Esophageal Squamous Cell Carcinoma and Aldehyde Dehydrogenase-2 Genotypes in Japanese Females

Impact of Alcohol-Induced Facial Flushing Phenotype on Alcohol Consumption Among Korean Adults: 2-Year Cross-Sectional Study

BACKGROUND

The alcohol-induced facial flushing phenotype (flushing) is common among East Asians. Despite a small intake of alcohol, they experience heightened levels of acetaldehyde, a group-1 carcinogen, which, in turn, causes unpleasant symptoms such as redness, acting as a robust protective mechanism against consuming alcohol. However, some individuals with this genetic trait exhibit weakened alcohol restraint, which increases the risk of developing alcohol-related cancers, such as esophageal and head or neck cancer, by several times. Although this flushing phenomenon is crucial for public health, there is a paucity of studies that have comprehensively investigated the effect of flushing or its genotype on alcohol consumption in a large group of East Asians while controlling for various sociodemographic and health-related variables at a country level.

OBJECTIVE

This 2-year cross-sectional study aims to explore the effect of flushing on drinking behavior in Koreans and to examine whether the effect varies across sociodemographic and health-related factors.

METHODS

We used data from the Korea National Health and Nutrition Examination Survey (KNHANES) for 2019 and 2020 conducted by the Korea Disease Control and Prevention Agency. Our sample comprised 10,660 Korean adults. The study investigated the association of 26 variables, including flushing, with drinking frequency and amount. The effect of flushing was examined with and without adjusting for the other 25 variables using multinomial logistic regression analysis. In addition, we tested the interaction effect with flushing and conducted a simple effect analysis. We used complex sample design elements, including strata, clusters, and weights, to obtain unbiased results for the Rao-Scott χ2 test, 2-tailed t test, and multinomial logistic regression analysis.

RESULTS

The suppressive effect of flushing was significant (P<.001) across all pronounced categories of alcohol consumption in 2019. The ranges of standardized regression slopes and odds ratios (ORs) were -6.70≥β≥-11.25 and 0.78≥OR≥0.50 for frequency and -5.37≥β≥-17.64 and 0.73≥OR≥0.36 for amount, respectively. The effect became somewhat stronger when adjusted for confounders. The effect also exhibited an overall stronger trend as the severity of alcohol consumption increased. The β values and ORs were consistently smaller in 2020 compared to the previous year. A simple effect analysis revealed a diminished alcohol-suppressive effect of flushing on alcohol consumption for specific groups (eg, those with low levels of education, limited family support, physical labor, or health-related issues).

CONCLUSIONS

Our findings suggest that flushing suppresses drinking in Koreans overall but has little or no effect in certain susceptible populations. Therefore, health authorities should conduct targeted epidemiological studies to assess drinking patterns and disease profiles, particularly regarding alcohol-related cancers, and establish effective preventive measures tailored to this population.

Association between alcohol flushing syndrome and cancer: A systematic review and meta-analysis

Introduction

Alcohol flushing syndrome (AFS) is experienced by up to 46% of East Asians. This study aimed to review the risk of cancers in AFS patients, elucidate an exposure-response relationship, and understand risk associated with alcohol intake and cancer.

Method

An electronic database search of PubMed, Embase, Scopus and Cochrane Library was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Observational studies on AFS' effects and all cancers risk were included. Studies including patients with existing malignancy were excluded. Dichotomous variables were pooled using the Mantel-Haenszel method with a random effects model. Sensitivity and subgroup analyses were performed. PROSPERO (CRD42023392916) protocol was followed.

Results

A total of 18 articles were included in the final analysis with a total of 387,521 participants. AFS was associated with an increased risk of all cancers (odds ratio [OR] 1.19, 95% confidence interval [CI] 1.06-1.34), esophageal squamous cell carcinoma (OR 1.47, 95% CI 1.05-2.05) and gastric adenocarci-noma (OR 1.40, 95% CI 1.14-1.72). Men with AFS exhibited an increased risk of all cancers (OR 1.34, 95% CI 1.13-1.59). However, this was not observed in women. All cancers risk was associated with AFS in those who consumed drink (i.e. consumed alcohol) more than 200 g of pure ethanol/week (OR 1.68, 95% CI 1.20-2.37) but not those who consumed less than 200 g of pure ethanol/week (OR 1.27, 95% CI 0.90-1.79) or non-drinkers (OR 0.99, 95% CI 0.67-1.47).

Conclusion

AFS is associated with an increased risk of all cancers, particularly esophageal squamous cell carcinoma and gastric adenocarcinoma.

The impact of alcohol consumption on hearing loss in male workers with a focus on alcohol flushing reaction: the Kangbuk Samsung Cohort Study

Background

Despite hearing loss being a prevalent chronic condition, estimated to nearly 20% of the global population by the World Health Organization, the specific association with individual lifestyle factors, particularly alcohol consumption, remains unclear. In South Korea, approximately 80% of the population engages in alcohol consumption, with a notably high prevalence among males, indicating a high-risk drinking pattern. Therefore, this study aimed to assess the correlation between alcohol consumption and hearing loss in male workers, as well as to analyze additional variables such as alcohol flushing reaction, with the intention of improving worker health.

Methods

The study was conducted from January 2012 to December 2019, targeting 114,114 participants who visited Kangbuk Samsung Hospital Total Healthcare Centers. Data were collected through pure-tone audiometry tests and alcohol-related questionnaire, and statistical analysis was performed using Cox regression analysis. Based on previous studies indicating a potential protective effect of light drinking on hearing loss, this group was designated as the reference. Additionally, stratified analyses were conducted based on the presence of alcohol flushing reaction and different working hours.

Results

The hazard ratio (95% confidence interval) for hearing loss was higher in the heavy drinking group (1.23 [1.11-1.37]) compared to the moderate drinking group (1.09 [0.98-1.20]). Stratified analyses revealed a significantly elevated the hazard ratio of hearing loss in groups with alcohol flushing reaction compared to those without this factor.

Conclusions

Our study demonstrated that moderate or heavy alcohol consumption in male workers can increase the risk of hearing loss, particularly in those with alcohol flushing reaction. These findings underscore the importance of addressing alcohol-related factors concerning hearing health among male workers.

Risk factors for the development of second primary esophageal squamous-cell carcinoma after endoscopic resection for esophageal squamous-cell carcinoma according to genetic polymorphisms related to alcohol and nicotine metabolism

BACKGROUND

Multiple development of esophageal squamous-cell carcinoma is explained by field cancerization and is associated with alcohol consumption and smoking. We investigated the association between the development of second primary esophageal squamous-cell carcinoma after endoscopic resection for esophageal squamous-cell carcinoma and genetic polymorphisms related to alcohol and nicotine metabolism.

METHODS

The study group comprised 56 patients with esophageal squamous-cell carcinoma after endoscopic resection. The main variables were the following: (i) cumulative incidence and total number of second primary esophageal squamous-cell carcinoma according to genetic polymorphisms in alcohol dehydrogenase 1B, aldehyde dehydrogenase 2 and cytochrome P450 2A6; and (ii) risk factors of second primary esophageal squamous-cell carcinoma identified using a multivariate Cox proportional-hazards model. The frequencies of alcohol dehydrogenase 1B, aldehyde dehydrogenase 2 and cytochrome P450 2A6 genetic polymorphisms in the buccal mucosa were analyzed.

RESULTS

The median follow-up was 92.8 months (range: 2.7-134.2). Slow-metabolizing alcohol dehydrogenase 1B was associated with a higher 7-year cumulative incidence of second primary esophageal squamous-cell carcinoma (fast-metabolizing alcohol dehydrogenase 1B vs slow-metabolizing alcohol dehydrogenase 1B: 20.5% vs 71.4%, P = 0.006). Slow-metabolizing alcohol dehydrogenase 1B (relative risk [95% confidence interval]: 3.17 [1.49-6.73]), inactive aldehyde dehydrogenase 2 (2.17 [1.01-4.63]) and poorly-metabolizing cytochrome P450 2A6 (4.63 [1.74-12.33]) had a significantly higher total number of second primary esophageal squamous-cell carcinoma per 100 person-years. In the multivariate Cox proportional-hazards model, slow-metabolizing alcohol dehydrogenase 1B was a significant risk factor of the development of second primary esophageal squamous-cell carcinoma (hazard ratio 9.92, 95% confidence interval: 2.35-41.98, P = 0.0018).

CONCLUSIONS

Slow-metabolizing alcohol dehydrogenase 1B may be a significant risk factor for the development of second primary esophageal squamous-cell carcinoma. In addition, inactive aldehyde dehydrogenase 2 and poorly-metabolizing cytochrome P450 2A6 may be important factors.

The long-term survival of esophageal cancer in elderly patients: A multi-center, retrospective study from China

BACKGROUND

Esophageal cancer (EC) often occurs in the elderly, and approximately 40% of patients are 70 years or older. To investigate the long-term survival of EC in elderly patients, to provide a theoretical direction for better management and predicting survival of EC based on the hospital-based multi-center study in China.

METHODS

The study was conducted in 18 hospitals including 6 provincial hospitals, 8 municipal hospitals, and 4 county hospitals. We extracted information from medical record homepage, records of admission and discharge, and pathological diagnosis reports from the medical record department of the elderly patients at 70-84 years old to obtain the 3-year and 5-year overall survival (OS), and main associated factors, and to analyze the current therapeutic effect of different treatment options for elderly patients.

RESULTS

The 3-year and 5-year OS rate of the 1013 elderly patients was 44.8% and 32.8%, respectively. Their median survival was 28.00 months. The median survival of patients with squamous cell carcinoma was longer than that of other pathological type (squamous vs. other types: 31.00 vs. 20.00 months, p = 0.018). The median survival of patients with surgery only or combined therapy was longer than that of radiotherapy, chemotherapy, and no therapy (surgery only vs. combined therapy vs. radiotherapy vs. chemotherapy vs. no therapy: 56.00 vs. 33.00 vs. 26.00 vs.18.00 vs. 16.00 months, p < 0.001). The 5-year OS rate of patients with highly differentiated cancer was higher than that of medium differentiated and poor differentiation/undifferentiated. In multivariate analysis, the older ages, pathological stage, were independent prognostic risk factors for poor EC survival. Treatment method was independent protective factors predictive of a good EC OS.

