Factors Associated with Clinical Outcomes of Differentiated Thyroid Cancer Following Radioiodine Therapy in Tanzania

Background: Thyroid cancer is the most common endocrine type of malignancy, accounting for 1-5% of all cancers worldwide. Most of the differentiated thyroid cancers are asymptomatic. Surgery is the mainstay of management to be followed by radioactive iodine (RAI). RAI accessibility is still a challenge in most developing countries including Tanzania. The aim of this study was to determine factors affecting the clinical outcome of patients with differentiated thyroid cancer (DTC) following RAI treatment in a resource limited setting. Methods: This was a prospective cohort study carried out from 2014 to 2018 at the Ocean Road Cancer Institute, in Tanzania. A total of 52 histologically proven differentiated thyroid cancer patients post- near or total thyroidectomy were recruited. All patients received RAI therapy until ablation was achieved, were maintained on thyroxine suppression dose, and were followed for two years. Results: A total of 52 differentiated thyroid cancer patients were recruited after surgery by convenience sampling. The median age of patients was 46 years (range 17-77), and 87% (n=45) were female. Distant metastases were detected in 60% of patients (n=20) at initial presentation. The most common clinical presentation was a neck mass without compression symptoms (85%). Analysis at the end of two years revealed that female gender, clinical-pathological presentation, and the absence of distant metastasis(es) at diagnosis and amount of RAI received, contributed significantly to improved outcome. Conclusion: In a limited resource setting, the outcome of DTC patients post RAI therapy can be improved by early diagnosis hence improving clinical outcome.