Time to reclassify? The prognostic value of radiologic splenic vessel involvement in resectable pancreatic ductal adenocarcinoma of the body and tail: a systematic review and meta-analysis

Background: The prognostic impact of radiographic splenic vessel involvement in pancreatic ductal adenocarcinoma (PDAC) of the body and tail remains controversial. Methods: A systematic search was performed using PubMed, Embase, the Cochrane Library, Web of Science, and Scopus in accordance with the PRISMA and AMASTAR guidelines. The primary outcome was 5-year overall survival (OS). Time-to-event method was used. Results: Eight articles involving 1678 patients were analyzed. Patients with radiological splenic artery (SA) invasion had poorer OS than those without (hazard ratio (HR) 1.61, 95% confidence interval (CI) 1.14–2.29; P = 0.007). Similarly, radiological splenic vein (SV) involvement was associated with significantly worse OS (HR 1.66, 95% CI 1.13–2.44; P = 0.010). Subgroup analyses for SA involvement, categorized by “abutment” and “encasement,” showed an overall HR of 2.35 (95% CI 1.72–3.19; P < 0.00001), with HRs of 1.77 (95% CI 1.25–2.59; P = 0.001) for abutment and 3.03 (95% CI 2.20–4.17; P < 0.00001) for encasement, indicating a significant difference between subgroups (P = 0.02). For SV involvement, the overall HR was 2.15 (95% CI 1.49–3.10; P < 0.001), with HRs of 1.66 (95% CI 0.97–2.84; P = 0.07) for abutment and 2.80 (95% CI 1.98–3.96; P < 0.0001) for encasement, showing no significant difference between subgroups (P = 0.11). Conclusion: This meta-analysis showed worse survival in patients with splenic vessel infiltration of PDAC. Therefore, SA and SV invasion may serve as indications for neoadjuvant therapy for resectable PDAC.