T J Matthews1, E Chua2, A Gargya2, J Clark1, K Gao3, M Elliott1. 1. Department of Head and Neck Surgery,Royal Prince Alfred Hospital,Sydney,New South Wales,Australia. 2. Department of Endocrinology,Royal Prince Alfred Hospital,Sydney,New South Wales,Australia. 3. Sydney Head and Neck Cancer Institute,Chris O'Brien Lifehouse at Royal Prince Alfred Hospital,New South Wales,Australia.
Abstract
BACKGROUND: Serum thyroglobulin is used as a surrogate marker for well-differentiated thyroid carcinoma recurrence. This study investigates whether thyroglobulin measured at the time of ablative radioactive iodine therapy predicts disease-free survival. METHODS: A retrospective review was conducted of patients with well-differentiated thyroid carcinoma presenting from 1989 to 2010 at the Royal Prince Alfred Hospital, New South Wales, Australia. Disease-free survival of patients with a significantly elevated stimulated thyroglobulin level (27.5 µg/l or higher) at the time of ablative radioactive iodine therapy was compared to that of patients without a significantly elevated thyroglobulin level using univariate analysis. RESULTS: Patients with a thyroglobulin level of 27.5 µg/l or higher had an increased relative risk of disease recurrence of 4.50 (95 per cent confidence interval = 1.35-15.04). If lateral neck dissection was required at the time of surgery, patients also had an increased relative risk of macroscopic disease recurrence of 4.94 (95 per cent confidence interval = 1.47-16.55). CONCLUSION: An elevated thyroglobulin level of 27.5 µg/l or higher at the time of ablative radioactive iodine therapy is a prognostic indicator for macroscopic disease recurrence in well-differentiated thyroid carcinoma.
BACKGROUND: Serum thyroglobulin is used as a surrogate marker for well-differentiated thyroid carcinoma recurrence. This study investigates whether thyroglobulin measured at the time of ablative radioactive iodine therapy predicts disease-free survival. METHODS: A retrospective review was conducted of patients with well-differentiated thyroid carcinoma presenting from 1989 to 2010 at the Royal Prince Alfred Hospital, New South Wales, Australia. Disease-free survival of patients with a significantly elevated stimulated thyroglobulin level (27.5 µg/l or higher) at the time of ablative radioactive iodine therapy was compared to that of patients without a significantly elevated thyroglobulin level using univariate analysis. RESULTS:Patients with a thyroglobulin level of 27.5 µg/l or higher had an increased relative risk of disease recurrence of 4.50 (95 per cent confidence interval = 1.35-15.04). If lateral neck dissection was required at the time of surgery, patients also had an increased relative risk of macroscopic disease recurrence of 4.94 (95 per cent confidence interval = 1.47-16.55). CONCLUSION: An elevated thyroglobulin level of 27.5 µg/l or higher at the time of ablative radioactive iodine therapy is a prognostic indicator for macroscopic disease recurrence in well-differentiated thyroid carcinoma.