Epidemiologic panorama of stomach cancer mortality in Mexico

Mortality trends and years of potential life lost from gastric cancer in Mexico, 2000-2012

BACKGROUND

In 2013 in Mexico, gastric cancer (GC) was the third leading cause of death from cancer in individuals 20 years of age or older. GC remains a public health problem in Mexico due to its high mortality and low survival rates, and the significantly lower quality of life of patients with this condition.

OBJECTIVES

The aims of this study were to determine mortality trends nationwide, by state and socioeconomic region, and to determine rates of age-adjusted years of potential life lost due to GC, by state and socioeconomic region, within the period of 2000-2012.

METHODS

Mortality records associated with GC for 2000-2012 were obtained from the National Health Information System of the Mexican Department of Health. Codes from the Tenth Revision of the International Classification of Diseases corresponding to the basic cause of death from GC were identified. Mortality and age-adjusted years of potential life lost rates, by state and socioeconomic region, were also calculated.

RESULTS

In Mexico, 69,107 individuals died from GC within the time frame of 2000-2012. The age-adjusted mortality rate per 100,000 inhabitants decreased from 7.5 to 5.6. The male:female ratio was 1.15:1.0. Chiapas had the highest death rate from GC (9.2, 95% CI 8.2-10.3 [2000] and 8.2, 95% CI 7.3-9 [2012]), as well as regions 1, 2, and 5. Chiapas and socioeconomic region 1 had the highest rate of years of potential life lost.

CONCLUSIONS

Using the world population age distribution as the standard, the age-adjusted mortality rate in Mexico per 100,000 inhabitants that died from GC decreased from 7.5 to 5.6 between 2000 and 2012. Chiapas and socioeconomic regions 1, 2, and 5 had the highest mortality from GC (Chiapas: 9.2, 95% CI 8.2-10.3 [2000] and 8.2, 95% CI 7.3-9 [2012], region 1: 5.5, 95% CI 5.2-5.9 [2000] and 5.3, 95% CI 4.9-5.7 [2012]; region 2: 5.3, 95% CI 5-5.6 [2000] and 5.4, 95% CI 5.1-5.8 [2012]; region 5: 6.1, 95% CI 5.6-6.6 [2000] and 4.6, 95% CI 4.2-5 [2012]). Chiapas and socioeconomic region 1 had the highest rate of years of potential life lost (Chiapas: 97.4 [2000] and 79.6 [2012] and region 1: 73.5 [2000] 65 [2012]).

Prevalence of Helicobacter pylori infection worldwide: a systematic review of studies with national coverage

The systematic assessment of large population-based surveys addressing the prevalence of Helicobacter pylori infection may provide robust evidence for understanding the trends in the exposure to this major risk factor across settings with distinct patterns of gastric cancer variation. Our aim was to describe the prevalence of H. pylori infection in different countries and periods, through systematic review of the literature. We searched PubMed from inception up to September 2013 to identify original studies reporting on the prevalence of H. pylori, and only those evaluating samples with national coverage were included. We identified 37 eligible studies including data for 22 countries. The prevalences were higher in Central/South America and Asia, and at least two-fold higher in countries with high gastric cancer incidence. In most countries presenting data for different time periods, the prevalences were usually lower in the most recent surveys. However, there was little variation in settings where prevalences were already low. Among countries with high prevalence of H. pylori infection there is an ample scope for reducing its burden in the next decades, whereas further declines in settings with already low prevalences will require more intensive efforts.

Omission of breakfast and risk of gastric cancer in Mexico

AIM

To investigate factors associated with gastric cancer (GC) in the Mexican population using a validated questionnaire.

METHODS

We designed and validated in Spanish a Questionnaire to Find Factors Associated with Diseases of the Digestive Tract using GC as a model. A cross-sectional study using 49 subjects, with confirmed histopathological GC diagnosis, and 162 individuals without GC participated. Odds ratio and 95% CIs were estimated in univariate and multivariate analysis adjusted for possible confounding factors. In order to match age groups, a multivariate sub-analysis was performed in subjects ≥ 39 years of age and in females and males separately.

