Novel epidemiologic evidence for the association between fermented fish sauce and esophageal cancer in South China

Environmental Cadmium Exposure Promotes the Development, Progression and Chemoradioresistance of Esophageal Squamous Cell Carcinoma

Cadmium (Cd) exposure has been implicated in the etiology of esophageal squamous cell carcinoma (ESCC), albeit with inconsistent results from epidemiologic studies and without causal evidence. In this study, we explore the relationship of Cd exposure and the development, progression and therapeutic resistance of ESCC. A total of 150 ESCC patients and 177 matched controls from a coastal region with a high incidence of ESCC in China were included in the study. It was found that the median blood Cd level (BCL) was significantly higher in ESCC patients than that in the controls. Odds ratios for ESCC risk were 3.12 (95% CI 1.54-6.30) and 3.71 (95% CI 1.84-7.48) in the third and fourth quartiles of Cd distribution, respectively. Notably, BCL above 4.71 μg/L was strongly associated with shorter progression-free survival time compared to that below 1.60 μg/L (p < 0.001). The chronic Cd-treated ESCC cells (CCT-ESCC) CCT-EC109 and CCT-EC9706 exhibited increased cell proliferation and tumorigenesis, enhanced migration and invasion, and upregulated EMT biomarkers following 12 weeks of exposure to 5 μM cadmium chloride. Furthermore, Cd treatment attenuated the efficacy of 5-fluorouracil, cisplatin and irradiation treatment in CCT-ESCC cells both in vitro and in vivo. Moreover, we revealed that Cd stimulated the cancer cell stemness and Wnt/β-catenin signaling pathway in the CCT-ESCC cells. Additionally, 5-aza-2-deoxy-cytidine treatment resulted in suppression of the Wnt/β-catenin signaling pathway and rescue of the Cd-induced cell radioresistance. These results offer new insights into the role of environmental Cd exposure in the development, progression and chemoradioresistance of ESCC.

Age-standardized mortality, disability-adjusted life-years and healthy life expectancy in different cultural regions of Guangdong, China: a population-based study of 2005-2015

BACKGROUND

Guangdong province is dominated by three cultural regions: Canton, Hakka and Hoklo. However, little is known about the disease burden within these regions, particularly because different population,environmental and socioeconomic risk factors might cause different patterns of mortality, disability-adjusted life-years (DALY), life expectancy and healthy life expectancy (HALE). We aimed to compare the patterns of disease burden in Canton, Hakka and Hoklo regions between 2005 and 2015.

METHOD

We calculated the mortality, YLL, YLD for 116 diseases for different cultural regions between 2005 and 2015. We calculated the DALYs for 116 causes as the sum of YLLs and YLDs. We estimated the life expectancy and HALE by using sex-specific mortality rates and YLDs for the three cultural regions.

RESULTS

With a respective reduction of 22.3, 15.8 and 17.8% in 2015 compared with 2005, the age-standardized DALY rates in 2015 was 19,988.0, 14,396.5 and 20,436.6 in Hakka, Canton and Hoklo region. Canton region had a significantly lower mortality and DALYs in most diseases, followed by Hoklo and Hakka regions. The life expectancy and HALE at birth were highest in Canton region in both 2005 and 2015, than in Hoklo and Hakka region.

CONCLUSIONS

Our findings call for improved public health care via the refinement of policy and effective measures for disease prevention. Understanding the environmental and culture-related risk factors of diseases in Hoklo and Hakka regions may help inform public health sectors to reduce the disease burden and the between-region inequality.

