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

Risk factors of secondary cancer in laryngeal, oropharyngeal, or hypopharyngeal cancer after definitive therapy

BACKGROUND

Our previous research showed that a high rate of secondary carcinogenesis is observed during follow-up after transoral surgery in patients with early-stage laryngeal, oropharyngeal, and hypopharyngeal cancers. We speculate that the contributing factors are alcohol drinking, smoking, and aging; however, we could not provide clear evidence. In this study, we aimed to identify the risk factors for secondary carcinogenesis in patients with these cancers, particularly factors associated with drinking and/or smoking.

METHODS

The medical records of all-stage laryngeal, oropharyngeal, and hypopharyngeal cancer patients who had undergone definitive treatment were retrospectively analyzed. Assessments included visual and endoscopic observations of the primary site, enhanced cervical CT or US of the primary site and regional lymph nodes, PET-CT, and enhanced whole-body CT. Clinical characteristics were compared in patients with and without secondary carcinogenesis and in patients with hypopharyngeal cancer and patients with other cancers.

RESULTS

Hypopharyngeal cancer was an independent risk factor for secondary cancer. The 5-year incidence rate of secondary cancer was 25.5%, 28.6%, and 41.2% in laryngeal, oropharyngeal, and hypopharyngeal cancers, respectively. Radiotherapy was defined as an independent risk factor in hypopharyngeal cancer patients with secondary cancers. No direct correlation was found between secondary carcinogenesis and alcohol consumption, smoking, or aging.

CONCLUSIONS

Patients with hypopharyngeal cancer require close follow-up as they are at high risk of developing secondary cancer, possibly because out-of-field radiation exposure may induce systemic secondary carcinogenesis in hypopharyngeal cancer patients with genetic abnormality induced by alcohol consumption.

Implementing precision medicine in endoscopy practice

In contrast to the "one-size-fits-all" approach, precision medicine focuses on providing health care tailored to individual variabilities. Implementing precision medicine in endoscopy practice involves selecting the appropriate procedures among the endoscopic armamentarium in the diagnosis and management of patients in a logical sequence, jointly considering the pretest probabilities of possible diagnoses, patients' comorbidities and preference, and risk-benefit ratio of the individual procedures given the clinical scenario. The aim of this review is to summarize evidence-supported strategies and measures that may enhance precision medicine in general endoscopy practice.

Alcohol Consumption, ALDH2 Polymorphism as Risk Factors for Upper Aerodigestive Tract Cancer Progression and Prognosis

The upper aerodigestive tract (UADT) is highly susceptible to multiple primary cancers originated from squamous epithelia and constitutes a field of cancerization. Patients with head and neck cancer (head and neck squamous cell carcinoma, HNSCC) are at high risk of developing multiple cancers in the esophagus (esophageal squamous cell carcinoma, ESCC). Conversely, esophageal cancer patients are prone to develop multiple primary tumors in the head and neck region. The East Asian-specific dysfunctional ALDH2*2 missense mutation is a genetic risk factor for UADT cancer. It is not only associated with increased incidences of UADT cancer, but is also implicated in faster cancer progression and poorer prognosis. Alcohol use is a major lifestyle risk factor which causes UADT cancer among ALDH2*2 carriers. The accumulation of the immediate metabolite of alcohol, acetaldehyde, is likely the genotoxic agents that is involved in the process of tumorigenesis. This review summarizes recent publications on the risk and association of ALDH2*2 mutation, alcohol consumption in synchronous, metachronous UADT cancer. Possible molecular mechanisms involved in cancer initiation, progress and prognosis are discussed. The review also highlights a need for precision medicine-based preventive and therapeutic strategies by integrating lifestyle and genetic risk factors, such as alcohol consumption, genotypes of the alcohol metabolizing genes, ADH1B and ALDH2, into a risk assessment model for better screening, surveillance and treatment outcome.