CONCLUSIONS

The survival rate of the elderly EC patients was still low in China. Age, therapy method, and pathological stage were mainly associated with the survival rate of EC in elderly patients.

Analysis of living habit risk factors for esophageal cancer in central China: A bi-center case-control study

Background

Esophageal cancer remains a public health problem in many countries, especially developing countries. The early lifestyle preventive measures mentioned in the treatment guidelines for esophageal cancer are very limited. We aimed to evaluate the risk factors for esophageal cancer in a high-incidence area in China and to provide evidence for clinical intervention in esophageal cancer prevention.

Methods

Symptom and lifestyle/habit questionnaires including 19 items were designed. The correlation between the occurrence of esophageal cancer and living habits was analyzed retrospectively through questionnaire survey. A total of 708 subjects (365 esophageal cancer, 343 non-esophageal cancer) enrolled from two hospitals in central China (Linzhou Esophageal Cancer Hospital and The Third Xiangya Hospital of Central South University) completed symptom and lifestyle/habit questionnaires. We used conditional logistic regression to estimate the odds ratio (OR) with consideration of 95% confidence interval (CI).

Results

The composition ratio analysis showed that the top five lifestyle factors related to esophageal cancer were eating too fast, drinking, hot drinks, smoking and overeating. Univariate analysis showed that 15 factors, including male sex, smoking, drinking, eating too fast, overeating, hot drinks, greasy food, acidic food, hard food, strong tea, coffee, bedtime immediately after meals, eating food before bedtime, difficult defecation, and an overtight belt, were associated with esophageal cancer (all P <0.05). Logistic multivariate regression analysis showed, drinking (OR 3.609, 95%CI 2.223-5.859; P=0.000); hot drinks (OR 2.672, 95%CI 1.786-3.997; P=0.000); overeating (OR 2.110, 95%CI 1.411-3.154; P=0.000); eating too fast (OR 1.879, 95%CI 1.274-2.772; P=0.001); strong tea (OR 1.882, 95%CI 1.171~3.023; P=0.009); hard food (OR 1.723, 95%CI 1.113-2.667; P=0.015); smoking (OR 1.686, 95%CI 1.045-2.720; P=0.032), which were significantly associated with the development of esophageal cancer.

Conclusion

The unhealthy lifestyles of patients in high-incidence areas of esophageal cancer in central China are significantly associated with the incidence of esophageal cancer. Lifestyle changes that address these factors, especially overeating and eating too fast, which are rarely studied or discussed despite being common, may improve esophageal cancer management and treatment outcomes. The present results may be used as a reference for preventive education and treatment.

Influence of alcohol sensitivity on bone metastases and skeletal-related events in primary operable breast cancer: A retrospective cohort study

Background

Bone metastases in breast cancer patients are a common concern for medical doctors and dentists. Bone-modifying agents, which are necessary to prevent skeletal-related events (SREs), are associated with osteonecrosis of the jaw as an adverse side effect. Hypersensitivity to alcohol is an unfavorable response caused by deficiency of aldehyde dehydrogenase-2 (ALDH2) activity. Inactive ALDH2 is associated with osteoporosis, but its influence on bone metastases is unclear. The aim of our study was to evaluate the effects of alcohol sensitivity on bone metastases and SREs in primary operable breast cancer patients.

Methods

We retrospectively analyzed patients who were administered docetaxel, an anti-tumor agent, for histologically diagnosed breast cancer between April 2004 and September 2015. Alcohol sensitivity was assessed based on medical records of hypersensitivity to alcohol. The primary endpoint was time to bone metastases and the secondary endpoint was time to first SRE from the initial docetaxel administration. Data were stratified by alcohol sensitivity and tumor stages, and differences were estimated by the Kaplan-Meier method. Prognostic risk factors were analyzed by the multivariate Cox proportional hazards model.

Results

The median follow-up period of patients with high sensitivity to alcohol (n = 45) was 54 months and that for those with low sensitivity (n = 287) was 64 months. Stratification by alcohol sensitivity revealed that tumor stage exhibited significant correlations with the cumulative incidence of bone metastases in low-sensitivity patients; however, no differences were found in high-sensitivity patients. In multivariate analysis, alcohol sensitivity was a significant prognostic risk factor for bone metastases (HR 2.721, 95% CI 1.268–5.841, P = 0.010).

Conclusion

Alcohol sensitivity may be a prognostic risk factor for bone metastases. More detailed genetic investigations and metabolic analyses are needed.

Field Effect of Alcohol, Cigarette Smoking, and Their Cessation on the Development of Multiple Dysplastic Lesions and Squamous Cell Carcinoma: A Long-term Multicenter Cohort Study

Background and Aims

Multiple developments of squamous dysplasia and squamous cell carcinoma (SCC) in the upper aerodigestive tract have been explained by field cancerization phenomenon and were associated with alcohol and cigarette use. Second primary SCC development after curative treatment impairs patients' quality of life and survival; however, how these consumption and cessation affect field cancerization is still unknown.

Methods

This is a multicenter cohort study including 331 patients with superficial esophageal SCC (ESCC) treated endoscopically and pooled data from 1022 healthy subjects for comparison. Physiological condition in the background esophageal mucosa was classified into 3 groups based on the number of Lugol-voiding lesions (LVLs) per endoscopic view: grade A, 0; grade B, 1-9; or grade C, ≥10 LVLs. Lifestyle surveys were conducted using a self-administered questionnaire. Patients were counseled on the need for alcohol and smoking cessation by physicians and were endoscopically surveyed every 6 months.

Results

LVL grades were positively associated with alcohol drinking intensity, flushing reactions, smoking, and high-temperature food and were negatively associated with eating green and yellow vegetables and fruit. Second primary ESCC and head/neck SCC were significantly more prevalent in the grade C LVL (cumulative 5-y incidences 47.1%, 95% confidence interval [CI] = 38.0-57.2 and 13.3%, 95% CI = 8.1-21.5, respectively). Alcohol and smoking cessation significantly reduced the development of second primary ESCC (adjusted hazard ratios 0.47, 95% = CI 0.26-0.85 and 0.49, 95% CI = 0.26-0.91, respectively).

Conclusion

Alcohol drinking, smoking, flushing reaction, and high-temperature food were closely associated with field cancerization, and cessation of alcohol and smoking significantly reduced the risk of development of second primary cancer. UMIN Clinical Trials Registry ID:UMIN000001676.

Alcohol Consumption and Cigarette Smoking among Young Adults: An Instrumental Variable Analysis Using Alcohol Flushing

Association between drinking and smoking has remained controversial since the association between two studies were influenced by various confounding. Thus, our study aimed to explore the causal effect of alcohol consumption and cigarette smoking using alcohol flushing as an instrument variable, which is free from confounders. We analyzed cross-sectional survey data from 2500 Korean young adults (1600 men and 900 women). Alcohol flushing was strongly associated with log transformed alcohol consumption (F = 272). In men, alcohol non-flushers were 1.41 times (95% CI 1.28-1.55) more likely to smoke 100 cigarettes in their lifetime in logistic regression analysis. Alcohol non-flushers were also 1.3 times (95% CI 1.21-1.40) more likely to become daily smokers and 1.39 times (95% CI 1.27-1.51) more likely to be current smokers than alcohol flushers. However, in an IV analysis, no causal relationships between alcohol consumption and smoking status were found. Alcohol consumption, on the other hand, was causally associated with lowering nicotine dependence and former smoking in men. Alcohol consumption determined by alcohol flushing status does not appear to be causally linked to the smoking behavior of young adults. The relationship between alcohol consumption and nicotine dependence and smoking cessation needs further study.

Combinations of alcohol-induced flushing with genetic polymorphisms of alcohol and aldehyde dehydrogenases and the risk of alcohol dependence in Japanese men and women

OBJECTIVE

The risk of alcohol dependence (AD) in Japanese men and women was evaluated according to combinations of alcohol flushing and aldehyde dehydrogenase-2 (ALDH2, rs671) and alcohol dehydrogenase-1B (ADH1B, rs1229984) genotypes, all of which are known to determine AD susceptibility in Asians. Previous studies have focused on men, since women account for a smaller proportion of AD subjects.

METHODS

Case control studies were conducted between 3721 male and 335 female AD Japanese and 610 male and 406 female controls who were asked about their current or former tendency to experience facial flushing after drinking a glass of beer and underwent ALDH2 and ADH1B genotyping. The time at which alcohol-induced facial flushing tendencies had disappeared in former-flushing AD subjects was also evaluated.

RESULTS

Current alcohol flushing, the inactive ALDH2*1/*2 genotype, and the fast-metabolizing ADH1B*2 allele were less frequently found in the AD groups. Although alcohol flushing was strongly influenced by the ALDH2 and ADH1B genotypes, multiple logistic model showed that never or former flushing and the genotype combinations were independent strong risk factors of AD in men and women. Never or former flushing (vs. current flushing) markedly increased the odds ratios of AD in carriers of each of the ALDH2 and ADH1B genotype combinations. The temporal profiles for drinking and flushing in former-flushing AD subjects revealed that the flushing response disappeared soon after or before the start of habitual drinking during young adulthood, regardless of the ALDH2 genotype.

CONCLUSION

Although alcohol flushing is influenced by the ALDH2 and ADH1B genotypes, constitutional or acquired flushing tolerance is an independent susceptibility trait for AD. The combination of the alcohol flushing status and the ALDH2 and ADH1B genotypes can provide a better new strategy for AD risk assessment than the alcohol flushing status alone or the genotypes alone in Asian men and women.

