The Clinical Utility of Preoperative Thyroglobulin for Surgical Decision Making in Thyroid Disease

Serum thyroglobulin (Tg) levels are used to monitor for differentiated thyroid cancer (DTC) recurrence and have been correlated with posttreatment disease burden. The clinical significance of Tg in the preoperative setting to predict the risk of DTC is unclear. Our aim is to examine the clinical utility of preoperative Tg levels in those undergoing thyroidectomies for DTC or benign disease.

From a prospectively collected database, we identified 385 patients who underwent thyroidectomy from 01/14 to 12/19 and had preoperative Tg levels available. Preoperative Tg levels were compared by preoperative indication for surgery, Bethesda category of biopsied nodules, presence of DTC on surgical pathology, and number of metastatic lymph nodes.

There was no difference in mean preoperative Tg level when comparing indication for surgery (P = 0.2) or Bethesda classification (P = 0.4). Mean preoperative Tg levels were lower in patients with DTC (238 ± 77) compared to without DTC (532 ± 97) on final pathology (P = 0.02). Among 188 DTC patients who had lymph nodes removed, there was no significant correlation between the preoperative Tg level and number of positive lymph nodes on final pathology (P = 0.4).

Preoperative serum Tg levels were lower in patients with DTC compared to those with benign disease on final pathology and did not correlate with extent of lymph node metastasis in patients with DTC. We found that serum Tg levels obtained in the preoperative setting do not predict DTC or lymph node metastasis and, therefore, do not inform the extent of surgery for differentiated thyroid cancer.