Risk factors for esophageal cancer in a low-incidence area of Brazil

High intake of cruciferous vegetables reduces the risk of gastrointestinal cancers: results from observational studies

The relationship between cruciferous vegetables (CV) and the risk of gastrointestinal (GI) cancers has been extensively investigated. However, epidemiologic investigations have produced inconsistent results. This meta-analysis investigated the association between CV intake and the risk of GI cancers. Due to the heterogeneity, fixed- or random-effects models were used for the analyses. The final analysis included 81 articles covering 89 studies. In comparison to the lowest consumption categories, the highest consumption categories of CV were associated with a lower risk for all GI cancers [rate ratio (RR): 0.81, 95% confidence interval (95% CI) 0.76-0.87]. Compared to a CV intake of 75 g/day, subjects with CV intake <75 g/day experienced a 7% reduction in risk (RR: 0.93; 95% CI: 0.84-0.96) for each 50 g increase in consumption. A negative correlation was identified between CV intake and the risk of esophageal cancer, gastric cancer, liver cancer, pancreatic cancer, and colorectal cancer (CRC), but not gallbladder cancer (RR: 0.70; 95% CI: 0.38-1.27). High intake of broccoli and cabbage was associated with a decreased risk of gastric cancer (RR: 0.64; 95% CI: 0.47-0.87) and gallbladder cancer (RR: 0.46; 95% CI: 0.29-0.75). These results confirm the association between high intake of CV with a reduced risk of GI cancers.

Wood cookstove use is associated with gastric cancer in Central America and mediated by host genetics

Biomass cookstove food preparation is linked to aero-digestive cancers, mediated by ingested and inhaled carcinogens (e.g., heterocyclic amines, and polycyclic aromatic hydrocarbons). We investigated the association between gastric adenocarcinoma, wood cookstove use, H. pylori CagA infection and risk modification by variants in genes that metabolize and affect the internal dose of carcinogens. We conducted a population-based, case-control study (814 incident cases, 1049 controls) in rural Honduras, a high-incidence region with a homogeneous diet and endemic H. pylori infection, primarily with the high-risk CagA genotype. We investigated factors including wood cookstove use, H. pylori CagA serostatus, and 15 variants from 7 metabolizing genes, and the interactions between wood stove use and the genetic variants. Male sex (OR 2.0, 1.6-2.6), age (OR 1.04, 1.03-1.05), wood cookstove use (OR 2.3, 1.6-3.3), and CagA serostatus (OR 3.5, 2.4-5.1) and two SNPs in CYP1B1 (rs1800440 and rs1056836) were independently associated with gastric cancer in multivariate analysis. In the final multivariate model, a highly significant interaction (OR 3.1, 1.2-7.8) was noted between wood cookstove use and the rs1800440 metabolizing genotype, highlighting an important gene-environment interaction. Lifetime wood cookstove use associates with gastric cancer risk in the high-incidence regions of Central America, and the association is dependent on the rs1800440 genotype in CYP1B1. H. pylori CagA infection, wood cookstove use and the rs1800440 genotype, all of which are highly prevalent, informs who is at greatest risk from biomass cookstove use.

Exposure to wildfire-related PM2.5 and site-specific cancer mortality in Brazil from 2010 to 2016: A retrospective study

BACKGROUND

Long-term exposure to fine particles ≤2.5 μm in diameter (PM2.5) has been linked to cancer mortality. However, the effect of wildfire-related PM2.5 exposure on cancer mortality risk is unknown. This study evaluates the association between wildfire-related PM2.5 and site-specific cancer mortality in Brazil, from 2010 to 2016.

