Any impact of pre-operative radiotherapy on renal function in retroperitoneal soft tissue sarcomas? A secondary ancillary analysis of the EORTC 62092 STRASS 1 trial

STRASS (NCT01344018), is a randomized phase III superiority trial whose goal was to evaluate if preoperative radiotherapy (RT) followed by surgery could improve outcome of patients with retroperitoneal sarcoma (RPS) when compared to patients treated with surgery alone. Surgical resection of RPS involves the removal of the ipsilateral kidney, and half of patients received radiotherapy. Is there an impact of such treatment, on renal function?

The present study aimed to evaluate the impact of kidney resection as well as low-dose radiotherapy on renal function, while also considering the effect of possible perioperative bleeding and pre-existing comorbidities. The primary objective was to compare creatinine clearance (CrCl) between patients treated with preoperative radiotherapy and those treated with surgery alone. The secondary objectives were to compare the incidence of RIFLE (Risk, Injury, Failure, Loss of kidney function, End-stage disease) events until day 60 post-surgery between the two treatment arms; and to assess whether radiotherapy parameters could be independent predictive factors for the risk of developing a RIFLE events among patients treated with preoperative radiotherapy.

Out of 266 patients in the STRASS study, only 181 patients were eligible for inclusion in this study because of a strict selection; 170 patients had RIFLE events, 88 (96.7%) in the surgery alone arm and 82 (91.1%) in the preoperative RT arm. There was no significant association between any of the radiotherapy dose parameters to kidney and the risk of RIFLE.

After prolonged follow-up of 80 months, the risk of renal complications did not seem increased by a pre-operative radiation approach as shown in this ancillary study of the STRASS randomized controlled trial.