Effect of family history of cancers and environmental factors on risk of nasopharyngeal carcinoma in Guangdong, China

Nasopharyngeal cancer mortality in disaggregated Asian and non-Asian Americans

BACKGROUND

Nasopharyngeal carcinoma (NPC) mortality varies based on multiple risk factors. While NPC mortality is higher in Asia, little is known about Asian subgroups in the United States (US).

METHODS

Using the 2005-2020 National Vital Statistics System, we examined NPC mortality by age, race (non-Hispanic black, Hispanic white (HW), non-Hispanic white (NHW), Chinese, Filipino, Asian Indian, Japanese, Korean, Vietnamese), sex, and nativity (Untied States or foreign-born).

RESULTS

Upon disaggregation, Chinese (1.96 [CI: 1.78-2.16]), Filipino (0.68 [0.68-1.11]), and Vietnamese Americans (0.68 [0.52-1.10]) had the top age-adjusted mortality rates (AAMR per 100 000 person-years). Foreign-born Chinese, Vietnamese, Filipinos, Asian Indians, and NHW had higher AAMRs compared to US-born persons. All male groups had higher AAMR compared to females. Stratifying for race, nativity, and sex, foreign-born Chinese males (4.09 [3.79-4.40]) had the highest AAMR.

CONCLUSION

These findings demonstrate the importance of disaggregating NPC mortality data by Asian subgroups, providing valuable insights for targeted public health interventions in the United States.

Supplemental folic acid and/or multivitamins in pregnancy is associated with a decreased risk of childhood and adolescent nasopharyngeal carcinoma

The aim of this study was to evaluate the association between prenatal and neonatal period exposures and the risk of childhood and adolescent nasopharyngeal carcinoma (NPC). From January 2009 to January 2016, a total of 46 patients with childhood and adolescent NPC (i.e., less than 18 years of age) who were treated at Sun Yat-sen University Cancer Center were screened as cases, and a total of 45 cancer-free patients who were treated at Sun Yat-sen University Zhongshan Ophthalmic Center were selected as controls. The association between maternal exposures during pregnancy and obstetric variables and the risk of childhood and adolescent NPC was evaluated using logistic regression analysis. Univariate analysis revealed that compared to children and adolescents without a family history of cancer, those with a family history of cancer had a significantly higher risk of childhood and adolescent NPC [odds ratios (OR) = 3.15, 95% confidence interval (CI) = 1.02-9.75, P = 0.046], and the maternal use of folic acid and/or multivitamins during pregnancy was associated with a reduced risk of childhood and adolescent NPC in the offspring (OR = 0.07, 95% CI = 0.02-0.25, P < 0.001). After multivariate analysis, only the maternal use of folic acid and/or multivitamins during pregnancy remained statistically significant. These findings suggest that maternal consumption of folic acid and/or multivitamins during pregnancy is associated with a decreased risk of childhood and adolescent NPC in the offspring.

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.

Dietary Pattern, Genomic Stability and Relative Cancer Risk in Asian Food Landscape

The incidence of cancer globally is increasing, partly due to lifestyle factors. Despite a better understanding of cancer biology and advancement in cancer management and therapies, current strategies in cancer treatment remain costly and cause socioeconomic burden especially in Asian countries. Hence, instead of putting more efforts in searches for new cancer cures, attention has now shifted to understanding how to mitigate cancer risk by modulating lifestyle factors. It has been established that carcinogenesis is multifactorial, and the important detrimental role of oxidative stress, chronic inflammation, and genomic instability is evident. To date, there is no study linking dietary pattern and genomic stability in cancer risk in the Asian food landscape. Thus, this present review article discusses recent literature on dietary pattern and genomic stability and its relationship with cancer risk in Asia.

Nasopharyngeal carcinoma among the Bidayuh of Sarawak, Malaysia: History and risk factors

Nasopharyngeal carcinoma (NPC) is a cancer of the epithelial cells lining the nasopharynx. The incidence of NPC has a distinct geographical distribution, mainly affecting the Chinese population of Southern China. In Malaysia, this cancer is exceptionally prevalent among males. There is a high incidence rate of NPC among the Bidayuh natives in Sarawak, Malaysia. Other than epidemiology reports, there has not been an article describing plausible cancer risk factors contributing to NPC within this native group. Researchers are still trying to understand the reasons the Bidayuh and Southern Chinese are highly susceptible to NPC. This article discusses the risk factors of developing NPC: Epstein-Barr virus infection, genetic predisposition, diet, environmental exposure and tobacco smoking. There is a need to improve the understanding of the role of risk factors to identify new ways to prevent cancer, especially among high-risk groups.

Risk factors for Epstein Barr virus-associated cancers: a systematic review, critical appraisal, and mapping of the epidemiological evidence

BACKGROUND

Epstein Barr Virus (EBV) infects 90%-95% of all adults globally and causes ~ 1% of all cancers. Differing proportions of Burkitt's lymphoma (BL), gastric carcinoma (GC), Hodgkin's lymphoma (HL) and nasopharyngeal carcinoma (NPC) are associated with EBV. We sought to systematically review the global epidemiological evidence for risk factors that (in addition to EBV) contribute to the development of the EBV-associated forms of these cancers, assess the quality of the evidence, and compare and contrast the cancers.