Current Status of Transoral Surgery for Patients With Early-Stage Pharyngeal and Laryngeal Cancers in Japan

As the laryngopharynx is closely related to swallowing, speech, and phonation, it is necessary to consider not only disease control but also a minimally invasive approach for the treatment of laryngopharyngeal cancer. Transoral surgery has been reported to be a minimally invasive method for treating these diseases. Transoral videolaryngoscopic surgery (TOVS) and endoscopic laryngo-pharyngeal surgery (ELPS) have been developed in Japan and recently emerged as treatments for patients with early stage pharyngeal and laryngeal cancers. However, securing an appropriate field of view and a narrow operating space during TOVS or ELPS are critical issues to be resolved for these surgeries. The clinical significance and safety of transoral robotic surgery (TORS) using the da Vinci Surgical System have been widely reported to provide surgeons with increased visualization and magnification, resulting in precise surgical margins and rapid functional recovery. In this context, a multi-institutional clinical study was conducted to evaluate the treatment outcomes of TORS for the treatment of laryngopharyngeal cancer in Japan, and the da Vinci Surgical System for oral robot-assisted surgery for these diseases was approved by the Pharmaceutical Affairs Agency in August 2018. This review provides an overview of the therapeutic effects of TOVS, ELPS, and TORS, with a particular focus on these therapeutic results in Japan.

Development and Validation of an Esophageal Squamous Cell Carcinoma Risk Prediction Model for Rural Chinese: Multicenter Cohort Study

BACKGROUND

There are rare prediction models for esophageal squamous cell carcinoma (ESCC) for rural Chinese population. We aimed to develop and validate a prediction model for ESCC based on a cohort study for the population.

METHODS

Data of 115,686 participants were collected from esophageal cancer (EC) early diagnosis and treatment of cancer program as derivation cohort while data of 54,750 participants were collected as validation cohort. Risk factors considered included age, sex, smoking status, alcohol drinking status, body mass index (BMI), tea drinking status, marital status, annual household income, source of drinking water, education level, and diet habit. Cox proportional hazards model was used to develop ESCC prediction model at 5 years. Calibration ability, discrimination ability, and decision curve analysis were analyzed in both derivation and validation cohort. A score model was developed based on prediction model.

RESULTS

One hundred eighty-six cases were diagnosed during 556,949.40 person-years follow-up in the derivation cohort while 120 cases from 277,302.70 in the validation cohort. Prediction model included the following variables: age, sex, alcohol drinking status, BMI, tea drinking status, and fresh fruit. The model had good discrimination and calibration performance: R 2, D statistic, and Harrell's C statistic of prediction model were 43.56%, 1.70, and 0.798 in derivation cohort and 45.19%, 1.62, and 0.787 in validation cohort. The calibration analysis showed good coherence between predicted probabilities and observed probabilities while decision curve analysis showed clinical usefulness. The score model was as follows: age (3 for 45-49 years old; 4 for 50-54 years old; 7 for 55-59 years old; 9 for 60-64 years; 10 for 65-69 years), sex (5 for men), BMI (1 for ≤25), alcohol drinking status (2 for alcohol drinkers), tea drinking status (2 for tea drinkers), and fresh fruit (2 for never) and showed good discrimination ability with area under the curve and its 95% confidence interval of 0.792 (0.761,0.822) in the deviation cohort and 0.773 (0.736,0.811) in the validation cohort. The calibration analysis showed great coherence between predicted probabilities and observed probabilities.

CONCLUSIONS

We developed and validated an ESCC prediction model using cohort study with good discrimination and calibration capability which can be used for EC screening for rural Chinese population.

Risk Factors for Non-Ampullary Duodenal Adenocarcinoma: A Systematic Review

INTRODUCTION

An increase in the incidence of duodenal adenocarcinoma has been recently reported. However, little is known about the risk factors for duodenal adenocarcinoma, which are important for screening purposes. We, therefore, aimed to conduct a systematic review to identify risk factors for non-ampullary duodenal adenocarcinoma.

METHODS

A medical literature search was performed using electronic databases, including PubMed, Cochrane Library, Japan Medical Abstracts Society, and Web of Science. Studies that assessed the association between dietary habits, lifestyle behaviors, comorbidities, and non-ampullary duodenal adenocarcinoma were extracted. The Newcastle-Ottawa Scale was used to assess the risk of bias in individual studies, and the Grading of Recommendations, Assessment, Development, and Evaluations approach was used to assess the quality of evidence across studies included in this review.

RESULTS

Out of 1,244 screened articles, 10 were finally selected for qualitative synthesis. In the general population, no consistent risk factors were identified except for Helicobacter pylori positivity, which was considered a risk factor in 2 studies, but the quality of evidence was considered very low because of the high risk of bias. In patients with familial adenomatous polyposis (FAP), Spigelman stage IV at initial endoscopy was considered a consistent risk factor in 3 studies.

