Active surveillance in papillary thyroid carcinoma: not easily accepted but possible in Latin America

To determine the percentage of patients with papillary thyroid carcinoma (PTC) who accepted active surveillance as an alternative to surgery in our clinical practice and to describe the clinical characteristics and outcomes of patients with Bethesda category V and VI thyroid nodules who chose active surveillance.

We included 136 PTC patients from the Hospital de Clínicas, University of Buenos Aires without (i) US extrathyroidal extension, (ii) tumors adjacent to the recurrent laryngeal nerve or trachea, and/or (iii) US regional lymph-node metastasis or clinical distant metastasis. PTC progression was defined as the presence of i) a tumor larger than ≥ 3 mm, ii) novel appearance of lymph-node metastasis, and iii) serum thyroglobulin doubling time in less than one year. For patients with these features, surgery was recommended.

Only 34 (25%) of 136 patients eligible for active surveillance accepted this approach, and around 10% of those who accepted abandoned it due to anxiety. The frequency of patients with tumor enlargement was 17% after a median of 4.6 years of follow-up without any evidence of nodal or distant metastases. Ten patients who underwent surgical treatment after a median time of 4 years of active surveillance (AS) had no evidence of disease after a median of 3.8 years of follow-up after surgery.

Although not easily accepted in our cohort of patients, AS would be safe and easily applicable in experienced centers.