METHODS

MEDLINE, Embase and Web of Science were searched for studies of risk factors for EBV-associated BL, GC, HL and NPC without language or temporal restrictions. Studies were excluded if there was no cancer-free comparator group or where analyses of risk factors were inadequately documented. After screening and reference list searching, data were extracted into standardised spreadsheets and quality assessed. Due to heterogeneity, a narrative synthesis was undertaken.

RESULTS

9916 hits were retrieved. 271 papers were retained: two BL, 24 HL, one GC and 244 NPC. The majority of studies were from China, North America and Western Europe. Risk factors were categorised as dietary, environmental/non-dietary, human genetic, and infection and clinical. Anti-EBV antibody load was associated with EBV-associated GC and BL. Although the evidence could be inconsistent, HLA-A alleles, smoking, infectious mononucleosis and potentially other infections were risk factors for EBV-associated HL. Rancid dairy products; anti-EBV antibody and EBV DNA load; history of chronic ear, nose and/or throat conditions; herbal medicine use; family history; and human genetics were risk factors for NPC. Fresh fruit and vegetable and tea consumption may be protective against NPC.

CONCLUSIONS

Many epidemiological studies of risk factors in addition to EBV for the EBV-associated forms of BL, GC, HL and NPC have been undertaken, but there is a dearth of evidence for GC and BL. Available evidence is of variable quality. The aetiology of EBV-associated cancers likely results from a complex intersection of genetic, clinical, environmental and dietary factors, which is difficult to assess with observational studies. Large, carefully designed, studies need to be strategically undertaken to harmonise and clarify the evidence.

REGISTRATION

PROSPERO CRD42017059806.

Association Between Alcohol Consumption and Risk of Nasopharyngeal Carcinoma: A Comprehensive Meta-Analysis of Epidemiological Studies

BACKGROUND

Alcohol consumption is increasing all over the world, but whether it is an independent factor affecting the occurrence of nasopharyngeal carcinoma (NPC) is inconsistent in many studies. We aimed to explore the association between alcohol consumption and NPC risk by integrating existing evidence in a meta-analysis.

METHODS

We searched for relevant articles published up to August 2018 in PubMed, Cochrane Library, Web of Science, and China National Knowledge infrastructure (CNKI). The Newcastle-Ottawa scale was used to assess the quality of the included studies. Odds ratios (ORs) or relative risks were pooled to estimate the associations between alcohol consumption and NPC risk.

RESULTS

The meta-analysis of cohort studies showed no significant association between alcohol consumption and NPC, but pooled results from case-control studies indicated that ever drinking increased the probability of NPC versus nondrinking (OR = 1.10; 95% confidence interval [CI]: 1.01, 1.19). As compared with nondrinkers, high-frequency drinking (≥7 times/wk) increased the NPC probability (OR = 1.29; 95% CI: 1.05, 1.53) and low-frequency drinking (<7 times/wk) decreased the probability (OR = 0.77; 95% CI: 0.60, 0.94), as did shorter duration of drinking (<20 years) (OR = 0.64; 95% CI: 0.49, 0.79). On subgroup analyses, significant pooled results were observed for studies with high quality, with hospital-based controls and with adjustment for confounding factors, smoking, age, and sex.

CONCLUSIONS

The risk of NPC may increase with alcohol consumption. Ever drinking increased the risk versus nondrinking. Additionally, high-frequency drinking increased the risk, but low-frequency drinking decreased it to some extent. Further intensive studies based on well-designed methods are needed to examine the association.

Smoking can increase nasopharyngeal carcinoma risk by repeatedly reactivating Epstein-Barr Virus: An analysis of a prospective study in southern China

Background

The association between smoking and nasopharyngeal carcinoma (NPC) is still uncertain. The aim of this study was to validate smoking effect on NPC and explore if smoking can induce NPC by persistently reactivating EBV in long‐term based on a prospective cohort design.

Methods

A NPC screening cohort with 10 181 eligible residents in Sihui city, southern China was conducted from 2008 to 2015. The smoking habit was investigated through the trained interviewers and EBV antibodies (VCA‐IgA, EBNA1‐IgA) as screening markers were tested periodically. New NPC cases were identified through local cancer registry. Cox's regression model was used to estimate the adjusted hazard ratios (aHRs) of smoking on NPC incidence. In the non‐NPC participants, the associations between smoking and EBV seropositivity in different periods were assessed by logistic regression and generalized estimating equations (GEE).

Results

With a median of 7.54 years, 71 NPCs were diagnosed ≥1 year after recruitment. Compared with never smokers, the aHRs of developing NPC among ever smokers were 3.00 (95%CI: 1.46‐6.16). Stratified by sex, the HRs of ever smoking were 2.59 (95%CI: 1.07‐6.23) for male and 3.75 (95%CI: 1.25‐11.20) for female, respectively. Among the non‐NPC individuals, ever smoking was not only associated with EBV seropositivity at baseline, but also in the 3‐5 years of follow up, with adjusted odds ratios (aORs) of 1.68 (95%CI: 1.29‐2.18) for VCA‐IgA and 1.92 (95%CI: 1.42‐2.59) for EBNA1‐IgA. Among the smokers who were tested EBV antibodies at least twice, the similar results were obtained using GEE.