CONCLUSIONS

There are currently limited data regarding risk factors for non-ampullary duodenal adenocarcinoma, and no conclusive risk factors were identified in the general population. However, in patients with FAP, Spigelman stage IV was identified as a consistent risk factor. Further studies are needed to improve diagnosis and support effective clinical management of this malignancy.

The incidence of newly diagnosed secondary cancer; sub-analysis the prospective study of the second-look procedure for transoral surgery in patients with T1 and T2 head and neck cancer

BACKGROUND

Our prospective study of patients with early T-stage head and neck cancer indicated a high incidence of newly diagnosed secondary malignancies during the follow-up period. We aimed to determine the incidence rate and risk factors of secondary malignancies in early-stage head and neck cancer patients.

METHODS

We sub-analyzed the patient data of a previous study focusing on secondary cancer incidence. The endpoints were statistical analyses of risk factors and survival and incidence rates.

RESULTS

The incidence rate of secondary cancer was 37%, the crude incidence of second primary cancers was 10.6 per 100 person-years, and the 5 year secondary cancer-free survival rate was 63%. The hypopharynx as the primary site was an independent significant predictive factor (odds ratio 3.96, 95% confidence interval 1.07-14.6, p = 0.039).

CONCLUSIONS

Early stages of laryngeal, oropharyngeal, and hypopharyngeal cancer had a risk of secondary cancer, especially hypopharyngeal cancer. Attention to the secondary cancer has to be paid during the follow-up period after controlling the early-stage disease. These findings highlight the need for awareness of the incidence of secondary cancer in cases of early-stage primary head and neck cancer.

Tolerability and efficacy of the concentration of iodine solution during esophageal chromoendoscopy: a double-blind randomized controlled trial

BACKGROUND AND AIMS

Esophageal chromoendoscopy with iodine solution is an important diagnostic method for the detection of superficial esophageal cancer. However, the concentration of iodine solution has differed among reports. This study aimed to evaluate patient discomfort with different iodine concentrations.

METHODS

We performed a prospective, double-blind, randomized study. We prospectively enrolled and analyzed 77 patients who were at high risk for esophageal carcinoma and scheduled to undergo EGD from March 2018 to January 2019. All patients were divided into 2 groups before the procedure to compare pain measurements: a 1% iodine solution group (group A) and a 2% iodine solution group (group B). The primary endpoint of this study was the difference in pain measurement between 1% and 2% iodine solution chromoendoscopy. Secondary endpoints were safety, detection yield, and color evaluation based on both the endoscopist's survey and color values, as determined using the Commission Internationale de l'Eclairage (CIELAB, Vienna, Austria) color evaluation system, in the iodine-faded and iodine-stained area of each group.

RESULTS

Heartburn and retrosternal pain in group A were significantly lower than those in group B (P = .02). Eleven patients reported heartburn and retrosternal pain (group A, 2; group B, 9). Four patients reported pain above the sternal angle and 7 below the sternal angle. There was no significant difference between the 2 groups with regard to detection yield, color evaluation by the endoscopist's assessment, or color values. No patients had any adverse events, and all safely completed this study.

CONCLUSIONS

The 2% iodine solution resulted in significantly greater pain than the 1% iodine solution, and the color of the stained esophageal images of each group was the same from this study. Therefore, the 1% iodine solution is recommended for esophageal chromoendoscopy. (Clinical trial registration number: UMIN 000029796.).

Alcohol Consumption, Aldehyde Dehydrogenase 2 Gene Polymorphisms, and Cardiovascular Health in Korea

Alcohol consumption is a serious health issue in Korea in terms of the amount consumed and the behavior related to its consumption. Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme in alcohol metabolism that degrades acetaldehyde to nontoxic acetic acid. The enzyme is coded by the ALDH2 gene, which is commonly polymorphic in East Asian populations. A point mutation in the ALDH2 gene (the rs671 allele) yields an inactive form of ALDH2 that causes acetaldehyde accumulation in the body after alcohol consumption, thereby inhibiting normal alcohol metabolism. Individuals who are homozygous for polymorphism in ALDH2 tend to refrain from drinking alcohol, decreasing their chances of developing alcoholism and exposure to the associated risks. Mendelian randomization (MR) studies have demonstrated that alcohol consumption predicted by ALDH2 genotype is causally related to cardiovascular risks. Moreover, recent MR studies suggest that the ALDH2 variant has mechanistic effects on some disease outcomes or mortality through increased blood levels of acetaldehyde, showing differences therein between heterozygotes (ALDH2*2*2) and homozygotes (ALDH2*1*2) in those who consume alcohol. Accordingly, consideration of ALDH2 genotype in alcohol prevention programs is warranted. In conclusion, strategies that incorporate genetic information and provide an evidential basis from which to help people make informed decisions on alcohol consumption are urgently required.