Distribution of N-nitrosamines in drinking water and human urinary excretions in high incidence area of esophageal cancer in Huai'an, China

The Huai'an area in Jiangsu Province of East China is an endemic region of esophageal cancer (EC). The regional heterogeneity of EC suggests that the levels of potential carcinogens might vary throughout the environment. It has been suggested that the most likely carcinogens related to EC are a group known as the N-nitrosamines. In this study, we measured the concentrations of nine nitrosamines in drinking water and human urine in two areas in China, one with a high incidence of EC (Huai'an) and one with a low incidence (Nanjing). Among the nine target analytes, N-nitrosodi-n-propylamine (NDPA), N-nitrosodibutylamine (NDBA), N-nitrosopyrrolidine (NPyr), N-nitrosodiethylamine (NDEA) and N-nitrosomorpholine (NMor) occurred at higher concentrations in drinking water in the high incidence area. Inhabitants from the high incidence area also had urinary excretions with significantly higher concentrations of NDEA, NDBA, N-nitrosopiperidine (NPip) and N-nitrosodiphenylamine (NDPhA). These findings indicated that people in the high EC incidence area were exposed to higher levels of nitrosamines. However, the association between the incidence of EC and nitrosamines exposure will need to be evaluated in more detail.

Nutritional Guidelines and Fermented Food Frameworks

This review examines different nutritional guidelines, some case studies, and provides insights and discrepancies, in the regulatory framework of Food Safety Management of some of the world’s economies. There are thousands of fermented foods and beverages, although the intention was not to review them but check their traditional and cultural value, and if they are still lacking to be classed as a category on different national food guides. For understanding the inconsistencies in claims of concerning fermented foods among various regulatory systems, each legal system should be considered unique. Fermented foods and beverages have long been a part of the human diet, and with further supplementation of probiotic microbes, in some cases, they offer nutritional and health attributes worthy of recommendation of regular consumption. Despite the impact of fermented foods and beverages on gastro-intestinal wellbeing and diseases, their many health benefits or recommended consumption has not been widely translated to global inclusion in world food guidelines. In general, the approach of the legal systems is broadly consistent and their structures may be presented under different formats. African traditional fermented products are briefly mentioned enhancing some recorded adverse effects. Knowing the general benefits of traditional and supplemented fermented foods, they should be a daily item on most national food guides.

Inclusion of fermented foods in food guides around the world

Fermented foods have been a well-established part of the human diet for thousands of years, without much of an appreciation for, or an understanding of, their underlying microbial functionality, until recently. The use of many organisms derived from these foods, and their applications in probiotics, have further illustrated their impact on gastrointestinal wellbeing and diseases affecting other sites in the body. However, despite the many benefits of fermented foods, their recommended consumption has not been widely translated to global inclusion in food guides. Here, we present the case for such inclusion, and challenge health authorities around the world to consider advocating for the many benefits of these foods.

Development of esophageal cancer in Chaoshan region, China: association with environmental, genetic and cultural factors

Esophageal squamous cell carcinoma (ESCC) is the eighth most common cancer by incidence worldwide. Although the cancer is located at a readily recognizable and accessible site in the body, it is the sixth most common cause of cancer death. The 1- and 5-year survival rates in China are 50% and 15%, respectively. Furthermore, the cancer has distinct geographic and etiological risk factors in different locations around the world. Since ESCC is highly prevalent in the Chaoshan (Southeastern) region of China, this report will focus on a review of risk factors for the cancer in this area. From the review, it is clear that some important and traditional factors are involved, e.g. environmental mutagens, genetic predisposition. However, unique factors, e.g. the drinking of very hot tea, may play an important role. This review highlights the role of complex risk factors (environmental, genetic and cultural) which contribute to the multistage development of cancer: localized injury, inflammation, mitogenesis, mutagenesis, carcinogenesis and eventually mortality. The latter is contributed by unnecessary delay in seeking medical care which may be culturally related. The review emphasizes the need to identify causal mechanisms for the complex carcinogenic process which can provide opportunity for prevention and treatment of this potentially curable cancer.

Meat consumption is associated with esophageal cancer risk in a meat- and cancer-histological-type dependent manner

BACKGROUND

We conducted a systematic review and meta-analysis of meat intake and esophageal cancer risk, with subgroup analyses based on meat type and histological type of cancer.

AIMS

The purpose of this study was to investigate the association between meat intake and risk of esophageal cancer.

METHODS

We searched MEDLINE, EMBASE and Cochrane Library (April 2013) for cohort and case-control studies that assessed meat intake and esophageal cancer risk. Random-effect or fixed-effect models were used to pool relative risks (RRs) from individual studies with heterogeneity and publication bias analyses carried out. Seven cohort and 28 case-control studies were included.

