RESUMO
OBJECTIVE: In patients with differentiated thyroid carcinoma (DTC), serum thyroglobulin levels measured at the time of remnant ablation after thyroid hormone withdrawal were shown to have prognostic value for disease-free status. We sought to evaluate serial thyroglobulin measurements at the time of recombinant human thyroid-stimulating hormone (rhTSH)-aided iodine 131 (131I) adjuvant treatment as prognostic markers of DTC. METHODS: Six hundred-fifty patients with DTC given total/near-total thyroidectomy and adjuvant radioiodine post-rhTSH stimulation were evaluated. Thyroglobulin was measured on day 1 (Tg1; at the time of the first rhTSH injection), day 3 (Tg3; 1 day after the second, final rhTSH injection), and day 6 (Tg6; 3 days post-radioiodine administration). Treatment failure was defined as histopathologically confirmed locoregional recurrence, or radiologically-evident distant metastases (signs of disease on computer tomography (CT) or magnetic resonance imaging (MRI), or abnormal foci of radioiodine or [18F] fluorodeoxyglucose ([18F]FDG) uptake. RESULTS: In univariate analysis, Tg1 (p < 0.001) and Tg3 (p < 0.001), but not Tg6, were significantly associated with structural recurrence. In multivariate analysis of the overall cohort, only Tg3 was independently associated with structural recurrence. In multivariate analysis of the subgroup (n = 561) with anti-Tg antibodies titers below the institutional cut-off, 115 IU/mL, Tg1 was an independent prognostic marker. Tg1 and Tg3 cutoffs to best predict structural recurrence were established at 0.7 ng/mL and 1.4 ng/mL, respectively. CONCLUSIONS: Tg1 and Tg3, measurements made after rhTSH stimulation but before radioiodine treatment, independently predict a low risk of treatment failure in patients with DTC. Levels measured post-radioiodine application (e.g., Tg6) are highly variable, lack prognostic value, and hence can be omitted.
Assuntos
Neoplasias da Glândula TireoideRESUMO
Papillary thyroid cancer (PTC) usually has a good prognosis. The treatment, including total thyroidectomy and complementary radioiodine (RAI) therapy, gives complete remission in 90% of patients. However, in 10% of subjects with metastatic disease, the prognosis is poor. In the group of patients with disease progression and no 131I uptake, searching for new therapeutic modalities before all tyrosine kinase inhibitors and other antiangiogenic agents is necessary. The study presents the case of a 55-year-old male with advanced PTC /pT3mNxMo/ diagnosed in 1993. Primary treatment by total thyroidectomy and 131I ablation led to complete remission. In 2000 local as well as lymph node recurrence was diagnosed and successively treated by surgery. In 2006 an increasing serum thyroglobulin level was noted and a single lung metastasis was diagnosed and operated on. In 2007 new foci in CNS and vertebral column with no 131I uptake were stated. Further progression (bones, CNS, and pterygoid muscle) was confirmed by PET-CT. The patient underwent neurosurgical metastasectomy twice and palliative CNS and vertebra's radiotherapy. Liver metastases were diagnosed in 2009. Treatment with increasing doses of thalidomide (up to 800 mg/d) was administered for 3 months with a good tolerance; however, the therapy was withdrawn due to cancer progression. Next, sorafenib (800 mg/d) was given for 16 weeks. Radiological examination performed after 16 weeks confirmed stable disease, whereas 2 months later, after sorafenib withdrawal due to lack of treatment possibility, further progression was observed. Metronomic chemotherapy with Adriamycin was instituted which gave disease stabilization for 6 months. The patient died with advanced disseminated disease due to pulmonary embolism. We present this case to document no adverse effects of therapy with sorafenib in a patient with brain DTC metastases. Sorafenib therapy was only short-term, but no progression occurred in this time.