Low-grade dysplasia in Barrett's esophagus has a high risk of progression

Background and study aims: Surveillance in Barrett's esophagus relies on the detection of dysplasia by histopathology. However, the natural history of this condition, particularly that of lowgrade dysplasia (LGD) is poorly understood. This paper describes our experience of LGD over a period of 21 years. Patients and methods: Between 1984 and January 1995, 357 patients with Barrett's esophagus without dysplasia were recruited for annual surveillance: 34 of these patients developed LGD during this period. This was a retrospective cohort study of this group in terms of survival and cancer outcomes >= 8 years after the original diagnosis of LGD, comparing them with the patients who did not develop LGD over the same period, with a histopathological review of the original diagnoses of LGD. The outcomes of 356/357 (99.7%) of the patients were established in December 2004. Results: After 8 years, high-grade dysplasia (HGD) or cancer had developed in 9/34 patients with LGD (27%) and in 16/322 controls (5%). Cox's proportional hazards model revealed that the time from the first diagnosis of Barrett's esophagus to the first "event" of either HGD, esophageal cancer, or death did not show a statistically significant difference between the two groups. A further analysis treating death as "loss to follow-up" showed a significantly increased risk for the LGD group to progress to HGD or cancer (hazard ratio 5.9 [95% confidence interval 2.6 - 13.41, P < 0.001). The histopathology review demonstrated a fair level of agreement between pathologists, with a kappa value of 0.48. Conclusions: Patients diagnosed with LGD during surveillance of Barrett's esophagus are at a considerably increased risk of progressing to develop esophageal cancer over an 8-year period but most deaths are not cancer-related.