Conclusion

Smoking could significantly increase the long‐term risk of NPC in southern China, partly by persistently reactivating EBV.

Nasopharyngeal carcinoma: understanding its molecular biology at a fine scale

Among all cancers, the incidence of nasopharyngeal carcinoma (NPC) is quite high in the endemic regions. NPC is a head and neck cancer with poor survival rate, and is rare throughout most of the world but common in certain geographic areas, like southern Asia and some regions of North East India (Nagaland, Manipur, and Mizoram). A clear understanding of its etiology is still lacking, but NPC is widely suspected to be the result of both genetic susceptibility and exposure to environmental factors or Epstein-Barr virus infection. Diagnosis in the early stages needs a high index of clinical acumen, and, although most cross-sectional imaging investigations show the tumor with precision, confirmation is dependent on histology. This article reviews all related research reports on NPC histopathological classifications worldwide that have been published within the past 20 years. Genome-wide association studies suggested that there might be common disease mechanisms between that disease and NPC. Personalized management rules, quality assessment of life in patients, and an understanding of the essential mechanisms of recurrence could be directed toward research into recurrent NPC. Hence, this literature would offer otolaryngologists a deeper insight into the etiological and management aspects of NPC.

Decreased oral Epstein-Barr virus DNA loads in patients with nasopharyngeal carcinoma in Southern China: A case-control and a family-based study

The link of nasopharyngeal carcinoma (NPC) with Epstein-Barr virus (EBV) has been established for decades. Although an abnormal high level of EBV sero-antibody spectrum and cell-free circulating EBV DNA loads were exhibited in NPC patients, oral EBV DNA loads, which are primarily responsible for the EBV transmission, has not been previously studied in NPC patients. We conducted an epidemiological study to measure the oral EBV loads, viral components, and the relationship with the serum antibody titers in a large case-control population (968 cases and 1656 controls) and a family-based population (91 cases and 165 unaffected family members). EBV DNA loads were detected by quantitative PCR approach targeting the BamHI-W region. Although a large individualized variation existed, we still observed a decreased oral EBV DNA loads in the population of NPC patients compared to that of healthy controls (ORs were 1.00, 0.69, 0.62, 0.33 classified by the quartiles of viral loads, Ptrend  < .001) and family members. In contrast, the elevated levels of oral EBV loads were present in asymptomatic males and elders, suggesting a different important source for EBV transmission. Notably, oral EBV loads were inversely associated with serum antibody titers of VCA-IgA, EA-IgA (All Ptrend  < .001) in the cases but not in the controls. Our study provides the first epidemiological data of oral EBV loads and viral components in NPC patients and controls in the highest risk area of Southern China, indicating that NPC status is unlikely to be an important determinant of EBV transmission.

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.

The incidence and prognosis of nasopharyngeal carcinoma patients with family history

Purpose

Epidemiological data showed that nasopharyngeal carcinoma (NPC) was a regional malignancy. It suggested that genetic factor may play an important role in tumorigenesis of NPC. The aim was to investigate the incidence and the prognosis of NPC patients with family history.

Methods

The clinical data of patients with NPC treated in Fudan University Shanghai Cancer Center from January 2008 to December 2012 were reviewed, and the patients with family history were selected. The prognosis of patients with family history was follow-up. The 5-year overall survival (OS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were analyzed by Kaplan-Meier and log-rank test. Cox proportional hazard model was used for multivariate analysis.

Results

There were 3.64% (135/3706) NPC patients with family history of NPC. Eighty-three percent (112/135) patients had only one family member suffering from NPC previously, and 74.1% (100/135) patients who had family history only in first-degree family members. Excluding five patients lost to follow-up, 130 patients were eventually used to analyze the prognosis. The 5-year OS, LRFS, and DMFS rates of all patients with family history were 84.1%, 83.4%, and 83.8%, respectively. There were no significant differences of OS, LRFS and DMFS between one relative group and at least two relatives group. In addition, the degree of NPC had no association with OS, LRFS and DMFS, respectively.

Conclusion

Our results showed that there was an incidence rate of 3.64% NPC patients with family history. These patients had a satisfied prognosis, and the prognosis of NPC patients with family history in different degree or numbers of relatives had no significant differences.

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.

Modification effects of genetic polymorphisms in FTO, IL-6, and HSPD1 on the associations of diabetes with breast cancer risk and survival

The contribution of diabetes to breast cancer remains uncertain among Chinese females, which may result from different genetic factors. We evaluated the associations of diabetes, combined with the polymorphisms in the genes of fat mass and obesity-associated gene (FTO), interleukin 6 (IL-6), and heat shock protein 60 (HSPD1), with breast cancer risk and survival in a Chinese Han population. The information on the history of diabetes was collected from 1551 incident breast cancer cases and 1605 age-frequency matched controls in Guangzhou, China. In total, 1168 cases were followed up. Diabetes was associated with both an increased risk of breast cancer [OR (95%CI): 1.67 (1.11, 2.52)] and a poor overall survival and progression free survival for breast cancer patients [HRs (95%CIs): 2.66 (1.10, 6.44) and 2.46 (1.29, 4.70), respectively]. IL-6 rs1800796 and HSPD1 rs2605039 had interactions with diabetes on breast cancer risk. Among women with CC genotype of IL-6 rs1800796 or GG genotype of HSPD1 rs2605039, diabetic individuals had a remarkably increased risk of breast cancer compared to non-diabetic women with ORs and 95%CIs of 2.53 (1.45, 4.41) and 6.40 (2.29, 17.87), respectively. GT/TT genotypes of HSPD1 rs2605039 was also associated with a better progression free survival for breast cancer patients [HR (95%CI): 0.70 (0.49, 0.99)]. Our results suggest that the contribution of diabetes to breast cancer risk might be modified by IL-6 rs1800796 and HSPD1 rs2605039. Diabetes and HSPD1 rs2605039 might also influence breast cancer prognosis.

