抄録
In patients with papillary thyroid carcinoma (PTC), detectable serum thyroglobulin (Tg) after total thyroidectomy implies biochemically persistent disease (BPD). We reported that the thyroglobulin-doubling time (Tg-DT) was a potent prognostic indicator in patients with BPD. To identify factors that are related to BPD and Tg-DT, we performed new analyses on the data gathered in our previous study. Using the data of 426 patients with PTC in whom the Tg-DT was computed after total thyroidectomy, multivariate logistic analyses for BPD and Tg-DT were performed. Postoperatively, 142 (33%) patients had BPD. The percentages of BPD patients were significantly higher among the young (<40 years) and elderly (≥60 years) patients compared to the middle-aged patients (41%, 41%, and 27%, respectively). Multivariate analysis showed that cN1b, tumor size ≥4 cm, and Ex2 were significantly associated with BPD. The percentage of patients with Tg-DT <2 years among the BPD patients increased with age: 6% in the young, 15% in the middle-aged, and 47% in the elderly patients. Multivariate analysis of the BPD patients revealed that Tg-DT was associated only with the age at surgery. The current analyses indicate that BPD is significantly correlated with the extent of disease status and that Tg-DT correlates only with patient age at surgery. Although our results clearly indicate that the biological behavior of PTC is age-related, the underlying reason for this remains to be established.