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.

Tolerability of magnifying narrow band imaging endoscopy for esophageal cancer screening

AIM: To compare the tolerability of magnifying narrow band imaging endoscopy for esophageal cancer screening with that of lugol chromoendoscopy.

METHODS: We prospectively enrolled and analyzed 51 patients who were at high risk for esophageal cancer. All patients were divided into two groups: a magnifying narrow band imaging group, and a lugol chromoendoscopy group, for comparison of adverse symptoms. Esophageal cancer screening was performed on withdrawal of the endoscope. The primary endpoint was a score on a visual analogue scale for heartburn after the examination. The secondary endpoints were scale scores for retrosternal pain and dyspnea after the examinations, change in vital signs, total procedure time, and esophageal observation time.

RESULTS: The scores for heartburn and retrosternal pain in the magnifying narrow band imaging group were significantly better than those in the lugol chromoendoscopy group (P = 0.004, 0.024, respectively, ANOVA for repeated measures). The increase in heart rate after the procedure was significantly greater in the lugol chromoendoscopy group. There was no significant difference between the two groups with respect to other vital sign. The total procedure time and esophageal observation time in the magnifying narrow band imaging group were significantly shorter than those in the lugol chromoendoscopy group (450 ± 116 vs 565 ± 174, P = 0.004, 44 ± 26 vs 151 ± 72, P < 0.001, respectively).

CONCLUSION: Magnifying narrow band imaging endoscopy reduced the adverse symptoms compared with lugol chromoendoscopy. Narrow band imaging endoscopy is useful and suitable for esophageal cancer screening periodically.

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.

Use of transoral endoscopy for pharyngeal examination: cross-sectional analysis

BACKGROUND AND AIM

Transoral endoscopy with narrow band imaging (NBI) is useful for identifying early-stage head and neck cancer. However, the screening capability of transoral upper gastrointestinal endoscopy has not yet been systematically evaluated. We evaluated the usefulness of transoral upper gastrointestinal endoscopy for pharyngeal examination.

METHODS

This cross-sectional study evaluated 480 patients. All endoscopic pharyngeal examinations with NBI were carried out in accordance with prescribed procedures, consisting of 10 images each and all images were assessed by a blinded reviewer. We examined the association between the diagnostic usefulness of pharyngeal examination and other factors.

RESULTS

Median subject age was 64 years (range 22-90 years), and 64% were male. Almost all patients (98%) had an Eastern Cooperative Oncology Group Performance Status of 0 or 1.Butylscopolamine bromide was given to 382 patients (80%), and a sedative was given to 460 (96%) patients. Median observation time was 74 s (range, 16-362 s), resulting in a mean of 9.0 usable images per patient. However, photographs of the right and left pyriform sinuses were consistently poor. Ordered logistic regression analysis showed that quality images were positively correlated with increased patient age.

CONCLUSIONS

Transoral endoscopic examination was possible in most patients for screening of the head and neck. However, results were poor in the pyriform sinuses, indicating that additional improvements of examination methods and instruments are needed to enhance screening accuracy.

Detection of pharyngeal cancer in the overall population undergoing upper GI endoscopy by using narrow-band imaging: a single-center experience, 2009-2012

BACKGROUND

Nonmagnifying observation by using narrow-band imaging (NBI) is useful for detecting pharyngeal lesions. Magnifying observation by using NBI can distinguish between cancerous and noncancerous lesions and is therefore useful for the early detection of pharyngeal cancer.

OBJECTIVE

To evaluate the usefulness of observation of the pharynx by using NBI in the overall population undergoing upper GI endoscopy.

DESIGN

Retrospective study.

SETTING

Single tertiary referral center.

PATIENTS

A total of 11,050 upper GI endoscopies between January 2009 and December 2012.

INTERVENTIONS

Observation of the pharynx by using NBI.

MAIN OUTCOME MEASURES

The rate of detection of pharyngeal cancer, the rates of detection according to the reason for endoscopy, and the types of cancers detected.

