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.