A LEADING cancer researcher has called for greater emphasis on personalised treatment after a landmark Australian study found the underlying genetic cause of pancreatic cancer differed among patients.
After sequencing the genome of 142 people and their pancreatic tumours, scientists found no two cancers were the same.
The findings, part of an international program to identify the genetic drivers behind 50 different cancers, have implications for the treatment of other types of tumours.
"The big thing to come out of this is that cancer is not one disease," said Andrew Biankin, from the Kinghorn Cancer Centre at the Garvan Institute of Medical Research and a lead author of the study. "While there are common genes in each tumour, based on this we think each cancer should be treated differently."
Pancreatic cancer is one of the most lethal cancers. The majority of patients die within a year of being diagnosed – a survival rate that has not improved in almost 50 years.
As part of the study, published in the journal Nature, the team identified more than 2000 genes involved in the cancer, adding to the half a dozen already linked to the disease.
While four genes were present in 50 per cent of pancreatic tumours, most mutations were found in less than 2 per cent of cancers.
Several study participants were placed on more targeted medication after their doctors were alerted to their genetic profile. "It changed the treatment of not just the individual patients but, because we've detected some inherited genes, it has also impacted on the wellbeing and the care of their families," he said.
One participant, Zenon Slotwinski, whose mother died of complications from pancreatic cancer in April 2010, learnt he and his two sisters had inherited a known cancer gene from her.
As a result, Mr Slotwinski, 54, is in a pancreatic and prostate cancer screening program, and his sisters have undergone preventative operations to remove susceptible organs. "For me knowledge is a good thing but everyone has a different view," he said.
Professor Biankin said standard cancer treatments were based on where the cancer originated, and doctors were required to first treat patients with drugs shown to be most effective on most patients before moving on to other medications.
"Unfortunately most patients with pancreatic cancer never get to the second drug because if they haven't responded to the first drug, the disease is so aggressive they end up dying before they get their second choice, [which] might have been the right one for [that patient]," he said.
To improve tumour treatments, researchers around the world are building a "genetic knowledge bank of cancers" that doctors could refer to when deciding the drug most suited to the genetic profile of their patient's cancer, Professor Biankin said.
Clinical trials are now conducted on a particular drug for a specific cancer, a process that can take years and require hundreds and sometimes thousands of patients. Personalised cancer treatments are being used throughout health systems in the United States, Britain and Europe but are yet to take hold in Australia, he said.
From next month the Australian Pancreatic Cancer Genome Initiative will run a clinical trial in which the treatment for pancreatic cancer patients will be matched to their genetic profile.