RESULTS

In the univariate analysis, we found an association between GC and education to primary level or below, low socioeconomic status, the use of dental prostheses, omission of breakfast, consumption of very hot food and drink, addition of salt to prepared foods, consumption of salt-preserved foods and the pattern of alcohol consumption. We found protection against GC associated with the use of mouthwash, food refrigeration and regular consumption of fruit and vegetables. In the multivariate sub-analysis with subjects of ≥ 39 years, the omission of breakfast was identified as a risk factor for GC.

CONCLUSION

Our study suggests an association between the omission of breakfast and the failure to refrigerate food with GC in the Mexican population.

Capsaicin consumption, Helicobacter pylori CagA status and IL1B-31C>T genotypes: a host and environment interaction in gastric cancer

Gastric cancer (GC) has been associated with a complex combination of genetic and environmental factors. In contrast to most countries, available information on GC mortality trends showed a gradual increase in Mexico. Our aim was to explore potential interactions among dietary (chili pepper consumption), infectious (Helicobacter pylori) and genetic factors (IL1B-31 genotypes) on GC risk. The study was performed in three areas of Mexico, with different GC mortality rates. We included 158 GC patients and 317 clinical controls. Consumption of capsaicin (Cap), the pungent active substance of chili peppers, was estimated by food frequency questionnaire. H. pylori CagA status was assessed by ELISA, and IL1B-31 genotypes were determined by TaqMan assays and Pyrosequencing in DNA samples. Multivariate unconditional logistic regression was used to estimate potential interactions. Moderate to high Cap consumption synergistically increased GC risk in genetically susceptible individuals (IL1B-31C allele carriers) infected with the more virulent H. pylori (CagA+) strains. The combined presence of these factors might explain the absence of a decreasing trend for GC in Mexico. However, further research on gene-environment interactions is required to fully understand the factors determining GC patterns in susceptible populations, with the aim of recommending preventive measures for high risk individuals.

Dietary intake of polyphenols, nitrate and nitrite and gastric cancer risk in Mexico City

N-nitroso compounds (NOC) are potent animal carcinogens and potential human carcinogens. The primary source of exposure for most individuals may be endogenous formation, a process that can be inhibited by dietary polyphenols. To estimate the risk of gastric cancer (GC) in relation to the individual and combined consumption of polyphenols and NOC precursors (nitrate and nitrite), a population-based case-control study was carried out in Mexico City from 2004 to 2005 including 257 histologically confirmed GC cases and 478 controls. Intake of polyphenols, nitrate and nitrite were estimated using a food frequency questionnaire. High intakes of cinnamic acids, secoisolariciresinol and coumestrol were associated with an approximately 50% reduction in GC risk. A high intake of total nitrite as well as nitrate and nitrite from animal sources doubled the GC risk. Odds ratios around 2-fold were observed among individuals with both low intake of cinnamic acids, secoisolariciresinol or coumestrol and high intake of animal-derived nitrate or nitrite, compared to high intake of the polyphenols and low animal nitrate or nitrite intake, respectively. Results were similar for both the intestinal and diffuse types of GC. Our results show, for the first time, a protective effect for GC because of higher intake of cinnamic acids, secoisolariciresinol and coumestrol, and suggest that these polyphenols reduce GC risk through inhibition of endogenous nitrosation. The main sources of these polyphenols were pears, mangos and beans for cinnamic acids; beans, carrots and squash for secoisolariciresinol and legumes for coumestrol.

Age and severity of mucosal lesions influence the performance of serologic markers in Helicobacter pylori-associated gastroduodenal pathologies

OBJECTIVE

The course of Helicobacter pylori infection and antibody response to CagA in patients with preneoplastic lesions and gastric cancer has not been thoroughly studied. We aimed to study H. pylori infection and antibody response to CagA in patients with non-atrophic gastritis, preneoplastic lesions, and gastric cancer.

METHODS

We studied patients attending one Oncology Hospital and one General Hospital in Mexico City. Diagnosis was based on endoscopy and histopathology in biopsies from six stomach regions. H. pylori infection was assessed by histology and serology, and antibodies against CagA were measured with immunoassay.