Impacts of interactions between ADH1B and ALDH2 genotypes on alcohol flushing, alcohol reeking on the day after drinking, and age distribution in Japanese alcohol-dependent men

OBJECTIVE

This study sought to evaluate the impacts of interactions between the alcohol dehydrogenase-1B (rs1229984) genotype and the aldehyde dehydrogenase-2 (rs671) genotype on alcohol flushing, alcohol reeking on the day after drinking, and the age distribution in alcohol-dependent patients.

METHODS

The study subjects were 4107 Japanese alcohol-dependent men who underwent alcohol dehydrogenase-1B and aldehyde dehydrogenase-2 genotyping: 4051 patients were asked about their current or former tendency to experience facial flushing after drinking a glass of beer, and 969 patients were asked about whether they had ever been told that they reeked of alcohol more than 12 hours after they had stopped drinking.

RESULTS

Current, former, and never flushing were reported in 3.5, 14.9, and 81.5%, respectively, of the subject, and alcohol reeking after more than 12 hours in 36.1% of the subjects. The fast-metabolizing ADH1B*2(+) genotype (*1/*2 or *2/*2) and the inactive ALDH2*2(+) genotype (*1/*2 or *2/*2) affected the multivariate odds ratios for current or former flushing [odds ratio, 95% confidence interval = 2.27 (1.79-2.86) and 23.0 (18.6-28.5), respectively, vs. *2(-) genotype] and for alcohol reeking [0.39 (0.29-0.52) and 1.56 (1.09-2.25), respectively, vs. *2(-) genotype]. An age-dependent decrease in the ADH1B*2(-) and ALDH2*2(-) combination from 32.3% in the 30-39-year age group to 12.5% in the 70-79-year age group and an age-dependent increase in the ADH1B*2(+) and ALDH2*2(-) combination from 52.5% in the 30-39-year age group to 70.5% in the 70-79-year age group were observed (P < 0.0001 for trend). The frequencies of the ADH1B*2(-) and ALDH2*2(+) combination (4.7-6.2%) and the ADH1B*2(+) and ALDH2*2(+) combination (8.9-12.0%) did not change markedly with increasing age.

CONCLUSION

Interactions between the alcohol dehydrogenase-1B and aldehyde dehydrogenase-2 genotypes modified alcohol flushing, alcohol reeking on the day after drinking, and the age distribution. These findings support the protective roles of the ADH1B*2(+) and ALDH2*2(+) genotypes against the development of alcohol dependence.

Impact of alcohol drinking on cancer risk with consideration of flushing response: The Japan Public Health Center-based Prospective Study Cohort (JPHC study)

Alcohol drinking is a risk factor for cancer. The degree of risk is increased in subjects showing the flushing response, which is due to aldehyde dehydrogenase 2 (ALDH2) polymorphism. The attributable risk of alcohol drinking for cancer in Japan has not been sufficiently investigated with consideration of flushing response. We followed 78,825 Japanese in JPHC study cohort II. The association between alcohol consumption and cancer incidence was assessed according to self-reported flushing response using Cox proportional hazards regression models. The population-attributable fraction (PAF) of cancer incidence was also estimated. During 1993-2013 (average follow-up, 16.8 years), 8486 incident cancers (included 4386 alcohol-related cancers) were reported. Half of men and 36% of women had flushing response. In men with flushing response, moderate or higher alcohol drinking increased the risk of alcohol-related cancers compared with non-drinkers (150-299 g/week, HR 1.63, 95% CI, 1.43-1.99; 300-449 g/week, HR 2.02 95% CI, 1.67-2.44; ≥450 g/week, HR 1.75, 95% CI, 1.39-2.21). When flushing response was considered in comparisons between non-drinkers and non-flushers, non-flushing heavy drinkers had a slightly higher PAF than flushers (all cancers: flushers, 2.0% and non-flushers, 2.2%; alcohol-related cancers: flushers, 3.8% and non-flushers, 5.8%). Although the risk of alcohol-related cancer in men with flushing response increased with increasing alcohol consumption, heavy drinkers were also at high risk regardless of flushing response. Considering the PAF of alcohol consumption on cancer, efforts to discourage heavy alcohol consumption to reduce the incidence of alcohol-related cancers appear warranted regardless of flushing response.

Endoscopic screening using esophageal iodine staining and genotypes of ADH1B and ALDH2 in Japanese alcohol-dependent women

BACKGROUND

The presence of large or multiple esophageal distinct iodine-unstained lesions (DIULs) is a strong predictor of field cancerization in the upper aerodigestive tract. Several risk factors for DIULs, including genetic polymorphisms of alcohol and aldehyde dehydrogenases (ADH1B, rs1229984; ALDH2, rs671), have been demonstrated in Japanese alcohol-dependent men. However, few evaluations of alcohol-dependent women have been conducted in this field.

METHODS

Using multiple logistic regression models, we investigated the results of screening using esophageal iodine staining and the identification of determinants for esophageal DIULs in 472 Japanese alcohol-dependent women.

RESULTS

DIULs ≥5 mm, multiple DILUs, and both characteristics were observed in 35 (7.4%), 31 (6.6%), and 16 (3.4%) patients, respectively. DIULs ≥5 mm were histologically diagnosed as low-grade intraepithelial neoplasia in 26 patients and superficial squamous cell carcinoma in 9 patients. Although the inactive heterozygous ALDH2*1/*2 genotype was more common (33.3% vs. 11.4%, p = 0.002) in the group with DIULs ≥5 mm than in the group without DIULs ≥5 mm, no significant differences in the results of a questionnaire asking about current and past facial flushing after a glass of beer were seen between the groups with and without DIULs ≥5 mm. When individuals with current or former flushing were assumed to have inactive ALDH2, the sensitivity and specificity of current or former flushing to identify the presence of inactive ALDH2 were 50.0% and 93.5%, respectively; these values were previously reported to be 88% and 92%, respectively, in a Japanese general female population. The low sensitivity in the present study suggests that a lack of alcohol flushing may play a crucial role in the development of alcohol dependence in women with inactive ALDH2. No significant differences in age, usual alcohol consumption, or smoking habits were observed according to ADH1B and ALDH2 genotypes. Multiple logistic regression analyses showed that the slow-metabolizing ADH1B*1/*1 genotype (odds ratio [95% confidence interval], 12.5 [4.82-32.4] and 9.89 [3.50-27.9]), the inactive heterozygous ALDH2*1/*2 genotype (2.94 [1.18-7.38] and 3.79 [1.40-10.3]), a lower body mass index per -1 kg/m2 (1.17 [1.02-1.35] and 1.38 [1.14-1.67]), and a mean corpuscular volume ≥106 fl (3.70 [1.56-8.81] and 3.27 [1.24-8.64]) increased the risk of DIULs ≥5 mm and multiple DIULs, respectively. The combination of ADH1B*1/*1 and ALDH2*1/*2 markedly increased the risk of esophageal DIULs ≥5 mm (39.3 [10.6-146]).

CONCLUSIONS

Japanese alcohol-dependent women shared several common risk factors for esophageal squamous cell neoplasia with alcohol-dependent men, but with considerably different magnitudes.

Alcohol and coronary artery calcification: an investigation using alcohol flushing as an instrumental variable

Background

We examined whether alcohol flushing could be used as an instrumental variable (IV) and investigated the effect of alcohol consumption on coronary calcification using alcohol flushing status as an IV.

Methods

We analysed cross-sectional data from 24 681 Korean adults (20 696 men and 3985 women) who had been administered a questionnaire assessing alcohol consumption and alcohol flushing, as well as a coronary artery calcium (CAC) measurement. The associations of alcohol flushing status with potential confounders and alcohol consumption were examined. We employed two-stage predictor substitution methodology for the IV analysis.

Results

The prevalence of alcohol flushing did not differ depending on gender, education, household income, cigarette smoking or physical activity. Balanced levels of confounders were observed between alcohol flushers and non-flushers. Alcohol flushing was closely related to alcohol consumption and levels of liver enzymes. In men, a doubling in alcohol consumption was associated with increased odds of coronary calcification in both the IV analysis [odds ratio (OR) of CAC scores of 1 or over = 1.11; 95% confidence interval (CI) = 1.03-1.20) and the multivariable regression analysis (OR = 1.04; 95% CI = 1.01-1.07). For cardiovascular risk factors, the IV analysis showed a positive association between alcohol consumption and blood pressure and high-density lipoprotein-cholesterol.

Conclusions

Alcohol flushing can be used as an IV in studies evaluating the health impact of alcohol consumption, especially in East Asian countries. Through such an analysis, we found that increased alcohol consumption was associated with an increased risk of subclinical coronary atherosclerosis.

Association of low-activity ALDH2 and alcohol consumption with risk of esophageal cancer in Chinese adults: A population-based cohort study

Existing evidence remains inconclusive as to how the association between inactive ALDH2 and esophageal cancer (EC) depends on alcohol consumption. The study is based on the China Kadoorie Biobank cohort, with 10 years follow‐up of 0.5 million adults aged 30–79 years. ALDH2 activity was assessed by both self‐reported flushing response and Glu504Lys (rs671 G > A) polymorphism. Among both male and female participants who consumed alcohol less than weekly (n = 69,519; 211 EC cases), low active or inactive ALDH2 was not associated with increased EC risk [HRs (95% CIs): GA vs. GG 0.75 (0.54, 1.04); AA vs. GG 1.01 (0.46, 2.20)]. Among male weekly alcohol consumers, both flushing response [n = 59,380; 501 EC cases; HRs (95% CIs): “soon after drinking” vs. “no” flushing response 1.45 (1.05, 2.01)] and rs671 [n = 10,692; 94 EC cases; GA vs. GG 3.31 (1.94, 5.67)] were associated with EC risk. The increased EC risk associated with “soon” response or rs671 GA was apparent in men consuming alcohol ≥30g/d. Among male daily consumers, the HRs (95% CIs) for EC associated with 15g/d of alcohol were 1.28 (1.15, 1.44) for “soon” response [vs. other responses: 1.12 (1.09, 1.15); p_interaction = 0.047; n = 36,401, 425 EC cases] and 1.41 (1.08, 1.82) for rs671 GA [vs. GG: 1.16 (1.06, 1.27); p_interaction = 0.493; n = 6,607, 80 EC cases]. Self‐reported flushing response had low sensitivity (56.8%) and high specificity (88.4%) in identifying rs671 A allele among male weekly alcohol consumers. In conclusion, low‐activity ALDH2 was associated with increased EC risk among male heavy alcohol consumers. More accurate measurement of alcohol‐related EC risk allows better achievement of precision prevention.

