The contribution of chest CT-scan at diagnosis in children with unilateral Wilms' tumour. Results of the SIOP 2001 study.

BACKGROUND: The SIOP 2001 nephroblastoma study hypothesised that patients with 'CT-only' pulmonary nodules would have the same outcome as patients with localised disease of same stage and histology.

PATIENTS: Unilateral Wilms' tumour (WT) patients, who had chest CT scans at diagnosis showing any sized pulmonary nodules undetected on chest X-ray, between November 2001 and November 2009, were selected from the SIOP 2001 database.

RESULTS: Among 2532 WT patients, 103 unilateral nephroblastoma patients with CT-only lung lesions were found. Thirty-seven patients received preoperative treatment according to the localised-disease protocol, and 66 according to the metastatic-disease protocol. The 3-year event-free survival (EFS) was 70% (95% CI: 55-89%) and 77% (95% CI: 66-89%), respectively. Corresponding 3-year overall survival (OS) was 89% (95% CI: 77-100%) and 85% (95% CI: 75-96%), respectively (p-value not significant). EFS and OS of all 2071 patients with true localised disease were 87% (95% CI: 86-89%) and 96% (95% CI: 94-97%), respectively. Patients with metastatic disease (n = 358) had 3-year EFS and OS estimates of 68% (95% CI: 63-74%) and 77% (95% CI: 72-82%), respectively.

CONCLUSIONS: EFS and OS of patients with CT-only lung lesions were inferior to that of true localised-disease patients and superior to that of patients with metastatic disease. However, no significant difference was found in EFS and OS between CT-only patients treated for localised or metastatic disease. The clinician's preference to treat patients with CT-only pulmonary nodules as metastatic disease is not evidence-based. Chest CT at diagnosis does not improve outcome but presents paediatric oncologists with a difficult dilemma.