Thyroglobulin antibodies common in paediatric thyroid cancer
Circulating thyroglobulin antibodies (TgAb) are not infrequent at diagnosis in children with thyroid cancer, but these resolve within a year or two in almost half of patients, according to a recent study. Furthermore, TgAb is associated with the presence of lymph node metastasis at diagnosis, but the long-term prognostic significance remains to be known.
Researchers conducted a retrospective cohort study in a single academic paediatric centre to examine the prevalence, natural history and clinical significance of TgAb in children with nonmedullary thyroid cancer. A total of 73 consecutive patients who had serum TgAb measured within 6 months after diagnosis were included.
There were 30 children (41 percent) diagnosed with TgAb, which also correlated with lymph node metastasis (83 vs 53 percent; p=0.01) but not distant metastasis.
At a median follow-up of 3.8 years, resolution occurred in 11 (44 percent) of 25 patients with TgAb, with a median time to clear TgAb of 10.7 months. Ten (91 percent) of these participants who cleared did so within 2 years. Resolution of TgAb correlated with lower initial TgAb level (median 4.5 vs 76 normalized units; p=0.003).
There was no independent association observed between TgAb positivity at diagnosis and persistent or recurrent disease (odds ratio, 3.20; 95 percent CI, 0.95 to 10.80; p=0.06).
These findings are consistent with those of an earlier study. Xu and colleagues said that TgAb are common in patients with thyroid cancer but resolve after treatment at about ‒11 percent IU/mL per month from preoperative levels with median resolution at 11.0 months. Furthermore, persistently elevated levels after thyroidectomy did not correlate with disease recurrence in their series. [J Surg Res 2015;198:366-70]