METHODS AND FINDINGS

Nationwide cancer death records were collected during 2010-2016 from the Brazilian Mortality Information System. Death records were linked with municipal-level wildfire- and non-wildfire-related PM2.5 concentrations, at a resolution of 2.0° latitude by 2.5° longitude. We applied a variant difference-in-differences approach with quasi-Poisson regression, adjusting for seasonal temperature and gross domestic product (GDP) per capita. Relative risks (RRs) and 95% confidence intervals (CIs) for the exposure for specific cancer sites were estimated. Attributable fractions and cancer deaths were also calculated. In total, 1,332,526 adult cancer deaths (age ≥ 20 years), from 5,565 Brazilian municipalities, covering 136 million adults were included. The mean annual wildfire-related PM2.5 concentration was 2.38 μg/m3, and the annual non-wildfire-related PM2.5 concentration was 8.20 μg/m3. The RR for mortality from all cancers was 1.02 (95% CI 1.01-1.03, p < 0.001) per 1-μg/m3 increase of wildfire-related PM2.5 concentration, which was higher than the RR per 1-μg/m3 increase of non-wildfire-related PM2.5 (1.01 [95% CI 1.00-1.01], p = 0.007, with p for difference = 0.003). Wildfire-related PM2.5 was associated with mortality from cancers of the nasopharynx (1.10 [95% CI 1.04-1.16], p = 0.002), esophagus (1.05 [95% CI 1.01-1.08], p = 0.012), stomach (1.03 [95% CI 1.01-1.06], p = 0.017), colon/rectum (1.08 [95% CI 1.05-1.11], p < 0.001), larynx (1.06 [95% CI 1.02-1.11], p = 0.003), skin (1.06 [95% CI 1.00-1.12], p = 0.003), breast (1.04 [95% CI 1.01-1.06], p = 0.007), prostate (1.03 [95% CI 1.01-1.06], p = 0.019), and testis (1.10 [95% CI 1.03-1.17], p = 0.002). For all cancers combined, the attributable deaths were 37 per 100,000 population and ranged from 18/100,000 in the Northeast Region of Brazil to 71/100,000 in the Central-West Region. Study limitations included a potential lack of assessment of the joint effects of gaseous pollutants, an inability to capture the migration of residents, and an inability to adjust for some potential confounders.

CONCLUSIONS

Exposure to wildfire-related PM2.5 can increase the risks of cancer mortality for many cancer sites, and the effect for wildfire-related PM2.5 was higher than for PM2.5 from non-wildfire sources.

A multinational review: Oesophageal cancer in low to middle-income countries

Oesophageal cancer (OC) is an aggressive neoplasm that manifests in the gastrointestinal tract and is the result of numerous factors that can contribute to the development of the disease. These may include old age, nutritional deficiencies, oesophageal obstruction and food ingestion difficulties. Environmental factors serve a large role in increasing the risk of developing OC. Two factors that serve an increasing risk of developing OC are the use of tobacco and the consumption of alcohol. Genetic factors also exhibit a large effect on the risk of developing OC, for example, the causative genes in Black Africans differ from other races. OC is 3–4 times more common among men than women. OC has been previously reported in >450 000 individuals worldwide, and its incidence is increasing. The current review compares OC in low to middle-income countries with developed countries. The incidence of OC, particularly squamous cell carcinoma (SCC) is high in low and middle-income countries. In developed countries, the incidence of SCC is low compared with adenocarcinoma. The majority of OC cases are diagnosed in the late stages of the disease, leading to high mortality rates. The current review aimed to discuss factors that contribute to the development of this disease in different geographical areas and genetic mechanisms governing these findings. The current review also aims to discuss the preventative treatment options for the disease, and also discusses the diagnosis and surveillance in five LMICs, including South Africa, China, Tanzania, India and Brazil.

Chemoradiotherapy With or Without Surgery for Esophageal Squamous Cancer According to Hospital Volume

PURPOSE

Esophageal squamous cell cancer (ESCC) is still associated with a dismal prognosis. However, surgical series have shown that high-volume hospitals have better outcomes and that the impact of center volume on definitive chemoradiotherapy (dCRT) or CRT plus surgery (CRT + S) remains unknown.

METHODS

We performed a retrospective analysis of patients with locally advanced stage II-III (non-T4) ESCC treated with dCRT or CRT + S in São Paulo state, Brazil. Descriptive variables were assessed with the χ2 test after categorization of hospital volume (high-volume [HV] center, top 5 higher volume, or low-volume [LV] center). Overall survival (OS) was assessed with Kaplan-Meier curves, log-rank tests, and Cox proportional hazards. Finally, an interaction test between each facility's treatments was performed.

