Chronic lymphocytic thyroiditis does not influence the risk of recurrence in patients with papillary thyroid carcinoma and excellent response to initial therapy

This study evaluated the recurrence in patients with papillary thyroid cancer and an excellent response to initial therapy, comparing those with and without chronic lymphocytic thyroiditis. This was a prospective study. Patients who met the following criteria were selected: diagnosis of papillary thyroid cancer; submitted to total thyroidectomy followed or not by ablation with I-131; and neck ultrasonography without abnormalities, nonstimulated thyroglobulina (Tg) <= 0.2 ng/ml, and undetectable antithyroglobulin antibodies (TgAb) 12-18 months after initial therapy. The patients were divided into two groups: group A, with chronic lymphocytic thyroiditis on histology; group B, without chronic lymphocytic thyroiditis on histology. Groups A and B were similar in terms of sex and age of the patients, characteristics of the tumor, tumor-node-metastase stage and risk category. The time of follow-up ranged from 24 to 120 months (median 66 months). During follow-up, 5 patients of group A (2.6 %) and 9 patients of group B (2 %) developed recurrence (p = 0.77). Patients with chronic lymphocytic thyroiditis were more likely to progress to persistently borderline TgAb. No patient had positive TgAb (above the reference value) during follow-up. Recurrences occurred in 12/588 patients (2 %) with undetectable TgAb in all measurements, in 1/32 (3.1 %) with detectable TgAb on some occasion but that returned to undetectable spontaneously, and in 1/13 (7.7 %) with persistently borderline TgAb. These rates did not differ significantly (p = 0.25). The results of the present study showed the absence of an association between chronic lymphocytic thyroiditis and recurrence risk at least in patients with an excellent response to initial therapy.