Preoperative thyroglobulin antibody concentrations and prediction of papillary thyroid carcinoma recurrence

Objective Autoimmune thyroiditis (AIT), a common chronic autoimmune inflammation of the thyroid, has been associated with an elevated risk of papillary thyroid carcinoma (PTC). However, the impact of AIT on the prognosis of PTC remains uncertain. As thyroid autoantibodies were indicators for AIT, this study aimed to investigate the recurrence risk in different levels of preoperative thyroid autoantibodies in PTC patients. Methods This retrospective study analyzed 1122 PTC patients undergoing total thyroidectomy or lobectomy. We assessed associations of preoperative antithyroglobulin (TGAb) and antithyroid peroxidase antibodies (TPOAb) with cancer recurrence using Cox regression, restricted cubic spline models and subgroup analysis. Results The median follow-up for all patients was 40 months (95%CI, 37.9-41.9) and the 3-year recurrence-free survival rate was 86.6%. Elevated TGAb >15 IU/mL independently predicted cancer recurrence risk (HR, 2.56; 95% CI, 1.21-5.44; P = 0.014). In contrast, increasing TPOAb levels were associated with a trend toward decreased risk of PTC recurrence (P for trend = 0.037), though the highest quartile (TPOAb >50 IU/mL) was not independently significant after adjustment (HR, 0.69; 95% CI, 0.41-1.15; P = 0.157). In combination, TGAb > 15 IU/mL and TPOAb <= 50 IU/mL predicted the highest recurrence risk (HR, 4.52; 95% CI, 1.54-13.29, P = 0.006). Female patients or patients < 55 years old with TGAb > 15 IU/mL and TPOAb <= 50 IU/mL had more risk of recurrence (HR, 4.68, 95% CI, 1.36-16.07; P = 0.014; HR, 5.27, 95% CI, 1.54-17.98; P = 0.008). Conclusion Preoperative TGAb, but not TPOAb, is an independent prognostic factor for PTC. The elevation of preoperative TGAb correlates with an increased recurrence rate of PTC. PTC patients with elevated preoperative TGAb levels may necessitate greater clinical attention owing to higher recurrence rates, which challenges the conventional notion that PTC concomitant with AIT is invariably indolent.