Clinical presentation and survival of children with Orbital Rhabdomyosarcoma at Uganda Cancer Institute.

Abstract

Introduction: Orbital rhabdomyosarcoma (ORMS) accounts for 4% of all solid tumours in children worldwide and 10% of orbital malignant tumors. Orbital Rhabdomyosarcoma is highly curable, with about 90% survival and 85% globe conservation in the developed world however little is known about ORMS survival in developing countries like Uganda. General objective: To determine the clinical presentation and survival among children managed for orbital rhabdomyosarcoma at Uganda Cancer Institute. Methods: This was a retrospective cohort study of 71 children with histological diagnosis of ORMS at Uganda Cancer Institute between January 2008 and December 2019 using chart review. Secondary data on demographics, clinical, imaging, laboratory, treatment characteristics and vital status were collected and entered into a computer for analysis with STATA 16. Kaplan –Meier survival curves were used to describe survival. Cox regression analysis was used to determine the predictors of survival at 5% level of significance. Results: A total of 71 participants were included in the study. Median age at diagnosis was 6years (IQR;4-12) and 39 (55%) were male. The total follow-up time was of 177.3 person-years and (58%) died during the study period. The median survival time was 2 years. The commonest clinical presentation was proptosis (90%), chemosis (88.7%) and decreased vision (85.9%). The 3-year and 5year survival rate was 44.1% and 42.0% respectively. The predictors of survival were; Age at diagnosis, with age groups 3 to <7years (HR: 0.30, 95% CI: O.11-0.81) and 7 to <15years (HR: 0.26, 95%CI: 0.10-0.66). Primary orbital tumor (HR: 0.37, 95%CI: 0.16-0.83), baseline tumor stage III (HR:0.21 95%CI:0.05-0.95, duration of symptoms above 6months (HR:0,24 95%CI 0.06-0.92) and disease progression (HR 5.93, 95% CI: 2.14-16.45). Conclusion and recommendations: The commonest clinical presentations of ORMS were proptosis, chemosis and decreased vision. Majority of our participants presented with advanced disease that is group III and IV tumor (60.5% and 19.5%) respectively. There are low survival probabilities of children with orbital Rhabdomyosarcoma treated at Uganda Cancer Institute. Age, primary orbital tumor, baseline tumor stage, duration of symptoms, and disease progression significantly predicted survival of children with orbital Rhabdomyosarcoma. Efforts should be made towards early diagnosis of this rapidly growing tumor so to improve the survival and creation of ORMS biorepository.