Stomach cancer burden in Central and South America

- Stomach cancer incidence and mortality rates varied by 6 and 5-6-fold, respectively.
- The highest incidence was seen in Chile, Costa Rica, Colombia, Ecuador, Brazil and Peru.
- Chile (males) and Guatemala (females) had some of the highest mortality rates in the world.
- Incidence rates declined by 4% annually in Brazil, Chile and Costa Rica from 1997 to 2008.
- Mortality declined by 4% annually in Chile and Costa Rica from 1997 to 2008.
- Non-cardia cancers were 2-13-times more frequent than cardia cancers.

Rationale and objectiveStomach cancer mortality rates in Central and South America (CSA) are among the highest in the world. We describe the current burden of stomach cancer in CSA.MethodsWe obtained regional and national-level cancer incidence data from 48 population-based registries (13 countries) and nation-wide cancer deaths from WHO's mortality database (18 countries). We estimated world population age-standardized incidence (ASR) and mortality (ASMR) rates per 100,000 and estimated annual percent change to describe time trends.ResultsStomach cancer was among the 5 most frequently diagnosed cancers and a leading cause of cancer mortality. Between CSA countries, incidence varied by 6-fold and mortality by 5-6-fold. Males had up to 3-times higher rates than females. From 2003 to 2007, the highest ASRs were in Chile, Costa Rica, Colombia, Ecuador, Brazil and Peru (males: 19.2-29.1, females: 9.7-15.1). The highest ASMRs were in Chilean, Costa Rican, Colombian and Guatemalan males (17.4-24.6) and in Guatemalan, Ecuadorian and Peruvian females (10.5-17.1). From 1997 to 2008, incidence declined by 4% per year in Brazil, Chile and Costa Rica; mortality declined by 3-4% in Costa Rica and Chile. 60-96% of all the cancer cases were unspecified in relation to gastric sub-site but, among those specified, non-cardia cancers occurred 2-13-times more frequently than cardia cancers.ConclusionThe variation in rates may reflect differences in the prevalence of Helicobacter pylori infection and other risk factors. High mortality may additionally reflect deficiencies in healthcare access. The high proportion of unspecified cases calls for improving cancer registration processes.