Characteristics and outcome of synchronous bilateral Wilms tumour in the SIOP WT 2001 Study: Report from the SIOP Renal Tumour Study Group (SIOP-RTSG)

Abstract

Background: Among patients with nephroblastoma, those with bilateral disease are a unique population where maximising tumour control must be balanced with preserving renal parenchyma.

Methods: The SIOP 2001 protocol recommended surgery after neoadjuvant cycle(s) of Dactinomycin and Vincristine (AV) with response-adapted intensification, if needed. Adjuvant treatment was given based on the lesion with the worst histology.

Results: Three hundred and twenty seven patients with stage V disease were evaluable: 174 had bilateral Wilms tumour (BWT), 101 unilateral WT and contralateral nephroblastomatosis (NB) and 52 bilateral nephroblastomatosis. In these three groups, the estimated 5y-EFS was 76.1%, 84.6%, and 74.9%, respectively. AV chemotherapy alone was the successful chemotherapy for 58.7% of all the patients and 65.6% of the non-metastatic patients. Among the 174 patients with BWT, 149 (88.2%) had at least one nephron-sparing surgery. Twenty of 61 bilateral stage I patients were treated with four-week AV postoperatively achieving 94.4% 5y-EFS. At last follow-up, 87% of patients had normal renal function.

Conclusions: This study demonstrates that AV without anthracyclines is sufficient to achieve NSS and good survival in the majority of patients. For patients with bilateral stage I WT and intermediate risk histology, only four weeks adjuvant AV seems to be sufficient.

Clinical trial registration: NCT00047138.

Fig. 1. Preoperative treatment.

BWT bilateral Wilms Tumour, NB nephroblastomatosis, TN Total Nephrectomy, NSS nephron Sparing Surgery, AV Vincristine + Actinomycin D, AVD Vincristine + Actinomycin D + Doxorubicin.

Fig. 2. Event-free survival in the 44 patients with stage I, IR tumours on both sides according to the adjuvant treatment: AV1/ AV2/AVD.

EFS Event Free Survival, AV1 Vincristine + Actinomycin for 4 weeks, AV2 Vincristine + Actinomycin for 27 weeks.

Fig. 3. EFS and OS for the three groups.

a EFS = Event-free survival for the 3 groups, Bilateral Wilms Tumour (BWT); Unilateral WT + nephroblastomatosis (NB); bilateral nephroblastomatosis. b OS = Overall survival for the 3 groups: Bilateral Wilms Tumour (BWT); Unilateral WT + nephroblastomatosis (NB); bilateral nephroblastomatosis.

Fig. 4. Overall survival by time to surgery (BWT- Bilateral Wilms Tumour- only).

OS Overall Survival; wks weeks.

Fig. 5. EFS and OS according to the chemotherapy strategy (AV only versus others).

a EFS = Event-free survival: comparison between patients treated by vincristine + actinomycin D only and patients treated by other chemotherapy. b OS = Overall survival: comparison between patients treated by vincristine + actinomycin D only and patients treated by other chemotherapy. AV1 Vincristine + Actinomycin for 4 weeks; AV2 Vincristine + Actinomycin for 27 weeks.