Published online Jun 28, 2020. doi: 10.3748/wjg.v26.i24.3447
Peer-review started: February 1, 2020
First decision: March 6, 2020
Revised: March 29, 2020
Accepted: June 12, 2020
Article in press: June 12, 2020
Published online: June 28, 2020
Majority of gastric cancers (GC) of intestinal type develop through precancerous states of atrophic gastritis and intestinal metaplasia (IM). Precancerous changes, male gender, smoking, and aging are risk factors for GC. Two staging systems have previously been developed to predict GC risk. Operative link for gastritis assessment (OLGA) staging assesses the degree of atrophy in gastric biopsies, and in operative link on gastric intestinal metaplasia assessment (OLGIM) staging, atrophy is replaced with IM.
In low-risk gastric cancer countries there are no screening programs, and five-year survival of GC patients is poor. There is a need to specify patients at highest risk. In this study, the usability of OLGA and OLGIM stagings were evaluated. In addition, we developed a new staging system named TAIM (abbreviation from topography, atrophy, and intestinal metaplasia), which combines atrophy and IM into one staging.
The main objectives were to evaluate OLGA, OLGIM, and TAIM stagings in predicting long-term GC risk in elderly male smokers with low pepsinogen I (PGI). The main questions were: Can OLGA and OLGIM stagings segregate patients with highest GC risk among those with several risk factors? What is the predictive value of TAIM staging when compared to OLGA and OLGIM?
In this retrospective cohort study, 1147 elderly smoking men with low PGI, as a marker of atrophic corpus gastritis, participated in screening gastroscopies. The median follow-up was 13.7 years, and maximum over 27 years. Gastroscopy biopsy specimen were analyzed by using Updated Sydney System, and then scored by OLGA, OLGIM, and TAIM staging systems. In TAIM staging, the most severe finding of atrophy or IM defined the degree of severity (non-existing, mild, moderate, or marked), and then changes were evaluated to exist in antrum only, corpus only, or in whole stomach. The GC risk was scored as low or high in TAIM staging. The GC risk was compared to age and gender matched general population in all three staging systems. The follow-up data was achieved from the Finnish Cancer Registry and the Population Register Centre of Finland.
Twenty-eight gastric cancers were diagnosed during the follow-up period. For the first ten years there was no notable difference in GC risk between low and high-risk patients, but thereafter the difference started to separate. OLGIM and TAIM stagings showed statistically significant difference in GC risk when risk scores increased. In all high-risk groups, the GC risk was three to four times higher compared to general male population of same age.
OLGIM and TAIM showed predictive value in evaluating the gastric cancer risk among elderly male smokers. Combining atrophy and IM into one staging system can be promising. Our results are preliminary, and TAIM staging has not been tested previously. Unlike patients in low risk TAIM group, OLGA and OLGIM both low (0-II) and high (III-IV) cancer risk groups and TAIM high risk group showed statistically significantly increased gastric cancer risk compared to the general population, respectively.
In the future, TAIM staging should be evaluated in other populations in both genders and different age groups. The results would be interesting to see in low- and high-risk countries.