Pancreatic Cystic Neoplasms Rarely Turn Cancerous, Study Shows

Individuals with intraductal papillary mucinous neoplasms (IPMNs) that lack "worrisome or high-risk features" have no greater risk of pancreatic cancer than individuals without IPMNs, based on a retrospective cohort study from Mayo Clinic.

These findings, if validated in a larger population, could challenge current surveillance practices for IPMNs, reported researchers who were led by Shounak Majumder, MD, a gastroenterologist in the pancreas clinic at Mayo Clinic, Rochester, Minn. The study was published in JAMA Network Open.

"Among intraductal papillary mucinous neoplasms (IPMNs) that were Fukuoka negative at baseline, fewer than 10% developed worrisome or high-risk features on follow-up. Pancreatic cancer development in IPMN was a rare event overall," the authors wrote.

"Current international consensus guidelines for the management of IPMNs recommend image-based surveillance with the aim to detect clinical and imaging features of advanced neoplasia," the authors wrote. Yet "there are no population-based estimates of the burden of pancreatic cancer in individuals with IPMNs or the proportion of pancreatic cancers that develop from or adjacent to an IPMN."

Researchers aimed to address this knowledge gap with a population-based cohort study. Drawing data from the Rochester Epidemiology Project, which includes longitudinal medical records from residents of Olmsted County, Minn., investigators identified two cohorts. The first group comprised 2,114 patients 50 years old or older who had undergone abdominal CT scans between 2000 and 2015, among whom 231 (10.9%) had IPMNs. The second cohort included 320 patients diagnosed with pancreatic cancer between 2000 and 2019, among whom 31 (9.8%) had IPMNs.

Further analysis showed that 81% of the patients with IPMNs in the first cohort lacked Fukuoka high-risk or worrisome features. Within this subgroup, the incidence rate of pancreatic cancer per 100 years was not significantly different than among individuals without IPMNs.

"Although the risk of IPMN-PC is has been extensively described, our population-based study further demonstrates that most IPMNs did not progress in Fukuoka stage and did not transform into pancreatic cancer, a similar message was expressed by the current American Gastroenterological Association pancreatic cyst guidelines, published in 2015, and studies published in 2022 and 2016," the investigators wrote.

Analyzing the cohort of 320 patients with pancreatic cancer showed those with IPMNs had significantly better outcomes than those without IPMNs, including longer survival and lower rate of metastatic disease upon diagnosis. These findings align with previous research, the investigators wrote.

In an accompanying editorial, Stefano Crippa, MD, PhD, of Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, and colleagues offered their perspective on the findings.

"Although results of this study should be validated in larger cohorts, they represent useful clinical data from an unselected population-based cohort that helps challenge current IPMN surveillance policies that recommend lifetime active surveillance for all fit individuals," they wrote. "Currently, we can use follow-up data from studies like this one to identify patients with IPMNs who are not at risk of progression based on clinical-radiological parameters. We can furthermore start selecting subgroups of patients with limited life expectancy due to age or comorbidities to be considered for surveillance discontinuation."

Timothy Louis Frankel, MD, a gastrointestinal surgeon at the University of Michigan, Ann Arbor, specializing in malignancies, said the findings are most useful for reassuring patients who have been diagnosed with an IPMN.

"The real take-home message is that in the absence of worrisome features people [with an IPMN] should feel comfortable that their risk is no higher than the general population for developing pancreatic cancer," Dr. Frankel said in an interview.

Before any changes to surveillance can be considered, however, Dr. Frankel echoed the investigators' call for a larger study, noting the relatively small population, most of whom (92%) were White.

"We do know that pancreas cancer and pancreas diseases vary significantly by race," Dr. Frankel said. "So we do need to be a little bit cautious about changing the way that we manage patients based on a fairly homogeneous subset."

He also pointed out that two patients had IPMNs that developed increased risk over time.

"They actually went from no risk features to having features that put them at risk," Dr. Frankel said. "Those are patients who were saved by surveillance. So I'm not sure that this study was necessarily designed to let us know if and when we can stop following these lesions."

Study authors had no relevant disclosures. The editorial writers reported no conflicts of interest.

This article originally appeared in GI and Hepatology News.

© 2023  Frontline Medical Communications Inc.

Cite this: Pancreatic Cystic Neoplasms Rarely Turn Cancerous, Study Shows - Medscape - Nov 30, 2023.