Quantification of familial risk of nasopharyngeal carcinoma in a high-incidence area

BACKGROUND

To the authors' knowledge, no studies to date have explored familial risks of nasopharyngeal carcinoma (NPC) in detail and quantified its lifetime risk in high-incidence populations.

METHODS

The authors conducted a population-based case-control study of 2499 NPC cases and 2576 controls randomly selected in southern China from 2010 through 2014. Unconditional logistic regression was used to estimate multivariable-adjusted odds ratios (ORs) with 95% confidence intervals (95% CIs) associated with a family history of NPC. In addition, the authors compiled a reconstructed cohort comprising 40,781 first-degree relatives of cases and controls to calculate the lifetime cumulative risk of NPC.

RESULTS

Individuals with a first-degree family history of NPC were found to be at a >4-fold risk of NPC (OR, 4.6; 95% CI, 3.5-6.1) compared with those without such a history, but had no excess risk of other malignancies. The excess risk was higher for a maternal than a paternal history and was slightly stronger for a sibling compared with a parental history, and for a sororal than a fraternal history. Among relatives of cases, the cumulative risk of NPC up to age 74 years was 3.7% (95% CI, 3.3%-4.2%), whereas that among relatives of controls was 0.9% (95% CI, 0.7%-1.2%). Cumulative risk was higher in siblings than in parents among relatives of cases, whereas no such difference was noted among relatives of controls.

CONCLUSIONS

Individuals with a family history of NPC have a substantially higher risk of NPC. These relative and cumulative risk estimates can guide the development of strategies for early detection and clinical consultation in populations with a high incidence of NPC. Cancer 2017;123:2716-25. © 2017 American Cancer Society.

Cancer prevention and control: alarming challenges in China

China is geographically the third largest country in the world and the most populated low-to-middle-income country. Cancer incidence and mortality rates for some cancers in the USA and European countries have steadily decreased over the last decades, whereas the incidence and mortality of certain cancers in China have been increasing at an alarming speed. Rapid industrialization and urbanization in China have been accompanied by incredible changes in lifestyle and environment combined with an aging population. Mortality caused by lung, colorectal and breast cancers has been steadily increasing, whereas cancer mortality from gastric, esophageal and cervical tumors has tended to decrease. Similar to what has occurred in the United States, unhealthy lifestyles in China, including heavy smoking and poor diet combined with pollution, have contributed to increased cancer risk. China is facing many challenges in cancer treatment and prevention for the general population. The major areas that need to be addressed in the control of cancer in China include cancers associated with environmental pollution, tobacco use, occupational carcinogens, infection, excessive alcohol consumption, dietary deficiencies and obesity. In this perspective, we review the problems in each area and suggest ideas for future directions in cancer research and strategies and actions to reduce the incidence of cancer in China.

Genetic variants in EBV reactivation-related genes and the risk and survival of breast cancer

Tumor susceptibility gene 101 (TSG101) and activating transcription factor 2 (ATF2) have been suggested to involve in the reactivation of EBV which has implications in the development and progression of breast cancer. Therefore, the polymorphisms of TSG101 and ATF2 may associate with breast cancer risk and prognosis. A case-control study with 1551 breast cancer cases and 1605 age-matched controls were conducted in Guangzhou, China. We have also successfully followed up 1168 cases until December 31, 2014. The variant allele of TSG101 rs2292179 was associated with a non-significant reduced risk of breast cancer, particularly among women with BMI < 24 (kg/m(2)) (P for interaction <0.05). For ATF2 rs3845744, the variant allele was also associated with a significantly reduced breast cancer risk [odds ratio (OR) (95 % confidence interval (CI)) 0.86 (0.74∼1.00)], and the association occurred among only postmenopausal women [OR (95 % CI) 0.69 (0.54∼0.88)] (P for interaction <0.05). Breast cancer risk was further reduced with the increasing numbers of the variant G alleles of the two polymorphisms (P for trend <0.05). We did not find an overall association of the two loci with breast cancer prognosis, while the hazard ratios of the two loci (AG/GG vs. AA) were significantly higher among postmenopausal women than premenopausal women (P = 0.046, 0.016 for TSG101 rs2292179 and ATF2 rs3845744, respectively). In summary, the variant alleles of TSG101 rs2292179 and ATF2 rs3845744 were associated with a reduced risk of breast cancer, particularly for subjects with BMI <24 (kg/m(2)) and postmenopausal women, respectively. The two SNPs and menopausal status may have a significant interaction on breast cancer progression.