RESULTS

The summary RRs for esophageal cancer for the highest versus lowest consumption categories were 1.19 (95 % confidence interval [CI] 0.98-1.46) for total meat, 1.55 (95 % CI 1.22-1.96) for red meat, 1.33 (95 % CI 1.04-1.69) for processed meat, 0.72 (95 % CI 0.60-0.86) for white meat, 0.83 (95 % CI 0.72-0.96) for poultry, and 0.95 (95 % CI 0.76-1.19) for fish. When striated by histological subtype, positive associations were seen among esophageal squamous cell carcinoma and red meat, white meat and poultry, and esophageal adenocarcinoma with total meat and processed meat.

CONCLUSIONS

Meat consumption is associated with esophageal cancer risk, which depends on meat type and histological type of esophageal cancer. High intake of red meat and low intake of poultry are associated with an increased risk of esophageal squamous cell carcinoma. High meat intake, especially processed meat, is likely to increase esophageal adenocarcinoma risk. And fish consumption may not be associated with incidence of esophageal cancer.

Statistical analysis of human papillomavirus in a subset of upper aerodigestive tract tumors

Human papilloma virus (HPV) has been detected in some upper aerodigestive tract tumors, but the correlation between HPV and these tumors is not well understood. There is also some controversy regarding this correlation because a large variation in the prevalence of HPV in these tumors has been reported. To discuss the impact of HPV infection on upper aerodigestive tract tumors, this review estimated systematically the prevalence and risk of HPV in upper aerodigestive tract tumors from studies published between 1982 and 2012. In total, 418 articles were selected, which included 273 studies on the head and neck and 145 studies on esophageal squamous cell carcinoma. The overall prevalence of HPV in the 5,467 head and neck squamous cell carcinoma specimens was 36.3%. HPV was detected more frequently in the Americas (40%), than in Asia (38.6%), Europe (32%), or others regions (30.5%). The prevalence of HPV was significantly higher in oropharyngeal (48.5%) than in oral (32.5%), laryngeal (30.7%), and unselected head and neck squamous cell carcinoma (33.3%) (P < 0.001). The pooled prevalence of HPV in the 6,912 esophageal squamous cell carcinoma cases was 38.9% and it was significantly higher in China (44%) versus other regions (31.3%) (P < 0.05). Meta-analysis showed that head and neck and esophageal squamous cell carcinoma are associated with HPV infection (combined OR: 3.58, OR for head and neck and esophageal squamous cell carcinoma: 4.20). These findings suggest that HPV might be linked etiologically to the development of some upper aerodigestive tract tumors.

Comparison of prevalence, viral load, physical status and expression of human papillomavirus-16, -18 and -58 in esophageal and cervical cancer: a case-control study

BACKGROUND

Human papillomavirus (HPV) infection is a major risk factor for the development of nearly all cases of cervical cancer worldwide. The presence of HPV DNA in cases of esophageal squamous-cell carcinoma (ESCC) has been reported repeatedly from Shantou, China, and other regions with a high incidence of esophageal carcinoma (EC). However, unlike in cervical squamous-cell carcinoma (CSCC), in ESCC, the characteristics of HPV are unclear. Thus, the role of high-risk HPV types in the carcinogenesis of ESCC remains uncertain.

METHODS

Seventy cases of ESCC with 60 controls and 39 cases of CSCC with 54 controls collected from patients in Shantou region in China were compared for the distributions of HPV-16, -18 and -58; viral load; and viral integration using real-time PCR assay and HPV-16 expression using immunostaining.

RESULTS

The detection rates and viral loads of HR-HPV infection were significantly lower in ESCC than in CSCC (50.0% vs. 79.48%, P = 0.005; 2.55 ± 3.19 vs. 361.29 ± 441.75, P = 0.002, respectively). The combined integration level of HPV-16, -18 and -58 was slightly lower in ESCC than in CSCC (P = 0.022). HPV-16 expression was detected in 59.26% of ESCC tissue and significantly associated with tumour grade (P = 0.027).

