Association between the body mass index and the risk of Barrett's esophagus in Japan

Etiologic factors for Barrett's esophagus: toward countermeasures in Asia

INTRODUCTION

Over the past several decades, Europe and the United States have experienced a rapid increase in esophageal adenocarcinoma. Research and countermeasures against Barrett's esophagus, its precancerous lesion, are progressing. Because esophageal adenocarcinoma has an extremely poor prognosis when diagnosed in an advanced stage, recommendations for early cancer detection have been made based on the various proven etiological factors of Barrett's esophagus and the actual cancer risk of Barrett's esophagus. In recent years, there have been indications of an increase in esophageal adenocarcinoma in Japan, and a similar trend of cancer will occur shortly in other Asian countries. Consequently, Asian countries must implement similar countermeasures against Barrett's esophagus and esophageal adenocarcinoma, referencing the knowledge gained thus far in Europe and the United States.

AREAS COVERED

This review summarizes the latest findings on the etiologic factors of Barrett's esophagus and discusses the differences between Westerners and Asians. The current status of Barrett's esophagus in Japan and other Asian countries is also summarized.

EXPERT OPINION

The etiological factors and cancer incidence of Barrett's esophagus in Asia diverge somewhat from those observed in Europe and America. Therefore, it is imperative to implement measures that are tailored to the actual circumstances of Asian people.

Long-term endoscopic surveillance for Barrett's esophagus in Japan: Multicenter prospective cohort study

OBJECTS

Although a recent study showed the cancer incidence of Barrett's esophagus (BE) to be 1.2%/year in 251 patient-years in Japan, the long-term outcomes remain unclear. The present study estimated the cancer risk of BE in Japan using our original prospective multicenter cohort.

METHODS

A total of 98 patients with BE of maximum length of ≥2 cm were enrolled during the period of 2010-2012 and received at least one follow-up endoscopy over 5 years thereafter. Cancer incidence rates with 95% confidence interval for occurrence of esophageal adenocarcinoma (EAC) were calculated as the number of events divided by patient-years of follow-up and were expressed as %/year.

RESULTS

Overall, the median endoscopic follow-up period was 59.9 (first and third quartiles, 48.5-60.8) months, constituting a total of 427 patient-years of observation. Since two EAC cases developed, the cancer incidence was 0.47% (0.01%-1.81%)/year. The cancer incidence was 0.39% (-0.16% to 2.44%) in 232 patient-years and 0.31% (-0.13% to 1.95%)/year in 318 patient-years for 55 cases with specialized intestinal metaplasia and 70 with BE ≥3 cm (maximum), respectively. At the end of follow-up, 12 of 92 patients (13.0%) died, but none died from EAC.

CONCLUSION

This is the largest prospective follow-up study with endoscopy to investigate the incidence of EAC in unequivocal BE with the maximum length of ≥2 cm in Japan. Although a further large-scale study will be required to validate our results, the cancer risk of BE in Japan would be lower than previously reported (0.47% vs 1.2%/year).

Lifestyle interventions can reduce the risk of Barrett's esophagus: a systematic review and meta-analysis of 62 studies involving 250,157 participants

Background

Barrett's esophagus (BE) is a well‐established risk factor for esophageal adenocarcinoma. Our objective was to investigate the effectiveness of lifestyle interventions on BE risk.

Methods

We searched PubMed, Embase, and Web of Science up to 30 September 2020. The summary relative risks (RRs) and 95% confidence intervals (CIs) for the highest versus lowest categories of exposure were assessed. Analyses of subgroup, dose–response, sensitivity, and publication bias were conducted.

Results

Sixty‐two studies were included that involved more than 250,157 participants and 22,608 cases. Seven lifestyle factors were investigated: smoking, alcohol, body mass index (BMI), physical activity, sleep time, medication, and diet. We observed statistically significant increased BE risks for smoking (RR = 1.35, 95% CI = 1.16–1.57), alcohol intake (RR = 1.23, 95% CI = 1.13–1.34), body fatness (RR = 1.08, 95% CI = 1.03–1.13), less sleep time (RR = 1.76, 95% CI = 1.24–2.49), and proton pump inhibitors use (RR = 1.64, 95% CI = 1.17–2.29). Reduced risks of BE were found for aspirin (RR = 0.70, 95% CI = 0.58–0.84) and the intake of vitamin C (RR = 0.59, 95% CI = 0.44–0.80), folate (RR = 0.47, 95% CI = 0.31–0.71), and fiber (RR = 0.95, 95% CI = 0.93–0.97). The quality of most included studies was high and the subgroup analysis according to the quality score showed significant results (p < 0.05). There was no publication bias for smoking and alcohol. Although the analysis suggested significant evidence of publication bias for BMI, sensitivity analysis showed that the changes in the recalculated RRs were not significant.