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

BACKGROUND

Epidemiological studies show that cigarette smoking increase the risk of nasopharyngeal carcinoma (NPC), however, whether other common, potentially adverse household inhalants increase NPC risk remains uncertain.

METHODS

We conducted a large case-control study to explore the effects of household inhalants, such as incense, mosquito coil, cooking fumes, and wood combustion, on NPC risk. We recruited 1,845 cases and 2,275 controls from Guangdong province, a high-risk area for NPC in China, to obtain the demographic data and relevant exposure information through face-to-face interviews.

RESULTS

We found that incense burning was associated with NPC risk by comparing frequent incense use with never using incense [OR and 95% confidence interval (CI) = 1.73, (1.43, 2.09)]. Wood fuel use was also associated with NPC risk compared with non-wood fire use [OR and 95% CI = 1.95, (1.65, 2.31)]. More intriguingly, we observed a significant addictive interaction between frequent incense burning and heavy cigarette smoking on NPC risk [synergistic index (SI) = 1.67; 95% CI: 1.01, 2.76]. We also found a significant joint effect between wood fuel use and NPC family history for NPC risk (SI = 1.77; 95% CI: 1.06, 2.96). However, neither mosquito oil nor cooking fumes were associated with NPC risk.

CONCLUSIONS

Our study shows that incense smoke is not only the potential independent risk factor but also co-contributes with cigarette smoking to NPC risk. Moreover, wood combustion is another potential environmental risk factor and exerts a joint effect with NPC family history on NPC.

Pretreatment Serum Lactate Dehydrogenase and N Classification Predict Long-Term Survival and Distant Metastasis in Patients With Nasopharyngeal Carcinoma Who Have A Positive Family History of Cancer

The purpose of the present study was to evaluate prognostic factors in patients with nasopharyngeal carcinoma (NPC) from the endemic area of southern China who have a positive family history (FH) of cancer. Retrospective analysis of 600 patients with nondisseminated NPC and a positive FH was conducted. The prognostic value of different factors for overall survival (OS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and local relapse-free survival (LRFS) were assessed using Cox regression models. The 3-year OS, DMFS, DFS, and LRFS rates were 93.8%, 91.3%, 86.3%, and 93.8%, respectively. The FH tumor type was NPC for 226/600 (37.7%) patients and other cancers for 374/600 (62.3%) patients. The 3-year OS and DMFS rates for patients with an FH of NPC were 91.2% and 89.8%, respectively. Thirty of 600 (5.0%) patients had elevated pretreatment serum lactate dehydrogenase (LDH >245.0 IU/L). In multivariate analysis, N classification (HR 4.56, 95% CI 2.13-9.74, P < 0.0001) and elevated pretreatment serum LDH (HR 2.87, 95% CI 1.08-7.62, P = 0.034) were independent prognosticators for OS. Female patients (HR 0.42, 95% CI 0.19-0.95, P = 0.037) and patients with normal pretreatment serum LDH (HR 2.42, 95% CI 1.02-5.78, P = 0.046) had better DMFS. Elevated pretreatment serum LDH and N classification are independent prognostic factors for poorer survival in patients with NPC who have a positive FH of cancer.

Cancer Prevention Research in China

Although cancer incidence and mortality rates in the United States and some European countries have started to decrease, those in developing countries are increasing. China, the most populous developing country, is facing a serious challenge from cancer. Cancer incidence has been increasing for decades, and cancer is the leading cause of death in China. In 2012, the cancer incidence was 174.0 per 100,000, and the cancer mortality was 122.2 per 100,000 in China. In addition to the still-prevalent traditional Chinese cancers of the stomach, liver, esophagus, cervix, and nasopharynx, the incidence of "Western" cancers such those of the lung, breast, and colorectum has increased alarmingly in recent years. These increases are likely due to the lifestyle and environmental changes associated with rapid economic development and population aging. More importantly, a large portion of these cancers are preventable. Researchers in China have made important contributions to cancer prevention research, especially in the traditional Chinese cancers. More cancer prevention research and measures, especially on the major emerging cancers, are urgently needed. This review article highlights some of the past achievements and present needs in cancer prevention research in China and suggests important areas for future studies.

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 .

Contribution of susceptibility locus at HLA class I region and environmental factors to occurrence of nasopharyngeal cancer in Northeast India

High incidence of nasopharyngeal carcinoma (NPC) has been reported from China, Southeast Asia and Northeast (NE) region of India. Populations at geographic regions having higher incidence of NPC display human leukocyte antigen (HLA) distribution patterns different from areas having low incidence. The current study has investigated the contribution of environmental risk factors and ethnic variation of microsatellite markers in HLA region for the high incidence of NPC in NE India. Genotyping of HLA region using 33 microsatellite markers by fragment length analysis was done in 220 study subjects (120 NPC patients and 100 healthy controls). Association analysis showed two adjacent microsatellite markers HL003 (allele 121) and D6S2704 (allele 218) in the HLA class I region having association with high risk of NPC while allele 127 of HL003 and allele 255 of D6S2678 conferred a protective effect. The environmental factors mainly use of firewood (odds ratio (OR) = 3.797385, confidence interval (CI) = 1.97-7.30, P < 0), living in mud house (OR = 3.46, CI = 1.19-10.08, P = 0.022) and consumption of alcohol (OR = 2.11, CI = 1.02-4.37, P = 0.043) were found as major risk factors for NPC. Higher-order interaction showed combination of smoked food consumption and firewood use for cooking in multifactor dimensionality reduction (MDR) analysis and interaction of non-firewood users, non-ventilated houses and residence in mud houses in classification and regression tree (CART) analysis as the significant risk factors for NPC. Expression of Epstein-Barr virus (EBV) RNA was found in 92% (23/25) of NPC cases suggesting its significant role in NPC aetiopathogenesis. This study identified association of NPC with a susceptibility locus in the HLA class I region which has complex interaction with viral DNA and environmental factors.

