Lawrence SA et al. – This study evaluated the yield of continued surveillance of pancreatic cysts up to and after 5 years of follow up. The study demonstrated that future growth, cross–over to resection, or carcinoma development was not prevented by the cyst size stability at the 5–year time point. Furthermore, a 3–fold higher risk of developing cancer was observed in patients who were stable at 5 years compared with the general population, hence patients with cystic lesions of the pancreas should be continued on long–term radiographic surveillance.

Methods

• A prospectively maintained registry was queried for patients with pancreatic cysts (1995–2016).
• Patients who initially underwent radiographic surveillance were categorized into those with <5 years and ≥5 years of follow up and were subsequently analyzed for the presence of cyst growth (>5 mm increase in diameter), cross–over to resection, and development of carcinoma.

Results

• Of the 3024 patients identified, 2472 patients (82%) were undergoing initial surveillance.
• A greater frequency of cyst growth (44% vs. 20%; P<.0001), a lower rate of cross–over to resection (8% vs 11%; P = .02), and a similar frequency of progression to carcinoma (2% vs 3%; P = .07) was observed in the ≥5 year group (n = 596) compared with the <5 year group (n = 1876).
• 69% of the patients in the ≥5 year group demonstrated radiographic stability at the 5–year time point.
• In addition, patients in the ≥5 year group experienced similar rates of cyst growth (19% vs. 20%; P = 0.95) and lower rates of cross–over to resection (5% vs 11%; P<.0001) and development of carcinoma (1% vs 3%; P = .008) when compared with the <5 year group.
• The observed rate of developing cancer was 31.3 per 100,000 per year in those radiographically stable at the 5–year time point, whereas the expected national age–adjusted incidence rate for the same group was 7.04 per 100,000 per year