The Relationship of Clinicopathological Factors of the Tumor with Preoperative TSH Level in Papillary Thyroid Cancers.

Objective: Thyroid-stimulating hormone/thyrotropin (TSH) is known to induce malignancies and tissue growth of the thyroid gland. While the relationship of higher levels of TSH with advanced stages of cancer had been published in previous studies, the relationship of the tumor with the clinicopathological factors had not been completely evaluated. The aim of the present study was to evaluate the relationship between highly risky clinicopathological factors with preoperative high levels of TSH.

Materials and Methods: The records of 89 patients (67 females and 22 males) who underwent surgery for differentiated thyroid cancer between 2011 and 2013 were reviewed. The relationship of preoperative TSH between tumor size, multicentricity, lymphovascular invasion, extrathyroidal extension, central neck metastasis, and lateral neck metastasis was evaluated.

Results: The preoperative TSH levels were high in patients with multicentricity (p=0.022), lymphovascular invasion (p=0.018), and central neck metastasis (p=0.002). The prevalence of extrathyroidal extension (p=0.41), lymphovascular invasion (p=0.020), and central metastasis (p=0.009) was significantly high in patients with a TSH level ≥2.5 mIU/L. The preoperative TSH levels were determined as an independent predictive risk factor for central neck metastases (p=0.012) and extrathyroidal extension (p=0.041) in multinomial logistical regression analysis.

Conclusion: The power of radiological imaging for the identification of central neck metastases in preoperative evaluation is limited. The preoperative high level of TSH is an independent predictive factor for central metastases and extrathyroidal extension. It can help to predict tumor staging. Furthermore, related with multicentricity and lymphovascular invasion, it can affect the high risk characteristics of the tumor except the stage. The preoperative TSH level can be considered for the probability of preoperative metastases and can contribute to plan the extent of surgery.