Gene test helps identify precancerous pancreatic cysts

In collaboration with the Press Association

US scientists have developed a new gene-based test that can determine if pancreatic cysts are likely to develop into cancer.

Pancreatic cysts are abnormal pockets of fluid formed on or within the pancreas. Many pancreatic cysts are harmless and produce no symptoms, but some are cancerous or precancerous (which have the potential to become cancerous).

The tests developed at Johns Hopkins University in Baltimore could eliminate the need for patients with harmless pancreatic cysts to undergo unnecessary surgery.

Lead researcher Professor Bert Vogelstein and his team examined precancerous cysts for mutations in common cancer-causing genes. Not only did they discover mutations in a gene that is often faulty in pancreatic cancers - called KRAS - they also identified variations in a second gene called GNAS, which previously had not been associated with the disease.

The small study found that the size or grade of cyst had no impact on its likelihood of containing a gene mutation. The presence of GNAS or KRAS mutations was also not affected by differences in age, gender or smoking history.

Researchers also tested the tissue of pancreatic cancers from eight people with GNAS mutations in their cysts and found that seven of the eight had GNAS mutations both in the cancer and in their cysts.

Professor Vogelstein, Clayton Professor of Oncology at the Johns Hopkins Kimmel Cancer Center, said: "There has long been a need for accurate, quantitative ways to identify cysts that are more worrisome and to help patients avoid unnecessary surgeries for harmless cysts."

Pathologist and director of Hopkins' Sol Goldman Pancreatic Cancer Research Center, Ralph Hruban, said: "Most cysts are benign but distinguishing between the harmless and dangerous ones is challenging for doctors and patients alike."

Larger studies must be done before the gene-based test can be widely offered.

Oliver Childs, senior science information officer at Cancer Research UK, commented: "Pancreatic cancer represents one of our biggest challenges - we simply haven't seen the same progress in this disease as we have in other cancers.

"This work is encouraging - pancreatic cysts are relatively common in the general population, so finding ways to distinguish between harmless ones and rare ones that might develop into cancer is crucial. It will be interesting to see if these results are replicated in larger trials in the future."

References

  • Wu, J. et al. Recurrent GNAS mutations define an unexpected pathway for pancreatic cyst development. Sci Transl Med DOI: 10.1126/scitranslmed