Radioactive iodine offers survival improvement in patients with follicular carcinoma of the thyroid.

ABSTRACT

BACKGROUND: The use of radioactive iodine (RAI) in patients with follicular thyroid carcinoma is well established. How its use affects patient outcome and which patients benefit is understood poorly. This study seeks to determine how RAI influences survival and to delineate the populations that are impacted most. METHODS: The Surveillance, Epidemiology, and End Results database is a sample of approximately 14% of the US population. It was used to identify patients with follicular thyroid carcinomas and the treatment that they received. Factors such as the presence of lymph node and distant metastases, age, and tumor size were included for analysis. RESULTS: A total of 4317 patients were identified with follicular thyroid carcinoma. Of these, the records of 2112 patients who were entered in the study after 1988 contained the required data and were included for analysis. Median follow-up time was 95 months. Factors that were associated with increased risk of death included distant metastatic disease, cervical lymph node disease, and the lack of RAI use. Protective factors were tumor size of <2 cm and age of <45 years. Some patients with a greater number of risk factors benefited from RAI. CONCLUSION: RAI provides survival benefit to some patients with follicular carcinoma of the thyroid. The greatest improvements were seen in those patients with locoregional or distant disease spread.