RESULTS

Between 2000 and 2013, 1,347 patients were analyzed (77% treated with dCRT and 65.7% in HV centers) with a median follow-up of 23.7 months. The median OS for dCRT was 14.1 months (95% CI, 13.3 to 15.3 months) and for CRT + S, 20.6 months (95% CI, 16.1 to 24.9 months). In the multivariable analysis, dCRT was associated with worse OS (hazard ratio [HR], 1.38; 95% CI, 1.19 to 1.61; P < .001) compared with CRT + S. HV hospitals were associated with better OS (HR, 0.82; 95% CI, 0.71 to 0.94; P = .004) compared with LV hospitals. Importantly, CRT + S superiority was restricted to HV hospitals (dCRT v CRT + S: HR, 1.56; 95% CI, 1.29 to 1.89; P < .001), while in LV hospitals, there was no statistically significant difference (HR, 1.23; 95% CI, 0.88 to 1.43; P = .350), with a significant interaction test (Pinteraction = .035).

CONCLUSION

Our data show that CRT + S is superior to dCRT in the treatment of ESCC exclusively in HV hospitals, which favors the literature trend to centralize the treatment of ESCC in HV centers.

Household Fuel Use and the Risk of Gastrointestinal Cancers: The Golestan Cohort Study

BACKGROUND

Three billion people burn nonclean fuels for household purposes. Limited evidence suggests a link between household fuel use and gastrointestinal (GI) cancers.

OBJECTIVES

We investigated the relationship between indoor burning of biomass, kerosene, and natural gas with the subsequent risk of GI cancers.

METHODS

During the period 2004-2008, a total of 50,045 Iranian individuals 40-75 years of age were recruited to this prospective population-based cohort. Upon enrollment, validated data were collected on demographics, lifestyle, and exposures, including detailed data on lifetime household use of different fuels and stoves. The participants were followed through August 2018 with < 1 % loss.

RESULTS

During the follow-up, 962 participants developed GI cancers. In comparison with using predominantly gas in the recent 20-y period, using predominantly biomass was associated with higher risks of esophageal [hazard ratio (HR): 1.89; 95% confidence interval (CI): 1.02, 3.50], and gastric HR: 1.83; 95% CI: 1.01, 3.31) cancers, whereas using predominantly kerosene was associated with higher risk of esophageal cancer (HR: 1.84; 95% CI: 1.10, 3.10). Lifetime duration of biomass burning for both cooking and house heating (exclusive biomass usage) using heating-stoves without chimney was associated with higher risk of GI cancers combined (10-y HR: 1.14; 95% CI: 1.07, 1.21), esophageal (10-y HR: 1.19; 95% CI: 1.08, 1.30), gastric (10-y HR: 1.11; 95% CI: 1.00, 1.23), and colon (10-y HR: 1.26; 95% CI: 1.03, 1.54) cancers. The risks of GI cancers combined, esophageal cancer, and gastric cancer were lower when biomass was burned using chimney-equipped heating-stoves (strata difference p -values = 0.001 , 0.003, and 0.094, respectively). Duration of exclusive kerosene burning using heating-stoves without chimney was associated with higher risk of GI cancers combined (10-y HR: 1.05; 95% CI: 1.00, 1.11), and esophageal cancer (10-y HR: 1.14; 95% CI: 1.04, 1.26).

DISCUSSION

Household burning of biomass or kerosene, especially without a chimney, was associated with higher risk of some digestive cancers. Using chimney-equipped stoves and replacing these fuels with natural gas may be useful interventions to reduce the burden of GI cancers worldwide. https://doi.org/10.1289/EHP5907.

Biomass Smoke Exposure Is Associated With Gastric Cancer and Probably Mediated Via Oxidative Stress and DNA Damage: A Case-Control Study

PURPOSE

We investigated the association between gastric cancer and environmental and dietary exposures. In addition, we explored probable mechanistic pathways for the influence of biomass smoke on gastric carcinogenesis.