What's new?

Acetaldehyde is a toxic metabolite considered a major cause of alcohol‐induced carcinogenesis. The key enzyme for acetaldehyde elimination is acetaldehyde dehydrogenase 2 (ALDH2), and an association between ALDH2 genotype and EC risk that is dependent on alcohol consumption has been suggested. The evidence remains inconclusive, however. In this large prospective cohort of Chinese adults, the ALDH2 rs671 A allele was not associated with increased EC risk in the absence of alcohol consumption. The increased EC risk associated with low‐activity ALDH2, characterized as self‐reported flushing response or rs671 GA, was apparent in men consuming alcohol ≥30g/day, but not among light‐to‐moderate consumers.

Development of a prediction model and estimation of cumulative risk for upper aerodigestive tract cancer on the basis of the aldehyde dehydrogenase 2 genotype and alcohol consumption in a Japanese population

Alcohol consumption and the aldehyde dehydrogenase 2 (ALDH2) polymorphism are associated with the risk of upper aerodigestive tract cancer, and a significant gene-environment interaction between the two has been confirmed in a Japanese population. To aid the development of a personalized prevention strategy, we developed a risk-prediction model and estimated absolute risks stratified by a combination of the ALDH2 genotype and alcohol consumption. We carried out two age-matched and sex-matched case-control studies: one (630 cases and 1260 controls) for model derivation and the second (654 cases and 654 controls) for external validation. On the basis of data from the derivation study, a prediction model was developed by fitting a conditional logistic regression model using the following predictors: age, sex, smoking, drinking, and the ALDH2 genotype. The risk model, including a combination of the ALDH2 genotype and alcohol consumption, provided high discriminatory accuracy and good calibration in both the derivation and the validation studies: C statistics were 0.82 (95% confidence interval 0.80-0.84) and 0.83 (95% confidence interval 0.81-0.85), respectively, and the calibration plots of both studies remained close to the ideal calibration line. Cumulative risks were obtained by combining odds ratios estimated from the risk model with the age-specific incidence rate and population size. For heavy drinkers with a heterozygous genotype, the cumulative risk at age 80 was above 20%. In contrast, risk in the other groups was less than 5%. In conclusion, modification of alcohol consumption according to the ALDH2 genotype will have a major impact on upper aerodigestive tract cancer prevention. These findings represent a simple and practical model for personalized cancer prevention.

Exploring the utility of alcohol flushing as an instrumental variable for alcohol intake in Koreans

Previous studies have indicated an association of higher alcohol intake with cardiovascular disease and related traits, but causation has not been definitively established. In this study, the causal effect of alcohol intake on hypertension in 2,011 men and women from the Ansan-Ansung cohort was estimated using an instrumental variable (IV) approach, with both a phenotypic and genotypic instrument for alcohol intake: alcohol flushing and the rs671 genotype (in the alcohol dehydrogenase 2 [ALDH2] gene), respectively. Both alcohol flushing and the rs671 genotype were associated with alcohol intake (difference in alcohol intake with alcohol flushers vs. non-flushers: −9.07 g/day; 95% confidence interval [CI]: −11.12, −7.02; P-value: 8.3 × 10⁻¹⁸ and with the rs671 GA + AA vs. GG genotype: −7.94 g/day; 95% CI: −10.20, −5.69; P-value: 6.1 × 10⁻¹²). An increase in alcohol intake, as predicted by both the absence of alcohol flushing and the presence of the rs671 GG genotype in the IV analyses, was associated with an increase in blood pressure in men from this Korean population. In conclusion, this study supports a causal effect of alcohol intake on hypertension and indicated that alcohol flushing may be a valid proxy for the ALDH2 rs671 polymorphism, which influences alcohol intake in this Korean population.

Alcohol metabolism and oesophageal cancer: a systematic review of the evidence

Alcohol is a major risk factor for oesophageal squamous cell carcinoma (OSCC), the most prevalent histological subtype of oesophageal cancer (OC) worldwide. The metabolism of alcohol is regulated by specific enzymes whose activity and expression is influenced by genetic polymorphisms. We conducted a systematic review of current epidemiological evidence of the relationship between alcohol intake and OC risk, including the role of tobacco smoking and functional polymorphisms of alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases (ALDHs). Potential biological mechanisms underlying oesophageal carcinogenesis are also discussed. Frequency and intensity of alcohol intake have been consistently associated with an increased risk of OSCC in regions with low and high incidence of the disease. The highest risk was reported among tobacco smokers, whereas the association between alcohol and OSCC risk was weak in the absence of tobacco use. The ADH1B, ADH1C and ALDH2 gene polymorphisms influence the risk of OSCC through modulation of acetaldehyde metabolism and propensity to alcohol intake. These functional variants may be suitable proxies of alcohol exposure for use in Mendelian randomization studies if complemented by reported alcohol intake data. Recent epidemiological and experimental studies investigating the role of alcohol consumption in OC development have implicated the microbiome as a new promising avenue for research, which entail novel potential mechanisms of alcohol-related oesophageal carcinogenesis. Microbial communities associated with alcohol consumption might be used as biomarkers to raise the potential of intervening among susceptible individuals.

Alcohol abstinence and risk assessment for second esophageal cancer in Japanese men after mucosectomy for early esophageal cancer

BACKGROUND

Alcohol consumption combined with inactive aldehyde dehydrogenase-2 (ALDH2) and the presence of multiple esophageal Lugol-voiding lesions (LVLs; dysplasia) are strong predictors for multiple development of esophageal squamous cell carcinoma (ESCC) in East Asians. We invented a health risk appraisal (HRA) model for predicting the risk of ESCC based on drinking, smoking, dietary habits, and alcohol flushing, i.e., past or present facial flushing after drinking a glass of beer, a surrogate marker for inactive ALDH2.

METHODS

Prospective follow-up examinations (median follow-up time, 50.3 months) were performed in 278 Japanese men after endoscopic mucosectomy for early ESCC (UMIN Clinical Trials Registry ID: UMIN000001676).

RESULTS

Sixty-four subjects developed metachronous ESCC. A receiver operating characteristic curve showed that HRA scores ≥12 best predicted the development of metachronous ESCC. The ESCC detection rate per 100 person-years was 9.8 in the high-HRA-score group (n = 104) and 4.5 in the low-HRA-score group (n = 174), and the risk of development of metachronous ESCC was higher in the high-HRA-score group than in the low-HRA-score group (adjusted hazard ratio: 2.00 [95% CI: 1.12-3.30]). Multiple LVLs was a very strong predictor of the development of metachronous SCC, but high HRA scores predicted it independently. The cumulative incidences of metachronous ESCC decreased after drinking cessation in the high-HRA-score drinker group (adjusted hazard ratio: 0.37 [0.14-0.97]).

CONCLUSIONS

Both the HRA model that included alcohol flushing and the multiple LVL grade predicted the development of metachronous ESCC in Japanese men after endoscopic mucosectomy for ESCC. Drinking cessation in the high-HRA-score drinker group reduced the rate of metachronous ESCC.

ALDH2-deficiency as genetic epidemiologic and biochemical model for the carcinogenicity of acetaldehyde

Humans are cumulatively exposed to acetaldehyde from various sources including alcoholic beverages, tobacco smoke, foods and beverages. The genetic-epidemiologic and biochemical evidence in ALDH2-deficient humans provides strong evidence for the causal relationship between acetaldehyde-exposure due to alcohol consumption and cancer of the upper digestive tract. The risk assessment has so far relied on thresholds based on animal toxicology with lower one-sided confidence limit of the benchmark dose values (BMDL) typically ranging between 11 and 63 mg/kg bodyweight (bw)/day dependent on species and endpoint. The animal data is problematic for regulatory toxicology for various reasons (lack in study quality, problems in animal models and appropriateness of endpoints - especially cancer - for transfer to humans). In this study, data from genetic epidemiologic and biochemical studies are reviewed. The increase in the daily exposure dose to acetaldehyde in alcohol-consuming ALDH2-deficients vs. ALDH2-actives was about twofold. The acetaldehyde increase due to ALDH2 inactivity was calculated to be 6.7 μg/kg bw/day for heavy drinkers, which is associated with odds ratios of up to 7 for head and neck as well as oesophageal cancer. Previous animal toxicology based risk assessments may have underestimated the risk of acetaldehyde. Risk assessments of acetaldehyde need to be revised using this updated evidence.

Facial flushing after alcohol consumption and the risk of cancer: A meta-analysis

BACKGROUND

The association between facial flushing after alcohol consumption and the risk of cancer remains controversial. The aim of this study was to evaluate the relation between facial flushing and cancer risk.

METHODS

PubMed, EMBASE, and Cochrane Library were searched for relevant literature. The patients' baseline characteristics and estimated risks were extracted. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled to estimate the risk of facial flushing in cancer, and subgroup analysis was performed.

RESULTS

Ten studies with 89,376 participants from East Asia were included. The pooled OR of facial flushing in all cancers was 1.43 (95% CI, 1.08-1.91), with the pooled ORs of 1.94 (95% CI, 1.33-2.83) and 0.95 (95% CI, 0.80-1.12) in men and women, respectively. The pooled ORs were also estimated in different cancer types.

CONCLUSION

Our results showed that facial flushing response to alcohol was associated with higher cancer risk in men in East Asia, especially in esophageal squamous cell carcinoma, yet facial flushing was not significantly associated with cancer risk among women.

