Scientists discover more potential biomarkers of early pancreatic cancer

Another team of researchers has found another group of small molecules whose presence in the blood may be used to test for early signs of pancreatic cancer - a disease with a poor survival rate that affects around 46,000 people a year in the US and ranks fourth as a leading cause of cancer deaths among Americans.

Imaging techniques like CT scanning and MRI are unable to tell you if pancreatic lesions are benign or malignant.

The researchers, from H. Lee Moffitt Cancer Center in Tampa, FL, report their findings in the journal PLOS ONE.

Only around 6% of people with pancreatic cancer survive more than 5 years after diagnosis. 

The main reason is because of the lack of reliable tools to diagnose the disease early enough so surgeons can remove the cancer before it spreads.

Like work currently going on in other research centers, the Moffitt team focused on a small group of molecules called microRNAs. But in their case, they looked specifically at microRNAs linked to intraductal papillary mucinous neoplasms (IPMNs).

IPMNs are a type of pancreatic cyst or lesion that can lead to pancreatic cancer in the same way that precancerous polyps can lead to colon cancer.

IPMN lesions can be seen on computed tomography (CT) scans and magnetic resonance imaging (MRIs), but these scanning techniques are unable to tell you if the cysts are benign (low risk of cancer) or malignant (high risk of cancer).

Currently, the only way to test if the pancreatic lesions are high risk or low risk for cancer is to remove them with surgery - but this is itself high risk because it can result in long-term diabetes and death.

The other option is to wait and see if the lesions lead to cancer, but this is far from ideal because it denies doctors the chance to cure their patients of a potentially life-threatening condition.

Study found six microRNAs that differentiate high- and low-risk pancreatic lesions

MicroRNAs are small molecules that act as "master regulators" that control many cancer processes in the body. They can be found in tumor tissue and in blood and other body fluids.

There is growing evidence that microRNAs could serve as biomarkers of early pancreatic cancer.

For example, in October 2014, a team of researchers from Indiana University School of Medicine reported that they found a panel of microRNAs that could be used as a blood test for pancreatic cancer.

In that study, the team suggested three microRNAs - miR-10b, miR-155 and miR-106b - might serve as highly accurate early indicators of pancreatic ductal adenocarcinoma (PDAC) - the most common type of pancreatic cancer.

In this new study, the Moffitt team looked for microRNAs that might be linked with high-risk IPMN lesions that should probably be removed as soon as possible to avoid full-blown pancreatic cancer.

To do this, they analyzed IPMN tissue that had been surgically removed from patients diagnosed and treated at Moffitt and found six microRNAs that appeared to differentiate high-risk from low-risk lesions.

The six microRNAs may also contribute to pancreatic cancer progression

The six microRNAs the Moffitt team identified are: miR-100, miR-99b, miR-99a, miR-342 -3p, miR-126 and miRNA-130a.

The team also found evidence to suggest these microRNAs may contribute to pancreatic cancer progression.

"The hope is that this line of research may eventually lead to a microRNA-based blood test that could be used in conjunction with imaging features and other factors to aid the medical team and patient in accurately predicting disease severity at the time of IPMN diagnosis or follow-up."

And in a more general sense, as with other groups coming forward with potential new biomarkers, the team hopes their findings will also help find new ways to prevent and detect pancreatic cancer earlier and improve the current poor prognosis for most patients with the disease.

Funds for the study came from the American Cancer Society, the National Cancer Institute, the United States Public Health Service and the Moffitt Gastrointestinal Oncology Program.

References:

1.  A genome-wide investigation of microRNA expression identifies biologically-meaningful microRNAs that distinguish between high-risk and low-risk intraductal papillary mucinous neoplasms of the pancreas, Jennifer Permuth-Wey, et al., PLOS ONE, doi: 10.1371/journal.pone.0116869, published online 21 January 2015.
2.  Moffitt Cancer Center news release, accessed 3 February 2015.