New genetic insights into oesophageal cancer

An international study involving researchers from QIMR Berghofer Medical Research Institute has identified several new genes involved in oesophageal cancer.

The research was a major international collaboration that was led by scientists from QIMR Berghofer, the University of Cambridge, the University of Central Lancashire and the University of Bonn. The findings have been published in the journal Lancet Oncology.

QIMR Berghofer’s Associate Professor Stuart MacGregor – who co-led the study – said the international collaboration identified new genetic variants, or genetic ‘typos’, that increase a person’s risk of developing oesophageal cancer or a condition called Barrett’s oesophagus.

Barrett’s oesophagus can be a precursor to oesophageal cancer; however, only a small proportion of people with Barrett’s oesophagus will go on to develop oesophageal cancer.

Researchers have previously identified eight genetic variants that increase a person’s risk of developing Barrett’s oesophagus. In this study, the scientists identified another eight genes, bringing the total to 16.

“Previous work in this area had suggested that the genetic predisposition to oesophageal cancer was solely due to a person’s genes increasing their risk of developing Barrett’s oesophagus,” Associate Professor MacGregor said.

“Interestingly, in this study, we have for the first time identified a gene which increases the risk of Barrett’s oesophagus developing into oesophageal cancer.

“We think that in future this will help us to better understand why some people with Barrett’s oesophagus go on to develop oesophageal cancer and others don’t.”

The study also discovered an unexpected genetic link between oesophageal cancer and the debilitating lung disease cystic fibrosis.

“One of the gene mutations we identified in this study is on a gene called CFTR,” Associate Professor MacGregor said.

“Cystic fibrosis is caused by mutations on the same gene. People with cystic fibrosis get oesophageal reflux, a risk factor for oesophageal cancer.

“We think what this means is that extreme changes in that gene lead to cystic fibrosis, reflux and other conditions, while less extreme changes in that gene lead to reflux and Barrett’s oesophagus.

“Our previous genetic work suggested that obesity was likely to be causally related to oesophageal cancer.

“In this new study we have identified a gene that influences both obesity and oesophageal cancer. The fact that some of the same genes influence both is further evidence that being obese increases a person’s risk of developing oesophageal cancer.

“This aggressive cancer has very poor survival rates. Therefore, to reduce the risk of developing it later in life, the best thing people can do is maintain a healthy bodyweight earlier in life.”

The study received funding from the National Health and Medical Research Council (NHMRC) of Australia and the US National Institutes of Health (NIH).