CONCLUSIONS

High levels of HR-HPV expression and integration may be an indicator of the risk of ESCC, at least for patients in the Shantou region of China. However, a relatively low HPV copy number and infection rate in ESCC is unlikely to play an essential a role in the carcinogenesis of ESCC as in cervical cancer. Factors other than HR-HPV infection may contribute to the carcinogenesis of ESCC.

Genetic heterogeneity of oesophageal cancer in high-incidence areas of southern and northern China

BACKGROUND AND OBJECTIVE

Oesophageal cancer is one of the most common and deadliest cancers worldwide. Our previous population-based study reported a high prevalence of oesophageal cancer in Chaoshan, Guangdong Province, China. Ancestors of the Chaoshan population migrated from the Taihang Mountain region of north-central China, which is another high-incidence area for oesophageal cancer. The purpose of the present study was to obtain evidence of inherited susceptibility to oesophageal cancer in the Chaoshan population, with reference to the Taihang Mountain population, with the eventual goal of molecular identification of the disease genes.

METHODS

We conducted familial correlation, commingling, and complex segregation analyses of 224 families from the Chaoshan population and 403 families from the Taihang population using the FPMM program of S.A.G.E. version 5.3.0. A second analysis focused on specific families having large numbers of affected individuals or early onset of the disease.

RESULTS

For the general population, moderate sib-sib correlation was noticed for esophageal cancer. Additionally, brother-brother correlation was even higher. Commingling analyses indicated that a three-component distribution model best accounts for the variation in age of onset of oesophageal cancer, and that a multifactorial model provides the best fit to the general population data. An autosomal dominant mode and a dominant or recessive major gene with polygenic inheritance were found to be the best models of inherited susceptibility to oesophageal cancer in some large families.

CONCLUSIONS

The current results provide evidence for inherited susceptibility to oesophageal cancer in certain high-risk groups in China, and support efforts to identify the susceptibility genes.

Characterization of one newly established esophageal cancer cell line CSEC from a high-incidence area in China

The Chaoshan littoral is located in a high-incidence area of esophageal cancer in the south of China. In this study, a new esophageal cancer cell line CSEC was established from a 47-year-old female Chinese patient in this district. The biological characters of the cultured cells were investigated, including morphology, ultrastructure, growth kinetic features, tumorigenicity, expression of tumor-associated antigen and cytogenetic features. CSEC cell line grew continuously with a doubling time of 39.5 h and had been passaged over 80 times. The CSEC cells possessed features of squamous epithelial cells with cytokeratin indicated by immunohistochemical staining and tonofilaments and desmosomes revealed by electron microscopy. Tumorigenicity to severe combined immunodeficient mice was confirmed and the tumors developed revealed well-differentiated squamous cell carcinoma, similar to the origin tumor from which the cell line derived. The cytogenetic analysis demonstrated hypertetraploid karyotypes. Chromosome structure aberrations were common and complicated. Immunohistochemical staining showed that CSEC cells were infected with HPV and over-expressed p53. In summary, the CSEC cell line is a well-differentiated esophageal squamous cell carcinoma cell line from a high-incidence area in southern China. It may provide a useful model for the pathogenesis and therapeutic research of esophageal squamous cell carcinoma.

Association between diet and esophageal cancer in Taiwan

BACKGROUND

Several studies have reported the importance of dietary factors in the development of esophageal cancer. The purpose of the present study was to evaluate the effects of several common dietary factors on the risk of squamous cell carcinoma of the esophagus in a Taiwanese population.

METHODS

The association between diet and esophageal cancer was examined in 284 male patients and 480 male controls, who were recruited during 6 year period.

RESULTS

Consumption of preserved and overheated foods was found to be associated with increased risk of esophageal cancer, whereas intake of fresh fruits, vegetables, and tea was inversely associated with this risk. Men who consumed fermented bean products, salted food and preserved/pickled vegetables more than once a week after age 40 years had a 3.4-fold risk (95% confidence interval (CI): 1.9-6.2), 2.3-fold risk (95%CI: 1.2-4.2), and 2.5-fold risk (95%CI: 1.3-4.5), respectively, compared to men eating these items less than once a week. It was further found that these preserved foods were more strongly associated with esophageal cancer among men who consumed fruit less than once per day than those who consumed fruits one or more times per day.

