Horm Metab Res 2013; 45(12): 911-914
DOI: 10.1055/s-0033-1347264
Humans, Clinical
© Georg Thieme Verlag KG Stuttgart · New York

Follow-up of Patients with Low-risk Papillary Thyroid Carcinoma and Undetectable Basal Serum Thyroglobulin After Ablation Measured with a Sensitive Assay: A Prospective Study

P. W. S. Rosario
1   Postgraduation Program, Endocrinology Service, Santa Casa de Belo Horizonte, Minas Gerais, Brazil
,
J. B. N. dos Santos
1   Postgraduation Program, Endocrinology Service, Santa Casa de Belo Horizonte, Minas Gerais, Brazil
,
M. R. Calsolari
1   Postgraduation Program, Endocrinology Service, Santa Casa de Belo Horizonte, Minas Gerais, Brazil
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Publikationsverlauf

received 24. März 2013

accepted 13. Mai 2013

Publikationsdatum:
11. Juni 2013 (online)

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Abstract

The importance of thyroglobulin (Tg) stimulation after ablation in patients with papillary thyroid carcinoma (PTC) and undetectable basal Tg measured with sensitive assays has been questioned. However, there is a need for prospective studies that evaluate the evolution of these patients when stimulated Tg is omitted and this was the objective of the present investigation. One hundred twenty-two consecutive patients with PTC with the following characteristics were evaluated: submitted to total thyroidectomy and remnant ablation; low risk for recurrence; undetectable basal Tg (functional sensitivity of 0.1 ng/ml) 6 months after initial therapy; anti-Tg antibodies (TgAb) negative, and neck ultrasound (US) showing no abnormalities. These patients were not submitted to Tg stimulation. After follow-up for 24–78 months, only one patient (0.8%) presented apparent disease (lymph node metastases). TgAb were detected at low titers and without progression in 1 patient (0.8%). Tg became detectable and continued to be detectable in 3 patients (2.4%), but at concentrations ≤0.3 ng/ml in the absence of further increases, with stimulated Tg < 1.4 ng/ml. A total of 117 patients (96%) coursed with no apparent disease throughout follow-up and had undetectable Tg at the end of the study. Of these, 111 showed undetectable Tg in all measurements and 6 showed detectable Tg in some of them, although Tg later returned spontaneously to an undetectable range. After ablation, the risk of recurrence is very low in patients with low-risk PTC who show undetectable basal Tg measured with a sensitive assay, negative TgAb and negative US.