Comparison of Patient-Reported Outcomes Between Active Surveillance and Immediate Lobectomy in Patients with Low-Risk Papillary Thyroid Microcarcinoma: Initial Findings from the KoMPASS Cohort

Background: Patients diagnosed with low-risk papillary thyroid microcarcinoma (PTMC) face the decision between thyroid lobectomy and active surveillance (AS). This study aimed to investigate the factors influencing treatment decisions in low-risk PTMC and to compare the quality of life (QoL) according to the treatment plan. Methods: The multicenter prospective cohort study comparing AS and thyroid lobectomy was conducted. Clinical characteristics were compared between the AS and Lobectomy groups. QoL questionnaires were administered every 6 months in the initial year and annually thereafter. Results: A total of 927 patients (453 in the AS group and 474 in the Lobectomy group) with low-risk PTMC were included in this study. The mean age was 47.4 ± 12.2 years, and 72.2% of the patients were women. Older age (odd ratio [OR] 1.04, confidence interval [CI] 1.02-1.05, p < 0.001), smaller tumor size (OR 0.78, CI 0.69-0.87, p < 0.001), family history of thyroid cancer (OR 1.48, CI 1.03-2.12, p = 0.035), prior awareness of AS (OR 1.53, CI 1.16-2.02, p = 0.003), and higher income (OR 1.79, CI 1.13-2.83, p = 0.013) were significantly associated with a higher likelihood of choosing AS. The median follow-up was 27.3 months (23.9-43.9) in the AS group and 28.7 months (20.4-44.5) in the Lobectomy group. During the follow-up period, the AS group showed significantly better QoL scores compared with the Lobectomy group (β 0.17, CI 0.02-0.33, p = 0.029). Although baseline QoL scores favored the AS group significantly (7.1 ± 1.2 vs. 6.7 ± 1.2, p < 0.001), no significant difference was observed after 12 months (7.2 ± 1.2 vs. 7.1 ± 1.2, p = 0.592). Conclusions: This study demonstrated that age, tumor size, family history of thyroid cancer, awareness of AS, and income were associated with patients' treatment choices. Although the overall QoL scores were significantly higher in the AS group, the QoL became similar between the two groups after 12 months. Clinical Trial Registration: KCT0004935.