Population-based overall and net survival of childhood leukemia at 1-, 5-, and 10-years of follow-up in three regions of Colombia.

Background: Childhood leukemia (CL) is the most common type of childhood cancer worldwide and in Colombia. Thanks to therapeutic innovations and improved access, the survival of children and adolescents with leukemia has increased considerably worldwide, especially in high-income countries. In Colombia, a middle-income country, survival has also been observed to increase in big cities. However, the survival rate in intermediate cities is still unknown.

Objective: This study aimed to assess short- and long-term survival rates of children with leukemia coming from three intermediate Colombian cities as well as to compare overall survival (OS) rates versus relative survival (RS) rates of this population of children.

Methods: Data from population-based cancer registries in three Colombian cities (Bucaramanga metropolitan area, Manizales and Pasto) were analyzed. OS and RS of up to 10 years were estimated for children who were diagnosed with leukemia at ages 0-18 years between 1998 and 2018 and followed up for vital status. RS was calculated using the Pohar-Perme method. We performed a separate survival analysis by gender and by period of diagnosis (before and after 2010).

Results: We included data from 507 children and adolescents diagnosed with leukemia. RS at 1, 5 and 10 years after diagnosis were similar between the populations for the respective timeframes (RS Bucaramanga 86.5%, 66.9% and 52.5%; Manizales 81.1%, 62.8% and 61.1%; Pasto 81.7% at 1 year, 66.2% at 5 years and 59.4% at 10 years). OS and RS were very similar for all estimates and periods. There were no clear differences in RS between genders across the three population-based cancer registries and there was an improvement in RS after 2010, particularly in Bucaramanga and Pasto.

Conclusion: Our study reports similar 5-year survival rates for CL in these Colombian cities compared to rates documented in other Latin American countries and larger Colombian cities. These are far below what is reported in high-income settings. This highlights opportunities for improvement in the Colombian health system, where numerous barriers persist in terms of suspicion, diagnosis and continuity of treatment for CL.