The incidence of esophageal adenocarcinoma among patients with Barrett’s esophagus was only 1.2 cases per 1,000 person-years in a study of the entire population of Denmark reported in the Oct. 13 issue of the New England Journal of Medicine.
That rate is four to five times lower than rates reported previously, said Dr. Frederik Hvid-Jensen of the department of surgical gastroenterology at Aarhus (Denmark) University and his associates.
"Our study provides solid evidence that esophageal adenocarcinoma will develop in very few patients with Barrett’s esophagus. Together with another recent study, as well as studies of cost-effectiveness and patients’ quality of life, the results of our study suggest that the risk of esophageal adenocarcinoma among patients with Barrett’s esophagus is so minor that in the absence of dysplasia, routine surveillance of such patients is of doubtful value," the investigators said.
The relevance of such surveillance programs has been questioned before because they have never been shown to improve survival and because an estimated 95% of patients with a new diagnosis of esophageal adenocarcinoma do not have a previous diagnosis of Barrett’s esophagus, they noted.
Dr. Hvid-Jensen and his colleagues used data from Denmark’s nationwide pathology and cancer registries to calculate the incidence of adenocarcinoma among patients with Barrett’s esophagus and compare it with the expected incidence in the general population of 5.4 million people.
A total of 11,028 patients underwent endoscopic biopsy and received a diagnosis of Barrett’s esophagus during 1992-2009. The median age at baseline was 63 years, and patients were followed for a median of 5.2 years.
"Our study provides solid evidence that esophageal adenocarcinoma will develop in very few patients with Barrett’s esophagus."
During that time, 197 of these patients with Barrett’s esophagus developed new esophageal adenocarcinomas, which comprised 7.6% of all the 2,602 incident esophageal adenocarcinomas diagnosed in the general Danish population during 1992-2009.
After excluding cancer cases that developed in the first year after a diagnosis of Barrett’s esophagus, the incidence of esophageal adenocarcinoma among patients with Barrett’s esophagus was found to be 1.2 cases per 1,000 person-years, the investigators said (N. Engl. J. Med. 2011;365:1375-83).
The annual risk of developing the malignancy was 0.12%, or one case of adenocarcinoma per 860 patient-years.
In contrast, four reviews of the literature published in the past decade, which pooled the results of numerous small studies conducted in the United States and Europe, calculated esophageal adenocarcinoma incidence as ranging from 5.2 to 7.0 cases per 1,000 person-years. And two previous registry studies calculated incidences of 4.0 and 5.0 cases per 1,000 person-years.
Current surveillance guidelines are based on these earlier studies, which appear to have overstated the risks, Dr. Hvid-Jensen and his associates said.
Their population-based, nationwide study is one of the largest studies of the issue; it included patients of all ages and both sexes and had almost no loss to follow-up. Because of Denmark’s universal health care plan, this study also had no referral bias or diagnostic bias. "The generalizability of our results is therefore high," they noted.
Moreover, a recent population-based study in Northern Ireland found remarkably similar results: an incidence of 1.3 cases of esophageal adenocarcinoma per 1,000 patient-years among people with Barrett’s esophagus. And another recent study "in which Markov models were used to evaluate available data on the incidence of adenocarcinoma supports our findings ... [and suggests] that surveillance is not beneficial," the researchers added.
This study was supported by the University of Aarhus Clinical Institute. No financial conflicts of interest were reported.