Clinical presentation, outcomes and prognostic factors of neuroblastoma among children at three cancer treatment centres in Uganda

Abstract

Background Neuroblastoma (NB) is the most common extracranial solid tumour of childhood. Although the incidence in high-income countries (HIC) is known, the true incidence in low-and middle- income countries (LMIC) is underreported. It’s clinical presentation is heterogeneous and often resembles that of common childhood illnesses hence the resultant misdiagnosis. The malignancy has a diverse clinical progression ranging from spontaneous regression to rapid tumour growth, advanced disease and death, and several prognostic factors have been described in HIC, through these have not been studied in Uganda. Objective: To describe the clinical presentation, and determine the overall survival and prognostic factors of neuroblastoma among children at three cancer treatment centres in Uganda. Methodology This was a retrospective chart review of children aged between 0 to 15 years diagnosed with NB from January 2010 to November 2020 at three cancer treatment centres in Uganda. Relevant information was extracted from the patients’ medical records including patient demographics, clinical presentation, tumour-, laboratory-, imaging-, and treatment- related factors. This data was analysed for survival outcomes from the time of diagnosis to death or study end point. Kaplan-Meier survival curves were used to estimate the one-year overall survival for 61 patients eligible for survival analysis. Cox regression analysis was used to assess the prognostic factors for NB and presented as adjusted Hazard ratios (HR) with their 95% confidence intervals at both bivariate and multivariate levels. Results Seventy-five children with NB were studied with a median age at diagnosis of 48 months (IQR 26-108). The male to female ratio was 0.9. Fever (74.7%), weight loss (74.7%), abdominal swelling (65.3%), abdominal pain (52%), and raised blood pressure (70.6%) were the most common presenting features. The median duration of symptoms was 12 weeks (IQR 4, 24). Suprarenal tumours were the most common primary location (52%) and the majority of the patients (70.7%) had stage IV disease. Metastases were present in 61 (81.3%) of the patients. Immunohistochemistry was performed for 39 (52%) of the patients for diagnosis purposes. Overall survival at 6 months, 12 months and 24 months was 77%, 61%, and 44%, with a median survival time of 18.1 months (95%CI; 11.5-30.1), range 0.1 -129.5months. xiii Age 18.1 to 60 months (aHR 0.05) and above 60 month (aHR 0.08), non-metastatic disease (aHR 0.24), lung metastases (aHR 5.46), elevated white blood cell counts (aHR 7.36) and low haemoglobin counts (aHR 2.94), were prognostic on multivariate analysis. Conclusion The clinical presentation of NB was largely similar to other studies done in Africa. The overall survival of the children with the tumour (61% at one year) was better than in other East African studies but still lower than middle income African countries. For the Ugandan population, better outcomes were predicted by age above 18 months, which was contrary to other studies, and only presenting with localized disease. Negative prognostic factors were the presence of lung metastases, elevated white blood cell count and low haemoglobin counts. Early identification of children with the presentation would hasten the diagnosis of NB as well as its treatment and hence improve survival.