Association of thyroglobulin antibody and thyroid peroxidase antibody status with aggressive features in papillary thyroid carcinoma with Hashimoto's thyroiditis.

Background: Thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) are thought to be linked to the development and prognosis of papillary thyroid carcinoma (PTC) combined with Hashimoto's thyroiditis (HT). However, the association between TgAb and TPOAb statuses and aggressive features in PTC with HT remains unclear. This study aims to elucidate the invasive or protective effects of different TgAb and TPOAb statuses in PTC patients with HT.

Methods: A total of 317 patients who were pathologically diagnosed with PTC and HT were enrolled in this retrospective study. Data on preoperative serum TgAb, TPOAb, and thyroid hormone levels, as well as histopathological and ultrasound characteristics, were collected and analyzed. Based on TgAb and TPOAb status, patients were divided into four groups. The Kruskal-Wallis H test and Pearson chi-squared test were applied to compare aggressive features between the groups.

Results: In our study, we enrolled 317 patients, who were divided into four groups based on TgAb and TPOAb status. Significant differences were found between groups in tumor size >4 cm (P=0.004), the number of central lymph node metastases (NCLNM, P=0.01), the central lymph node metastasis ratio (CLNMR, P=0.03), and the lateral lymph node metastasis ratio (LLNMR, P=0.01). Then we conducted pairwise comparisons between groups, which showed that the TgAb and TPOAb double-negative (TAb^-) group had a higher proportion of tumors >4 cm compared to the TgAb and TPOAb double-positive (TAb⁺) group (P=0.008) and the TPOAb-positive (TPOAb⁺) group (P=0.03). More importantly, the TAb^- group also exhibited significantly higher NCLNM than the TAb⁺ group (P=0.02) and TPOAb⁺ group (P=0.03), as well as higher CLNMR compared to the TPOAb⁺ group (P=0.02) and higher LLNMR compared to the TAb⁺ group (P=0.02).

Conclusions: The TAb^- group showed an increased risk of aggressive features, whereas the TAb⁺ and TPOAb⁺ groups indicated a reduced risk. These findings suggest that TgAb and TPOAb statuses may help predict tumor aggressiveness preoperatively.