Testing the genetic diversity of cells in the food pipe of people with Barrett’s esophagus could be an accurate and early way to discover their risk of developing esophageal cancer.
So concludes a study published in Nature Communications and co-led by Queen Mary University of London (QMUL) in the United Kingdom.
Barrett’s esophagus is a condition where normal cells in the food pipe (esophagus) are replaced by an unusual type of cell typical of the condition.
The condition most commonly develops in people with chronic gastroesophageal reflux disease (GERD).
People with Barrett’s esophagus have a higher risk of developing esophageal cancer – a cancer with a 5-year survival of 15 percent.
However, while having Barrett’s esophagus raises people’s risk for esophageal cancer, most with the condition will not get the cancer in their lifetime. It is the unfortunate few who do.
At present, there is no easy way to differentiate the high-risk from the low-risk Barrett’s patients.
- Esophageal cancer is about three to four times more common in men than women
- The chance of getting the cancer increases with age
- The approximate lifetime risk of esophageal cancer in the U.S. is 1 in 125 in men and 1 in 435 in women.
Regular monitoring with endoscopy is currently the best option. This procedure involves pushing a camera down the food pipe to look for early signs of cancer.
Identifying risk for esophageal cancer early would not only mean that affected patients would get the best care earlier, but it would also reduce the need for repeated endoscopies in Barrett’s patients at lower risk.
The new study takes a step in this direction because it reveals that Barrett’s patients whose food pipe contains lesions with a genetically diverse cell population have a higher risk of developing esophageal cancer.
One of the researchers, Dr. Trevor Graham from Barts Cancer Institute at QMUL, says once their results are validated in other patients over a longer period, they will be able to say with confidence which patients have the high cancer risk and which do not, and can therefore be spared unnecessary endoscopy and worry. He adds:
“This will dramatically improve the quality of life for people with Barrett’s, and provide substantial cost saving to healthcare providers.”
For their study, Dr. Graham and colleagues followed over 300 patients with Barrett’s for 3 years, over which time they analyzed over 50,000 cells in their food pipe lesions.
By analyzing Barrett’s cells one by one, the team tracked changes in genetic diversity of each lesion over time.
They found that measuring the genetic diversity between Barrett’s cells in any given lesion was a good predictor of which patients were more likely to develop esophageal cancer. This finding confirmed similar results from another group.
The researchers suggest the reason genetic diversity is a good predictor of cancer is that if the cell population of a Barrett’s lesion is genetically diverse, then there is a higher chance of some of those cells being rogue ones that progress to cancer.
A significant result of this particular study is that the team also found the genetic diversity changed little over the 3 years of the follow-up. This would mean genetic diversity in a patient’s Barrett’s cells is fixed from the outset, and any mutations arising will have little effect on lesion development.
“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.”
Dr. Trevor Graham