The Use of Post-ablation Stimulated Thyroglobulin in Predicting Clinical Outcomes in Differentiated Thyroid Carcinoma - What Cut-off Values Should We Use?
Clin Oncol (R Coll Radiol)
; 31(2): e11-e20, 2019 02.
Article
em En
| MEDLINE
| ID: mdl-30454940
ABSTRACT
AIMS:
Recently published international guidelines recommended using the stimulated thyroglobulin (sTg) post-radioactive iodine (RAI) ablation, in conjunction with tumour stage, as a risk stratification factor. The choice of cut-off values for sTg, namely 1 and 10 ng/ml, was, however, largely based on the functional sensitivities of the assays used, with relatively few published data addressing the prognostic impact of alternative cut-off values. Our study aims to provide data on the prognostic value of sTg at different levels of sensitivities and specificities. MATERIALS ANDMETHODS:
We conducted a retrospective review of all adult cases of differentiated thyroid carcinoma receiving RAI ablation at our centre from 2008 to 2010. All patients had sTg measured at around 6 months post-ablation. The functional sensitivity of our assay was 0.5 ng/ml. The outcome was adverse clinical event, defined as cancer-related death, persistent macroscopic disease demonstrable on imaging (including radioisotope scan) and/or receiving further treatment for persistent or recurrent disease. A receiver operating characteristic (ROC) analysis was carried out.RESULTS:
We identified 140 patients treated in the review period, with 106 of them suitable for further analysis. The reasons for exclusion included the presence of anti-thyroglobulin antibodies and medullary or anaplastic histological subtypes. Most (54.7%) had intermediate-risk disease as per the American Thyroid Association classification (2009). The median follow-up duration was 6.4 years; the minimum, excluding deaths, was 5.0 years. ROC analysis showed that the optimal cut-off value of sTg for predicting adverse clinical events was >1.0 ng/ml, associated with a sensitivity of 90.9%, a specificity of 81.0%, a positive predictive value of 55.6% and a negative predictive value of 97.1%.CONCLUSION:
Based on ROC analysis of sensitivities and specificities, our data showed that a post-ablation sTg value of 1 ng/ml is the optimal cut-off in prognostication of adverse clinical events.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tireoglobulina
/
Neoplasias da Glândula Tireoide
Tipo de estudo:
Etiology_studies
/
Guideline
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Observational_studies
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Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
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Aged
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Female
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Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Clin Oncol (R Coll Radiol)
Assunto da revista:
NEOPLASIAS
Ano de publicação:
2019
Tipo de documento:
Article