Outcomes of Conversion Surgery for Patients With Low-Risk Papillary Thyroid Carcinoma

Importance The outcomes of patients with low-risk thyroid cancer who undergo surgery following a period of active surveillance (AS) are not well-defined. Objective To evaluate surgical, pathologic, and oncologic outcomes among patients undergoing conversion surgery (CS) following AS for low-risk papillary thyroid carcinoma. Design, Setting, and Participants In this cohort study, patients who underwent CS for disease progression were compared with patients who underwent CS without disease progression and with a propensity score-matched cohort of patients who underwent initial surgery (IS). The median (IQR) postsurgical follow-up time was 40.3 (18.0-59.0) months. Patients were treated at a quaternary cancer referral center in the United States. Exposures Surgery. Main Outcomes and Measures Surgical complications, pathologic characteristics, overall survival (OS), and recurrence-free survival (RFS). Results Of 550 patients who underwent AS, 55 (10.0%) had CS, of whom 39 (7.1%) had surgery due to suspected disease progression (median [IQR] age, 48 [39-56] years; 32 [82.1%] female). There were no clinically meaningful differences in rates of surgical sequalae between the progression CS group (12 of 39 [30.7%]) and the nonprogression CS group (7 of 16 [43.8%]) (Cramer V, 0.2; 95% CI, 0.01-0.5). The 5-year OS was 100% (95% CI, 100%-100%) in both the disease-progression CS cohort and the IS cohort. Although the cohort of patients undergoing CS after disease progression was by definition a subset with more aggressive tumor behavior, no clinically meaningful differences were observed in the rates of regional recurrence (2 of 39 [5.1%] vs 0 of 39 patients with IS), local recurrence (0 patients), distant metastasis (0 patients), or disease-specific mortality (0 patients) when compared with the matched IS group. Five-year RFS rates were similar: 100% in the IS group and 86% (95% CI, 70%-100%) in the CS group. Conclusions and Relevance In this cohort study, CS for suspected disease progression was associated with surgical and oncologic outcomes similar to IS, supporting the feasibility and safety of AS for patients with low-risk papillary thyroid carcinoma.