Contemporary management of differentiated thyroid cancer in Latin America: results from the CaTaLiNA prospective multicenter registry.

BACKGROUND: International guidelines increasingly endorse treatment de-escalation for selected patients with differentiated thyroid cancer (DTC), including thyroid lobectomy and selective use of radioactive iodine (RAI) therapy. How contemporary clinical practice in Latin America aligns with these recommendations remains unclear. We evaluated contemporary management patterns and early outcomes within a large prospective regional registry.

METHODS: The Cancer de Tiroides en Latinoamerica (CaTaLiNA) registry is an international, prospective cohort study including patients treated at 11 centers across Ecuador, Peru, Mexico, Brazil, and Uruguay. Adult patients with histologically confirmed DTC undergoing initial thyroid surgery between June 1, 2023, and October 31, 2025, were analyzed. American Thyroid Association (ATA) 2015 risk of structural recurrence and AJCC 8th edition staging were assigned retrospectively. Primary outcomes were the extent of initial surgery, RAI utilization across the ATA risk categories, and early postoperative complications. Multivariable mixed-effects logistic regression was performed to identify factors associated with RAI use and postoperative complications.

RESULTS: A total of 901 patients were included (mean age 47.7 ± 13.3 years; 84.9% women). Papillary thyroid carcinoma accounted for 96.7% of cases. Most patients had early-stage disease (AJCC stage I, 81.5%). Total thyroidectomy was performed in 96.4% of patients. RAI was administered in 54.3% of patients, increasing across risk categories (40.7% low risk, 69.2% intermediate risk, and 59.6% high risk; p < 0.001). Tumor size, resection margin status, and a higher ATA 2015 risk category were independently associated with RAI use. Postoperative complications occurred in 15.4% of patients, predominantly transient hypocalcemia, and were more frequent in higher-risk groups; tumor size was the only independent predictor after adjustment.

CONCLUSIONS: In this large Latin American cohort, management of DTC frequently exceeded the intensity recommended by ATA guidelines, with high rates of total thyroidectomy and RAI, including among low-risk patients. The ATA 2015 framework enables more refined risk stratification; however, its integration into clinical practice remains incomplete. These findings provide important region-specific data and highlight opportunities to optimize risk-adapted care and reduce overtreatment in DTC.