Gastric cancer mortality related to direct radiographic and endoscopic screening: A retrospective study

BACKGROUND: Despite its decreased incidence in Japan, gastric cancer continues among the leading causes of cancer-related deaths in both men and women. Accordingly, efforts are still required to lower the mortality rate of gastric cancer in Japan. Maebashi City introduced endoscopic gastric cancer screening in 2004, and participants are able to choose between direct radiography and endoscopy. Hence, we expected to see a decrease in mortality rate from gastric cancer after introducing endoscopic screening and a difference in mortality rate reduction between screening methods. AIM: To evaluate the impact on gastric cancer mortality rate of two types of gastric cancer screening in Maebashi City, Japan. METHODS: Participants aged 40 to 79 years of the Maebashi City gastric cancer screening program in 2006 who were screened by direct radiography (n = 11155) or endoscopy (n = 10747) were included. Participants were followed until March 31, 2012, by cross-referencing their data against the Gunma Prefecture cancer registry data. We compared the detection rate of gastric cancers. Then, we compared the mortality rate between the two groups. The Cox proportional hazards model was used to estimate the hazard ratio (HR) of gastric cancer death. Finally, the reduction in gastric cancer mortality rate associated with each screening method was evaluated. RESULTS: Gastric cancer was detected in 22 participants undergoing direct radiography (detection rate, 0.20%) and in 52 participants undergoing endoscopy (detection rate, 0.48%). However, most gastric cancers detected by endoscopic screening were early cancers that may not have resulted in death. We found no significant difference in gastric cancer mortality rate between participants receiving annual screening and those who do not. When the number of gastric cancer deaths in the direct radiography group was set as 1 in the Cox proportional hazard analysis, the HR of gastric cancer death was 1.368 (95%CI: 0.7308–2.562) in the overall group of participants. The results showed no significant difference between the two screening methods in any of the analysis groups. CONCLUSION: Although endoscopic screening detected more gastric cancer than direct radiographic screening, no significant difference in the reduction of gastric cancer mortality rate between the two screening methods was found.