Precancerous lesions raise long-term risk of gastric cancer

Last Updated: 2015-08-11

By Rita Buckley

NEW YORK (Reuters Health) - Precancerous lesions increase long-term risk of developing gastric cancer, according to a new study.

Dr. Weimen Ye, of the Karolinska Institutet in Stockholm, Sweden, and colleagues measured the incidence of gastric cancer in low-risk patients who underwent gastroscopy for clinical indications compared with people who had normal mucosa on endoscopy and a matched general population.

The observational cohort study involved 405,211 Swedish patients who, between 1979 and 2011, had gastric biopsy samples taken for non-malignant indications. About 21% had repeat endoscopy exams and documented biopsy results.

Clinicians assessed patients for Correa's cascade or other diagnoses. In general, trends in the total cohort coincided with the pattern seen in the Correa's cascade group, according to an article online July 27 in BMJ.

Excluding the first two years of follow-up left 288,167 individuals in the Correa's cascade subcohort. During an average follow-up of about 10 years, or 7.9 years for those with intestinal metaplasia, researchers identified 1599 cases of gastric cancer overall (1388 non-cardia, 211 cardia) in patients whose mean age at study entry was 56 years.

In Cox regression modeling, compared with those who had normal mucosa at baseline, patients with minor changes had a hazard ratio of 1.8 for all gastric cancer. Those with gastritis had a HR of 2.6. The HR was 4.5 for atrophic gastritis, 6.2 for intestinal metaplasia, and 10.9 for dysplasia.

For crude annual incidence of gastric cancer, using 1.0 as a standardized incidence ratio for those in the normal mucosa group, the SIR came to 1.5 for patients with minor changes, 1.8 for gastritis patients, 2.8 for atrophic gastritis patients, 3.4 for intestinal metaplasia patients, and 6.5 for dysplasia patients.

Compared with initial grouping, repeated biopsy with upward or downward change in the Correa's cascade had "prognostic significance."

According to Dr. Paul J. Limburg, medical director of the Preventive Services Clinic at Mayo Clinic in Rochester, Minnesota, this finding supports the potential for modifying the precancerous state.

Dr. Limburg, who was not involved in the study, told Reuters Health by email that the study's results are a substantial addition to existing data on gastric cancer risks in patients with abnormal biopsy findings.

"They should inform further efforts to define optimal surveillance strategies in this population," he said.

Recommended time intervals for follow-up endoscopies may need to be adjusted based on further cost-benefit analysis, Dr. Ye told Reuters Health by email.

According to Dr. Ye, patients with dysplasia should have immediate endoscopic reassessment and more frequent surveillance. "For example, every two to three months within the first six months after diagnosis, and every six months out to two years," he said.

He reported that estimates on the cost-effectiveness of such a change have been hampered by a lack of reliable data on annual rates on progression of precancerous conditions and lesions.

"This is exactly what our results address," he said. "After 24 months, progression rates were stable and well-ranked with the severity of mucosal lesions."

The Swedish Research Council and Cancerfonden supported this research. The authors reported no disclosures.

SOURCE: http://bit.ly/1L3Ut5b

BMJ 2015.