Background The subtypes of gastric cancer (GC) and oesophageal cancer (EC) manifest distinct epidemiological profiles. Here, we aim to examine correlations in their incidence rates and to compare their temporal changes globally, both overall and by subtype.
Methods Long-term incidence data were obtained from population-based registries available from the Cancer Incidence in Five Continents series. Variation in the occurrence of EC and GC (overall and by subtype) was assessed using the GC:EC ratio of sex-specific age-standardised rates (ASR) in 2008–2012. Average annual per cent changes were estimated to assess temporal trends during 1998–2012.
Results ASRs for GC and EC varied remarkably across and within world regions. In the countries evaluated, the GC:EC ratio in men exceeded 10 in several South American countries, Algeria and Republic of Korea, while EC dominated in most sub-Saharan African countries. High rates of both cardia gastric cancer and oesophageal squamous cell carcinoma (ESCC) were observed in several Asian populations. Non-cardia gastric cancer rates correlated positively with ESCC rates (r=0.60) and negatively with EAC (r=−0.79). For the time trends, while GC incidence has been uniformly decreasing by on average 2%–3% annually over 1998–2012 in most countries, trends for EC depend strongly on histology, with several but not all countries experiencing increases in EAC and decreases in ESCC.
Conclusions Correlations between GC and EC incidence rates across populations are positive or inverse depending on the GC subsite and EC subtype. Multisite studies that include a combination of populations whose incidence rates follow and deviate from these patterns may be aetiologically informative.
- gastric cancer
- oesophageal cancer
- gastric adenocarcinoma
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information.
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Contributors ML performed all analyses under the supervision of MA, VMcC and JYP. All authors contributed to the discussion. ML drafted the first version of the text. ML and VMcC are overall guarantors.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
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