RESULTS

Thirty-eight cancerous lesions were detected in 29 patients (0.26%, 29/11,050). The rate of detection of pharyngeal cancer was significantly higher in patients with a history of head and neck cancer (9.7%, 3/31) or a history of esophageal cancer (3.5%, 10/282). In patients undergoing endoscopy for screening, pharyngeal discomfort, and a history of gastric cancer, the rates of detection of pharyngeal cancer were 0.11% (10/8872), 1.1% (3/265), and 0.19% (3/1600), respectively. Two patients (6.9%) were female. One had a history of esophageal cancer, and the other had pharyngeal discomfort.

LIMITATIONS

Single-center, retrospective study.

CONCLUSIONS

Observation of the pharynx by using NBI in patients with previous head and neck cancer or esophageal cancer or who have pharyngeal discomfort is very important. Moreover, pharyngeal cancer was certainly found in the male patients undergoing screening endoscopy, although the rate was lower.

p53 immunohistochemical expression and patient prognosis in esophageal squamous cell carcinoma

It is generally accepted that overexpression of p53 protein is associated with poor prognosis in gastric, lung, and other types of cancer. However, the prognostic significance of p53 aberrations in esophageal cancer remains unclear. This is the largest study (n = 266) examining clinical and prognostic features of p53 immunohistochemical expression in esophageal squamous cell carcinoma. In 139 (52%) esophageal tumors, nuclear immunoreactivity for p53 protein was detected. p53 aberrant expression was not associated with sex, age, preoperative treatment, TNM stage, or histological grade. Furthermore, p53 expression did not correlate with disease-free survival (P = 0.73) or overall survival (P = 0.62). In addition, no significant modification effect by any of the covariates in the survival analysis was observed (all P > 0.15). In conclusion, our large-scale study demonstrates that p53 expression has no impact on the prognosis of esophageal squamous cell carcinoma.

Is it proper to use non-magnified narrow-band imaging for esophageal neoplasia screening? Japanese single-center, prospective study

AIM

Most screening examinations in Japanese general hospitals are carried out by high-definition television-incompatible (non-HD) scopes and non-magnifying endoscopes. We evaluated the narrow-band imaging (NBI) real-time diagnostic yield of esophageal neoplasia in high-risk patients at a general hospital.

METHODS

In a single-center, prospective, non-randomized controlled trial, 117 consecutive screening patients with high risk for esophageal cancer received primary white-light imaging (WLI) followed by NBI and iodine-staining endoscopy (59 by HDTV-compatible [HD] endoscopy and 58 by non-HD endoscopy). The primary aim was to evaluate the diagnostic yield of non-magnified images in diagnosing esophageal neoplasia. The secondary aim was to compare HD endoscopy and non-HD endoscopy in terms of diagnostic performance.

RESULTS

Overall, the sensitivity of NBI for screening of esophageal neoplasia was superior to WLI, and equivalent to iodine staining (92% vs 42%; P < 0.05, 92% vs 100%; ns). The specificity of NBI was equivalent to WLI (89% vs 94%; ns). In HD, NBI sensitivity was equivalent to both iodine staining and WLI (100% vs 75%; ns). In non-HD, NBI sensitivity was equivalent to iodine staining, but WLI sensitivity was significantly inferior to NBI (88% vs 100%; ns, 25% vs 88%; P < 0.05). The NBI specificity was equivalent to WLI not only in HD but also in non-HD (90% vs 96%; ns, 88% vs 93%; ns).

CONCLUSION

In both HD and non-HD endoscopy, NBI is less likely than WLI to miss a lesion. Even with non-HD endoscopy, NBI is suitable for esophageal standard examinations in general hospitals.

Molecular basis of esophageal cancer development and progression

This article discusses the molecular basis of esophageal cancer development and subsequent progression of disease. Differing epidemiologic factors are associated with esophageal adenocarcinoma and squamous cell carcinoma. These 2 different histologic types have differing putative underlying mechanisms of transdifferentiation from normal esophageal mucosa to malignant histologies via gene dysregulation, biochemical modifications, and altered cell signaling pathways. Our developing understanding of the molecular events underlying esophageal cancer is leading to the establishment of identifiable biomarkers and the clinical use of molecularly targeted treatment agents. The identification of driving genetic mutations and altered signaling pathways has also had favorable outcomes.

LINE-1 hypomethylation in noncancerous esophageal mucosae is associated with smoking history

BACKGROUND

Cancer cells exhibit two types of DNA methylation alterations: global DNA hypomethylation and site-specific CpG island promoter hypermethylation. Selected gene promoter hypermethylation in normal esophageal mucosae has attracted attention as a surrogate marker for the epigenetic field defect induced by smoking and/or drinking in esophageal squamous cell carcinoma (ESCC). However, the significance of global DNA hypomethylation for field cancerization remains unclear.