A higher dietary ratio of long-chain omega-3 to total omega-6 fatty acids for prevention of COX-2-dependent adenocarcinomas

Compelling evidence that daily low-dose aspirin decreases risk for a number of adenocarcinomas likely reflects the fact that a modest but consistent inhibition of cyclooxygenase-2 (COX-2) activity can have a meaningful protective impact on risk for such cancers. The cancer-promoting effects of COX-2 are thought to be mediated primarily by prostaglandin E2 (PGE2), synthesized from arachidonic acid. The long-chain omega-3s eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), abundant in many fatty fish, can interfere with the availability of arachidonate to COX-2 by multiple complementary mechanisms; moreover, the PGE3 produced by COX-2 from EPA is a competitive inhibitor of the receptors activated by PGE2. These considerations have given rise to the hypothesis that a high dietary intake of EPA/DHA, relative to omega-6 (from which arachidonate is generated), should lessen risk for a number of adenocarcinomas by impeding PGE2 production and activity-while not posing the risk to vascular health associated with COX-2-specific nonsteroidal antiinflammatory agents. Analyses that focus on studies in which the upper category of fish consumption (not fried or salt-preserved) is 2 or more servings weekly, and on studies that evaluate the association of long-term fish oil supplementation with cancer risk yields a number of findings that are consistent with the hypothesis. Further studies of this nature may help to clarify the impact of adequate regular intakes of long-chain omega-3 on cancer risk, and perhaps provide insight into the dose-dependency of this effect.

Challenges to effective cancer control in China, India, and Russia

Cancer is one of the major non-communicable diseases posing a threat to world health. Unfortunately, improvements in socioeconomic conditions are usually associated with increased cancer incidence. In this Commission, we focus on China, India, and Russia, which share rapidly rising cancer incidence and have cancer mortality rates that are nearly twice as high as in the UK or the USA, vast geographies, growing economies, ageing populations, increasingly westernised lifestyles, relatively disenfranchised subpopulations, serious contamination of the environment, and uncontrolled cancer-causing communicable infections. We describe the overall state of health and cancer control in each country and additional specific issues for consideration: for China, access to care, contamination of the environment, and cancer fatalism and traditional medicine; for India, affordability of care, provision of adequate health personnel, and sociocultural barriers to cancer control; and for Russia, monitoring of the burden of cancer, societal attitudes towards cancer prevention, effects of inequitable treatment and access to medicine, and a need for improved international engagement.

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

Over the years, many studies have attempted to establish a link between tobacco smoking and an increased risk of nasopharyngeal carcinoma (NPC), but their results have been inconsistent. To clarify this link, we first conducted a comprehensive meta-analysis to integrate the findings of epidemiologic studies from the last half-century. The methodology used for this study followed the checklist proposed by the Meta-analysis of Observational Studies in Epidemiology (MOOSE) Group. Pooled risk estimates were generated using a random-effects model. Twenty-eight case-control studies and 4 cohort studies involving a total of 10,274 NPC cases and 415,266 comparison subjects were included. A substantial effect of smoking on the risk of NPC was identified in this study. The results showed that ever smokers had a 60% greater risk of developing the disease than never smokers (95% confidence interval: 1.38, 1.87); this was a robust dose-dependent association. More importantly, stronger associations were observed in low-risk populations and among persons with the predominant histological type of differentiated NPC than in high-risk populations and persons with an undifferentiated type; the odds ratios were 1.76 and 2.20, respectively, versus 1.29 and 1.27. In this comprehensive meta-analysis, well-established statistical evidence was provided about the role of tobacco smoking in the etiology of NPC.

Prognostic impact of family history in southern Chinese patients with undifferentiated nasopharyngeal carcinoma

Background:

Family history of cancer is associated with developing nasopharyngeal carcinoma (NPC); however, the impact of it on survival among established NPC patients remains unknown.

Methods:

We retrospectively analysed 1773 southern Chinese patients. Associations between a first-degree family history of NPC and overall survival (OS), locoregional relapse-free survival (LRFS) and distant metastasis-free survival (DMFS) were estimated by Cox regression.

Results:

Among 1773 patients, 207 (11.7%) reported a first-degree family history of NPC. Compared with patients without a family history, the adjusted hazard ratios among those with it were 0.60 (95% confidence interval (CI), 0.37–0.98; P=0.040) for OS, 0.52 (95% CI, 0.24–1.12; P=0.096) for LRFS and 0.51 (95% CI, 0.27–0.97; P=0.040) for DMFS. There were trends for improving OS, LRFS and DMFS with increasing number of affected relatives (P_trend: 0.050, 0.114 and 0.044, respectively). But no significant benefits of family history in second- or third-degree relatives were observed. In subgroup analysis, we observed the effects of family history with restriction to male patients and those of advanced stage and treated with conventional radiotherapy and addition of chemotherapy.