PATIENTS AND METHODS

The study was conducted in Lusaka, Zambia. Questionnaires were used to collect data on risk factors, whereas enzyme-linked immunosorbent assays and high-performance liquid chromatography were used to measure biologic exposures. Study data were analyzed using contingency tables and logistic regression.

RESULTS

We enrolled 72 patients with gastric adenocarcinoma and 244 controls. Gastric cancer was positively associated with rural residence (odds ratio [OR], 2.9; 95% CI, 1.5 to 5.3), poverty (OR, 4.2; 95% CI, 1.9 to 9.1), and daily consumption of processed meat (OR, 6.4; 95% CI, 1.3 to 32) and negatively associated with consumption of green vegetables (OR, 0.2; 95% CI, 0.1 to 0.5). Gastric cancer was also associated with biomass smoke exposure (OR, 3.5; 95% CI, 1.9 to 6.2; P < .0001), an association that was stronger for intestinal-type cancers (OR, 3.6; 95% CI, 1.5 to 9.1; P = .003). Exposure to biomass smoke in controls was associated with higher urinary levels of 8-isoprostane (P < .0001), 8-hydroxydeoxyguanosine (P = .029), and 1-hydroxypyrene (P = .041). Gastric cancer was not associated with biochemical measures of current exposure to aflatoxins or ochratoxins.

CONCLUSION

In Zambia, exposure to biomass smoke, daily consumption of processed meat, and poverty are risk factors for gastric cancer, whereas daily consumption of green vegetables is protective against gastric cancer. Exposure to biomass smoke was associated with evidence of oxidative stress and DNA damage, suggesting mechanistic plausibility for the observed association, and the association was restricted to intestinal-type gastric cancer.

Biomass fuel as a risk factor for esophageal squamous cell carcinoma: a systematic review and meta-analysis

BACKGROUND

The link between use of solid biomass fuel (wood, charcoal, coal, dung, and crop residues) for cooking and/or heating and esophageal squamous cell carcinoma (ESCC) is inconclusive.

OBJECTIVE

We systematically reviewed the literature and performed a meta-analysis to determine whether cooking fuel type influences esophageal squamous cell carcinoma.

METHODS

We searched MEDLINE, EMBASE, Web of Knowledge and Cochrane Database of Systematic Reviews for studies investigating cooking fuel and ESCC from 2000 until March 2019. We performed random effects meta-analysis stratified by the continent, World Bank's country income classifications and fuel type and calculated pooled odds ratios and 95% CIs for the risk of esophageal squamous cell carcinoma in biomass fuel users compared with non-users.

RESULTS

Our analysis included 16 studies (all case-control) with 16,189 participants (5233 cases and 10,956 controls) that compared risk of ESCC among those using nonsolid fuels and biomass fuels. We found use of biomass fuel was associated with Esophageal squamous cell carcinoma with a pooled odds ratio (OR) 3.02 (95% CI 2.22, 4.11, heterogeneity (I2) = 79%). In sub-group analyses by continent, Africa (OR 3.35, 95%CI 2.34, 4.80, I2 = 73.4%) and Asia (OR 3.08, 95%CI 1.27, 7.43, I2 = 81.7%) had the highest odds of ESCC. Use of wood as fuel had the highest odds of 3.90, 95% CI 2.25, 6.77, I2 = 63.5%). No significant publication bias was detected.

CONCLUSIONS

Biomass fuel is associated with increased risk of Esophageal squamous cell carcinoma. Biomass fuel status should be considered in the risk assessment for Esophageal squamous cell carcinoma.

Systematic review: the etiology of esophageal squamous cell carcinoma in low-income settings

