Researchers have made significant progress in understanding the biology of pancreatic tumors, suggesting that there may be ways of identifying the usually fatal cancer at a much earlier and more treatable stage.
A principal finding is that pancreatic tumors are not aggressive cancers. To the contrary, they grow slowly, taking an average of 21 years to become fatal.
In 2010, researchers made significant progress in understanding pancreatic tumors, suggesting that there may be ways to identify the usually fatal cancer at an earlier and more treatable stage. Pancreatic tumors were found to be slow-growing, taking an average of 21 years to become fatal, creating an opportunity for early detection and removal. Two groups of researchers, one from Johns Hopkins Medical Institutions and the other from the Sanger Institute, used a new method for decoding DNA very rapidly to identify a long series of mutations that had accumulated in the original tumors of seven patients, as well as in the secondary cancers that had spread from the pancreas to other tissues.
The researchers arranged the mutations in a family tree and were able to date the development of the tumors from the length of the branches in the tree. They found that at least 10 years elapse between the first cancerous cell and the emergence of the first cell with the ability to spread to other tissues, and at least five more years are required for this cell to develop metastatic ability. The researchers are now looking for specific DNA changes that might help diagnose pancreatic tumors, with a leading candidate being a gene called KRAS, which is involved in transmitting messages inside a cell.
The Sanger Institute researchers found that after the initial damage, possibly in the KRAS signaling gene, the natural controls on cell division are lost, unleashing a maelstrom of genetic instability. The stabilized cancer cells start to spread but must develop a further set of mutations that help them adapt to the specialized environment of the tumor’s target tissues. This is ominous for the treatment of cancer because all the metastasized tumors are slightly different and would need different treatments. There is some chance of picking up the KRAS mutation in stool, which is hard to do at present, but the techniques are getting better all the time.
By Nicholas Wade New York Times