Renal tumours in australian children: Thirty years of incidence, outcome, and second primary malignancy data from the australian childhood cancer registry

Abstract

Background/Objectives: To describe the incidence and outcomes of childhood renal malignancies in Australia using whole-country population data from the Australian Childhood Cancer Registry (ACCR). To describe the occurrence of second primary malignancy (SPM) in children treated for renal cancers. Design/Methods: All children (0-14 years) diagnosed with renal malignancies from 1983-2014 inclusive were identified in the ACCR. Demographic, tumour characteristic, incidence, mortality and treatment data were extracted from the Registry. Cause-specific (CS) and event-free (EFS) survival up to 20 years from diagnosis were estimated using the cohort method. Adjusted excess mortality hazard ratios (HR) were calculated using a multivariate flexible parametric survival model. Cumulative incidence, standardised incidence ratios (SIR), absolute excess risk (AER), and mortality relating to SPMs were calculated. Results: There were 1,007 children diagnosed with renal malignancies between 1983-2014 (91% nephroblastoma), generating an annual age-standardised incidence rate of 8 per million children. This incidence did not change over the study period. Cause-specific survival was 89% and 88% at 5 and 20 years, respectively. Five-year EFS was 82%. Five-year CS did not change over the study period. Five-year CS was highest in nephroblastoma (91%) and poorest for rhabdoid renal tumours (36%, HR=8.2 in comparison to nephroblastoma, p<0.001). All deaths from rhabdoid tumours occurred within 12 months of diagnosis. Of patients achieving remission, 15% relapsed and subsequent 5-year CS was 49%. Ten children were diagnosed with a SPM (cumulative incidence at 20 years = 2.8%), giving a SIR of 3.05, AER 5.1/10,000 person-years. Half of those with a SPM died within 5 years of second diagnosis. Conclusions: Children treated for renal malignancies in Australia have excellent long-term survival, unchanged since 1983. SPMs are uncommon following treatment for childhood renal cancer, but carry a poor prognosis. Relapse carries a similarly poor prognosis. These data are comparable to registry outcomes in similarly developed nations.L6241794322018-10-11 <br />