Increased Short- and Long-Term Risks of Pancreatic Malignancy in Patients With Pancreatic Cysts and Main Pancreatic Duct Dilation
Rajesh N. Keswani, MD, MS, reviewing Hamada T, et al. Clin Gastroenterol Hepatol 2023 Feb 12.
Pancreatic cysts, most commonly intraductal papillary mucinous neoplasms (IPMNs), are frequently identified incidentally on cross-sectional imaging. IPMNs have varying malignant potential based on risk factors; thus, guidelines recommend imaging surveillance to identify which cysts might require surgical resection. Multiple risk factors for malignancy have been studied, including the presence of a mural nodule (solid component), larger cyst size, and dilation of the main pancreatic duct. Although main pancreatic duct dilation ≥10 mm is treated as a main-duct IPMN and is known to be high risk, there is limited available evidence on the short- and long-term risks of malignancy for IPMNs with moderate dilation (5-9 mm) of the main duct.
In this study of a prospectively maintained database of all patients with IPMNs, the authors focused specifically on the patients with IPMNs and associated main pancreatic duct dilation. Of 2829 patients diagnosed with IPMNs, 282 were found to have main pancreatic duct dilation (pancreatic duct ≥5 mm). In follow-up, 96 patients (34%) were found to have pancreatic cancer, the vast majority at the site of the IPMN (89/96).
Of the 96 carcinomas, 72 were diagnosed within 6 months of identification of the cyst. The short-term risk for occult carcinoma among patients with an IPMN and main-duct dilation of 5 to 9 mm was 19%. Furthermore, in long-term follow-up, among all cysts, patients with the main pancreatic duct dilation of 5 to 9 mm and ≥10 mm were at 3-fold and 7-fold increased risks of being diagnosed with pancreatic carcinoma, respectively, compared with patients with no dilation. Of interest, there appeared to be a linear relationship between increasing pancreatic duct diameter and long-term cancer risk. In longitudinal follow-up, elevated Ca 19-9 levels were positively associated with the risk of pancreatic cancer.
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.
Hamada T, Oyama H, Nakai Y, et al. Clinical outcomes of intraductal papillary mucinous neoplasms with dilatation of the main pancreatic duct. Clin Gastroenterol Hepatol 2023 Feb 12. (Epub ahead of print) (https://doi.org/10.1016/j.cgh.2023.01.032)