Objective: To explore the relationship between serum level of thyroxin-stimulating hormone (TSH) and development and progression of papillary thyroid microcarcinoma (PTMC) in nodular thyroid disease.
Methods: A total of 365 eligible patients with thyroid nodules undergoing initial thyroidectomy were enrolled, including 113 patients with PTMC diagnosed by postoperative pathology (PTMC group) and 252 patients with benign thyroid nodules (BTN group). Their clinical data were retrospectively reviewed. The serum levels of TSH in two groups and the proportion of PTMC in different serum TSH level groups in all patients were compared respectively. The relationship of preoperative serum TSH levels with tumor size and lymphatic metastasis in patients with PTMC were analyzed.
Results: No significant difference existed in serum TSH levels between PTMC and BTN groups (P > 0.05). The median age was younger in PTMC group than that in BTN group (Z = -2.877, P = 0.004). And the TGAb levels were higher in PTMC group than those in BTN group (Z = -2.887, P = 0.004). They were divided into 6 groups according to the serum TSH levels, and there weren't significant difference in the proportion of PTMC among those group (P > 0.05). Binary logistic regression analysis showed age was the only risk factor of PTMC (OR = 0.971, 95%CI: 0.953-0.990, P = 0.003). The serum TSH levels were positively correlated with tumor size in patients with PTMC (r = 0.218, P = 0.025). However, the proportions of lymphatic metastasis were comparable among different TSH levels groups in patients with PTMC (P > 0.05).
Conclusion: Serum TSH is probably associated with the de novo oncogenesis of PTMC. However, serum TSH may be involved in the growth of preexisting PTMC.