The role of anti-thyroglobulin antibody in treatment and follow up of differentiated thyroid cancer

Aim: This study aimed to investigate the role of serum anti-thyroglobulin antibody (anti-TgAb) as a marker to predict the success of radioactive iodine (RAI) ablation therapy in differentiated thyroid cancer (DTC) patients and also investigate the role of anti-TgAb in the follow-up of thyroid cancer. Materials and Methods: One hundred thirteen DTC patients with total thyroidectomy who received RAI ablation therapy enrolled in this retrospective study. The first measurement was performed immediately before ablation therapy (thyroglobulin (Tg)1, anti-TgAb 1). The second measurement was performed just before the whole-body iodine 131 (I-131) scan (WBS) within 6-12 months after ablation (Tg 2, Anti-TgAb 2). Patients were divided into two groups according to ablation success: Group 1 (successful) and Group 2 (unsuccessful). Tg and anti-TgAb levels and the difference between two measurements were compared between groups. Results: In terms of Anti-Tg antibody positivity and the anti-Tg Ab 1 and anti-Tg Ab 2 levels, there was no statistically significant difference between groups (p= 0.661, p = 0.716, p = 0.764, respectively). When the groups were compared in terms of anti-Tg Ab level change after treatment, a statistically significant decrease was observed in Group 1 (p <0.001), but there was no statistically significant decrease in Group 2 (p = 0.277). Discussion: In conclusion, a reduction in anti-Tg Ab level, measured within 6-12 months after the ablation, can be used as an indicator of treatment success.