Gastrointestinal stromal tumors in Osijek- Baranja County (Eastern Croatia): a population-based incidence study (2004 – 2017)

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. The epidemiology of these tumors in Osijek-Baranja County is not known. The aim of this study is to determine the incidence of gastrointestinal stromal tumors (GIST) and anatomic localizations in Osijek Baranja County patients. In this study, we show the incidence of gastrointestinal stromal tumors (GISTs) in Osijek-Baranja County. We studied 65 cases of GIST diagnosed in Osijek-Baranja County in the period from January 1, 2004 to December 31, 2017. In this period, we registered 65 cases of GIST from which 29 females (44.6%) and 36 males (55.4%). The mean age at diagnosis was 66.9 years ranging from 37 to 86. Only 1.5% of tumors occurred before the age of 40 years. The crude incidence rate of GISTs was 1.47/100, 000 (1.26/100, 000 for females and 1.70/100, 000 for males). The age-standardized incidence rate was 0.76/100, 000 (0.60/100, 000 for females and 0.98/100, 000 for males). The annual European age-standardized incidence rate was 1.10/100, 000 (0.86/100, 000 for females and 1.44/100, 000 for males). GISTs were mostly localized in the stomach (33 cases) and small intestine (20 cases), followed by peritoneum and omentum (8 cases), two in the pancreas, 1 in the rectum and 1 in other locations. Gastrointestinal stromal tumors are rare, but more common in the older population. The incidence rate was higher among men. These results will serve as reference for studying the patterns of descriptive epidemiology of GISTs in Osijek-Baranja County and the surrounding region.