CONCLUSIONS

These results suggest that a high intake of preserved foods and overheated drinks might increase the risk of esophageal cancer, and intake of fruit, vegetables, and tea might be negatively associated with risk of esophageal cancer. The results also suggest that diet is an important factor in the development of esophageal cancer in Taiwan.

Genetic susceptibility and environmental factors of esophageal cancer in Xi’an

AIM: To analyse the role of genetic susceptibility and environmental factors in the process of esophageal cancer (EC) formation in Xi’an, China.

METHODS: A hospital based case-control study, combined with molecular epidemiological method, was carried out. A total of 127 EC cases and 101 controls were interviewed with questionnaires containing demographic items, habit of tobacco smoking, alcohol drinking, and family history of EC. Polymorphism of CYP1A1 and GSTM1 of 127 EC cases and 101 controls were detected by PCR method. The interactions between genetic susceptibility and environmental factors were also discussed.

RESULTS: Tobacco smoking, alcohol drinking and a family history of EC were risk factors for EC with an OR of 2.04 (95%CI 1.15-3.60), 3.45(95%CI 1.74-6.91), 3.14 (95%CI 1.28-7.94), respectively. Individuals carrying CYP1A1 Val/Val genotype compared to those with CYP1A1 Ile/Ile genotype had an increased risk for EC (OR 3.35, 95%CI 1.49-7.61). GSTM1 deletion genotype was a risk factor for EC (OR1.81, 95%CI 1.03-3.18). Gene-environment interaction analysis showed that CYP1A1 Val/Val genotype, GSTM1 deletion genotype had synergetic interactions with tobacco smoking, alcohol drinking and family history of EC.

CONCLUSION: Tobacco smoking, alcohol drinking and a family history of EC are risk factors for EC. CYP1A1 Val/Val and GSTM1 deletion genotypes are genetic susceptibility biomarkers for EC. There are synergic interactions between genetic susceptibility and environmental factors.

Chapter 9: Role of mucosal human papillomavirus in nongenital cancers

Established associations between human papillomavirus (HPV) and lower genital tract cancers provide a framework from which to evaluate a possible pathogenic role for the virus in cancers at nongenital sites. Proposed associations must fit coherently within the context of our current knowledge of the epidemiology and biology of HPV. In this article, insights obtained from studies of the etiologic link between mucosal-type HPV infection and four specific human cancers are described briefly. Specific characteristics, shared among cancers caused by HPV, are then used by extrapolation to discuss possible associations between certain other nongenital cancers and mucosal HPV infections in a manner intended to supplement, and in no way to supplant, the classic Hill criteria for causal inference.

Viral load of HPV in esophageal squamous cell carcinoma

We previously reported the presence of HPV DNA in esophageal squamous cell carcinoma (ESCC) cases from Hong Kong and Sichuan. The role of HPV in the carcinogenesis of ESCC remains unclear, partly due to the large variations in infection rates reported by different studies. While some of these variations may truly reflect different HPV infection rates in ESCC among different geographic regions, differences in sensitivity and specificity of the detection methods used also contribute. In the present study, we used quantitative real-time PCR to determine the copy numbers of HPV-16 and HPV-18 in ESCC from 5 different regions of China with different incidence rates of ESCC. Conforming to our previous reports, HPV infection was detected in 2-22.2% of samples. Infection with HPV-16 was again shown to be more common than that with HPV-18 among Chinese ESCC patients. The copy number of HPV-16 in these ESCC cases ranged from < or =1 to 157 copies/genome equivalent, with 65% of samples harboring fewer than 10 copies/genome equivalent. The median copy number of HPV-18 was 4.9/genome equivalent. Assays were validated using cervical carcinoma cell lines with known copy numbers of HPV-16 or HPV-18. The relatively low HPV copy number and infection rate in ESCC suggest that HPV is unlikely to play as essential a role in the carcinogenesis of ESCC as in cervical cancer. However, with the consistent detection of oncogenic HPVs in ESCC from some regions of China, the possibility of HPV infection being one of the multiple risk factors of ESCC in some geographic areas cannot be excluded.