SAN DIEGO — The risk for gastric cancer was more than 200 times higher in patients with gastric intestinal metaplasia on initial or repeat upper endoscopy, compared with the control population, in a retrospective study of 11,600 male veterans.
In all, 3% of the cohort (354 veterans) were diagnosed with gastric intestinal metaplasia (GIM) over a 19-year period; the investigators compared their records with those of 355 randomly selected patients who were seen at the GI clinic of the Brooklyn campus of the Veterans Affairs New York Harbor Healthcare System.
Of the veterans with GIM, 6% (21 patients) were diagnosed with gastric cancer, a rate that was 200-fold higher than the gastric cancer rate seen in the control group, Dr. Naveen Anand and his associates reported at the annual meeting of the American College of Gastroenterology.
Half of the cancer diagnoses were made on the initial endoscopy, and half were made on follow-up endoscopy, said Dr. Anand, a chief resident at the State University of New York Downstate Medical Center, Brooklyn. Repeat endoscopies were performed on 53% of the cohort (including 11% who underwent four or more endoscopies), and 47% underwent initial endoscopy only.
Gastric cancer was more likely to be diagnosed in patients with GIM who were older and black, or who had more severe gastritis on histology.
Patients with GIM—especially patients in these higher-risk subgroups—should undergo regular endoscopic surveillance with careful histologic diagnosis of GIM based on biopsies at multiple gastric locations, Dr. Anand suggested.
He acknowledged that increased surveillance has cost implications, but noted that the gastric cancer rate in patients with GIM is similar to that seen in patients with severe dysplasia. “If patients have severe dysplasia on biopsy, we will bring these patients back for follow-up. So, if we're seeing similar rates of progression to cancer from GIM, these patients probably should be followed up.
“We need a prospective study looking at these patients followed over time,” he said.
He and his associates were surprised to find that having a history of Helicobacter pylori infection did not significantly influence pathology results, compared with patients with no history of H. pylori. He attributed that to early intervention (that is, treatment that was initiated whenever H. pylori was diagnosed by histology).
Patients with GIM were more likely to be 70-90 years old, whereas those without GIM were more likely to be aged 50-70 years. About half of patients in the GIM and control groups were black and half were white, and there were small numbers of veterans of other races or ethnicities. Because the mean age in blacks was significantly older than in whites (75 vs. 71 years), blacks accounted for 67% of patients who developed gastric cancer, Dr. Anand said.
“We believe there is a long lead time between the premalignant lesion and intestinal metaplasia and intestinal-type gastric carcinoma, similar to what we see in colon cancer and cervical cancer, which gives us an opportunity for possible surveillance and even possible intervention,” Dr. Anand said.
The investigators reported no conflicts of interest.