Upper endoscopy screening in Koreans reduces risk of gastric cancer death

Last Updated: 2017-02-20

By Rita Buckley

NEW YORK (Reuters Health) – Upper endoscopy screening through the Korean National Cancer Screening Program reduces the risk of death from gastric cancer, researchers say.

Dr. Jae Kwan Jun from the National Cancer Control Institute and the National Cancer Center in Korea and colleagues conducted a nested case-control control study to compare the effectiveness of upper endoscopy versus upper gastrointestinal series examination on gastric cancer detection and mortality in the Korean population.

An upper gastrointestinal series examines upper and middle sections of the gastrointestinal tract using imaging technologies.

The study used data collected since 2002 from the Korean National Screening Program for gastric cancer.

The cancer-free cohort consisted of nearly 16.6 million men and women age 40 or older. Case subjects (n=54,418) were defined as individuals newly diagnosed with gastric cancer from 2004 through 2009 who died before the end of 2012.

Cases were matched with controls (subjects who were alive on the date of death of the corresponding case subject, n=271,672) for year of entry into the study cohort, age, sex, and socioeconomic status.

“As an observational study, we were unable to definitively control for such biases as self-selection and lead time,” the authors wrote, noting that participants in the Korean National Cancer Screening Program might over-represent healthy or health-conscious individuals, leading to an overestimation of gastric screening effectiveness.

Compared to subjects who had never been screened, the overall odds ratio for death from gastric cancer was 0.79 (95% CI 0.77-0.8), according to a report online January 29 in Gastroenterology.

According to screening modality, the odds ratios of death from gastric cancer were 0.53 (95% CI 0.51-0.56) for upper endoscopy, 0.98 (95% CI 0.95-1.01) for upper gastric intestinal series examinations, and 0.45 (95% CI 0.42-0.49) for both modalities.

The odds ratio of death from gastric cancer was significantly lower for endoscopically screened men and women between the ages of 40 and 74; this was not true for upper gastrointestinal series examinations.

Endoscopic screening results were dose-related. As the number of endoscopic screening tests per subject increased, the odds ratio for death from gastric cancer decreased: 0.63 (95% CI 0.57-0.63) for once; 0.32 (95% CI 0.28-0,37) for twice; and 0.19 (95% CI 0.14-0.26) for three or more times.

“The study is very important, but findings are limited to countries where the incidence of gastric cancer is much higher than it is in the United States, such as Japan, Korea, and China,” said Dr. Mandeep S. Sawhney, a gastroenterologist in the Division of Gastroenterology at Beth Israel Deaconess Medical Center in Boston, Massachusetts.

In a phone interview with Reuters Health, Dr. Sawhney, who was not part of the study, noted that case-control studies are good for testing hypothesis, but findings need to be corroborated by randomized controlled or cohort studies.

Dr. Paul J. Limburg, a consultant in the Division of Gastroenterology and Hepatology at Mayo Clinic in Rochester, Minnesota, who was not involved in the study, said in an email to Reuters Health that the results are encouraging.

“Symptoms and signs are often absent in early stages of gastric cancer, supporting a need for more effective prevention strategies, such as screening,” he said.

The corresponding author did not respond to requests for comment.

SOURCE: http://bit.ly/2lNAVaZ

Gastroenterology 2017.