But pancreatic cancer researchers have long suspected that long-term survivors also shared some unique and unknown quality that improved their chances.
The international team of researchers led by US scientists at Memorial Sloan Kettering Cancer Center,New York,compared the exome sequences of long-term survivors with those of patients who died soon after their diagnosis.
Professor Pesman was one of more than 150 Australian pancreatic cancer patients whose genomic data was collected by the Australian Pancreatic Cancer Genome Initiative (APGI) and analysed by the study researchers.
Using computational simulations,the scientists found that the cancer cells of long-term survivors produced peptides (neoantigens) that mimicked germs.
These unique neoantigens activated the body's T-cell immune response.These immune cells still appear to mistake the cancer-derived neoantigens for bacteria or viruses years after the cancer was treated,according to the study published inNature on Thursday,
The presence of these neoantigens predicted which patients would be long-term survivors,which suggested their immune systems were attacking them,like"built-in immunotherapy",said Professor Anthony Gill at the Garvan Institute of Medical Research,who is chair of the APGI and study collaborator.
"Traditionally,researchers spend a lot of time studying the sick patients,the patients whose cancer comes back,but in this study we've turned that on its head by looking at survivors and what's different about them,"Professor Gill said.
"If we can learn how the immune system reacts in these long-term survivors,the idea is we might be able to teach the immune systems of other patients to react the same way,"he said.
The findings could pave the way for a range of potential treatment pathways,including a vaccine or manipulating the microbiome by introducing'good bacteria',or better-targeted immunotherapies,but the research was still in its early stages,Professor Gill said.
Professor Pesman recently volunteered to again donate her genetic data to the APGI to further its research in the hope of helping other pancreatic cancer patients who were less lucky,but were no less deserving of survival.