Imaging defined risk factors: Impact on patients with neuroblastoma, a retrospective study

Abstract

Purpose: Neuroblastoma is the most common extra-cranial solid organ cancer of childhood1 with highly variable prognosis based on the clinicopathological International Neuroblastoma Staging System (INSS)1. Given significant advances in low risk cohort treatment, including surveillance without surgical debulking2, INSS, which relies on postsurgical outcomes cannot be uniformly applied nor data standardised. The 2009 International Neuroblastoma Risk Group (INRG)3 developed a consensus approach to pre-treatment risk stratification using imaging defined risk factors (IDRF)3. From this, a new pretreatment staging system (INRGSS) was developed3. This study aimed to examine epidemiological trends and assess the impact of IDRF and INRGSS on patient outcome. Methods and materials: A retrospective audit included all patients diagnosed with neuroblastoma from 2005 to 2010 at the Royal Children's Hospital in Brisbane. A database was collated with demographic data including sex and age at diagnosis, primary disease site, presence or absence of metastases, INSS stage and five year survival. Initial imaging was also reviewed for the presence or absence of IDRF, and INRG staging (L1, L2, M) recorded4. Results: Fifty-eight children (32 male) were included. Mean age at diagnosis was 2.25 years (range 0-14.42). The commonest disease site was abdominal (n = 39, 67%). Metastatic disease (Stage IV) was present in 27 (46.4%) children, which was lower than expected for equivalent cohorts (70%1,4, p < 0.001). For localised disease, 13 (41.9%) were Stage I, 8 (25.8%) were Stage II and 10 (32.2%) were Stage III. Overall five year survival was 72.4% (n = 42), which was higher than the expected rate of 58%1 (p < 0.05). Survival increased to 100% when Stage IV disease was excluded. Initial imaging was available for all children with localised disease, with IDRF present in 13 of 31 children. No IDRF were identified in Stage I patients. IDRF were present in 6 of 8 (75%) children with Stage II disease and 7 of 10 (70%) children with Stage III disease. IDRF (excluding metastases) were present in 20 of 25 children with Stage IV/M disease (80%, OR=4.0). Conclusions: Overall survival was higher than expected, in keeping with decreased incidence of Stage IV disease in comparison to similar populations. Survival was not impacted by the presence of IDRF in localised disease (100% survival L1 and L2). IDRF were highly correlated with Stage IV disease regardless of distant metastases. Further study is required to assess impact of IDRF on surgical outcome and event free survival.L6128935702017-01-25 <br />