A Clinical Perspective of Bilateral Renal Tumors - Data from Three Consecutive German Cooperative Trials

Abstract

PURPOSE The therapeutic approach for bilateral renal masses is different to unilateral renal masses. This is due to biological facts such as a remarkably higher number with nephroblastomatosis, but also to the fact that clinicians must keep drug doses as low as possible to prevent side effects. MATERIAL AND METHODS We analysed the prospectively collected data of 138 patients with bilateral renal masses registered in the consecutive German national trials SIOP9/GPO, SIOP93-01/GPOH and SIOP2001/GPOH from January 1989 to May 2005. RESULTS The median follow up was 6.2 years. All but one patient already had bilateral masses at diagnosis. Median age at diagnosis was 1.9 years with a female/male distribution of 1.5/1. 18 (13%) patients had distant metastases at diagnosis. 25% of all registered patients had a concomitant syndrome. Aiming to reduce the tumor mass as much as possible, 132 patients received preoperative chemotherapy according to the trial protocols for stage V, 6 patients underwent initial surgery. Preoperative treatment duration in the nephroblastoma group ranged from 1 to 12 weeks, leading to an average volume reduction of 44%. 11 patients with bilateral nephroblastomatosis suffered from progression, 3 eventually died from nephroblastoma. 2y/5y EFS and OS for the nephroblastoma group were 82.7/71.5% and 89/85.7%, respectively. Metastases at diagnosis, local stage III and anaplasia in histology had a negative impact on outcome. CONCLUSIONS Five treatment-associated deaths including one acute renal failure underline the importance of a cautious approach in the complex treatment of bilateral renal tumours, including nephron-sparing surgery. This aim often can be facilitated by multimodal preoperative treatment (e.g. 1, 2 or 3 four-weeks courses of actinomycin, vincristine and doxorubicin) tailored to the individual tumor status defined by imaging after each cycle.