Gastric cancer trends in Estonia 1995-2014 by age, subsite, morphology and stage

Gastric cancer (GC) is among the most common cancers and one of the leading causes of cancer deaths globally. In general, the incidence of GC has declined and survival improved in Europe. Nevertheless, previous analysis has shown that survival of GC patients in Estonia is still significantly lower compared to some European countries. Therefore, to improve patient outcomes, better overview of GC epidemiology is needed. The aim of this study was to describe the incidence and survival of GC in Estonia 1995-2014 in relation to age, subsite, morphology, and the extent of disease.

We used data from the population-based Estonian Cancer Registry on all incident cases of GC diagnosed in 1995-2014. Incidence rates and relative survival were calculated. Joinpoint regression modeling was used to estimate annual percentage change for incidence trends. Data were analyzed by age, sex, subsite, morphology, and the extent of disease. Changes between 1995-1999 and 2010-2014 were assessed.

The overall incidence of GC in Estonia decreased in 1995-2014. The age-standardized (world) incidence declined significantly for both sexes, for patients below 70 years of age, adenocarcinomas, NOS and other morphologies, non-cardia and unspecified cases, and for all known stages. Approximately 40% of GC cases were diagnosed with distant metastasis. Overall age-standardized 5-year relative survival of GC patients increased from 20% to 28%. Survival improved the most in age group 50-69 years. A large survival gain was also seen for localized (from 55% to 70%) and locally/regionally spread disease (from 23% to 37%).

In Estonia, the incidence of GC has declined and relative survival increased. However, special emphasis needs to be put on improving survival among men, elderly and in patients with metastatic disease.