RESULTS

We included 618 patients, 368 with non-atrophic gastritis, 126 with precancerous lesions, and 65 with gastric cancer; in addition, 59 patients with duodenal ulcer were studied. Detection of infection and IgG against CagA had a significant increase from non-atrophic gastritis to mild and up to advanced stages of metaplasia (P < 0.05), followed by decreased infection and IgG to CagA in patients with gastric cancer (P < 0.05). However, infection and CagA antibodies were associated with young gastric cancer cases. Duodenal ulcer showed a significant association with infection detected by histology and serology, particularly among women, and a trend to associate with IgG to CagA.

CONCLUSIONS

This study shows that H. pylori infection and CagA are risk markers for intestinal metaplasia. The prevalence of these risk markers decreases in gastric cancer, probably reflecting that infection decreases after advanced atrophy and metaplasia in the gastric mucosa. State of the disease, age, and sex influence the association of H. pylori infection and IgG response to CagA with gastroduodenal diseases.

Screening and identification of ATP/GTP binding protein 1 gene expressed highly in gastric cancer

AIM: To investigate the molecular mechanism of gastric carcinogenesis, screen and validate the genes expressed differently in gastric cancer.

METHODS: Messenger RNA differential display polymerase chain reaction (DD-PCR) was employed to search differently expressed fragments, some of which were cloned and sequenced. By homologous analysis in GenBank, the corresponding homologous genes of those fragments were found. The corresponding genes of those differently expressed fragments were validated by real-time semi-quantitative and quantitative PCR.

RESULTS: By DD-PCR, one expressed sequence tag (EST) was identified to be ATP/GTP binding protein 1 (A/GTPBP1) gene. The result of real-time semi-quantitative and quantitative PCR showed that the expression level of A/GTPBP1 gene in gastric cancer tissues was significantly higher than that in normal tissues. The open reading frame (ORF) of A/GTPBP1 gene, which encodes 1186 amino acids, was 3561-base pair long. The molecular weight was about 84.4 kDa. Protein sequence similarity analysis showed that A/GTPBP1 was a member of the G protein family.

CONCLUSION: The over-expression of AGTPBP1 gene in gastric cancer may play an important role in gastric carcinogenesis.

Hexavalent chromium, yellow water, and cancer: a convoluted saga

In this issue, Beaumont et al report cancer mortality rates associated with exposure to high concentrations of hexavalent chromium in well water in Liaoning Province, China. Contamination of drinking water at these levels has been reported only once before, among a small group in Mexico. The investigation in China is a convoluted tale. The first report indicated an increase in cancer mortality, while a subsequent publication with the same lead author claimed no increased risks. In 2006, the journal publishing the latter paper retracted it because of failure to disclose financial and intellectual input to the paper by outside parties (linked to chromium polluting industries). Beaumont and his colleagues now provide a further reanalysis of these data, showing increased mortality in particular from stomach cancer, but with serious limitations in the data and methods of analysis. These limitations are counterbalanced by the importance of a study of perhaps the highest exposure to hexavalent chromium in water that will ever be experienced by a population large enough to estimate risks of cancer.

Gastric cancer risk in a Mexican population: role of Helicobacter pylori CagA positive infection and polymorphisms in interleukin-1 and -10 genes

Several polymorphisms of the IL1B and IL10 gene promoters have been reported to be associated with gastric cancer risk in Caucasians. However, studies in other populations have shown differing results. We aimed to test for associations between polymorphisms in IL1B (-31 and +3954), IL10-592 and IL1RN variable number of tandem repeats (VNTR) and risk of gastric cancer in a Mexican population. DNA was extracted from sera of 183 gastric adenocarcinoma patients and 377 controls. The IL1B-31, IL1B+3954 and IL10-592 biallelic polymorphisms were discriminated using 5' Nuclease (TaqMan) assays and Pyrosequencing. The IL1RN penta-allelic VNTR polymorphism was genotyped using PCR followed by GeneScan analysis. A significant interaction was found between IL1B-31 and CagA status for the risk of intestinal-type gastric cancer (p = 0.023). Among CagA positive subjects, those with IL1B-31CC genotype had an increased risk of intestinal-type gastric cancer (OR 3.19, 95%CI = 1.05-9.68), compared to carriers of IL1B-31TT genotype. In contrast, among CagA negative subjects, no significant association of IL1B-31CC genotype with gastric cancer was observed. The IL10-592CC genotype was associated with more than doubling of the risk of the intestinal-type gastric cancer (OR, 2.20, 95%CI = 1.04-4.65). A nonsignificantly increased risk for intestinal-type gastric cancer was found in IL1RN*2 carriers (OR 1.49, 95%CI = 0.89-2.50). None of these polymorphisms was significantly related to the risk of diffuse-type gastric cancer. No significant association was found between risk of gastric cancer and the IL1B+3954 polymorphism. Individuals carrying 2 or more of the risk-associated alleles (IL1B-31C, IL1RN *2 and IL10-592C) were at increased risk for intestinal-type gastric cancer, compared to those with 0 or 1 risk-associated allele. The risk from multiple risk-associated alleles was especially high in subjects infected with CagA positive H. pylori. Our results support the identification of the IL1B-31 promoter polymorphism as a useful marker for risk of intestinal type gastric cancer in persons with CagA positive H. pylori infections.

