Cancer in IPMN? Don’t Stop Looking!
Bret T. Petersen, MD, FASGE reviewing Oyama H, et al. Gastroenterology 2019 Aug 29.
Pancreatic intraductal papillary mucinous neoplasia (IPMN) lesions pose a risk for progression to malignancy and are therefore closely surveyed for evidence of malignant transformation or high-risk features for evolving transformation. The optimal duration of surveillance for stable lesions is not well defined. Here the authors report the incidences for both pancreatic carcinoma arising from IPMN lesions (IPMN-Ca) and typical pancreatic ductal adenocarcinoma (PDAC) in a population of 1404 patients (48% male; mean age, 67.5 years) followed for branch-duct IPMN over many years.
Development of PDAC versus IPMN-Ca was characterized by mutations in GNAS and KRAS detected in the IPMN lesions and concurrent carcinomas. Thirty patients developed concurrent PDAC, while 38 developed IPMN-Ca (a total of 68 patients), during >9200 person-years of follow-up. The cumulative incidence rates of carcinoma among 805 patients followed for more than 5 years were 3.5% at 10 years and 12.0% at 15 years from diagnosis. The incidence of IPMN-Ca, but not of PDAC, was increased among those with a 10-mm increase in the size of IPMN lesions (subdistribution hazard ratio [SHR], 1.85; 95% confidence interval [CI], 1.38–2.48) and a 1-mm increase in the main pancreatic duct diameter (SHR, 1.56; 95% CI, 1.33–1.83). A mural nodule developed in 63% of patients progressing to IPMN-Ca.
COMMENT
While some guidelines suggest forgoing surveillance in IPMN patients with stable findings over 5 years, these results and others demonstrate further risk, potentially warranting indefinite surveillance among patients who remain surgical candidates. Persisting questions that merit additional study pertain to the survival benefits from ongoing surveillance, subsets of patients for whom surveillance might be safely discontinued, and both cost-effectiveness and quality of life for surveillance versus surgery.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
Bret T. Petersen, MD, FASGE
CITATION(S)
Oyama H, Tada M, Takagi K, et al. Long-term risk of malignancy in branch-duct intraductal papillary mucinous neoplasms. Gastroenterology 2019 Aug 29. (Epub ahead of print) (https://doi.org/10.1053/j.gastro.2019.08.032)
