Chronic Myeloid Leukemia in Tanzania: clinical profile and five-year survival

Abstract

ABSTRACT Keywords: Chronic Myeloid Leukemia (CML), Tanzania, Five-year Survival, Tyrosine Kinase Inhibitors (TKIs), Ocean Road Cancer Institute (ORCI) Background: Many patients with CML in Tanzania present with a bulky disease at diagnosis. However, limited information is available on the specific burden of CML in Tanzania. Despite over 20 years of CML treatment in Tanzania, little is known about the sociodemographic profiles, clinical characteristics, and survival of patients with CML in Tanzania. Currently, only ORCI and KCMC are the two institutions in Tanzania that receive free Tyrosine Kinase Inhibitor medications thanks to a donation from the Max Foundation. With this exclusive availability of medications in these two hospitals, more CML cases are likely to be attended in these hospitals compared to the past years. This study aims to investigate the disease burden and epidemiologic trends of chronic myeloid leukemia (CML) in Tanzania to bridge the knowledge gap between what is already known and the unknown about the disease in our locality. Objective: To determine the trend of CML incidence and the five-year overall survival of the patients who attended ORCI between January 2015 to December 2023. Materials and methods: This was a retrospective analysis of patients diagnosed and treated for chronic myeloid leukemia at Ocean Road Cancer Institute (ORCI) for the past 9 years. All patients with a histologically confirmed diagnosis of chronic myeloid leukemia from 2015 to 2023 were included. Data was gathered from the digital hospital record system and files of patients. Data was analyzed using STATA version 17. Descriptive statistics such as percentage and mean were used to describe the demographic, clinical, and laboratory characteristics of the patients. The chi-square test was used to test the trend in a number of new CML cases at ORCI between 2015 to 2023. Kaplan Meier estimation was used to determine the survival. A p-value of 0.05 was used to assess the significance of the obtained results. Results: The study analyzed 340 CML patients at ORCI's clinic in Tanzania. The number of new patients increased linearly between 2015 and 2023, with a dip during the COVID-19 pandemic. Younger patients predominate with a mean age of 38.5 years at diagnosis, highlighting the socioeconomic impact. The study found a high 5-year survival rate of 90.6%, comparable to high-income countries. Factors associated with CML survival included age at diagnosis, absolute monocyte count, and percentage of blasts at diagnosis. The study highlights the need for sustainable CML treatment and better patient tracking in low -resource setting. Conclusion: Chronic Myeloid Leukemia is among the most frequently diagnosed leukemia in Tanzania. The data reveals an upward trend in CML cases at ORCI from 2015 to 2023, likely due to improved diagnostics and decentralized services. Younger patients predominate, highlighting the socioeconomic impact. Survival rates are promising; however, challenges persist in the sustainability of the treatment program