Esophageal cancer and diet--a case-control study

Dietary habits, nutrition and esophageal cancer: A case-control study on Kazakhs in Xinjiang

OBJECTIVE

To explore associations between dietary habits and esophageal epithelial cell carcinoma (ESCC) and provide a potential direction for exploring how different dietary habits and nutrient intake might affect ESCC development.

METHODS

198 ESCC cases and 200 controls on Kazakhs were recruited in Xinjiang from 2010 to 2019 for a group-matched case-control study. The case group were recruited from the First Affiliated Hospital of Xinjiang Medical University and Affiliated Cancer Hospital of Xinjiang Medical University. The control population were recruited from two parts: hospital-based control and population-based control. The diagnosis was confirmed by histological examination. The food frequency questionnaire was used to investigate the dietary nutrients intake. Folic acid, vitamin B12, and DNA-methyltransferase 1(DNMT1) levels were measured in serum samples obtained from cases and controls.

RESULTS

The cholesterol intake of ESCC group was significantly higher than that of the control group while the intakes of protein, thiamin, riboflavin, folic acid, vitamin A, B6, C and E were significantly lower than the control group. Factors including lacking fresh vegetables and fruits, low educational level, low income, alcohol drinking, eating solid and dry food and smoked meat, dieting irregularly, salty taste preference, low serum folic acid level and high serum DNMT1 level were associated with increased risk of ESCC in Kazakhs.

CONCLUSION

Dietary habits and nutrient intake were associated with increased risk of ESCC in Kazakhs that may provide a potential direction for further studies.

The methylenetetrahydrofolate reductase C677T polymorphism influences risk of esophageal cancer in Chinese

Methylenetetrahydrofolate reductase (MTHFR) plays a central role in folate metabolism. This study with 381 esophageal cancer patients and 432 healthy controls was conducted to examine the association of MTHFR C677T and A1298C polymorphisms with susceptibility to esophageal cancer (EC) in a Chinese population. Compared with the CC genotype of MTHFR C677T, subjects carrying homozygote TT and variant genotypes (CT+TT) demonstrated reduced risk of EC with adjusted ORs (95% CI) of 0.44 (0.28-0.71) and 0.57 (0.37-0.88), respectively. However, no association was found between the MTHFR A1298C polymorphism and the risk of EC. Comparing to haplotype CA, haplotypes TA and TC could reduce the susceptibility to EC with adjusted ORs (95% CI) of 0.61(0.47-0.79) and 0.06 (0.01-0.43), respectively. In conclusion, the present study suggested that the MTHFR C677T polymorphism can markedly influence the risk of EC in Chinese.

Evaluation of MTHFR677C>T polymorphism in prediction and prognosis of esophageal squamous cell carcinoma: a case-control study in a northern Indian population

Early diagnosis and better prognosis of esophageal squamous cell carcinoma (ESCC) is still a challenge. Besides environmental risk factors, nutritional deficiencies have an established role in pathogenesis of ESCC. Folate deficiency and functional polymorphisms in folate metabolizing genes such as methylene tetrahydrofolate reductase (MTHFR) 677C>T may have oncogenic role through disruption of normal DNA methylation pattern, synthesis, and impaired DNA repair. MTHFR677C>T or A222V (rs1801133) polymorphism has conflicting role in susceptibility to ESCC among different populations. Thus, we aimed to study the role of MTHFR677C>T polymorphism in susceptibility, survival, and interaction with environmental risk factors in ESCC patients from a northern Indian population. A case control study was performed in 208 ESCC incident cases (including 114 follow-up cases) and 223 healthy controls, and genotyping was done by PCR-RFLP. Our results show no significant association of MTHFR677C>T polymorphism with ESCC, tumor locations, or gender of subjects. However, we found a trend of decreased risk of ESCC due to interaction of MTHFR677CT genotype with smoking and alcohol intake. Kaplan Meier, and Cox regression survival analysis showed no prognostic impact of MTHFR677C>T polymorphism in ESCC patients. In conclusion, MTHFR677C>T polymorphism does not seem to have significant role either in susceptibility or survival of ESCC in a northern Indian population.

Association of methylenetetrahydrofolate reductase and thymidylate synthase promoter polymorphisms with genetic susceptibility to esophageal and cardia cancer in a Chinese high-risk population

