Cancer Risk in Barrett's Esophagus Lower Than Expected

Janis C. Kelly

June 23, 2011

June 23, 2011 — Barrett's esophagus progresses to esophageal adenocarcinoma in a smaller proportion of patients than was thought, so routine endoscopic surveillance might not be cost effective, new research suggests.

Only 0.22% of patients with Barrett's esophagus progress to cancer each year, well below the rate of 1% per year that is thought to make routine surveillance cost effective, Shivaram Bhat, MB, and colleagues report online June 16 in the Journal of the National Cancer Institute.

Cancer risk was higher in patients in whom an initial endoscopy and biopsy showed low-grade dysplasia (1.40%) or specialized intestinal metaplasia (0.38%). Men were statistically significantly more likely to progress to malignancy than women, and people 60 to 69 years of age had a higher risk than those younger than 50 or 80 and older.

"Our study did find lower rates of neoplastic progression in Barrett's esophagus than previous studies. The findings are in keeping with the lower rates of progression seen in recent systematic reviews," said lead author Dr. Bhat, a research fellow at the Northern Ireland Cancer Registry, Queens University, Belfast, United Kingdom.

"Our study calls into question the cost effectiveness of current endoscopic surveillance programs," Dr. Bhat told Medscape Medical News. "However, it is important to note the difference between the cost effectiveness of surveillance and the overall need for surveillance. The differences in risks of malignant progression between subgroups of patients observed in our study suggest that there may be subgroups of patients in which endoscopic surveillance is more cost effective than others. Further research is needed in this area to allow clinicians to better risk-stratify patients at index diagnosis of Barrett's esophagus and to optimize the overall cost effectiveness of endoscopic surveillance."

The researchers prospectively followed 8522 patients in the Northern Ireland Barrett's Esophagus Registry, one of the largest registries in the world of people with the condition. After an average follow-up time of 7 years, 79 patients were diagnosed with esophageal cancer, 16 with cancer of the gastric cardia, and 36 with high-grade dysplasia. For the whole study population, the incidence of these 3 conditions combined was 0.22% per year. Previous studies have reported an annual incidence of cancer among people with Barrett's esophagus between 0.58% and 3.00%.

The researchers also looked at the incidence of cancer and high-grade dysplasia in different subgroups of patients.

According to Dr. Bhat, "our study provides some insight into the importance of the histological definition of Barrett's esophagus. There has been much debate as to the need for specialized intestinal metaplasia for the diagnosis of Barrett's esophagus. Our study showed that patients without histological specialized intestinal metaplasia at their index diagnosis of Barrett's esophagus had a particularly low risk of malignant progression, and that in this subgroup, the majority of patients who progressed to malignancy who also had an interim biopsy were diagnosed with specialized intestinal metaplasia at the interim biopsy (7 of 10 patients)."

The authors conclude that the risk of Barrett's esophagus progressing to esophageal cancer is less than previously reported, and that this finding has implications for clinical practice. "Current recommendations for surveillance are based on higher estimates of cancer risk among patients with [Barrett's esophagus] than were seen in this study, and therefore, they may not be justified," they write.

Dr. Bhat added that "a particularly interesting finding in our study was the constant rate of neoplastic progression observed over time from Barrett's esophagus diagnosis. This suggests that a uniform frequency of endoscopic surveillance, as currently practiced, is appropriate."

In an accompanying editorial, Douglas Corley, MD, PhD, from Kaiser Permanente's research division in Oakland, California, notes that the study provides one of the first estimates of incidence of esophageal cancer in people with Barrett's esophagus from a large multicenter population, but he also notes a major limitation: the investigators lacked detailed endoscopic data, so inclusion was based only on the presence of columnar mucosa on an esophageal biopsy, not on visible changes of Barrett's esophagus on endoscopy. This might have resulted in an underestimation of the risk for progression to malignancy.

Dr. Corley concludes that the study provides general support for the current management practices of Barrett's esophagus. He agrees with the researchers that patients without intestinal metaplasia are at relatively low risk for malignant progression and less likely to benefit from surveillance or treatment, and that patients with intestinal metaplasia are at increased risk and more likely to benefit from surveillance.

The big unknown, mentioned by both Dr. Bhat and Dr. Corley, is whether surveillance or treatment such as ablation or chemoprevention actually decrease cancer deaths in patients with Barrett's esophagus.

Dr. Bhat and Dr. Corley have disclosed no relevant financial relationships.

J Natl Cancer Inst. Published online June 16, 2011. Full text, Editorial

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