METHODS

By using histologically normal esophageal mucosa samples from 109 ESCC cases and 20 autopsy cases without ESCCs, we measured long interspersed nucleotide element 1 (LINE-1) methylation levels by pyrosequencing, which correlates with global DNA methylation level.

RESULTS

LINE-1 methylation levels in normal esophageal mucosae of ESCC patients were significantly lower than those of autopsy individuals (P = 0.017). LINE-1 methylation of noncancerous mucosae ranged 68.3-93.0 on a 0-100 scale (mean 81.7, median 82.2, standard deviation 5.9). LINE-1 hypomethylation was significantly associated with smoking history (P = 0.014 for smoking duration; P = 0.0017 for number of cigarettes per day; P = 0.0002 for tobacco pack-year). LINE-1 methylation was not associated with alcohol drinking or age at diagnosis.

CONCLUSIONS

A history of tobacco use was significantly associated with LINE-1 hypomethylation in noncancerous esophageal mucosae of ESCC patients. These results support the potential of LINE-1 methylation level as an indicator of epigenetic field for ESCC cancerization, particularly when caused by tobacco smoking.

A health-risk appraisal model and endoscopic mass screening for esophageal cancer in Japanese men

A strong association between inactive aldehyde dehydrogenase-2 (ALDH2) and risk of esophageal cancer has been demonstrated in East Asian drinkers. An alcohol flushing questionnaire asking about past and current tendency for facial flushing to occur after drinking a glass (≈180 mL) of beer predicts the presence of inactive ALDH2 among Japanese aged 40 years or older with a sensitivity and specificity of approximately 90%. We invented a health-risk appraisal (HRA) model that makes it possible to identify Japanese men who are at high risk for esophageal cancer based on their past and current alcohol flushing tendency, drinking, smoking, and intake of vegetables and fruits. Between 2008 and 2009, 2221 Japanese men aged 50 years or older filled out the HRA questionnaire before undergoing a screening examination by upper gastrointestinal endoscopy at five medical facilities. The endoscopic examination resulted in a diagnosis of esophageal cancer in 19 subjects, and 117 (5.27%) subjects had an HRA score ≥ 11. The proportion of subjects with an HRA score ≥ 11 was higher in the 50-69 age group (6.11-6.88%) than in 70-89 age group (2.84-2.86%). The esophageal cancer detection rate was 4.27% among the subjects with an HRA score ≥ 11 and only 0.67% among the other subjects. Based on a receiver operating characteristic curve analysis, when an HRA score of ≥ 9 was used for subjects aged 50-69 years and of ≥ 8 for those aged 70-89 years as the cutoff value to select individuals with a high risk for esophageal cancer, its sensitivity and false-positive rate was 52.6% and 15.2%, respectively, and the cancer detection rate was 2.91% in the high-risk group, as opposed to 0.48% in the other group. In conclusion, the high detection rates for esophageal cancer in the high-risk groups encouraged screening based on our HRA model in larger Japanese populations.

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.

Secondary prevention of esophageal squamous cell carcinoma in areas where smoking, alcohol, and betel quid chewing are prevalent

Esophageal cancer is ranked as the sixth most common cause of cancer death worldwide and has a substantial effect on public health. In contrast to adenocarcinoma arising from Barrett's esophagus in Western countries, the major disease phenotype in the Asia-Pacific region is esophageal squamous cell carcinoma which is attributed to the prevalence of smoking, alcohol, and betel quid chewing. Despite a multidisciplinary approach to treating esophageal cancer, the outcome remains poor. Moreover, field cancerization reveals that esophageal squamous cell carcinoma is closely linked with the development of head and neck cancers that further sub-optimize the treatment of patients. Therefore, preventive strategies are of paramount importance to improve the prognosis of this dismal disease. Since obstacles exist for primary prevention via risk factor elimination, the current rationale for esophageal cancer prevention is to identify high-risk groups at earlier stages of the disease, and encourage them to get a confirmatory diagnosis, prompt treatment, and intensive surveillance for secondary prevention. Novel biomarkers for identifying specific at-risk populations are under extensive investigation. Advances in image-enhanced endoscopy do not just substantially improve our ability to identify small precancerous or cancerous foci, but can also accurately predict their invasiveness. Research input from the basic sciences should be translated into preventive measures in order to decrease the disease burden of esophageal cancer.