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


METHODS
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.
Davids
Taryn
T
From the Departments of Otolaryngology (t.d., i.j.w., s.e., j.l.f.) and Endocrinology (p.g.w.), University of Toronto Medical School and Mount Sinai Hospital, Toronto, Ontario, Canada.
Witterick
Ian J
IJ
Eski
Spiro
S
Walfish
Paul G
PG
Freeman
Jeremy L
JL
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000139:chemically induced*; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D011446:Prospective Studies; D011788:Quality of Life; D012008:Recurrence; D013375:Substance Withdrawal Syndrome; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000628:therapy; D013965:Thyroidectomy; D013974:Thyroxine / Q000009:adverse effects*
D007457:Iodine Radioisotopes; D013974:Thyroxine