Causes of death in patients diagnosed with gastric adenocarcinoma in Sweden, 1970‐2014: A population‐based study

The causes of death in patients with gastric adenocarcinoma have not been well characterized. This nationwide population‐based cohort study included 56 240 patients diagnosed with gastric adenocarcinoma in 1970‐2014 in Sweden. We used competing‐risks regression to compare cause‐specific risks of death in patients with different characteristics and a multiple‐cause approach to assess proportions of deaths attributable to each cause. Among 53 049 deaths, gastric cancer was the main (77.7% of all deaths) underlying cause. Other major underlying causes were nongastric malignancies (8.0%), ischemic heart disease or cerebrovascular disease (6.5%), and respiratory diseases (1.4%). Risk of death from gastric cancer steadily decreased in patients with cardia adenocarcinoma over the study period, but remained relatively stable in patients with noncardia adenocarcinoma since the 1980s. Risk of death from other malignancies increased during later calendar periods (subhazard ratio [SHR] = 2.16, 95% confidence interval [CI] 1.97‐2.38, comparing 2001‐2014 with 1970‐1980). Compared with men, the risk of death in women with cardia adenocarcinoma was higher from gastric cancer (SHR = 1.18, 95% CI 1.10‐1.27), but lower from other malignancies (SHR = 0.80, 95% CI 0.71‐0.91). In multiple‐cause models, 60.4%‐71.2% of all deaths were attributable to gastric cancer and 9.5%‐12.1% to other malignancies. The temporal trends of cause‐specific risks from multiple‐cause models were similar to those of underlying causes. Our findings suggest that although most deaths in patients with gastric adenocarcinoma are due to gastric cancer, other causes of death are common. Patients with cardia adenocarcinoma face considerable increasing risk of death from other causes over time, particularly from other malignancies.