Genetic Analysis of Lesions Provides Accurate Esophageal Cancer Test

Barrett's Esophagus is a common condition that affects an estimated 1.5 million people in the UK alone, although many are undiagnosed. This condition involves normal cells in the esophagus being replaced by an unusual cell type called Barrett's Esophagus, and is thought to be a consequence of chronic reflux or heartburn.

People with Barrett's have an increased risk of developing esophageal cancer, a neoplasm that has a five year survival of 15% and although the overall lifetime risk of developing esophageal cancer in people with Barrett's is significant, most Barrett's patients will not develop cancer in their lifetime. It is the unfortunate few who will develop an aggressive cancer.

An international team of scientists led by those at the Queen Mary University of London (UK) followed up more than 300 Barrett's patients over three years, and analyzed around 50,000 cells in the process. They performed genetic analysis of individual cells and measured the genetic diversity in each lesion to track it over time. The results validated a previous group's discovery that measurement of the genetic diversity between Barrett's cells in any given lesion is a good predictor of which patients are at high risk of developing cancer. Genetic diversity describes how diverse the genetic make-up of individual cells is in any given group of cells.

In addition, the team found that there were no significant changes in genetic diversity during the three years that the patients were followed. Clonal expansions are rare, being detected once every 36.8 patient years, and growing at an average rate of 1.58 cm2 per year, often involving the p16 locus. This suggests that the genetic diversity amongst a person's Barrett's cells is essentially fixed over time, and mutations have little impact on the lesion's development. Whenever someone's Barrett's is tested, their future risk can be predicted regardless of how soon it is after the appearance of abnormal cells.

Trevor A. Graham PhD, a lecturer in Tumor Biology and senior author of the study said, “Our findings are important because they imply that a person's risk of developing esophageal cancer is fixed over time. In other words, we can predict from the outset which Barrett's patients fall into a high risk group of developing cancer and that risk does not change thereafter.” The study was published on August 19, 2016, in the journal Nature Communications.

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