SURVEILLANCE FOR PRESUMED BD-IPMN OF THE PANCREAS: STABILITY, SIZE AND AGE IDENTIFY TARGETS FOR DISCONTINUATION

Abstract
Background and Aims: Currently, most patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMN) are offered indefinite surveillance, resulting in health care costs with questionable benefits regarding cancer prevention. This study sought to identify patients where the risk of cancer is equivalent to an age-matched population, thereby justifying discontinuation of surveillance.

Methods: International multicenter study involving presumed BD-IPMN without worrisome features (WF) or high-risk stigmata (HRS) at diagnosis who underwent surveillance. Clusters of individuals at risk for cancer development were defined according to cyst size and stability for at least 5 years, and age-matched controls were used for comparison using standardized incidence ratios (SIRs) for pancreatic cancer.

Results: Of 3844 patients with presumed BD-IPMN, 843 (22%) developed a WF or HRS after a median surveillance of 53 (IQR 53) months and 164 patients (4.3%) underwent surgery. Of the overall cohort, 1617 patients (42%) remained stable without developing WF or HRS for at least 5 years. In patients 75 years or older, the SIR was 2.23 (95%CI 0.45-6.52), and in patients 65 year or older with stable lesions below 15mm in diameter after 5 years, the SIR was 1.77 (95%CI 0.20-6.39).

Conclusions: The risk of developing pancreatic malignancy in presumed BD-IPMN without WF or HRS after 5 years of surveillance is comparable to that of the general population depending on cyst size and patient age. Surveillance discontinuation could be justified after 5 years of stability in patients older than 75 years with cysts < 30 mm, and in patients 65 years or older who have cysts ≤ 15 mm.