The allele frequency of ALDH2*Glu504Lys and ADH1B*Arg47His for the Ryukyu islanders and their history of expansion among East Asians

OBJECTIVES

A cline of frequencies of the derived allele of the ALDH2 gene, which causes a deficiency of an enzyme and "facial flushing" in humans who drink alcohol, has been known among the people of the Japanese archipelago. This cline is conventionally explained by admixture with immigrants from the Asian continent occurring during the Yayoi period. Previous studies lack sufficient data from the peripheral regions of the indigenous Jomon people, and those data the ADH1B gene that is involved in the Class I ADH gene cluster and contains another variant leading to a functional change.

METHODS

We focused on the southwestern-most people from the Ryukyu Islands (n = 218) and those from northern Kyushu (n = 21) where the Yayoi immigrants likely arrived. We investigated both the Class I ADH and ALDH2 loci, as well as neutral genetic markers.

RESULTS

In the Ryukyu Islands, the frequencies of the ancestral alleles in both loci were always higher than those in mainland Japan, while the frequencies of ADH1B were less than those of the derived allele. A haplotype block was not observed in ALDH2 but was in Class I ADH.

DISCUSSION

Our data suggest that the derived allele of ALDH2 came with the Yayoi immigrants from the Asian continent to the Japanese archipelago. However, the derived allele of ADH1B is unlikely to be related to the Yayoi migration. Therefore, we postulate that the expansion of the derived allele of ADHIB in East Asia could be traced back to the last glacial period.

Facial flushing response to alcohol and the risk of esophageal squamous cell carcinoma: A comprehensive systematic review and meta-analysis

OBJECTIVE

The alcohol flushing response is common among ethnic East Asian populations, and has been associated with an increased risk in developing esophageal cancer, especially squamous cell esophageal cancer (ESCC). We aimed to quantify the relationship between the facial flushing response to alcohol consumption and ESCC.

METHODS

We conducted a meta-analysis of studies reporting on the association between the facial flushing response to alcohol consumption and ESCC. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated using a random effects model for the risk of ESCC associated with the facial flushing response in general, as well for different levels of alcohol consumption. Four databases, Medline, PubMed, Embase, and Current Contents Connect, were searched to 31 August 2015.

RESULTS

Seven studies, with 1014 ESCC cases, met the inclusion criteria. There was a positive relationship between the flushing response and ESCC (OR 1.97; 95% CI 1.25-3.13). Heterogeneity was observed (I(2)= 80%, P<0.001). Publication bias was not present. An increased risk of ESCC was present in the moderate and heavy drinkers who experienced flushing, compared with moderate and heavy drinkers who did not (OR 2.54; 95% CI 1.64-3.91, and OR 2.90; 95% CI 1.82-4.82, respectively).

CONCLUSION

Individuals who experience a facial flushing response to alcohol intake may be at increased risk of developing ESCC, particularly if they are moderate to heavy drinkers.

Estimates of alcohol-related oesophageal cancer burden in Japan: systematic review and meta-analyses

OBJECTIVE

To refine estimates of the burden of alcohol-related oesophageal cancer in Japan.

METHODS

We searched PubMed for published reviews and original studies on alcohol intake, aldehyde dehydrogenase polymorphisms, and risk for oesophageal cancer in Japan, published before 2014. We conducted random-effects meta-analyses, including subgroup analyses by aldehyde dehydrogenase variants. We estimated deaths and loss of disability-adjusted life years (DALYs) from oesophageal cancer using exposure distributions for alcohol based on age, sex and relative risks per unit of exposure.

FINDINGS

We identified 14 relevant studies. Three cohort studies and four case-control studies had dose-response data. Evidence from cohort studies showed that people who consumed the equivalent of 100 g/day of pure alcohol had an 11.71 fold, (95% confidence interval, CI: 2.67-51.32) risk of oesophageal cancer compared to those who never consumed alcohol. Evidence from case-control studies showed that the increase in risk was 33.11 fold (95% CI: 8.15-134.43) in the population at large. The difference by study design is explained by the 159 fold (95% CI: 27.2-938.2) risk among those with an inactive aldehyde dehydrogenase enzyme variant. Applying these dose-response estimates to the national profile of alcohol intake yielded 5279 oesophageal cancer deaths and 102,988 DALYs lost - almost double the estimates produced by the most recent global burden of disease exercise.

CONCLUSION

Use of global dose-response data results in an underestimate of the burden of disease from oesophageal cancer in Japan. Where possible, national burden of disease studies should use results from the population concerned.

Clinical significance of ALDH2 rs671 polymorphism in esophageal cancer: evidence from 31 case-control studies

Background

Aldehyde dehydrogenase 2 (ALDH2), a critical enzyme for the detoxification of alcohol, is associated with many types of cancers. To verify the relationship of ALDH2 rs671 G>A polymorphism and esophageal cancer (EC), we performed a meta-analysis of a total of 31 published data including 8,510 patients and 16,197 controls.

Methods

The pooled odds ratio (OR) and the 95% confidence interval (CI) were calculated using a fixed or random-effects model. Heterogeneity (P_H), publication bias, and sensitivity analysis were also determined.

Results

Although a protective effort was found in the rs671 homozygote comparison (AA/GG: OR=0.69; 95% CI=0.48–0.98), the heterozygote comparison was apparently associated with the risk of EC, particularly in the Chinese population (AG/GG: OR=1.39; 95% CI=1.03–1.87). Alcohol consumption remarkably increased this risk, especially in the AG genotype. Drinking men with the AG genotype appeared to show a higher risk (AG/GG: OR=4.39; 95% CI=1.24–6.55) than drinking women.

Conclusion

The present meta-analysis provided advanced information regarding the association of the ALDH2 A>G polymorphism and EC. Taken together, insights from this study suggested an enhanced effect on the development of EC through a genetic–environmental interaction.

Genetic polymorphisms of alcohol dehydrogense-1B and aldehyde dehydrogenase-2, alcohol flushing, mean corpuscular volume, and aerodigestive tract neoplasia in Japanese drinkers

Genetic polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) modulate exposure levels to ethanol/acetaldehyde. Endoscopic screening of 6,014 Japanese alcoholics yielded high detection rates of esophageal squamous cell carcinoma (SCC; 4.1%) and head and neck SCC (1.0%). The risks of upper aerodigestive tract SCC/dysplasia, especially of multiple SCC/dysplasia, were increased in a multiplicative fashion by the presence of a combination of slow-metabolizing ADH1B*1/*1 and inactive heterozygous ALDH2*1/*2 because of prolonged exposure to higher concentrations of ethanol/acetaldehyde. A questionnaire asking about current and past facial flushing after drinking a glass (≈180 mL) of beer is a reliable tool for detecting the presence of inactive ALDH2. We invented a health-risk appraisal (HRA) model including the flushing questionnaire and drinking, smoking, and dietary habits. Esophageal SCC was detected at a high rate by endoscopic mass-screening in high HRA score persons. A total of 5.0% of 4,879 alcoholics had a history of (4.0%) or newly diagnosed (1.0%) gastric cancer. Their high frequency of a history of gastric cancer is partly explained by gastrectomy being a risk factor for alcoholism because of altered ethanol metabolism, e.g., by blood ethanol level overshooting. The combination of H. pylori-associated atrophic gastritis and ALDH2*1/*2 showed the greatest risk of gastric cancer in alcoholics. High detection rates of advanced colorectal adenoma/carcinoma were found in alcoholics, 15.7% of 744 immunochemical fecal occult blood test (IFOBT)-negative alcoholics and 31.5% of the 393 IFOBT-positive alcoholics. Macrocytosis with an MCV≥106 fl increased the risk of neoplasia in the entire aerodigestive tract of alcoholics, suggesting that poor nutrition as well as ethanol/acetaldehyde exposure plays an important role in neoplasia.

Flushing response modifies the association of alcohol consumption with markers of glucose metabolism in Japanese men and women

BACKGROUND

Influences of alcohol use on glucose metabolism may depend on alcohol flushing response. We investigated the effect of alcohol flushing response on the associations between alcohol consumption and markers of glucose metabolism in Japanese men and women.

METHODS

The subjects were 979 employees (885 men and 94 women), aged 18 to 69 years, of a manufacturing company in Japan. Flushing response and alcohol consumption were determined using a self-administered questionnaire. Homeostasis model assessment-insulin resistance (HOMA-IR) and homeostasis model assessment for β-cell function (HOMA-β) were computed using fasting plasma glucose and insulin. For each group of flushers and nonflushers, multiple regression analysis was used to estimate means of fasting plasma glucose, hemoglobin A1c (HbA1c), and HOMAs for each category of alcohol consumption, with adjustments for potential confounders.

RESULTS

In flushers, alcohol consumption was associated with HbA1c levels in a U-shaped manner, with the lowest HbA1c levels being observed at an alcohol consumption level of 23.0 to <34.5 g ethanol/d (p for quadratic trend = 0.002). In nonflushers, alcohol consumption was linearly and inversely associated with HbA1c levels (p for linear trend = 0.001). Decreases in HbA1c were more evident among flushers compared with nonflushers at moderate alcohol consumption levels (p for interaction = 0.049). An increase of fasting glucose associated with highest alcohol consumption was observed in both flushers and nonflushers. A statistically significant decrease in HOMA-IR with increasing alcohol consumption was observed in flushers (p for trend = 0.007), whereas HOMA-IR levels slightly decreased at higher alcohol consumption in nonflushers. HOMA-β similarly decreased with increasing alcohol consumption in both flushers and nonflushers (both p for trend < 0.001).

CONCLUSIONS

The results suggest that the alcohol flushing response may improve glucose metabolism and insulin resistance at moderate alcohol use levels in apparently healthy Japanese adults.

