Prognosis of papillary thyroid cancers with positive serum thyroglobulin antibody after total thyroidectomy

Background/Objective To investigate the influence of serum anti-thyroglobulin antibody (TgAb) on the prognosis in papillary thyroid cancer (PTC) patients. Methods In this retrospective study, the participants were enrolled from 1206 PTC patients (927 women, 279 men; mean age, 42.2 years) with T2 and higher, or N1 or M1 classifications in tumor–node–metastasis staging after total thyroidectomy. We recorded the final serum TgAb data (on thyroxin therapy) at the end of follow-up in 2012. Patients were classified as negative TgAb or positive TgAb groups on the basis of their serum TgAb levels (< 70 IU/mL or ≥ 70 IU/mL). Results Among the 1206 patients, after mean follow-up for 11.6 ± 6.1 years (range, 2.0–29.2 years), there were 75 with positive TgAb and 1131 with negative TgAb. Patient categorization depending on the follow-up time (2–5 years after surgery, 5–10 years after surgery, and 10–30 years after surgery) was performed. In comparison to traditional risk factors, such as age, tumor size, and sex, which were important prognostic factors for cancer recurrence and mortality in PTC patients, there was no significant difference in the prognosis between positive TgAb patients and negative TgAb patients by the multivariate analyses (cancer recurrence, p = 0.164, p = 0.112, p = 0.202, respectively; cancer mortality, p = 0.181, p = 0.646, p = 0.656, respectively) based on the different follow-up times. Conclusion Positive serum TgAb was not a risk factor, and was not associated with the prognosis of PTC patients.