RELATIONSHIP BETWEEN OESOPHAGEAL ADENOCARCINOMA AND GASTRIC CANCER INCIDENCE RATES IN EUROPEAN GRELL COUNTRIES Fabio Falcini, Emanuele Crocetti, Alessandra Ravaioli, Silvia Mancini, Orietta Giuliani, Lauro Bucchi Romagna Cancer Registry Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori IRST-IRCCS, Meldola, Forlì, Italy Table 1: Crude Pearson’s Correlation coefficients between EAC and NCGC and GC for overall, for countries and for sexes. OBJECTIVE In Europe the incidence of gastric cancers is decreasing, while oesophageal adenocarcinomas (EAC) are increasing. It has been suggested that these trends could be both caused by the decrease of the prevalence of the infection of Helicobacter pylori (H. pylori) [1]. The aim of this study was to evaluate the relationship between the incidence of these two cancers in some European Grell countries. EAC-NCGC EAC-GC MEN WOMEN Overall -0.53* -0.43* -0.48* -0.41* France +0.36 +0.39 -0.36* Italy +0.06 +0.17 +0.07 +0.15 Spain -0.20 -0.44 -0.24 -0.36 Switzerland -0.37 -0.04 -0.18 0.007 Table 2: Weighted (on EAC frequency) Pearson’s Correlation coefficients between EAC and NCGC and GC for overall, for countries and for sexes. METHODS Age world standardised incidence rates for gastric cancer (non-cardia, NCGC and overall, GC) and for EAC were retrieved from the Cancer Incidence in 5 Continents - X website [2]. We focused on European Grell Countries for which such data were available (Belgium, France, Italy, Spain, Portugal and Switzerland). Crude and weighted (either on EAC frequency and on population adjusted for old-age index) Pearson's correlation coefficients were computed between EAC and NCGC and GC, overall, for countries with regional cancer registries, and for sexes. EAC-NCGC EAC-GC MEN WOMEN Overall -0.66* -0.56* -0.59* -0.52* France +0.23* -0.46* +0.28* -0.39* Italy -0.21* +0.45* Spain -0.28* -0.36* -0.30* -0.26* Switzerland +0.11 -0.37* -0.001 -0.34 Table 3: Weighted (on population adjested for old-age index) Pearson’s Correlation coefficients between EAC and NCGC and GC for overall, for countries and for sexes. EAC-NCGC EAC-GC MEN WOMEN Overall -0.61* -0.50* -0.56* -0.48* France +0.34 -0.41 +0.36 -0.36 Italy -0.08 +0.26 -0.09 +0.25 Spain -0.30 -0.32 -0.34 Switzerland +0.19 -0.18 +0.04 -0.14 RESULTS Data from 64 population-based cancer registries were included (Belgium, 11 France, 33 Italy, 13 Spain, 5 Switzerland and 1 Portugal). The frequency of EAC varied across registries from 0 to 1212 cases, while the population adjusted for old-age index from 59,947 to 6,415,149. The correlations between EAC and GC, and EAC and NCGC were significantly negative both among men (-0.48 and -0.53) and women (-0.41 and -0.43). The use of weights changes the values but not the meanings of the correlations. Results did not change removing the registry with the greatest case-series. However, when single countries were examined, different correlations appeared across them and between sexes. * p < 0.05 CONCLUSIONS The overall data from European Grell countries showed a negative correlation observed in the period 2003-2007 between incidence of EAC and GC, either considering only NCGC. This result supported the hypothesis of a common factor which acts in opposite directions for the two cancers. However, when single countries were analysed an unclear pattern emerged. REFERENCES Derakhshan MH et al “Worldwide inverse association between gastric cancer and esophageal adenocarcinoma suggesting a common environmental factor exerting opposing effects”. Am J Gastroenterol 2015. doi:10.1038/ajg.2015.405. http://ci5.iarc.fr/CI5-X/Default.aspx rtromagna@irst.emr.it