Conclusion:

A first-degree family history of NPC is associated with improved survival of patients.

ABO blood group and nasopharyngeal carcinoma risk in a population of Southeast China

Previous studies found that the ABO blood type alters the individual susceptibility of some malignancies. However, whether such an association exists between ABO blood type and nasopharyngeal carcinoma (NPC) remains unknown. A case-control study was conducted, with 1,538 patients who had NPC and 1,260 cancer-free controls. The association between ABO blood type and NPC incidence was evaluated using unconditional logistic regression analysis. Compared with subjects with blood type O, a relatively higher risk was observed among cases with blood types A or AB, with ORs (95% confidence interval) of 1.287 (1.072 - 1.545), p = 0.007 and 1.390 (1.007 - 1.919), p = 0.045, respectively, after adjusting for gender, age, smoking status and family history of cancer. The rate of distant metastasis was significantly higher among male patients with blood type A than in patients with non-A blood types (6.8 vs. 3.5%, p = 0.027). Our results suggest that blood types A or AB is associated with an increased risk of NPC. Further studies are needed to confirm this association and to explore the mechanisms involved.

SPLUNC1 regulates cell progression and apoptosis through the miR-141-PTEN/p27 pathway, but is hindered by LMP1

Little is known about the role of the host defensive protein short palate, lung and nasal epithelium clone 1 (SPLUNC1) in the carcinogenesis of nasopharyngeal carcinoma (NPC). Here we report that SPLUNC1 plays a role at a very early stage of NPC carcinogenesis. SPLUNC1 regulates NPC cell proliferation, differentiation and apoptosis through miR-141, which in turn regulates PTEN and p27 expression. This signaling axis is negatively regulated by the EBV-coded gene LMP1. Therefore we propose that SPLUNC1 suppresses NPC tumor formation and its inhibition by LMP1 provides a route for NPC tumorigenesis.

Associations of polymorphisms in the genes of FGFR2, FGF1, and RBFOX2 with breast cancer risk by estrogen/progesterone receptor status

Genetic polymorphisms of fibroblast growth factor receptor 2 (FGFR2) have been demonstrated to be associated with breast cancer risk, presumably through elevation of FGFR2 expression. Fibroblast growth factor 1 (FGF1) and RNA binding protein fox-1 homolog 2 (RBFOX2), which are functionally related to FGFR2, may also associate with breast cancer risk. We investigated the associations between breast cancer risk and the polymorphisms of FGFR2 rs2981582, FGF1 rs250108, and RBFOX2 rs2051579 among 839 incident breast cancer cases and 863 age-matched controls in the Guangzhou Breast Cancer Study. Stratified odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by estrogen receptor (ER)/progesterone receptor (PR) status using multivariate logistic regression. FGFR2 rs2981582 was confirmed to be significantly associated with the risk of ER-positive but not ER-negative breast cancer. In contrast, FGF1 rs250108 was significantly associated with the risk of ER-negative breast cancer (OR (95% CI) = 1.68 (1.20-2.35) for CT + TT vs. CC genotype) but not ER-positive breast cancer. CA + AA genotypes at RBFOX2 rs2051579 were associated with a reduced risk of ER-negative (0.71 (0.52-0.97)) but not ER-positive breast cancer compared to the CC genotype. Similar results were observed when differentiating breast cancer cases by PR status. Neither of the pairs between the three SNPs had a significant interaction on breast cancer risk. Our findings show a suggestively stronger association between FGFR2 rs2981582 and ER-positive breast cancer risk and suggest a greater association of FGF1 rs250108 and RBFOX2 rs2051579 with ER-negative compared to ER-positive breast cancer.

An epidemiological and molecular study of the relationship between smoking, risk of nasopharyngeal carcinoma, and Epstein-Barr virus activation

BACKGROUND

Elevated levels of antibodies against antigens in the Epstein-Barr virus (EBV) lytic phase are important predictive markers for nasopharyngeal carcinoma (NPC) risk. Several lifestyle factors, including smoking, have also been associated with NPC risk. We hypothesized that some specific lifestyle factors induce transformation of EBV from the latent to the lytic stage and contribute to NPC occurrence.

METHODS

We conducted a case-control study using data from male case patients (n = 1316) and control subjects (n = 1571) living in Guangdong Province, an area in China at high risk for NPC, to study potential NPC risk factors and EBV inducers. Two independent healthy male populations from a second high-risk area (n = 1657) and a low-risk area (n = 1961) were also included in the analysis of potential EBV inducers using logistic regression models. In vitro assays were performed to investigate the effect of cigarette smoke extract on EBV activation in two EBV-positive cell lines. All statistical tests were two-sided.

