What Is the Best Way to Identify Malignant Transformation Within Pancreatic IPMN: A Systematic Review and Meta-Analyses

Abstract

Objectives:Pancreatic intraductal papillary mucinous neoplasias (IPMNs) represent 25% of all cystic neoplasms and are precursor lesions for pancreatic ductal adenocarcinoma. This study aims to identify the best imaging modality for detecting malignant transformation in IPMN, the sensitivity and specificity of risk features on imaging, and the usefulness of tumor markers in serum and cyst fluid to predict malignancy in IPMN.Methods:Databases were searched from November 2006 to March 2014. Pooled sensitivity and specificity of diagnostic techniques/imaging features of suspected malignancy in IPMN using a hierarchical summary receiver operator characteristic (HSROC) approach were performed.Results:A total of 467 eligible studies were identified, of which 51 studies met the inclusion criteria and 37 of these were incorporated into meta-analyses. The pooled sensitivity and specificity for risk features predictive of malignancy on computed tomography/magnetic resonance imaging were 0.809 and 0.762 respectively, and on positron emission tomography were 0.968 and 0.911. Mural nodule, cyst size, and main pancreatic duct dilation found on imaging had pooled sensitivity for prediction of malignancy of 0.690, 0.682, and 0.614, respectively, and specificity of 0.798, 0.574, and 0.687. Raised serum carbohydrate antigen 19-9 (CA19-9) levels yielded sensitivity of 0.380 and specificity of 0903. Combining parameters yielded a sensitivity of 0.743 and specificity of 0.906.Conclusions:PET holds the most promise in identifying malignant transformation within an IPMN. Combining parameters increases sensitivity and specificity; the presence of mural nodule on imaging was the most sensitive whereas raised serum CA19-9 (>37 KU/l) was the most specific feature predictive of malignancy in IPMNs.

Pancreatic fat content may increase the risk of imaging progression in low‐risk branch duct intraductal papillary mucinous neoplasm

“…Revisions to the Fukuoka guidelines recommend that low‐risk BD‐IPMN should be followed up by CT, MRI, and/or EUS at appropriate intervals, based on the size of each initial cyst. The main concern is the development of malignancy in the cyst and many studies have reported the natural history of malignant progression of low‐risk BD‐IPMN . However, the majority of incidental IPMN in clinical setting are small in size and lack currently defined high‐risk features.…”

“…It is also essential to identify factors associated with disease progression to malignancy in BD‐IPMN. Several studies have reported that those factors included cystic features (cyst size, the presence of a mural nodule, MPD dilatation, and growth rate in size) and patient's factors (symptoms, diabetes mellitus, smoking, or obesity). However, few data are available on risk factors of imaging progression in low‐risk BD‐IPMN .…”

“…For the patients having BD‐IPMN but without high‐risk stigmata or worrisome features (low‐risk BD‐IPMN), who comprise most cases of IPMN, management may depend on the initial cyst size. Several studies have reported factors that are associated with malignant IPMN, which include features of the cyst (size >3 cm, the presence of a mural nodule, main pancreatic duct dilatation, and growth rate in size) as well as patients' factors (symptoms, presence of diabetes mellitus, or smoking status). Although the main concern of IPMN is the onset of malignancy, Crippa et al recently reported that 52% of the 281 patients, including 159 with BD‐IPMN and high‐risk stigmata or worrisome features, had imaging progression such as an increase in cyst size, main pancreatic duct (MPD) dilatation, new nodules, or presence of new or recurrent symptoms during a median follow‐up period of 51 months.…”

Serum Carbohydrate Antigen 19-9 in Differential Diagnosis of Benign and Malignant Pancreatic Cystic Neoplasms: A Meta-Analysis

“…Our viewpoint was also agreed by many other researchers, who reported that serum CA 19–9 was a useful non-invasive tool for distinguishing malignant IPMNs, and should be taken into account in the decision to offer surgery. [ 15,17,36 ]…”

“…[ 23,40 ] The pooled sensitivity and specificity of 18-FDG PET were 0.968 (95% CI: 0.90–0.99) and 0.91(0.81–0.99). [ 36 ] As 18-FDG PET is not routinely performed for its high cost and radiation, the decision of whether to do a surgery or not remains challenging. [ 41 ] Studies of molecular markers were also reported recently.…”