Rabeprazole containing triple therapy to eradicate Helicobacter pylori infection on the Texas-Mexican border

BACKGROUND

Antibiotic resistance and duration of therapy influence the success of proton-pump inhibitor-containing Helicobacter pylori eradication therapy. Clarithromycin resistance is associated with treatment failure.

AIM

To examine the success of a 7-day rabeprazole-clarithromycin-amoxicillin therapy in the study population.

METHODS

Adults from Ciudad Juarez with H. pylori infections identified by culture or histology received rabeprazole 20 mg, clarithromycin 0.5 g and amoxicillin 1 g, each b.d. for 7 days. Outcome was assessed by 13C-urea breath test carried out 4+ weeks after treatment.

RESULTS

A total of 111 patients were enrolled and evaluated by urea breath test; 102 completed the full 7 days therapy. Two deviated from protocol, and five stopped because of adverse events. The cure rate (intention-to-treat) was 85% (95% CI: 78-91%); the per-protocol cure rate was 85% (95% CI: 78-91%). Side-effects were not serious and only 6.6% of those with adverse events stopped medication. Only three isolates were clarithromycin-resistant and none was cured. Compliance explained most of the successes.

CONCLUSIONS

In the study population a 7-day rabeprazole triple eradication therapy was both effective and well-tolerated. Clarithromycin resistance was uncommon. We observed a slightly better outcome but consistent with results from recent large studies in US populations.

[Mortality rate of gastric cancer in the population of Belgrade for 1990-2002 period]

BACKGROUND

Worldwide, gastric cancer is the fourth leading cause of diseases, and the second leading cause of cancer deaths.

AIM

To analyze the differences between men and women in mortality rate of gastric cancer in Belgrade from 1990-2002.

METHODS

Mortality rates standardized directly to the "World population", and regression analysis were used.

RESULTS

In Belgrade population, 29.2% out the total number of deaths attributable to cancer were caused by gastric cancer. Gastric cancer was the second most common cause of death among digestive tract cancers. In women, in the period between 1990 and 1993, an average annual decline of mortality was 9.0% (95% confidence interval (CI) = 5.9-13.1), and between 1994 and 2002, an average annual increase was 10.3% (CI = 8.4-12.6). Mortality rate series of gastric cancer in men did not fit any of the usual trend functions. The male/female gastric cancer mortality ratio was 1.7 : 1. Mortality rates for gastric cancer rose with age in both sexes and they were higest in the age group of 70 and more years. From 1990-2002, in both sexes aged 70 years and more, mortality from gastric cancer rose by 67.2% (CI = 58.0-76.4) in men and by 69.6% (CI = 60.6-78.6) in women. During the same period, the death rates in men decreased by 75.9 % (CI = 67.5-84.4) in the age group of 30-39 years, and by 48.1% (CI = 38.4-57.9) in women aged 50-59 years. In both sexes mortality rate series of all other age groups did not fit any of the usual trend functions.

CONCLUSIONS

The increase in mortality rate of gastric in women over the past few years, showed the necessity of instituting primary and secondary preventive measures.

Trends in cancer mortality in Mexico, 1970–1999

BACKGROUND

Few data on cancer mortality have been published for Mexico over the last few decades. It is therefore of interest to conduct a systematic and updated analysis of cancer mortality in this country.

PATIENTS AND METHODS

Age-standardised (world population) mortality rates, at all ages and truncated at age 35-64 years, from major cancers and all cancers combined were computed on the basis of certified deaths derived from the World Health Organization database for the period 1970-99.

