Pancreatic Cancer is ‘Four Separate Diseases’
Researchers who have carried out detailed analysis of gene expression, molecular pathways, and DNA disruption in hundreds of tumours, have concluded that pancreatic cancer is not one disease, but actually four separate diseases, and that each one has a different genetic trigger and requires different treatment.
According to researchers, knowing which pancreatic cancer a patient has will allow doctors to give more accurate prognoses and treatment recommendations.
These results have also raised the possibility of being able to treat certain types of pancreatic cancer with cancer drugs already used to treat other cancer with similar underlying genetics.
Prof. Sean Grimmond of the University of Melbourne, Australia, and who also leads research based at the University of Glasgow in the UK, explained that the team classified pancreatic cancer into the following four sub-types:
- Pancreatic progenitor
- Aberrantly differentiated endocrine eXocrine (ADEX)
Prof. Grimmond went on to explain, “We identified 32 genes from 10 genetic pathways that are consistently mutated in pancreatic tumours, but further analysis of gene activity revealed four distinct sub-types of tumours.”
According to the study, each sub-type of pancreatic cancer has different survival rates and underlying genetics, and requires different treatments.
The study addresses an urgent need to improve our understanding of the causes of pancreatic cancer – particularly at the genetic and molecular level. Pancreatic cancer is currently fatal within a few months of diagnosis and is set to become the second most common cancer in the westernised world within the next 10 years.
The team analysed the genomes of 456 pancreatic tumours to identify the underlying genetic and molecular processes that go wrong inside cells when normal pancreatic tissue changes into aggressive cancer, and made some very unexpected discoveries.
The study found that some types of pancreatic cancer have mutations typically seen in leukaemia and colon cancer, for which there are already treatments available.
Other types of pancreatic cancer bear strong similarities to some bladder and lung cancers, says Prof. Grimmond, “and we can start to draw on that knowledge to improve treatments.”
The team used an approach called “integrated genomic analysis,” bringing together techniques that analyse not only genetic code, but also variations in structure and gene activity and say that this is the first time such an analysis revealed such a huge amount regarding the genetic damage that leads to pancreatic cancer.
Dr. Peter Bailey, first author, also based both at the University of Melbourne and the University of Glasgow, says the treatments for pancreatic cancer have not changed much in the last 20 years. “There are various types of chemotherapy, but it is not very selective, “it’s like hitting the disease with a mallet with your eyes closed,” he notes.
Leanne Reynolds, head of research for Pancreatic Cancer UK, says: “The findings of this research are incredibly exciting for anyone affected by pancreatic cancer, as they should mean that in the future the right patients can be given the right treatment at the right time.”
This study builds on earlier work by the team as part of the International Cancer Genome Consortium (ICGC).