Gastric Cancer Mortality Has Decreased in Latin America

Among the Hispanic/Latino population, the reported mortality rate of gastric cancer is low to moderate. In 2017, with regard to gastric cancer among men, the highest age-standardized mortality rates (ASMRs) per 100,000 person-years were in Chile (31.8), Colombia (24.3), and Costa Rica (24.3). Among women, the highest ASMRs were in Guatemala (17.2), Peru (13.5), and Costa Rica (13.3). Among men, Puerto Rico (6.2), the United States (7.0), and Paraguay (9.4) had the lowest ASMRs, according to a study conducted by Latin American researchers.

In almost all countries, mortality decreased among individuals aged 50 years and older. However, age-specific trends were not parallel (P < .05) in Brazil, Colombia, Mexico, the United States, and Venezuela for men and women and in five additional countries for only women. On the other hand, a few countries showed stable or slightly increasing trends for individuals aged 25−49 years.

Smith Torres, MD, professor at the Scientific Southern University of Lima, Peru, and principal investigator of the study, pointed out that the study shows what is happening in Latin America regarding this kind of tumor. Gastric cancer is associated with high mortality and high disease burden. Having accurate epidemiologic data makes it possible to address this disease from other perspectives with more targeted promotion and prevention measures. Continuing to delve into the risk factors associated with gastric cancer and understanding the data to propose strategies that reduce the figures make a difference.

The study evaluates the mortality rates between 1997 and 2017 by sex and age. The 21-year trend shows a reduction of between 2% and 3% per year in the rates in all countries, but they are high compared with those of European countries, in which mortality decreased between 4% and 5%.

Many aspects need to be improved, including epidemiologic reports, hygiene measures, and the identification of risk factors, all of which will allow early detection of cases and thereby reduce mortality. In Latin America, gastric cancer is not detected in a timely way, and when a diagnosis is made, disease is already in an advanced stage, said Torres.

He highlighted that the high mortality rates in Chile, Guatemala, Costa Rica, Ecuador, and Peru are a call for the health bodies of each country to improve surveillance and carry out more effective interventions.

The study provides guidelines for further evaluation of Helicobacter pylori infection as an important risk factor for the development of gastric cancer, for which drug treatment is not easy. The rate of bacterial resistance to clarithromycin has reached 20%. Challenges involve determining the best treatment option and correctly identifying patients who need treatment. Carrying out the ecologic and exploratory analysis of these data provides a new perspective of the risk factors and treatment associated with the tumor.

The Lancet study was striking because it shows a downward trend in mortality among patients older than 50 years and an increase in mortality among patients younger than 50 years. It must not be assumed that gastric cancer is a problem for older adults, that it will be easily solved, and that efforts must be invested in other tumors, because there is still a lot to be done in this area.

Most of the tumors in the younger-than-50-years age group go unnoticed, owing to the complexity of differentiating symptoms with other pathologies. In addition, the young population has unhealthy lifestyles; a greater number of people who are overweight, and greater consumption of junk food. These are risk factors for more gastric cancer. There is still a long way to go, and hard and focused work is needed to solve the problem in the region, said Torres.

The study also provides predictive data on mortality rates for 2030, suggesting that the rates will decrease. According to the age-period-cohort predictions, in almost all countries, gastric cancer mortality should be decreasing among men, with an increase in population size and a decrease in change due to risk. Among women, mortality reduction from gastric cancer would be reduced in most countries. However, in Puerto Rico and El Salvador, the reduction in the risk of death would exceed the increase, owing to changes in the population size and structure (8.3 and 4.2, respectively).

It is striking that in 2017, countries such as Argentina and Mexico reported mortality rates of 9.1 and 8.9/100,000 inhabitants, respectively. José Fabián Martínez, MD, a Mexican oncologist at the ABC Cancer Center in Mexico City, a clinical researcher at Health Pharma, and an expert on the subject, mentioned that thanks to these studies, epidemiologic data can be obtained that allow government decision-makers to identify the problems that a disease such as gastric cancer entails.

In Mexico, gastric cancer causes most deaths, but efforts are focused on breast and prostate cancer. The reported rate reflects the country’s death reports. These data draw attention, however, because other publications show that in countries in the Andes, such as Peru and Colombia, the incidence, prevalence, and mortality from gastric cancer is higher. The risk factors are concurrent with living conditions, which, despite improvements (for example, in hygiene measures, food refrigeration, and identification of H pylori infection) do not indicate that the mortality rate is really decreasing. This observation would go against what is expected for 2030: a decrease in the rate of 1 point (7.9/100,000 inhabitants).

Underreporting of epidemiologic data is common in Latin American countries, and better reporting of deaths is needed to allow the consistency of that information to be evaluated, said Martínez.

Alejo Albornoz, MD, an oncologist at the Nuclear Medicine School Foundation in San Rafael, Mendoza, Argentina, indicated that although endoscopy is the screening test to identify gastric cancer in early stages, such testing is not always possible, owing to access problems or the type of coverage in each country. The goal with gastric cancer is to provide a curative treatment, and that entails identifying the people who are at risk and intervening in a timely fashion. In addition, each region should be carefully studied to determine the real rates in the countries.

For example, mortality from gastric cancer is high in Mendoza due to its proximity to Chile and the mixed population, but no information system links the deaths, as each one is provincial, and data can be lost, he added.

The two specialists agreed that Latin America needs an ethnic background to verify epidemiologic information and that strengthening gastric cancer data and identifying the risk factors will make it possible to determine adequate prevention and promotion measures and reduce the rate of mortality.

Torres, Martínez, and Albornoz have disclosed no relevant financial relationships.

Follow Natalia Martínez Medina of Medscape Spanish Edition on Twitter @nataliamame.

This article was translated from the Medscape Spanish Edition.

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