Isolated para-aortic lymph node recurrence from colorectal cancer treated by radiotherapy: a systematic review and meta-analysis

Optimal management for isolated para-aortic lymph node (PALN) recurrence from colorectal cancer (CRC) remains undefined. We evaluated the efficacy and safety of radiotherapy (RT) for this indication. A PRISMA-compliant systematic review and meta-analysis (PROSPERO CRD42025634494) was conducted using four databases through April 2025. Pooled locoregional progression-free survival (LPFS), progression-free survival (PFS), and overall survival (OS) were estimated using a random-effects model. Five retrospective studies (n = 220) were included. Pooled 1- and 3-year LPFS were 84% (95% CI, 78-89%) and 69% (62-76%), respectively. Pooled 1- and 3-year PFS were 54% (42-65%) and 22% (14-32%). Pooled 1- and 3-year OS were 91% (87-95%) and 64% (54-73%). Primary colon tumors were associated with poorer survival outcomes, while female sex predicted improved 3-year PFS. Severe (grade ≥ 3) acute and chronic toxicities were low (7.7% and 0.5%, respectively). Modern RT for PALN recurrence from CRC provides favorable local control with acceptable toxicity. With a 3-year OS of 64%, RT offers a potential survival benefit for carefully selected patients.