The epidemiology of gastric cancers in the era of Helicobacter pylori eradication: a nation-wide cancer registry-based study in Taiwan

Background:Helicobacter pylori (H.P.) eradication has been shown to decrease gastric adenocarcinoma risk. The epidemiology of gastric lymphoma, which is also associated with H.P., and other rare subtypes of gastric cancer is less clear. This study comprehensively evaluated the incidence trend and the survival of gastric cancer in Taiwan by histologic subtype. Methods:The incidence trends of gastric cancer in Taiwan from 1996 and 2013 were evaluated using data from the Taiwan Cancer Registry. The life-table method and the Cox proportional hazards analysis were used to evaluate the survival of gastric cancer. Results:The incidence of all gastric cancers in Taiwan decreased from 15.97 per 100,000 in 1996 to 11.57 per 100,000 in 2013. The most frequent histologic subtype of gastric cancer in Taiwan was adenocarcinoma, followed by lymphoma, and sarcoma (mainly gastrointestinal stromal tumor). The best survival was in patients with sarcoma, followed by lymphoma, neuroendocrine tumor and adenocarcinoma. Generally women had a better survival than men. The incidence of adenocarcinoma significantly decreased from 13.56 per 100,000 in 1996 to 9.82 per 100,000 in 2013 (P<0.0001). In contrast, the incidences of mucosa-associated lymphoid tissue lymphoma and diffuse large B cell lymphoma did not decrease. Conclusions:The incidence of adenocarcinoma and lymphoma, both of which are associated with H.P., showed diverging trends. The survival of gastric cancer differed by histologic subtype and sex. Impact:The disparity in the incidence trends between gastric lymphoma and adenocarcinoma, both associated with H.P., warranted the need to search for additional risk factors of gastric lymphoma.