RESULTS

Mortality rates for all neoplasms showed an upward trend in men of all ages (from 58.2/100,000 in 1970-74 to 87.1/100,000 in 1995-99) and in middle-aged men (from 76.1 to 93.7/100,000, respectively). This reflects the rise until the early 1990s in lung cancer mortality (from 8.1/100,000 in 1970-74 to 15.6/100,000 in 1995-99) and prostate cancer (from 5.5 to 12.2/100,000, respectively). In women, overall mortality rates showed an increase between the early 1970s (75.4/100,000) and the late 1990s (82.3/100,000). Total cancer mortality rates remained low, however, compared with other American countries (e.g. 153.3/100,000 men and 108.6/100,000 women in 1999 in the United States). Truncated rates were stable (126.5/100,000 in 1970-74 and 125.8/100,000 in 1995-99), although they were much higher than overall rates, reflecting exceedingly high rates for uterine (mostly cervical) cancer mortality in middle-aged women (29.5/100,000 in 1995-99).

CONCLUSIONS

Total cancer mortality in Mexico has remained comparably low on a worldwide scale, and the upward trends in mortality rates for lung and other tobacco-related neoplasms have tended to level off over the last decade. However, steady rises have been observed for other major cancers, including prostate and breast. Cervical cancer remains a major health problem in women.

Geography of diabetes mellitus mortality in Mexico: an epidemiologic transition analysis

BACKGROUND

The worldwide prevalence of diabetes mellitus (DM) will increase from 135 to 300 million cases by the year 2025. In Mexico, DM is the third cause of general mortality and the primary cause of mortality in the 55- to 64-year-old age group. The purpose of this study was to analyze the characteristics of DM mortality trends in Mexico from 1980 to 2000 in the context of this epidemiologic transition.

METHODS

Age-adjusted mortality rates were estimated for DM as underlying cause of death using World Health Organization (WHO) reference population. To evaluate magnitude of risks, standardized mortality ratio (SMR) was calculated; prematurity of mortality was evaluated by means of potential lost life years index (PLLYI). Diabetes mortality trends in the U.S. were calculated with information from the Centers for Disease Control (CDC) public registry and were age-adjusted for comparison.

RESULTS

Total number of deaths due to DM during the period was 582,826. Standardized mortality ratio by state showed higher mortality in the northern Mexican states; PLLYI was higher in the northern states. Mortality trends in Mexico showed a rapid increase during the 1980s followed by a less acute increment in the 1990s. Age-adjusted mortality rate trends in the U.S. were lower than those in Mexico.

CONCLUSIONS

This study shows an increase in DM age-adjusted mortality trends during the years 1980-2000 in Mexico. The observed pattern of mortality varies widely throughout the country, probably due to differences in socioeconomic conditions and in access to healthcare.

Capsaicin consumption, Helicobacter pylori positivity and gastric cancer in Mexico

Gastric cancer (GC) incidence has not declined in Mexico. We assessed whether the intake of capsaicin (CAP), the pungent compound of chili peppers, increases the risk of GC independently of H. pylori positivity (Hp). From 1994 to 1996, a hospital-based case-control study was performed in 3 areas of Mexico; 234 cases of GC and 468 matched controls were enrolled and their diet and other characteristics were inquired. Chili pepper intake was queried by interview and CAP content of chilies was determined in a separate analysis by gas chromatography to estimate CAP intake; IGg Hp serum antibodies were determined by ELISA. The risk of GC was increased (OR = 1.71; 95% CI = 0.76-3.88) among high-level consumers of CAP (90-250 mg of capsaicin per day, approximately 9-25 jalapeño peppers per day) as compared to low-level consumers (0-29.9 mg of capsaicin per day, approximately 0 to less than 3 jalapeño peppers per day; p for trend p = 0.026); this effect was independent of Hp status and other potential GC determinants and was higher among diffuse GC cases (OR = 3.64; 95% CI = 1.09-12.2; p for trend = 0.002) compared to intestinal GC cases (OR = 1.36; 95% CI = 0.31-5.89; p for trend = 0.493). No significant interaction was found between CAP intake and Hp on GC risk. Chili pepper consumption might be an independent determinant of GC in Mexico.