Conclusions

The large meta‐analysis revealed that lifestyle modifications could reduce the risks of BE and, consequently, esophageal adenocarcinoma.

Barrett's esophagus patients are becoming younger: analysis of a large United States dataset

BACKGROUND

Barrett's esophagus (BE), a complication of long-term gastroesophageal reflux disease (GERD), has been reported to affect 6-8% of those with heartburn. Most patients are males, Caucasians and middle aged. However, there are no recent demographic studies that evaluated the proportion trends of BE. We aimed to assess proportion trends of BE over an 11-year period, using a very large national dataset.

METHODS

This was a population-based analysis of the national Explorys dataset. Explorys is an aggregate of electronic medical record database representing over 54 million patients. Proportions of BE's variables such as age, gender, race, BMI, and treatment with PPI were recorded during an 11-year period. BE patients were classified into seven age groups (15-19, 20-29, 30-39, 40-49, 50-59, 60-69, ≥ 70 years old). Secular trends of the proportion of BE were assessed over time for each age group.

RESULTS

The majority of patients diagnosed with BE were ≥ 70 years old across all calendar years. However, the proportion of BE patients who were ≥ 70 years old has significantly decreased between 2006 and 2016 (- 19.9%, p < 0.001). The proportion of patients with BE increased in all age groups but most prominently in the age groups, 30-39: 2.07%, 40-49: 3.64%, 50-59: 6.89%, 60-69: 6.18%, p < 0.001. BE was significantly more common in those who were Caucasian and male. PPI usage fell significantly in those who were ≥ 70 years old (- 20.8%, p < 0.001), but increased in the other remaining age groups.

CONCLUSIONS

The proportion of BE patients who are 70 years and older has significantly dropped. Younger patients' groups have demonstrated the highest increase in the proportion of BE patients, especially those in the age group of 30-39 years old.

Prognostic significance of combined pretreatment body mass index (BMI) and BMI loss in patients with esophageal cancer

Background: Body mass index (BMI) has been associated with a risk of esophageal cancer. However, the influence of BMI and BMI loss on people with esophageal cancer that were treated with different therapies has not been described in China.

Methods: In total, 615 consecutive patients that underwent esophagectomy and/or chemotherapy/radiotherapy were classified according to the Asian-specific BMI (kg/m²) cutoff values. The impact of BMI and BMI loss on long-term overall survival (OS) was estimated using the Kaplan–Meier method and Cox proportional hazard models.

Results: Multivariate analysis showed that overweight and obese patients had a more favorable survival than normal weight and underweight patients (p=0.017). Patients with a low BMI and high BMI loss before therapy had worse OS than others (p=0.001). Subgroup analysis showed that patients with a high BMI were more likely to suffer hypertension (p<0.001) and receive only surgery (p<0.001), and they were less likely to be smokers (p=0.007) and anemic (p<0.001). Conversely, patients with high BMI loss were more likely to be anemic (p=0.001), to have advanced pathological stage (p=0.012), and to receive chemotherapy and radiotherapy (p=0.001). Moreover, the mortality rate was higher when patients had a high BMI loss. There is no survival benefit of higher BMI in the non-esophageal squamous cell carcinoma (ESCC) group.

Conclusion: Pretreatment BMI was an independent prognostic factor for long-term survival in esophageal cancer patients treated with different treatments. The overall survival was increased in esophageal cancer patients with a high pretreatment BMI and no BMI loss. There is no survival benefit of higher BMI in the non-ESCC group.

Trajectories of endoscopic Barrett esophagus: Chronological changes in a community-based cohort

AIM

To elucidate longitudinal changes of an endoscopic Barrett esophagus (BE), especially of short segment endoscopic BE (SSBE).