Esophageal carcinoma causes over 380 000 deaths per year, ranking sixth worldwide in mortality amongst all malignancies. Globally, the squamous cell subtype is most common and accounts for 80% of esophageal cancers. Nonetheless, esophageal squamous cell carcinoma is much more poorly understood than esophageal adenocarcinoma, including what is driving such high prevalences, why it often presents in young patients, and shows such marked geographical delineations Areas covered: The current literature was searched for articles focusing on aetiopathogenesis of squamous cell esophageal carcinoma via a systematic review, particularly in low-resource settings. This was supplemented by papers of interest known to the authors. Expert commentary: Current putative mechanisms include polycyclic aromatic hydrocarbons, nitrosamines, acetaldehyde, cyclo-oxygenase-2 pathways, androgen and their receptor levels, as well as smoking & alcohol, micronutrient deficiencies and diet, mycotoxins, thermal damage, oral hygiene and microbiotal factors, inhaled smoke, viral infections such as HPV, and chronic irritative states. Etiology is likely multifactorial and varies geographically. Though smoking and alcohol play a predominant role in high-income settings, there is strong evidence that mycotoxins, diet and temperature effects may play an under-recognized role in low and middle-income settings.

Exposure to biomass smoke as a risk factor for oesophageal and gastric cancer in low-income populations: A systematic review

Background

Upper gastrointestinal cancers contribute significantly to cancer-related morbidity and mortality in sub-Saharan Africa, but they continue to receive limited attention. The high incidence in young adults remains unexplained, and the risk factors have not been fully described.

Methods

A literature search was conducted using the electronic database PubMed. Beginning from January 1980 to February 2016, all articles evaluating biomass smoke exposure with oesophageal and gastric cancer were reviewed.

Results

Over 70% of the African population relies on biomass fuel, meaning most Africans are exposed to biomass smoke throughout their lives. Cigarette smoke is an established risk factor for upper gastrointestinal cancers, and some of its carcinogenic constituents are also present in biomass smoke. We found eight case-control studies reporting associations between exposure to biomass smoke and oesophageal cancer, and two linking biomass smoke to gastric cancer. All of these papers reported significant positive associations between exposure and cancer risk. Further research is needed in order to fully define the constituents of biomass smoke, which could each have varying specific and synergistic or independent contributions to the development of upper gastrointestinal cancers

Conclusions

Exposure to biomass smoke is an environmental factor influencing the development of upper gastrointestinal cancers, especially in low-resource settings.

Mutational profile of TP53 in esophageal squamous cell carcinoma associated with chagasic megaesophagus

Chaga's disease is an important communicable neglected disease that is gaining wider attention due to its increasing incidence worldwide. Achalasia due to chagasic megaesophagus (CM), a complication of this disease, is a known-yet, poorly understood-etiological factor for esophageal squamous cell carcinoma (ESCC) development. In this study, we aimed to perform the analysis of TP53 mutations in a series of Brazilian patients with ESCC that developed in the context CM (ESCC/CM), and to compare with the TP53 mutation profile of patients with benign CM and patients with nonchagasic ESCC. Additionally, we intended to correlate the TP53 mutation results with patient's clinical pathological features. By polymerase chain reaction (PCR) followed by direct sequencing of the hotspot regions of TP53 (exon 5 to 8), we found that TP53 mutations were present in 40.6% (13/32) of the ESCC/CM group, 45% (18/40) of the nonchagasic ESCC group, and in only 3% (1/33) of the benign CM group. Missense mutations were the most common in the three groups, yet, the type and mutated exon mutation varied significantly among the groups. Clinically, the groups exhibited distinct features, with both cancer groups (ESCC and ESCC/CM) been significantly associated higher consumption of alcohol and tobacco, older age, worse Karnofsky performance status, poor outcome than the patients with benign CM. No significant association was found between TP53 mutation profile and clinical-pathological features in any of the three groups. We describe first the time the analysis of TP53 mutations in ESCC that developed in the context of CM, and the observed high frequency of mutations, suggest that TP53 also plays an important role in the tumorigenic process of this unexplored etiological condition.

Environmental risk factors for oesophageal cancer in Malawi: A case-control study

AIM

There is a high burden of oesophageal cancer in Malawi with dismal outcomes. It is not known whether environmental factors are associated with oesophageal cancer. Without knowing this critical information, prevention interventions are not possible. The purpose of this analysis was to explore environmental factors associated with oesophageal cancer in the Malawian context.

