Vol. 27: Gastric Camera or Barium—Which Should You Choose? And Is a Stomach Screening Even Necessary?

"Should I choose barium or a gastric camera for my stomach screening?"—This is one of the most frequently asked questions in the field of health checkups, alongside the "mammography or ultrasound?" question for breast cancer screening (Vol. 26: Mammography or Ultrasound—Which Should You Choose? Thinking Through the Meaning of "Evidence." | Dr. O). However, while these two questions may seem structurally similar, there is one decisive difference. In the previous article (

Vol. 26: Mammography or Ultrasound—Which Should You Choose? Thinking Through the Meaning of "Evidence." | Dr. O), which compared mammography and ultrasound, there was a clear asymmetry: "Only mammography has evidence of reducing mortality as an organized screening program, and the government recommends it." However, for gastric cancer screening, both the gastric X-ray (barium) and the gastric endoscopy (gastric camera) are recommended by national guidelines. This is an important starting point. The National Cancer Center's Guidelines for Effectiveness Evaluation (2014 edition) recommend "either a gastric X-ray or a gastric endoscopy" once every two years for those aged 50 and older. For barium, meta-analyses of multiple observational studies in Japan have shown a 40–48% reduction in gastric cancer mortality through screening (sensitivity 70–80%, specificity 85–90%). Regarding endoscopy, a large-scale Japanese study that followed 80,272 people for a median of 13 years (Narii N, et al. Cancer Sci. 2022) showed that the gastric cancer mortality rate for those who underwent endoscopic screening was 61% lower (HR=0.39) compared to those who did not. So, "which one should you choose?" Many gastroenterological endoscopists feel that endoscopy is superior for detecting early-stage lesions, and this intuition is based on certain evidence. Early gastric cancer often appears as slight color changes or minute irregularities, and endoscopy, which allows for direct observation of the mucosa, is superior at pointing out such changes. With endoscopy, it is possible to perform a definitive diagnosis by taking tissue samples from suspicious areas, and the esophagus and duodenum can also be observed at the same time. If an abnormality is found with barium, it results in the "extra trouble" of having to undergo an endoscopy for confirmation. There are also several studies suggesting that endoscopic screening may have a greater mortality reduction effect compared to barium screening (Hamashima C, et al. Cancer Sci. 2015). However, at this point, we have not reached a conclusion that gastric endoscopy is clearly superior to barium examination as an organized screening program (or that one should not undergo barium). By the way, is gastric cancer screening even necessary for people who do not have H. pylori? It is said that the majority of gastric cancers (over 90% in Japanese reports, 75–90% internationally) occur against a background of H. pylori infection. It is certain that

individuals who have never been infected with H. pylori have an extremely low risk of gastric cancer



. "If so, shouldn't people confirmed to be H. pylori negative skip gastric cancer screening?"—This question is logically sound, and it is possible that things will move in that direction in the future. However, at present, a method that divides the target for gastric cancer screening based on whether or not one is H. pylori negative has not been proposed as a national organized screening program. There are several reasons for this. First, a "H. pylori negative" result does not necessarily mean "truly uninfected." In situations such as after eradication, accidental eradication, natural disappearance due to the progression of gastric mucosal atrophy, or false negatives, the gastric mucosa may already be damaged even if the test comes back negative. Furthermore, there are no high-quality clinical trials that have verified the impact on mortality when excluding H. pylori-negative individuals from the target, and there is no evidence to support applying this to the entire population. Finally, I will write about something that is a bit difficult to say regarding the reality of health checkup sites. Not limited to stomach examinations, the content of medical checkups and corporate health screenings is often determined by contracts between health insurance associations and screening facilities. If the health insurance association includes "conducting a stomach examination" as a screening item, the screening facility is, in principle, required to fulfill that content. It does not necessarily mean that the examination content is always performed according to evidence or physician recommendations. In order to accurately judge whether "this examination is truly necessary for this examinee right now," it is necessary for physicians who can correctly assess the effectiveness, target, and interval of screenings to be involved on the side of the health insurance association, but at present, it seems that not all health insurance associations are in such a situation.

Source:
National Cancer Center "Guidelines for Gastric Cancer Screening Based on Effectiveness Evaluation (2014 Edition)" https://ganjoho.jp/med_pro/cancer_control/screening/screening_stomach.html
National Cancer Center "About Gastric Cancer Screening" (Updated September 20, 2024) https://ganjoho.jp/public/pre_scr/screening/stomach.html
Narii N, Sobue T, Zha L, et al. Effectiveness of endoscopic screening for gastric cancer: the Japan public health center-based prospective study. Cancer Sci. 2022;113(11):3922-3931. PMID: 36002149 Hamashima C, Shabana M, Okada K, Okamoto M, Osaki Y. Mortality reduction from gastric cancer by endoscopic and radiographic screening. Cancer Sci. 2015;106(12):1744-1749. PMID: 26432528

#Cancer #CancerScreening #GastricCancerScreening #GastricEndoscopy #Barium #HPylori #Evidence