Comparison of operative link for gastritis assessment, operative link on gastric intestinal metaplasia assessment, and TAIM stagings among men with atrophic gastritis

Background: Gastric cancer is the world's third most lethal malignancy. Most gastric cancers develop through precancerous states of atrophic gastritis and intestinal metaplasia. Two staging systems, operative link for gastritis assessment (OLGA) and operative link on gastric intestinal metaplasia assessment (OLGIM), have been developed to detect high gastric cancer risk. European guidelines recommend surveillance for high-risk OLGA/OLGIM patients (stages III-IV), and for those with advanced stage of atrophic gastritis in the whole stomach mucosa. We hypothesize, that by combining atrophy and intestinal metaplasia into one staging named TAIM, more patients with increased gastric cancer risk could be detected.

Aim: To evaluate the clinical value of the OLGA, OLGIM, and novel TAIM stagings as prognostic indicators for gastric cancer.

Methods: In the Helsinki Gastritis Study, 22346 elderly male smokers from southwestern Finland were screened for serum pepsinogen I (PGI). Between the years 1989 and 1993, men with low PGI values (PGI < 25 μg/L), were invited to undergo an oesophagogastroduodenoscopy. In this retrospective cohort study, 1147 men that underwent gastroscopy were followed for gastric cancer for a median of 13.7 years, and a maximum of 27.3 years. We developed a new staging system, TAIM, by combining the topography with the severity of atrophy or intestinal metaplasia in gastric biopsies. In TAIM staging, the gastric cancer risk is classified as low or high.

Results: Twenty-eight gastric cancers were diagnosed during the follow-up, and the incidence rate was 1.72 per 1000 patient-years. The cancer risk associated positively with TAIM [Hazard ratio (HR) 2.70, 95%CI: 1.09-6.69, P = 0.03]. The risk increased through OLGIM stages 0-IV (0 vs IV: HR 5.72, 95%CI: 1.03-31.77, P for trend = 0.004), but not through OLGA stages 0-IV (0 vs IV: HR 5.77, 95%CI: 0.67-49.77, P for trend = 0.10). The sensitivities of OLGA and OLGIM stages III-IV were low, 21% and 32%, respectively, whereas that of TAIM high-risk was good, 79%. On the contrary, OLGA and OLGIM had high specificity, 85% and 81%, respectively, but TAIM showed low specificity, 42%. In all three staging systems, the high-risk men had three- to four-times higher gastric cancer risk compared to the general male population of the same age.

Conclusion: OLGIM and TAIM stagings show prognostic value in assessing gastric cancer risk in elderly male smokers with atrophic gastritis.