title: 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.
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.
authors.affiliation: Postgraduation Program, Endocrinology Service, Santa Casa de Belo Horizonte, Minas Gerais, Brazil.
authors.forename: P W S
authors.initials: PW
authors.lastname: Rosario
authors.forename: J B N
authors.initials: JB
authors.lastname: dos Santos
authors.forename: M R
authors.initials: MR
authors.lastname: Calsolari
mesh_terms: D055011:Ablation Techniques; D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000097:blood* / Q000601:surgery*; D002291:Carcinoma, Papillary; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000097:blood* / Q000601:surgery*; D055815:Young Adult
chemical_list: D013954:Thyroglobulin