By Megan Brooks
NEW YORK (Reuters Health) - 6/8/2019
The U.S. Preventive Services Task Force (USPSTF) continues to advise against routine screening for pancreatic cancer in asymptomatic adults.
This grade "D" recommendation, in today's JAMA, reaffirms 2004 advice from the task force. A "D" recommendation means there is "moderate or high certainty" that the service has no net benefit or that the harms outweigh the benefits.
To update the 2004 recommendation, the task force reviewed the latest evidence on the benefits and harms of screening for pancreatic cancer, the diagnostic accuracy of screening tests for pancreatic cancer, and the benefits and harms of treatment of screen-detected or asymptomatic pancreatic cancer.
They found no evidence on the accuracy of imaging-based screening tests (computed tomography scan, magnetic resonance imaging or endoscopic ultrasonography) for detecting pancreatic cancer.
Pancreatic cancer is a condition that is "begging for more research," USPSTF member Dr. Chyke Doubeni said in a JAMA podcast. "It's a relatively uncommon cancer affecting about 13 out of 100,000 people a year," he explained, "but the prognosis is poor."
The task force also found no evidence that screening for pancreatic cancer or treatment of screen-detected pancreatic cancer improves disease-specific morbidity or mortality, or all-cause mortality.
There is adequate evidence, they say, that the magnitude of the benefits of screening for pancreatic cancer in asymptomatic adults are "no greater than small" and that the potential harms are "at least moderate."
Therefore, the task force concludes that there is "no new evidence that warrants a change in the prior D recommendation and reaffirms its previous conclusion that the potential benefits of screening for pancreatic cancer in asymptomatic adults do not outweigh the potential harms."
"This recommendation," Dr. Doubeni emphasized, "is for people who do not have signs or symptoms or any high-risk condition, including family history but also genetic conditions that would put them at high risk for having pancreatic cancer."
Pancreatic-cancer screening faces "significant challenges," write the authors of an editorial in JAMA. "The disease is relatively rare, and the pretest probability in the general population is therefore very low. Even an extremely specific screening test (99% specificity) will generate a large number of false positives when applied to the general population."
Yet, at the same time, Dr. Ralph Hruban from Johns Hopkins in Baltimore and Dr. Keith Lillimoe from MassGeneral Hospital in Boston say the future for pancreatic screening looks "extraordinarily bright, with considerable advances and substantial opportunities on the near horizon."
"One can easily imagine the day in which high-risk individuals will be screened using new molecular-based technologies," the editorial writers say. "In parallel, all abdominal imaging will be scanned using deep learning and other approaches to identify subtle changes in the pancreas. Individuals found to have a precancer will not undergo invasive surgery but instead will receive a therapeutic vaccine that will selectively kill the precancerous lesion before it has the opportunity to progress to invasive carcinoma."
"This vision is not that far off," Drs. Hruban and Lillimoe write. "Early results from the Cancer of the Pancreas Screening (CAPS) trial, led by Canto et al, suggest that screen-detected pancreatic cancers are smaller and have a better prognosis than cancers detected because the patients were symptomatic. This is a critical advance because it suggests that down staging, and therefore real benefit, is possible."
"We are optimistic. Although the student may be getting a grade of D, this student deserves an A for effort, and we see a most improved award on the near horizon," they conclude.