The Cost of Surveying Intraductal Papillary Mucinous Neoplasms
Since first described by Ohashi in 1982, the incidence of intraductal papillary mucinous neoplasms (IPMNs) has surged despite an incomplete understanding of its natural history.1–3 Using data from the Rochester Epidemiology Project, between 1985 and 2005, there has been a 14-fold increase in the incidence of IPMNs; the widespread use of high-resolution cross-sectional imaging only has increased the identification of IPMNs, often in the absence of symptoms.4,5 Furthermore, the presence of an IPMN can potentially result in significant costs because of specialty referral, invasive evaluation, and surgical intervention. Thus, the primary aim of our study is to quantify the cost to patients enrolled in a long-term IPMN surveillance program. A priori, we hypothesized that patients enrolled in an IPMN surveillance program likely incurred significant health care costs.
This single-center, retrospective cohort study included patients with IPMNs diagnosed and enrolled in an IPMN surveillance program between 2002 and 2010 at Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire. Collected data included patient demographics, IPMN characteristics, number of surveillance imaging studies (abdomen and pelvis computed tomography [CT] scans, abdomen and pelvis magnetic resonance imaging [MRI] scans, and endoscopic ultrasounds [EUSs]) and IPMN-focused gastroenterology and surgery clinic visits, time in surveillance, and clinical outcomes. The primary study outcome was the cost per year enrolled in the IPMN surveillance program. The total cost of enrolling in the surveillance program per patient and cost per year for those with malignant transformation were also calculated.
A total of 180 patients had a confirmed diagnosis of IPMN requiring surveillance per the Sendai criteria; however, 90 patients were excluded from data analysis because they were either enrolled in the surveillance program for less than 2 years or lost to follow-up. The study group eligible for analysis included 90 patients—36 females (40%) and 54 males (60%)—with 45 patients with main duct IPMN and 45 with branch duct IPMN. There was no statistical difference among baseline patient demographics between the 2 groups. As well, there was no difference between the 2 cohorts in terms of number of surveillance CTs, MRIs, EUS, or gastroenterology clinic visits (P = 0.12, 0.50, 0.40, and 0.57, respectively). Of the main duct IPMNs, 40% were stable in follow-up whereas 20% were surgically resected. Of the branch duct IPMNs, 56% were stable in follow-up whereas 13.3% were surgically resected. In both groups, 4% (n = 2) of IPMNs underwent malignant transformation.
The mean total surveillance cost per patient was US $17,482 (range, $340–$61,494) in the main duct IPMN cohort and US $15,338 (range, $340–$55,070) in the branch duct IPMN cohort (P = 0.39, Table 1). The cost per year enrolled in the surveillance program was US $4653 and $3940, respectively (P = 0.17). Furthermore, the cost per year for surveillance per each cyst undergoing malignant transformation was US $4548 in the main duct IPMN group as compared with US $5133 in the branch duct IPMN group.
This study represents the first attempt in patients with IPMNs to evaluate the exact cost of cyst surveillance as recommended by several international consensus guidelines. It demonstrates that long-term surveillance of both main and branch duct IPMN is associated with substantial annual costs to enrolled patients. In this study, patients spent a mean of 4 years in surveillance with some accruing costs in excess of US $60,000; only 2 patients (4%) in each cohort developed malignant transformation of their IPMN.
Although there is an association between IPMNs and malignancy, our data underscore the need to pursue a careful risk-to-benefit analysis when engaging patients in a long-term surveillance program.