Methylenetetrahydrofolate reductase (MTHFR) and thymidylate synthase (TS) are key enzymes in folate metabolism, which is essential for normal DNA methylation and synthesis. Common polymorphisms at the MTHFR nucleotides position 677 (C-T) and a 28-bp tandem repeat polymorphism (2R or 3R) in the TS promoter enhancer region (TSER) have been reported to be functional and are supposed to disturb the normal DNA methylation and synthesis leading to carcinogenesis. To investigate the association between these polymorphisms and the risk of esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinoma (GCA), we conducted a case-control study in the Anyang area where the incidence of ESCC is highest in northern China. Subjects consisted of 275 cases with ESCC, 129 cases with GCA and 310 sex- and age-matched cancer-free controls. The risk was evaluated in terms of age-sex adjusted odds ratios (ORs) and 95% confidence intervals (CIs) by unconditional logistic regression model. The ORs for the MTHFR677TT genotype compared with the MTHFR677CC/CT genotype were 1.62 (95% CI = 1.15-2.30) and 1.81 (1.17-2.81) for ESCC and GCA, respectively. The ORs for the TSER 2R/2R genotype relative to the other genotypes were 2.44 (0.89-6.73) and 3.94 (1.29-12.0) for SCC and GCA, respectively. These findings indicated that the folate metabolism plays an important role in carcinogenesis of ESCC and GCA and the common functionally polymorphisms MTHFRC677T and TSER have substantial influence in this metabolic pathway.

Diet and cancer prevention

Dietary effects are presumed to underlie many of the large international differences in incidence seen for most cancers. Apart from alcohol and a few micronutrients, however, the role of specific nutritional factors remains ill-defined. The evidence for a role of energy balance, physical inactivity, and obesity has strengthened, while for dietary fat it has weakened. Phytochemicals such as folate, lycopene and flavonoids are still the subject of active research. As the mechanisms underlying human carcinogenesis are better understood, dietary research will focus increasingly on intermediate markers such as the insulin-like growth factors and potentially carcinogenic metabolites.

Methylenetetrahydrofolate reductase C677T polymorphism and predisposition towards esophageal squamous cell carcinoma in a German Caucasian and a northern Chinese population

PURPOSE

Folate deficiency is considered to increase the risk of developing esophageal cancer. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme involved in folate metabolism. A single C --> T substitution at nucleotide 677 of the MTHFR cDNA influences enzyme activity. The purpose of this study is to compare the association of the MTHFR C677T polymorphism with susceptibility to esophageal squamous cell carcinoma (ESCC).

METHODS

Using real-time PCR and melting curve analysis, the MTHFR C677T genotypes were determined in 430 patients with ESCC (241 German Caucasians and 189 northern Chinese) and 397 unrelated healthy controls (256 German Caucasians and 141 northern Chinese).

RESULTS

A significant difference in MTHFR C677T genotype distribution was observed between German Caucasian controls (C/C, 41.8%, C/T, 44.9%, T/T, 13.3%) and northern Chinese controls (C/C, 17.7%, C/T, 38.3%, T/T, 44.0%) (chi(2)=52.19, P<0.001). The distribution of the MTHFR C677T genotypes among German ESCC patients (C/C, 39.0%, C/T, 48.1%, T/T, 12.9%) was not significantly different from that among healthy controls (chi(2)=0.531, P=0.767). In contrast, the frequency of the C/C genotype among Chinese ESCC patients (8.5%) was significantly lower than among Chinese healthy controls (17.7%) (chi(2)=6.37, P=0.012). The C/C genotype was correlated with a significantly reduced risk for the development of ESCC as compared to the combination of C/T and T/T genotypes (adjusted OR=0.38, 95% CI=0.16-0.88).

CONCLUSIONS

Our results suggest that, in contrast to German Caucasians, the MTHFR 677CC homozygous wild-type plays a protective role in the development of ESCC in the northern Chinese population.

Diet and oral, pharyngeal, and esophageal cancer

Cancers of the upper digestive tract, including those arising in the oral cavity, pharynx, and esophagus, present a significant public health problem worldwide. These cancers are associated with high morbidity and mortality, and identification of protective factors is very important. A number of epidemiological studies have examined the association between vegetables, fruits, carotene, vitamin A, vitamin C, and vitamin E and oral, pharyngeal, and esophageal cancers. The results of 35 epidemiological studies, including one prospective cohort study, one nested case-control study, two randomized controlled trials, nine population-based case-control studies, and 22 hospital-based case-control studies, in addition to in vitro and animal studies, were examined to determine whether the criteria for causal assumption were satisfied for a protective role of these dietary components against development of oral, pharyngeal, and esophageal cancers. There is enough evidence to point to a preventive role of vegetable intake, including green vegetables, cruciferous vegetables, and yellow vegetables, total fruit intake, and citrus fruit intake. Yellow fruits are likely to be protective. Carotene, vitamin C, and vitamin E are protective, most likely in combination with each other and other micronutrients. The role of vitamin A is not clear because of conflicting findings in the studies reviewed.

