Pancreatic cancer years in the making
Decade elapses from first mutation to tumor formation, and years more until the disease spreads
By Nathan Seppa
The lead time for cancer of the pancreas to develop is extensive, possibly opening up a decade-long window of opportunity for doctors to someday screen for and remove tumors on this vital organ, a study in the Oct. 28 Nature shows. A companion study finds unusual chromosomal rearrangements in this deadly cancer, a characteristic that might provide insights into the cancer formation process.
Scientists have puzzled over the deadly nature of pancreatic cancer, in which fewer than 5 percent of patients survive for five years after being diagnosed. By then the cancer has usually spread beyond the pancreas to lymph nodes or other organs.
Some researchers argue that the cancer is so lethal because it is fast-growing and aggressive, while others suggest the cancer’s deadliness stems from an ability to remain hidden for years. The new research suggests the slow-growth theory might be on target.
In 2008, cancer geneticist Bert Vogelstein and his colleagues at Johns Hopkins University in Baltimore published the complete genetic profiles of 24 pancreatic cancers, identifying more than 60 mutations common to the tumors. One of the new studies used those data to calculate the pace of cancer growth in the pancreas. Using that figure and the average cell proliferation rate in the organ provides a molecular clock of sorts with which scientists can figure out how long it has taken for the first cancer-related mutation in a pancreas cell to develop into cancer.