Late-Stage Pancreatic Cancer Detected During High-Risk Individual Surveillance: A Systematic Review and Meta-Analysis

Identification and resection of successful targets, that is, T₁ N₀M₀ pancreatic ductal adenocarcinoma (PDAC) and high-grade precursors during surveillance of high-risk individuals (HRIs) confers improved survival. Late-stage PDACs refer to T_2-4 N₀M₀ and nodal or distant metastatic PDAC stages diagnosed during the follow-up phase of HRI surveillance. This study aimed to quantify late-stage PDACs during HRI surveillance and identify associated clinicoradiologic factors.

A systematic search (PROSPERO:CRD42018117189) from Cochrane Library, Embase, Google Scholar, Medline, PubMed, Scopus, and Web of Science was last performed on April 18, 2021. Only original HRI surveillance manuscripts that specified follow-up strategies were included, and studies with only baseline information were excluded. Cumulative incidences of advanced neoplasia: high-grade precursors and all PDACs, and surveillance-detected/interval late-stage PDACs were calculated through random-effects model. Incidence of late-stage PDACs underwent metaregression to identify association with HRI clinicoradiologic features. Publication bias was assessed through the funnel plot and Egger's regression line.

Thirteen original surveillance studies included 2169 HRIs followed over 7302.72 patient-years. Cumulative incidence of advanced neoplasia and late-stage PDACs was 3.3 (95% confidence interval [CI]: 0.6-7.4) and 1.7 (95% CI: 0.2-4.0) per 1000 patient-years, respectively. Late-stage PDACs lacked significant association with surveillance imaging, baseline pancreatic morphology, study location, genetic background, gender, or age. Limited information on diagnostic error, symptoms, timing of presentation, lesion site, and surveillance adherence precluded formal meta-analysis.

A sizeable proportion of late-stage PDACs were detected during follow-up. Their incidence lacked association with baseline clinicoradiologic features. Further causal investigation of stage-based outcomes is warranted for overall improvement in HRI surveillance.