RESULTS

Smoking was associated with an increased risk of NPC among the Guangdong participants with 20-40 and 40 or more pack-years vs never smokers (OR = 1.52, 95% CI = 1.22 to 1.88 and OR = 1.76, 95% CI = 1.34 to 2.32, respectively; P (trend) < .001). Smoking was the only factor linked to EBV seropositivity among the expanded control group and the independent low-risk population. In vitro experiments showed that cigarette smoke extract promoted EBV replication, induced the expression of the immediate-early transcriptional activators Zta and Rta, and increased transcriptional expression levels of BFRF3 and gp350 in the lytic phase.

CONCLUSION

Smoking is not only associated with NPC risk in individuals from China but is also associated with EBV seropositivity in healthy males and is involved in EBV activation.

Joint effects of febrile acute infection and an interferon-γ polymorphism on breast cancer risk

Background

There is an inverse relationship between febrile infection and the risk of malignancies. Interferon gamma (IFN-γ) plays an important role in fever induction and its expression increases with incubation at fever-range temperatures. Therefore, the genetic polymorphism of IFN-γ may modify the association of febrile infection with breast cancer risk.

Methodology and Principal Findings

Information on potential breast cancer risk factors, history of fever during the last 10 years, and blood specimens were collected from 839 incident breast cancer cases and 863 age-matched controls between October 2008 and June 2010 in Guangzhou, China. IFN-γ (rs2069705) was genotyped using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry platform. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated using multivariate logistic regression. We found that women who had experienced ≥1 fever per year had a decreased risk of breast cancer [ORs and 95% CI: 0.77 (0.61–0.99)] compared to those with less than one fever a year. This association only occurred in women with CT/TT genotypes [0.54 (0.37–0.77)] but not in those with the CC genotype [1.09 (0.77–1.55)]. The association of IFN-γ rs2069705 with the risk of breast cancer was not significant among all participants, while the CT/TT genotypes were significantly related to an elevated risk of breast cancer [1.32 (1.03–1.70)] among the women with <1 fever per year and to a reduced risk of breast cancer [0.63 (0.40–0.99)] among women with ≥1 fever per year compared to the CC genotype. A marked interaction between fever frequencies and the IFN-γ genotypes was observed (P for multiplicative and additive interactions were 0.005 and 0.058, respectively).

Conclusions

Our findings indicate a possible link between febrile acute infection and a decreased risk of breast cancer, and this association was modified by IFN-γ rs2069705.

Pretreatment lifestyle behaviors as survival predictors for patients with nasopharyngeal carcinoma

BACKGROUND

Lifestyle behaviors have been widely reported to influence the survival of patients with head and neck cancer. However, the relationship between pretreatment lifestyle behaviors and survival among patients with nasopharyngeal carcinoma (NPC) is unclear.

METHODS

A prospective cohort study was designed to determine the relationship between lifestyle behaviors and survival in 1,533 NPC patients recruited from October 2005 to October 2007. Pretreatment lifestyle behaviors (such as body-mass index [BMI], smoking, alcohol, diet) of the patients were investigated. Univariate and multivariate proportional-hazards models were used to assess the impact of lifestyle behaviors on patient survival.

RESULTS

Smoking was a predictor of survival; both current smokers (hazard ratio [HR] = 1.88; 95% CI, 1.33 to 2.65) and heavy smokers (≥ 25 Pack-years; HR = 1.84; 95% CI, 1.30 to 2.60) showed associations with poor survival. Higher BMI was significantly associated with a lower risk of death (P(trend) = 0.002). Compared with under/normal-weight patients (BMI less than 22.99 kg/m(2)), the multivariate HR for survival was 0.66 (95% CI, 0.48 to 0.90) and 0.47 (95% CI, 0.23 to 0.97) for overweight and obese patients, respectively. No alcohol intake and high fruit intake were associated with favorable survival in the univariate analysis but lost significance in the multivariate model.

CONCLUSION

Our findings indicate that pretreatment lifestyle behaviors, especially smoking status and BMI, as easily available data, provide prognostic value for survival in NPC patients.

Non-viral environmental risk factors for nasopharyngeal carcinoma: a systematic review

This review aims to systematically summarize the epidemiological studies on nasopharyngeal carcinoma (NPC) conducted over the past half century, covering descriptive epidemiological studies and reports on non-viral risk factors. Multiple lines of epidemiologic evidence for established risk factors are systematically presented in comprehensive tables. The potential interactions among environmental factors and genetic components, and also the impacts of parallel sequencing technology on the aetiology of NPC are discussed. Finally, we propose a modified model for the pathogenesis of nasopharyngeal carcinoma based on the current knowledge.

Epstein-Barr virus and breast cancer: serological study in a high-incidence area of nasopharyngeal carcinoma

We investigated IgA and IgG levels against EBV viral capsid antigen (VCA) and nuclear antigen-1 (EBNA-1) in serum of 223 women with breast cancer (BC) and 309 controls in Guangzhou, China. VCA IgA levels were significantly associated with an elevated risk of BC, with adjusted ORs (95%CIs) of 1.70 (1.05-2.76) (seropositivity) and 2.21 (1.11-4.40) (unit increases in OD value). This association was stronger among young, lean, and HER2+ women. The EBNA-1 IgA levels in OD value, but not seropositivity, were associated with an increased risk of BC among ER+, PR+, and HER2+ patients. None of the IgG variables was related to BC. These results suggest the EBV association with BC in an endemic area of nasopharyngeal carcinoma.