Preoperative radiotherapy combined with surgery versus surgery alone for primary retroperitoneal sarcoma: a meta-analysis.

The efficacy of preoperative radiotherapy combined with surgery (preRT + S) for primary retroperitoneal sarcoma (RPS) remains unclear. This study aimed to compare preRT + S with surgery alone (SA) in patients with RPS. Core databases were searched for directly comparative studies depending on preRT. Thirteen studies included 2,439 patients with SA and 1,453 with preRT + S. PreRT + S in all RPS patients led to significantly low local recurrence (LR) (hazard ratios [HR],0.575; p = 0.008) compared to SA. Among the liposarcoma patients, PreRT + S did not clearly affect LR or abdominal recurrence-free survival (ARFS). Excluding dedifferentiated liposarcoma (DDLPS), the patients underwent preRT + S significantly improved LR (HR,0.430; p = 0.002) and ARFS (HR,0.706; p = 0.045). In another subgroup analysis of patients with well-differentiated liposarcoma and grade 1-2 DDLPS, preRT + S significantly extended ARFS (HR,0.601; p = 0.014) compared to SA. There was no significant difference in overall survival (OS) (HR,0.904; p = 0.362 [RPS]; HR,0.724; p = 0.348 [WDLPS + G1-2DDLPS]) between preRT + S and SA in all comparisons. PreRT + S group demonstrated higher incidence of total (odds ratio [OR],1.580; p = 0.007) and severe (OR,3.680; p = 0.004) complications than the SA group. PreRT + S prevent recurrence in patients with WDLPS and low-grade DDLPS but is associated with increased complications, resulting in similar OS compared to SA.