Role of dietary habits in the development of esophageal cancer in Assam, the north-eastern region of India

The etiology of esophageal cancer remains largely unknown. In recent years, the role of dietary habits in the development of esophageal cancer has received much attention. Prevalence of esophageal cancer in Assam is highest among all the states of India. To identify the possible risk factors, a hospital-based case-control study was conducted with 502 cases and 1,004 controls. "Kalakhar," a unique and locally made food item, has emerged as a significant risk factor (odds ratio = 8.0, 95% confidence interval = 5.1-11.5, p < 0.001). Consumption of very spicy foods, hot foods and beverages, a diet containing high amounts of chili, and leftover food was positively associated with the risk of esophageal cancer. Green leafy vegetables and fruits were protective for esophageal cancer. The risk factors associated with consumption of locally prepared food items, e.g., kalakhar, and some dietary practices did not decrease, even after adjustments with different confounding factors. However, further studies are required to conclusively implicate these factors in causation of esophageal cancer.

Effects of zinc and nutritional status on clinical outcomes in head and neck cancer

The head and neck cancer patient often presents with both protein malnutrition and trace element deficiencies. Zinc has been found to be deficient in many head and neck cancer patients. In this study, pretreatment zinc status and nutritional status (measured by the Prognostic Nutritional Index [PNI]) were correlated with clinical outcomes in 47 patients. The patients were followed-up for a median of 52 mo from the time of enrollment. Our results showed that the tumor size and overall stage correlated significantly to zinc status whereas no such correlation was seen with PNI, alcohol intake, or smoking in our subjects. The results also showed that impaired zinc status was associated with an increased number of treatment morbidities, unplanned hospitalizations, and treatment delays (P < 0.05). Nutritional status was not associated with any studied outcome variable. The disease-free interval was highest for the group which had both zinc-sufficient and nutrition-sufficient status. Although our data do not prove conclusively, they do suggest that impaired zinc status at presentation may contribute to treatment morbidity, and that for an optimal mean disease-free interval, a sufficient zinc and nutritional status is required.

Correlation between the levels of certain carcinogenic and anticarcinogenic trace elements and esophageal cancer in northern Iran

Levels of four carcinogenic (Ni, Fe, Cu, Pb) and four anticarcinogenic (Zn, Se, Mn, Mg) trace elements were measured in hair samples from esophageal cancer patients, their unaffected family members, and members of families with no history of cancer. Measurements were also made in non-esophageal cancer patients, using atomic absorption spectroscopy, inductively coupled plasma-emission spectroscopy, and neutron activation analysis. The results showed that Ni and Cu concentrations were significantly higher and Mg and Mn concentrations were significantly lower in all cancer cases. Levels of Zn, Fe, Se, and Pb were not significantly different in the above-mentioned groups. In addition, the serum albumin fraction, which is reported to have antioxidant activity, was found to be significantly lower among esophageal cancer patients.

A case study of nutrient intervention of oral precancerous lesions in India

Tobacco chewing and/or smoking are strongly related to several cancers, mainly of the upper aerodigestive tract. Several studies on diet and cancer links suggest that micronutrients, particularly antioxidant vitamins and minerals, are risk modifiers of cancers of epithelial origin. This study looks at the impact of micronutrients such as vitamin A, riboflavin, zinc and selenium as intervention agents in subjects with and without precancerous lesions in a high risk group (reverse smokers of chutta-rolled tobacco leaf). Reverse smokers from four villages were enrolled in the study. 150 subjects were supplemented with four nutrients, namely vitamin A, riboflavin, zinc and selenium in the form of a capsule twice a week for 1 year. 148 controls received a placebo capsule containing lactose for the same period. Clinical history and anthropometric data were collected from all the subjects and a clinical photograph of the palate was taken. Micronutrients were estimated in random blood collected from a sub-sample before and after the study. Micronutrients improved the vitamin A, riboflavin and selenium nutriture in the supplemented group with a concomittant regression of precancerous lesions present on the palate. Clinically complete remission of white, red and combination lesions was seen in 57% of subjects on supplements whereas 8% on placebo showed a positive response. Further progression of these lesions was seen in 10% of the supplemented group compared with 47% in the placebo group (P < 0.001). In the non-lesion group, new lesions appeared in 12% on supplements while more than 38% on the placebo developed new lesions (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Folate and cancer: A review of the literature

Folate, a water-soluble vitamin, part of the vitamin B complex, plays an important role in methylation reactions and DNA/RNA synthesis. This review examines the experimental and epidemiological evidence for the association between folate status and risk of cancer. Data have accumulated indicating that low folate status may promote carcinogenesis. Low folate levels are associated with cytogenetic abnormalities in vivo and in vitro. Findings from animal studies are conflicting and suggest that the effect of folate on neoplasia depends on factors such as the animal and tumor model, the type, timing, dose, and length of application of carcinogen, the stage of carcinogenesis, and the level and form of folate administered. Epidemiological studies examined the association between folate and cancer of the cervix, colorectum, lung, esophagus, and brain and suggest that low folate status may play an important role early in the neoplastic process. The potential for inhibition of precursor lesions in the cervix and colorectum, namely, cervical intraepithelial neoplasia and adenomatous polyps, respectively, is of particular interest. Additional research designed to clarify the role of folate in carcinogenesis is warranted.