Surgical intervention contribute to survival for patients with para-aortic lymph node metastasis from colorectal cancer, a meta-analysis and systematic review

Abstract Background Para-aortic lymph node metastasis (PALNM) in colorectal cancer (CRC) is a rare but prognostically significant condition, occurring in approximately 1–2% of patients. Current guidelines classify PALNM as stage IV disease but provide no clear consensus on optimal management. Treatment strategies vary widely, and the role of para-aortic lymph node dissection (PALND) remains controversial due to limited evidence from small, retrospective studies and the absence of randomized controlled trials. This study aimed to perform a comprehensive meta-analysis of survival outcomes in CRC patients with PALNM undergoing PALND compared with non-surgical management. Methods A systematic literature search of PubMed, Embase, and Cochrane Library was conducted up to 23 March 2026. Eight retrospective cohort studies comprising 929 patients met the inclusion criteria. Individual patient data for overall survival (OS) were reconstructed from published Kaplan–Meier curves using validated methodology. Hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled using random-effects models. Sensitivity, subgroup, and time-to-event analyses were performed, and risk of bias was assessed using the ROBINS-I V2 tool. Results Pooled analysis demonstrated that PALND was associated with significantly improved OS compared with non-surgical management (HR = 0.49, 95% CI: 0.39–0.63, P < 0.001), representing a 51% reduction in mortality risk. Median OS was 36.8 months in the surgery group versus 12.9 months in the non-surgery group. The 3-year and 5-year OS rates were 50.5% and 38.8% in the surgery group, compared with 27.5% and 11.0% in the non-surgery group, respectively. Restricted mean survival time analysis demonstrated a 12.1-month gain (95% CI: 8.7–15.6, P < 0.001) at 60 months. Sensitivity analyses confirmed the robustness of findings, with HRs ranging from 0.33 to 0.52 across multiple scenarios. Subgroup analyses revealed more pronounced benefit in metachronous metastases (HR = 0.34, 95% CI: 0.22–0.51) versus synchronous disease (HR = 0.63, 95% CI: 0.45–0.88). Moderate heterogeneity (I² = 43.1%) was observed overall but reduced to near-zero levels across all subgroup analyses. Conclusion This IPD-based meta-analysis provides the most comprehensive evidence to date that PALND is associated with a significant survival benefit in selected CRC patients with PALNM. Despite the inherent limitations of retrospective data, these findings support consideration of surgical resection as a viable treatment option in appropriately selected patients.