Genetics and alcoholism

Alcohol is widely consumed; however, excessive use creates serious physical, psychological and social problems and contributes to the pathogenesis of many diseases. Alcohol use disorders (that is, alcohol dependence and alcohol abuse) are maladaptive patterns of excessive drinking that lead to serious problems. Abundant evidence indicates that alcohol dependence (alcoholism) is a complex genetic disease, with variations in a large number of genes affecting a person's risk of alcoholism. Some of these genes have been identified, including two genes involved in the metabolism of alcohol (ADH1B and ALDH2) that have the strongest known affects on the risk of alcoholism. Studies continue to reveal other genes in which variants affect the risk of alcoholism or related traits, including GABRA2, CHRM2, KCNJ6 and AUTS2. As more variants are analysed and studies are combined for meta-analysis to achieve increased sample sizes, an improved picture of the many genes and pathways that affect the risk of alcoholism will be possible.

Genetic variants at 4q23 and 12q24 are associated with head and neck cancer risk in China

A recent genome-wide association study (GWAS) reported significant associations of several novel genetic variants with risk of upper aerodigestive tract (UADT) cancers including head and neck cancer (HNC) in Europeans. However, these findings have not been confirmed in other populations including Chinese. According to the findings from the GWAS and other publications, we genotyped six genetic variants (rs1494961, rs1229984, rs1789924, rs971074, rs4767364, and rs671) in a case-control study with 397 HNC cases and 900 controls in China, by using the TaqMan allelic discrimination assay. We found that rs1229984 at 4q23 significantly increased the risk of HNC [dominant model: adjusted odds ratio (OR) = 1.34, 95% confidence interval (CI) = 1.05-1.71; additive model: adjusted OR = 1.24, 95% CI = 1.04-1.50], while rs671 at 12q24 significantly decreased the risk of HNC (recessive model: adjusted OR = 0.46, 95% CI = 0.25-0.85). Furthermore, when these two loci were evaluated together by the number (0-4) of putative risk alleles (rs1229984 G and rs671 G), a significant locus-dosage effect was found between the groups and risk of HNC (Ptrend  = 0.016). Compared with the "0-1" group, groups with "2" risk alleles and "3-4" risk alleles significantly increased the risk of HNC with adjusted ORs of 1.17 (95% CI = 0.84-1.64) and 1.51 (95% CI = 1.06-2.15), respectively. However, no significant association was detected between other four variants (rs1494961, rs1789924, rs971074, and rs4767364) and HNC risk. These findings suggest that rs1229984 at 4q23 and rs671 at 12q24 may serve as candidate markers for susceptibility to HNC in Chinese population.

Interactions between migraine and tension-type headache and alcohol drinking, alcohol flushing, and hangover in Japanese

The aim of the study was to investigate associations between headache types and alcohol drinking, alcohol flushing, and hangover. Alcohol consumption is inhibited by the presence of inactive aldehyde dehydrogenase-2 (ALDH2) whose carriers are susceptible to alcohol flushing and hangovers. We conducted a cross-sectional study of the 2,577 subjects (men/women: 1,018/1,559) who reported having ever experienced headaches unrelated to common colds and alcohol hangovers among 5,408 (2,778/2,630) Tokyo health checkup examinees. We used a questionnaire inquiring about current and past facial flushing after drinking a glass of beer which identifies the presence of inactive ALDH2 with a sensitivity and specificity of approximately 90%. Based on ICHD-II criteria migraine was diagnosed in 419 (75/344) subjects, and tension-type headache (TTH) in 613 (249/364). We classified the headaches of the remaining 1,545 (694/851) of headaches sufferers into the category "other headaches (OH)". The migraineurs drank alcohol less frequently than the subjects with TTH among current/past alcohol flushers and than the subjects with OH regardless of flushing category. No such difference in drinking frequency was observed between TTH and OH. Current/past flushers drank alcohol less frequently than never flushers, and the likelihood that male migraineurs would avoid alcohol drinking than men with TTH or OH was stronger among current/past flushers than among never flushers. Flushers and women were more susceptible to hangover than never flushers and men, respectively, regardless of headache type. Among never flushers, women with migraine were more susceptible to hangover than women with OH. The difference in alcohol sensitivity may partly explain less alcohol consumption by migraineurs.

Cigarette smoking and esophageal cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population

OBJECTIVE

Although cigarette smoking is considered as an important risk factor for esophageal cancer, the magnitude of the association might be varied among geographic areas. Therefore, we reviewed epidemiologic studies on the association between cigarette smoking and esophageal cancer among the Japanese population.

METHODS

Original articles were obtained from MEDLINE searched using PubMed or from searches of the Ichushi database, complemented by manual searches. Evaluation of associations was based on the strength of evidence ('convincing', 'probable', 'possible' or 'insufficient') and the magnitude of association ('strong', 'moderate', 'weak' or 'no association'), together with biological plausibility as previously evaluated by the International Agency for Research on Cancer.

RESULTS

We identified four cohort studies and 11 case-control studies. All cohort studies and eight case-control studies showed strong positive associations between esophageal cancer and cigarette smoking. All cohort studies and five case-control studies showed that cigarette smoking had dose-response relationships with esophageal cancer. Meta-analysis of 12 studies indicated that the summary estimate for ever smokers relative to never smokers was 3.01 (95% confidence interval: 2.30-3.94). Summary relative risk for current and former smokers relative to never smokers was 3.73 (2.16-6.43) and 2.21 (1.60-3.06), respectively.

CONCLUSIONS

We conclude that there is convincing evidence that cigarette smoking strongly increases the risk of esophageal cancer in the Japanese population.

Multi-susceptibility genes associated with the risk of the development stages of esophageal squamous cell cancer in Feicheng County

BACKGROUND

The purpose of this study was to evaluate the association of multi-genotype polymorphisms with the stepwise progression of esophageal squamous cell cancer (ESCC) and the possibility of predicting those at higher risk.

METHODS

A total of 1,004 subjects were recruited from Feicheng County, China, between Jan. 2004 and Dec. 2007 and examined by endoscopy for esophageal lesions. These subjects included 270 patients with basal cell hyperplasia (BCH), 262 patients with esophageal squamous cell dysplasia (ESCD), 226 patients with ESCC, and 246 controls with Lugol-voiding area but diagnosed as having normal esophageal squamous epithelial cells by histopathology. The genotypes for CYP2E1 G1259C, hOGG1 C326G, MTHFR C677T, MPO G463A, and ALDH2 allele genes were identified in blood samples collected from all participants.

RESULTS

The alleles ALDH2 and MTHFR C677T were critical for determining individual susceptibility to esophageal cancer. Compared to the ALDH 1*1 genotype, the ALDH 2*2 genotype was significantly associated with increased risks of BCH, ESCD, and ESCC. However, the TT genotype of MTHFR C677T only increased the risk of ESCC. Further analysis revealed that the combination of the high-risk genotypes 2*2/1*2 of ALDH 2 and TT/TC of MTHFR C677T increased the risk of BCH by 4.0 fold, of ESCD by 3.7 fold, and ESSC by 8.72 fold. The generalized odds ratio (ORG) of the two combined genotypes was 1.83 (95%CI: 1.55-2.16), indicating a strong genetic association with the risk of carcinogenic progression in the esophagus.

CONCLUSIONS

The study demonstrated that the genotypes ALDH2*2 and MTHFR 677TT conferred elevated risk for developing esophageal carcinoma and that the two susceptibility genotypes combined to synergistically increase the risk.

Multi-susceptibility genes associated with the risk of the development stages of esophageal squamous cell cancer in Feicheng County

Background

The purpose of this study was to evaluate the association of multi-genotype polymorphisms with the stepwise progression of esophageal squamous cell cancer (ESCC) and the possibility of predicting those at higher risk.

Methods

A total of 1,004 subjects were recruited from Feicheng County, China, between Jan. 2004 and Dec. 2007 and examined by endoscopy for esophageal lesions. These subjects included 270 patients with basal cell hyperplasia (BCH), 262 patients with esophageal squamous cell dysplasia (ESCD), 226 patients with ESCC, and 246 controls with Lugol-voiding area but diagnosed as having normal esophageal squamous epithelial cells by histopathology. The genotypes for CYP2E1 G1259C, hOGG1 C326G, MTHFR C677T, MPO G463A, and ALDH2 allele genes were identified in blood samples collected from all participants.

Results

The alleles ALDH2 and MTHFR C677T were critical for determining individual susceptibility to esophageal cancer. Compared to the ALDH 1*1 genotype, the ALDH 2*2 genotype was significantly associated with increased risks of BCH, ESCD, and ESCC. However, the TT genotype of MTHFR C677T only increased the risk of ESCC. Further analysis revealed that the combination of the high-risk genotypes 2*2/1*2 of ALDH 2 and TT/TC of MTHFR C677T increased the risk of BCH by 4.0 fold, of ESCD by 3.7 fold, and ESSC by 8.72 fold. The generalized odds ratio (OR_G) of the two combined genotypes was 1.83 (95%CI: 1.55-2.16), indicating a strong genetic association with the risk of carcinogenic progression in the esophagus.

Conclusions

The study demonstrated that the genotypes ALDH2*2 and MTHFR 677TT conferred elevated risk for developing esophageal carcinoma and that the two susceptibility genotypes combined to synergistically increase the risk.