METHODS

A hospital-based case-control study of the association between environmental risk factors and oesophageal cancer was conducted at Kamuzu Central Hospital in Lilongwe, Malawi and Queen Elizabeth Central Hospital in Blantyre, Malawi. Ninety-six persons with squamous cell carcinoma and 180 controls were enrolled and analyzed. These two groups were compared for a range of environmental risk factors, using logistic regression models. Unadjusted and adjusted odds ratios and 95% confidence intervals (CI) were calculated.

RESULTS

Firewood cooking, cigarette smoking, and use of white maize flour all had strong associations with squamous cell carcinoma of the oesophagus, with adjusted odds ratios of 12.6 (95% CI: 4.2-37.7), 5.4 (95% CI: 2.0-15.2) and 6.6 (95% CI: 2.3-19.3), respectively.

CONCLUSIONS

Several modifiable risk factors were found to be strongly associated with squamous cell carcinoma. Research is needed to confirm these associations and then determine how to intervene on these modifiable risk factors in the Malawian context.

HIV infection and domestic smoke exposure, but not human papillomavirus, are risk factors for esophageal squamous cell carcinoma in Zambia: a case-control study

There is emerging evidence that esophageal cancer occurs in younger adults in sub-Saharan Africa than in Europe or North America. The burden of human immunodeficiency virus (HIV) is also high in this region. We postulated that HIV and human papillomavirus (HPV) infections might contribute to esophageal squamous cell carcinoma (OSCC) risk. This was a case–control study based at the University Teaching Hospital in Lusaka, Zambia. Cases were patients with confirmed OSCC and controls had completely normal upper endoscopic evaluations. A total of 222 patients were included to analyze the influence of HIV infection; of these, 100 patients were used to analyze the influence of HPV infection, alcohol, smoking, and exposure to wood smoke. The presence of HIV infection was determined using antibody kits, and HPV infection was detected by polymerase chain reaction. HIV infection on its own conferred increased risk of developing OSCC (odds ratio [OR] 2.3; 95% confidence interval [CI] 1.0–5.1; P = 0.03). The OR was stronger when only people under 60 years were included (OR 4.3; 95% CI 1.5–13.2; P = 0.003). Cooking with charcoal or firewood, and cigarette smoking, both increased the odds of developing OSCC ([OR 3.5; 95% CI 1.4–9.3; P = 0.004] and [OR 9.1; 95% CI 3.0–30.4; P < 0.001], respectively). There was no significant difference in HPV detection or alcohol intake between cases and controls. We conclude that HIV infection and exposure to domestic and cigarette smoke are risk factors for OSCC, and HPV immunization unlikely to reduce OSCC incidence in Zambia.

Epidemiological features of esophageal cancer. Squamous cell carcinoma versus adenocarcinoma

PURPOSE

To analyze the epidemiological features of patients with esophageal cancer according to the histopathological types: squamous cell carcinoma or adenocarcinoma.

METHODS

A total of 100 patients with esophageal cancer, being 50 squamous cell carcinomas and 50 adenocarcinomas were analyzed for demographics, nutritional factors, lifestyle habits, benign pathological conditions associated, like Barrett's esophagus and megaesophagus, tumor stage and survival rates. The nutritional factors evaluated included body mass index, percent weight loss, hemoglobin and albumin serum levels.

RESULTS

Esophageal cancer occurred more often in men over 50 years-old in both histological groups. No significant differences on age and gender were found between the histological groups. Squamous cell carcinoma was significantly more frequent in blacks than adenocarcinoma. Alcohol consumption and smoking were significantly associated with squamous cell carcinoma. Higher values of body mass index were seen in patients with adenocarcinoma. Barrett's esophagus was found in nine patients (18%) with adenocarcinoma, and megaesophagus in two patients (4%) with squamous cell carcinoma. The majority of patients were on stages III and IV in both histological groups. The mean survival rates were 7.7 ± 9.5 months for patients with squamous cell carcinoma and 8.0 ± 10.9 months for patients with adenocarcinoma. No significant differences on tumor stage and survival rates were detected between the histological groups.

CONCLUSION

Epidemiological features are distinct for the histopathological types of esophageal cancer. Squamous cell carcinoma is associated with black race, alcohol and smoking, while adenocarcinoma is related to higher body mass index, white race and Barrett's esophagus.