Outcomes and predictors of survival among children with hodgkin lymphoma at Uganda Cancer Institute

Abstract

Background: Hodgkin Lymphoma (HL) is one of the most curable childhood malignancies. HL represents 6% of all childhood cancers and has an incidence rate of 12 cases/million/year in the 0–14-year age group worldwide It has been noted to be more prevalent in children less than 10 years of age in sub-Saharan Africa (SSA), likely driven by Epstein-Barr virus (EBV) which has been identified as an important factor in the pathogenesis of HL. Despite the high survival rates worldwide, survival in Sub-Saharan Africa is still low. The low survival rates in SSA have been attributed to delayed diagnosis, inaccessibility to chemotherapy, unavailability of radiotherapy, and a low level of supportive care. In recent years, Uganda Cancer Institute has improved diagnosis, treatment and follow-up of children with HL. However, the current outcomes of treatment and predictors of survival have not been assessed in this patient population. Objective: This study aimed at determining the outcomes and predictors of survival among children with Hodgkin Lymphoma at Uganda Cancer Institute. Methodology: This was a retrospective cohort study which involved chart review for children diagnosed with Hodgkin Lymphoma from January 2010 to December 2019 at Uganda Cancer Institute. Relevant data on Socio-demographics, clinical and laboratory characteristics, disease and treatment factors, and the vital status were abstracted and analyzed. The data was entered into Epi data version 4.2 and then exported to Stata version 15.1/MP for analysis. Kaplan-Meier survival curves were used to estimate the 1-, 3-, and 5-year survival. Cox regression analysis was used to assess the predictors of survival and presented as Hazard ratios with their 95% confidence interval at both bivariate and multivariate levels. Results: A total of 92 patients were studied, of whom (n = 53, 57.6%) were below 10 years old. The males were 74 (80.4%) and 18 (19.6%) were females. The overall survival at 1 year, 3 years, and 5 years was 89%, 81%, and 76% respectively, while the Event-free survival rate at 1year, 3 years and 5 years was 48%, 40%, and 35% respectively. By 5 years, 39 (42%) were lost to follow up, 25 (27%) were in remission, and 19 (21%) had died, only 2 (2%) had relapsed, and 7 (8%) had stable disease. Age of ≥ 10 years [aHR=2.8, 95%CI: 1.06-7.39 P=0.037], a WBC of ≥11.5 x109/L [aHR=3.73, 95%CI: 1.45-9.61 P=0.006] and PLT of <150 x109/L [aHR=3.34, 95%CI: 1.31-8.49 P=0.011] were predictors of survival on the multivariate cox regression analysis. Conclusion and Recommendation: Although the overall survival rates of children with Hodgkin Lymphoma were higher than what has been seen in other studies in Sub-Saharan Africa, they remain significantly low compared to the high-income countries. Age ≥ 10 years, WBC of ≥11.5 x109/L and PLT of <150 x109/L were negative predictors of survival. Efforts to reduce loss to follow up and treatment abandonment need to be addressed in order to improve outcomes of this otherwise curable cancer.