Alcohol and aldehyde dehydrogenase polymorphisms and a new strategy for prevention and screening for cancer in the upper aerodigestive tract in East Asians

The ethanol in alcoholic beverages and the acetaldehyde associated with alcohol consumption are Group 1 human carcinogens (WHO, International Agency for Research on Cancer). The combination of alcohol consumption, tobacco smoking, the inactive heterozygous aldehyde dehydrogenase-2 genotype (ALDH2*1/*2) and the less-active homozygous alcohol dehydrogenase-1B genotype (ADH1B*1/*1) increases the risk of squamous cell carcinoma (SCC) in the upper aerodigestive tract (UADT) in a multiplicative fashion in East Asians. In addition to being exposed to locally high levels of ethanol, the UADT is exposed to a very high concentration of acetaldehyde from a variety of sources, including that as an ingredient of alcoholic beverages per se and that found in tobacco smoke; acetaldehyde is also produced by salivary microorganisms and mucosal enzymes and is present as blood acetaldehyde. The inefficient degradation of acetaldehyde by weakly expressed ALDH2 in the UADT may be cri! tical to the local accumulation of acetaldehyde, especially in ALDH2*1/*2 carriers. ADH1B*1/*1 carriers tend to experience less intense alcohol flushing and are highly susceptible to heavy drinking and alcoholism. Heavy drinking by persons with the less-active ADH1B*1/*1 leads to longer exposure of the UADT to salivary ethanol and acetaldehyde. The ALDH2*1/*2 genotype is a very strong predictor of synchronous and metachronous multiple SCCs in the UADT. High red cell mean corpuscular volume (MCV), esophageal dysplasia, and melanosis in the UADT, all of which are frequently found in ALDH2*1/*2 drinkers, are useful for identifying high-risk individuals. We invented a simple flushing questionnaire that enables prediction of the ALDH2 phenotype. New health appraisal models that include ALDH2 genotype, the simple flushing questionnaire, or MCV are powerful tools for devising a new strategy for prevention and screening for UADT cancer in East Asians.

Alcohol drinking and esophageal squamous cell carcinoma with focus on light-drinkers and never-smokers: a systematic review and meta-analysis

Quantification of the association between alcohol drinking and risk of esophageal squamous cell carcinoma (ESCC) is an open issue, particularly among light alcohol drinkers, never-smokers, and Asian populations, in which some high-risk polymorphisms in alcohol metabolizing genes are more prevalent. To address these issues, we conducted a systematic review and meta-analysis using 40 case-control and 13 cohort studies that reported on the risk associated with alcohol drinking for at least three levels of consumption. In studies adjusted for age, sex, and tobacco smoking, the relative risk (RR) and 95% confidence interval (CI) for the association between light alcohol drinking (≤ 12.5 g/d) and risk of ESCC was 1.38 (1.14-1.67). The association was slightly stronger in Asian countries than in other populations. The adjusted RRs (95% CIs) were 2.62 (2.07-3.31) for moderate drinking (>12.5-<50 g/d) and 5.54 (3.92-7.28) for high alcohol intake (≥50 g/d); the RRs were slightly higher in non-Asian populations. In prospective studies, the RR (95% CI) was 1.35 (0.92-1.98) for light, 2.15 (1.55-2.98) for moderate, and 3.35 (2.06-5.46) for high alcohol intakes; light drinking showed an association with ESCC in Asia (five studies) but not in other regions (three studies). Among never-smokers (nine studies), the RR (95% CI) was 0.74 (0.47-1.16) for light, 1.54 (1.09-2.17) for moderate, and 3.09 (1.75-5.46) for high intakes. This meta-analysis further corroborates the association of moderate and high alcohol intake with risk of ESCC and provides risk estimates based on multiple prospective studies. Light alcohol intake appears to be associated to ESCC mainly in studies in Asia, which suggests a possible role of genetic susceptibility factors.

Acetaldehyde and gastric cancer

Aldehyde dehydrogenase (ALDH2) and alcohol dehydrogenase (ADH) gene polymorphisms associating with enhanced acetaldehyde exposure and markedly increased cancer risk in alcohol drinkers provide undisputable evidence for acetaldehyde being a local carcinogen not only in esophageal but also in gastric cancer. Accordingly, acetaldehyde associated with alcoholic beverages has recently been classified as a Group 1 carcinogen to humans. Microbes are responsible for the bulk of acetaldehyde production from ethanol both in saliva and Helicobacter pylori-infected and achlorhydric stomach. Acetaldehyde is the most abundant carcinogen in tobacco smoke and it readily dissolves into saliva during smoking. Many foodstuffs and 'non-alcoholic' beverages are important but unrecognized sources of local acetaldehyde exposure. The cumulative cancer risk associated with increasing acetaldehyde exposure suggests the need for worldwide screening of the acetaldehyde levels of alcoholic beverages and as well of the ethanol and acetaldehyde of food produced by fermentation. The generally regarded as safe status of acetaldehyde should be re-evaluated. The as low as reasonably achievable principle should be applied to the acetaldehyde of alcoholic and non-alcoholic beverages and food. Risk groups with ADH-and ALDH2 gene polymorphisms, H. pylori infection or achlorhydric atrophic gastritis, or both, should be screened and educated in this health issue. L-cysteine formulations binding carcinogenic acetaldehyde locally in the stomach provide new means for intervention studies.

Alcohol drinking and esophageal cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population

Although alcohol drinking is considered as an important risk factor for esophageal cancer, the magnitude of the association might be varied among geographic areas. Therefore, we reviewed epidemiologic studies on the association between alcohol drinking and esophageal cancer among the Japanese population. Original data were obtained from MEDLINE, searched using PubMed or from searches of the Ichushi database, complemented with manual searches. Evaluation of associations was based on the strength of evidence ('convincing', 'probable', 'possible' or 'insufficient') and the magnitude of association ('strong', 'moderate', 'weak' or 'no association'), together with biological plausibility as previously evaluated by the International Agency of Research on Cancer. We identified four cohort studies and nine case-control studies. All cohort studies and case-control studies showed strong positive associations between esophageal cancer and alcohol drinking. All cohort studies and six case-control studies showed that alcohol drinking had the dose- or frequency-response relationships with esophageal cancer. In addition, four case-control studies showed that acetaldehyde dehydrogenase Glu504Lys polymorphism had strong effect modification with alcohol drinking. We conclude that there is convincing evidence that alcohol drinking increases the risk of esophageal cancer in the Japanese population.

Relationship between genetic polymorphisms of ALDH2 and ADH1B and esophageal cancer risk: A meta-analysis

AIM: To evaluate the contribution of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) polymorphisms to the risk of esophageal cancer.

METHODS: Nineteen articles were included by searching MEDLINE, EMBASE and the Chinese Biomedical Database, 13 on ADH1B and 18 on ALDH2. We performed a meta-analysis of case-control studies including 13 studies on ADH1B (cases/controls: 2390/7100) and 18 studies on ALDH2 (2631/6030).

RESULTS: The crude odds ratio [OR (95% confidence interval)] was 2.91 (2.04-4.14) for ADH1B*1/*1 (vs ADH1B*2/*2) and 1.32 (1.17-1.49) for ADH1B*1/*2. The crude OR for ALDH2*1/*2 (vs ALDH2*1/*1) was 2.52 (1.76-3.61). ADH1B*1/*1 increased the risk of esophageal cancer among never/rare [1.56 (0.93-2.61)], moderate [2.71 (1.37-5.35)], and heavy drinkers [3.22 (2.27-4.57)]. ADH1B*1/*2 was associated with a modest risk among moderate drinkers [1.43 (1.09-1.87)]. ALDH2*1/*2 increased the risk among never/rare [1.28 (0.91-1.80)], moderate [3.12 (1.95-5.01)], and heavy [7.12 (4.67-10.86)] drinkers, and among ex-drinkers [5.64 (1.57-20.25)]. ALDH2*2/*2 increased the risk among drinkers [4.42 (1.72-11.36)]. ADH1B*1/*1 plus ALDH2*1/*2 was associated with the highest risk for heavy drinkers [12.45 (2.9-53.46)]. The results of the meta-regression analysis showed that the effects of ADH1B*1/*1 and ALDH2*1/*2 increased with the level of alcohol consumption. ALDH2*1/*2 was associated with a high risk among Taiwan Chinese and Japanese drinkers, as opposed to a moderate risk among drinkers in high-incidence regions of Mainland China. ADH1B*1/*1 in heavy drinkers and ALDH2*1/*2 in moderate-to-heavy drinkers was associated with similarly high risk among both men and women.

CONCLUSION: ADH1B/ALDH2 genotypes affect the risk of esophageal cancer, and the risk is modified by alcohol consumption, ethnicity, and gender.

Comparison between self-reported facial flushing after alcohol consumption and ALDH2 Glu504Lys polymorphism for risk of upper aerodigestive tract cancer in a Japanese population

Some Japanese exhibit facial flushing after drinking alcohol. Facial flushing was considered to be caused by acetaldehydemia. The concentration of blood acetaldehyde was concerned with the catalytic activity of acetaldehyde dehydrogenase (ALDH). Acetaldehyde dehydrogenase (ALDH)-2 polymorphism (rs671, Glu504Lys) was known to be associated with upper aerodigestive tract (UAT) cancer due to modulation of ALDH2 enzyme activity. It remains controversial whether facial flushing is useful in predicting UAT cancer risk as a surrogate marker of ALDH2 polymorphism. We conducted a case-control study to assess the risk of UAT cancer and facial flushing and ALDH2 polymorphism. Cases and controls were 585 UAT cancer patients and matched 1170 noncancer outpatients of Aichi Cancer Center Hospital. Information on facial flushing and other lifestyle factors was collected via a self-administered questionnaire. Association between facial flushing, polymorphism, and UAT cancer was assessed by odds ratios and 95% confidence intervals by using conditional logistic regression models. The facial flushing had no significant association with UAT cancer, although ALDH2 Lys allele was significantly associated with UAT cancer. No significant interaction between facial flushing and alcohol consumption was observed in this study, whereas ALDH2 Lys allele had significant association with UAT cancer. The misclassification between facial flushing and ALDH2 genotype was observed in 18% of controls with ALDH2 Glu/Glu genotype and in 16% of controls with ALDH2 Glu/Lys genotype. Facial flushing was less useful to predict UAT cancer risk than genotyping ALDH2 polymorphism.

Association of genetic polymorphisms of aldehyde dehydrogenase-2 with esophageal squamous cell dysplasia

AIM: To demonstrate the possible associations between genetic polymorphisms of aldehyde dehydrogenase-2 (ALDH2) and esophageal squamous cell dysplasia (ESCD).

