies against EBV viral capsid antigen (VCA/IgA). Among high-risk subjects, information on detailed cigarette smoking history was collected among 313 male subjects. The associations between cigarette smoking and EBV antibody levels, EBV DNA load of the nasopharynx were analyzed.

RESULTS

No significant association was observed between either nasopharyngeal EBV DNA load or serum VCA/IgA titers and smoking status, age at smoking initiation, daily smoking intensity, smoking duration, cigarette type, or pack-years of smoking. Cigarette smoking characteristics in all subgroups did not correlate with nasopharyngeal EBV DNA positivity or EBV VCA/IgA seropositivity.

CONCLUSIONS

In a population at high risk of NPC, our study suggests that cigarette smoking is neither associated with nasopharyngeal EBV DNA load nor serum VCA/IgA antibody level. Smoking-associated NPC carcinogenesis may act through other mechanisms than reactivating nasopharyngeal EBV replication.

Exposure to biomass smoke as a risk factor for oesophageal and gastric cancer in low-income populations: A systematic review

Background

Upper gastrointestinal cancers contribute significantly to cancer-related morbidity and mortality in sub-Saharan Africa, but they continue to receive limited attention. The high incidence in young adults remains unexplained, and the risk factors have not been fully described.

Methods

A literature search was conducted using the electronic database PubMed. Beginning from January 1980 to February 2016, all articles evaluating biomass smoke exposure with oesophageal and gastric cancer were reviewed.

Results

Over 70% of the African population relies on biomass fuel, meaning most Africans are exposed to biomass smoke throughout their lives. Cigarette smoke is an established risk factor for upper gastrointestinal cancers, and some of its carcinogenic constituents are also present in biomass smoke. We found eight case-control studies reporting associations between exposure to biomass smoke and oesophageal cancer, and two linking biomass smoke to gastric cancer. All of these papers reported significant positive associations between exposure and cancer risk. Further research is needed in order to fully define the constituents of biomass smoke, which could each have varying specific and synergistic or independent contributions to the development of upper gastrointestinal cancers

Conclusions

Exposure to biomass smoke is an environmental factor influencing the development of upper gastrointestinal cancers, especially in low-resource settings.

Associations between maternal exposure to incense burning and blood pressure during pregnancy

Incense burning is a popular practice in Asian and Arabic countries. Previous studies show that incense burning was associated with increased risks of adverse outcomes among non-pregnant population. However, very few studies explored its health effects among pregnant women, who are more susceptible to environmental stressor. We aimed to examine the association between incense burning at home and hypertensive disorders as well as blood pressure levels during pregnancy, using data from 10,563 pregnant women recruited in Born in Guangzhou Cohort Study, China between January 2013 and December 2015. Information on frequency and duration of exposure to incense burning were collected at early and late pregnancy using questionnaire. Data on outcome variables, including hypertensive disorders diagnosis and blood pressure levels at the final antenatal visit before delivery, were extracted from medical records. We used Poisson regression model and general linear model to examine the associations between incense exposure and the outcomes. We found incense use at early pregnancy was not significantly associated with outcomes. Pregnant women who frequently smelled the incense burning at late pregnancy was associated with higher risk of hypertensive disorders (relative risk, 1.84; 95% confidence interval, 1.14-2.98) and higher levels of blood pressure (1.6mmHg increase of systolic blood pressure; 95% confidence interval, 0.4-2.8mmHg) before delivery, compared to those did not burn incense. These associations tended to more evident among women without active and passive smoking. We did not observe significant dose-response relationship between exposure duration and the risk of hypertensive disorders. We firstly reported exposure to incense burning was associated with the risk of hypertensive disorders and blood pressure levels during pregnancy. Given hypertensive disorders in pregnancy are well-established risk factors for a variety of adverse outcomes and the incense burning is a modifiable factor, our finding may have important public health significance.

Cigarette smoking and the risk of nasopharyngeal carcinoma: a meta-analysis of epidemiological studies

OBJECTIVE

The role of cigarette smoking as an independent risk factor for patients with nasopharyngeal carcinoma (NPC) is controversial. We attempted to provide evidence of a reliable association between cigarette smoking and the risk of NPC.

DESIGN

Meta-analysis.

DATA SOURCES

PubMed online and the Cochrane Library of relevant studies published up to February 2016.

ELIGIBILITY CRITERIA

All studies had to evaluate the relationship between NPC and cigarette smoking with never smokers as the reference group.

OUTCOMES

The primary outcome was the adjusted OR, RR or HR of NPC patients comparing smoking with never-smoking; the second was the crude OR, RR or HR.

RESULTS

We identified 17 case-control studies and 4 cohort studies including 5960 NPC cases and 429 464 subjects. Compared with never smokers, current smokers and ever smokers had a 59% and a 56% greater risk of NPC, respectively. A dose-response relationship was identified in that the risk estimate rose by 15% (p<0.001) with every additional 10 pack-years of smoking, and risk increased with intensity of cigarette smoking (>30 cigarettes per day). Significantly increased risk was only found among male smokers (OR, 1.36; 95% CI 1.15 to 1.60), not among female smokers (OR, 1.58; 95% CI 0.99 to 2.53). Significantly increased risk also existed in the differentiated (OR, 2.34; 95% CI 1.77 to 3.09) and the undifferentiated type of NPC (OR, 1.15; 95% CI 0.90 to 1.46). Moreover, people who started smoking at younger age (<18 years) had a greater risk than those starting later for developing NPC (OR, 1.78; 95% CI 1.41 to 2.25).

CONCLUSIONS

Cigarette smoking was associated with increased risk of NPC, especially for young smokers. However, we did not find statistical significant risks of NPC in women and in undifferentiated type, which might warrant further researches.