METHODS

This study comprised 779 patients who underwent two or more endoscopies between January 2009 and December 2015. The intervals between the first and the last endoscopy were at least 6 mo. The diagnosis of endoscopic BE was based on the criteria proposed by the Japan Esophageal Society and was classified as long segment (LSBE) and SSBE, the latter being further divided into partial and circumferential types. The potential background factors that were deemed to affect BE change included age, gender, antacid therapy use, gastroesophageal reflux disease-suggested symptoms, esophagitis, and hiatus hernia. Time trends of a new appearance and complete regression were investigated by Kaplan-Meier curves. The factors that may affect appearance and complete regression were investigated by χ² and Student-t tests, and multivariable Cox regression analysis.

RESULTS

Incidences of SSBE and LSBE were respectively 21.7% and 0%, with a mean age of 68 years. Complete regression of SSBE was observed in 61.5% of initial SSBE patients, while 12.1% of initially disease free patients experienced an appearance of SSBE. Complete regressions and appearances of BE occurred constantly over time, accounting for 80% and 17% of 5-year cumulative rates. No LSBE development from SSBE was observed. A hiatus hernia was the only significant factor that facilitated BE development (P = 0.03) or hampered (P = 0.007) BE regression.

CONCLUSION

Both appearances and complete regressions of SSBE occurred over time. A hiatus hernia was the only significant factor affecting the BE story.

Gender difference in gastro-esophageal reflux diseases

The incidence of esophageal adenocarcinoma (EAC) has risen sharply in western countries over the past 4 decades. This type of cancer is considered to follow a transitional process that goes from gastro-esophageal reflux disease (GERD) to Barrett's esophagus (BE, a metaplastic condition of the distal esophagus), a precursor lesion and ultimately adenocarcinoma. This spectrum of GERD is strongly predominant in males due to an unidentified mechanism. Several epidemiologic studies have described that the prevalence of GERD, BE and EAC in women is closely related to reproductive status, which suggests a possible association with the estrogen level. Recently, we revealed in an in vivo study that the inactivation of mast cells by the anti-inflammatory function of estrogen may account for the gender difference in the GERD spectrum. Other studies have described the contribution of female steroid hormones to the gender difference in these diseases. Estrogen is reported to modulate the metabolism of fat, and obesity is a main risk factor of GERDs. Moreover, estrogen could confer esophageal epithelial resistance to causative refluxate. These functions of estrogen might explain the approximately 20-year delay in the incidence of BE and the subsequent development of EAC in women compared to men, and this effect may be responsible for the male predominance. However, some observational studies demonstrated that hormone replacement therapy exerts controversial effects in GERD patients. Nevertheless, the estrogen-related endocrine milieu may prevent disease progression toward carcinogenesis in GERD patients. The development of innovative alternatives to conventional acid suppressors may become possible by clarifying the mechanisms of estrogen.

Association of Visceral Fat Area, Smoking, and Alcohol Consumption with Reflux Esophagitis and Barrett's Esophagus in Japan

BACKGROUND

Central obesity has been suggested as a risk factor for gastroesophageal reflux disease. The aim of this study was to evaluate the association of visceral fat area and other lifestyle factors with reflux esophagitis or Barrett's esophagus in Japanese population.

METHODS

Individuals who received thorough medical examinations including the measurement of visceral fat area by abdominal computed tomography were enrolled. Factors associated with the presence of reflux esophagitis, the severity of reflux esophagitis, or the presence of Barrett's esophagus were determined using multivariable logistic regression models.

RESULTS

A total of 2608 individuals were eligible for the analyses. Visceral fat area was associated with the presence of reflux esophagitis both in men (odds ratio, 1.21 per 50 cm2; 95% confident interval, 1.01 to 1.46) and women (odds ratio, 2.31 per 50 cm2; 95% confident interval, 1.57 to 3.40). Current smoking and serum levels of triglyceride were also associated with the presence of reflux esophagitis in men. However, significant association between visceral fat area and the severity of reflux esophagitis or the presence of Barrett's esophagus was not shown. In men, excessive alcohol consumption on a drinking day, but not the frequency of alcohol drinking, was associated with both the severity of reflux esophagitis (odds ratio, 2.13; 95% confident interval, 1.03 to 4.41) and the presence of Barrett's esophagus (odds ratio, 1.71; 95% confident interval, 1.14 to 2.56).

CONCLUSION

Visceral fat area was independently associated with the presence of reflux esophagitis, but not with the presence of Barrett's esophagus. On the other hand, quantity of alcohol consumption could play a role in the development of severe reflux esophagitis and Barrett's esophagus in Japanese population.