METHODS: All participants came from an area of high incidence of esophageal cancer and underwent an endoscopic staining examination; biopsies were taken from a non-staining area of the mucosa and diagnosed by histopathology. Based on the examinations, the subjects were divided into the control group with normal esophageal squamous epithelial cells and the ESCD group. ALDH2 genotypes of 396 cases were determined including 184 ESCD cases and 212 controls. The odds ratio (OR) and 95% confidence intervals (95% CI) were calculated by binary logistic regression models.

RESULTS: The distribution of ALDH2 genotypes showed significant differences between the two groups. The adjustment factors were gender and age in the logistic regression models. Compared with 2*2/2*2 genotype, 2*1/2*1 genotype was found to be a risk factor for ESCD, and the OR (95% CI) was 4.50 (2.21-9.19). There were significant correlations between ALDH2 genotypes and alcohol drinking/smoking/history of esophageal cancer.

CONCLUSION: The ALDH2 polymorphism is significantly associated with ESCD.

Acetaldehyde as a common denominator and cumulative carcinogen in digestive tract cancers

The key issue in cancer prevention is the identification of specific aetiologic factors. Acetaldehyde, the first metabolite of ethanol oxidation, is carcinogenic in animals. ADH and ALDH2 gene mutations provide an exceptional human model to estimate the long-term effects of acetaldehyde exposure in man. These models provide strong evidence for the local carcinogenic potential of acetaldehyde also in humans. Ethanol is metabolized to acetaldehyde by both mucosal and microbial enzymes. Many microbes produce acetaldehyde from ethanol, but their capacity to eliminate acetaldehyde is low, which leads to the accumulation of acetaldehyde in saliva during an alcohol challenge. Acetaldehyde is the most abundant carcinogen in tobacco smoke, and it readily dissolves into saliva during smoking. Fermented food and many alcoholic beverages can also contain significant amounts of acetaldehyde. Thus acetaldehyde, derived from mucosal or microbial oxidation of ethanol, tobacco smoke, and/or diet, appears to act as a cumulative carcinogen in the upper digestive tract of humans. The evidence strongly suggests the importance of world-wide screening of acetaldehyde and ethanol levels in many beverages and foodstuffs, as well as an urgent need for regulatory measures and consumer guidance. Screening of the risk groups with enhanced acetaldehyde exposure, e.g. people with ADH and ALDH2 gene polymorphisms and hypochlorhydric atrophic gastritis, should also be seriously considered. Most importantly, the GRAS (generally regarded as safe) status of acetaldehyde, which allows it to be used as a food additive, should be re-evaluated, and the classification of acetaldehyde as a carcinogen should be upgraded.

High-temperature beverages and foods and esophageal cancer risk--a systematic review

Coffee, tea and maté may cause esophageal cancer (EC) by causing thermal injury to the esophageal mucosa. If so, the risk of EC attributable to thermal injury could be large in populations in which these beverages are commonly consumed. In addition, these drinks may cause or prevent EC via their chemical constituents. Therefore, a large number of epidemiologic studies have investigated the association of an indicator of amount or temperature of use of these drinks or other hot foods and beverages with risk of EC. We conducted a systematic review of these studies and report the results for amount and temperature of use separately. By searching PubMed and the ISI, we found 59 eligible studies. For coffee and tea, there was little evidence for an association between amount of use and EC risk; however, the majority of studies showed an increased risk of EC associated with higher drinking temperature which was statistically significant in most of them. For maté drinking, the number of studies was limited, but they consistently showed that EC risk increased with both amount consumed and temperature, and these 2 were independent risk factors. For other hot foods and drinks, over half of the studies showed statistically significant increased risks of EC associated with higher temperature of intake. Overall, the available results strongly suggest that high-temperature beverage drinking increases the risk of EC. Future studies will require standardized strategies that allow for combining data and results should be reported by histological subtypes of EC.

Refined geographic distribution of the oriental ALDH2*504Lys (nee 487Lys) variant

Mitochondrial aldehyde dehydrogenase (ALDH2) is one of the most important enzymes in human alcohol metabolism. The oriental ALDH2*504Lys variant functions as a dominant negative, greatly reducing activity in heterozygotes and abolishing activity in homozygotes. This allele is associated with serious disorders such as alcohol liver disease, late onset Alzheimer disease, colorectal cancer, and esophageal cancer, and is best known for protection against alcoholism. Many hundreds of papers in various languages have been published on this variant, providing allele frequency data for many different populations. To develop a highly refined global geographic distribution of ALDH2*504Lys, we have collected new data on 4,091 individuals from 86 population samples and assembled published data on a total of 80,691 individuals from 366 population samples. The allele is essentially absent in all parts of the world except East Asia. The ALDH2*504Lys allele has its highest frequency in Southeast China, and occurs in most areas of China, Japan, Korea, Mongolia, and Indochina with frequencies gradually declining radially from Southeast China. As the indigenous populations in South China have much lower frequencies than the southern Han migrants from Central China, we conclude that ALDH2*504Lys was carried by Han Chinese as they spread throughout East Asia. Esophageal cancer, with its highest incidence in East Asia, may be associated with ALDH2*504Lys because of a toxic effect of increased acetaldehyde in the tissue where ingested ethanol has its highest concentration. While the distributions of esophageal cancer and ALDH2*504Lys do not precisely correlate, that does not disprove the hypothesis. In general the study of fine scale geographic distributions of ALDH2*504Lys and diseases may help in understanding the multiple relationships among genes, diseases, environments, and cultures.

Associations between headache and stress, alcohol drinking, exercise, sleep, and comorbid health conditions in a Japanese population

We conducted a cross-sectional survey of 12,988 subjects aged 20–79 years (5,908 men and 7,090 women) receiving health checkups at a Tokyo clinic. They filled out a self-administered structured questionnaire, and 5.4% of the men and 15.4% of the women reported having headaches. Younger subjects were more prone to having headaches. The likelihood of having headaches increased with stress level and decreased ability to relieve stress in both genders. There was an inverse dose–response relationship between having headaches and alcohol consumption, and less walking/exercise and sleep problems increased the likelihood of headaches in both genders. Headache sufferers of both genders were more likely to report multiple additional poor health conditions. A multivariate stepwise logistic analysis showed that age, self-estimated degree of stress, reported number of additional poor health conditions, and less alcohol consumption were independently correlated with having headaches. In conclusion, although women were more susceptible to headache, Japanese men and women in Tokyo shared factors associated with headache, including age, stress, having other poor health conditions, alcohol consumption, sleep, and exercise.

The alcohol flushing response: an unrecognized risk factor for esophageal cancer from alcohol consumption

Philip Brooks and colleagues discuss evidence linking the alcohol flushing response (predominantly due to ALDH2 deficiency) with a much higher risk of esophageal cancer from alcohol consumption.

Health risk appraisal models for mass screening for esophageal and pharyngeal cancer: an endoscopic follow-up study of cancer-free Japanese men

PURPOSE

To assess the performance of our health risk appraisal (HRA) models for screening individuals at high risk of esophageal/pharyngeal squamous cell carcinoma (EPSCC).

METHODS

Based on the results of our previous case-control study, we invented HRA models that enable screening for EPSCC cases in Japanese men with high sensitivity and specificity based on either their aldehyde dehydrogenase-2 genotype (HRA-G model) or alcohol flushing (HRA-F model) and drinking, smoking, and dietary habits. Follow-up endoscopy combined with esophageal iodine staining (median follow-up period: 5.0 years) was done on 404 Japanese men (50-78 years) who were registered as cancer-free controls in the previous study.

RESULTS

The follow-up endoscopy resulted in a diagnosis of 6 esophageal SCC (T(is) in 5 and T(1) in 1), 1 hypopharyngeal SCC (T(2)), and 1 oropharyngeal SCC (T(2)). Seven and 6 of the 8 EPSCC cases were in the top 10% risk group at baseline according to the HRA-G and HRA-F models, respectively. The EPSCC detection rates per 100 person-years in the top 10% risk groups by the HRA-G and HRA-F models were 4.38 (95% confidence interval, 1.76-9.01) and 3.48 (95% confidence interval, 1.28-7.58), respectively. Their age-adjusted relative risk was 95.1- and 26.3-fold, respectively (P < 0.0001), higher than in the bottom 90% risk groups.

CONCLUSIONS

The high detection rates for EPSCC in the top 10% risk group of this preliminary follow-up study were in good agreement with those predicted by the HRA models and thus encouraged the screening based on our HRA models in larger populations of Japanese men.

Health risk appraisal models for mass screening of esophageal cancer in Japanese men

BACKGROUND

Because early squamous cell carcinoma (SCC) of the esophagus is detectable by endoscopic esophageal iodine staining with high accuracy and is easily treated by endoscopic mucosectomy, it is important to develop efficient methods for screening candidates for the endoscopic examination. Inactive aldehyde dehydrogenase-2 (ALDH2) is a very strong risk factor for esophageal SCC in alcohol drinkers and thus may be suitable as a screening tool.

PURPOSE

To assess the performance of health risk appraisal (HRA) models in screening for esophageal SCC in the Japanese male population.

METHODS

Two types of HRA models were developed based on our previous case-control study, which included assessment of ALDH2 activity and selected risk factors (HRA-G and HRA-F: activities of ALDH2 assessed by genotype and questionnaire for alcohol flushing, respectively). Each individual's risk of esophageal SCC was calculated quantitatively as a risk score. The sensitivity and specificity of the HRA models at various cutoff values of risk score was estimated by a leave-one-out cross-validation. The positive predictive value was estimated assuming the prevalence of esophageal SCC in the whole population to be 0.17% or 0.39% according to literatures.

RESULTS

When individuals ranked in the top 10% of the HRA-F risk score was screened, the sensitivity was 57.9% and positive predictive value was 0.93% or 2.12% according to the above assumptions, respectively. The sensitivity was slightly better by the HRA-G model than by the HRA-F model.

CONCLUSION

The HRA models may provide an important approach to early intervention strategies to control esophageal SCC in Japanese men.