Percentage of Pancreatic Cysts on MRI With a Pancreatic Carcinoma: Systematic Review and Meta‐Analysis

Abstract

BackgroundPancreatic cystic lesions (PCLs) are frequent on MRI and are thought to be associated with pancreatic adenocarcinoma (PDAC) necessitating long‐term surveillance based on older studies suffering from selection bias.PurposeTo establish the percentage of patients with PCLs on MRI with a present or future PDAC.Study TypeSystematic review, meta‐analysis.PopulationAdults with PCLs on MRI and a present or future diagnosis of PDAC were eligible. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Scopus were searched to April 2022 (PROSPERO:CRD42022320502). Studies limited to PCLs not requiring surveillance, <100 patients, or those with a history/genetic risk of PDAC were excluded.Field Strength/Sequence≥1.5 T with ≥1 T2‐weighted sequence.AssessmentTwo investigators extracted data, with discrepancies resolved by a third. QUADAS‐2 assessed bias. PDAC was diagnosed using a composite reference standard.Statistical TestsA meta‐analysis of proportions was performed at the patient‐level with 95% confidence intervals (95% CI).ResultsEight studies with 1289 patients contributed to the percentage of patients with a present diagnosis of PDAC, and 10 studies with 3422 patients to the percentage with a future diagnosis. Of patients with PCLs on MRI, 14.8% (95% CI 2.4–34.9) had a PDAC at initial MRI, which decreased to 6.0% (2.2–11.3) for studies at low risk of bias. For patients without PDAC on initial MRI, 2.0% (1.1–3.2) developed PDAC during surveillance, similar for low risk of bias studies at 1.9% (0.7–3.6), with no clear trend of increased PDAC for longer surveillance durations. For patients without worrisome features or high‐risk stigmata, 0.9% (0.1–2.2) developed PDAC during surveillance. Of 10, eight studies had a median surveillance ≥3 years (range 3–157 months). Sources of bias included retrospectively limiting PCLs to those with histopathology and inconsistent surveillance protocols.Data ConclusionA low percentage of patients with PCLs on MRI develop PDAC while on surveillance. The first MRI revealing a PCL should be scrutinized for PDAC.Level of Evidence3Technical EfficacyStage 2