Three-week thyroxine withdrawal: a thyroid-specific quality of life study.

Objectives/hypothesis: The purpose of this study is to determine the impact of a 3-week T4 withdrawal test on the quality of life (QOL) of patients undergoing investigation for residual/recurrent well-differentiated thyroid cancer.

Study Design: Prospective survey study.

Methods: 181 patients with well-differentiated thyroid cancer were surveyed using a thyroid-specific QOL-thyroid survey at three times throughout the study: prior to T4 withdrawal, after the 3-week withdrawal period, and 4 weeks after resuming T3/T4 combination therapy.

Results: A very small, though statistically significant, reduction was observed in the four domains of QOL defined by the QOL-thyroid survey from baseline values to 3 weeks after T4 withdrawal. The maximal difference was 2.04 (fatigue), out of a possible 10 point score, in the physical well-being category.

Conclusions: The thyroid-specific QOL questionnaire demonstrates a statistically significant though very small and probably not clinically significant reduction in the QOL of thyroid cancer patients undergoing an induced 3-week hypothyroid state. Three-week T4 withdrawal is a simple, cost-effective, and readily available test.