Thyrotropin serum concentrations in patients with papillary thyroid microcancers.

BACKGROUND

Recent studies have shown that elevated serum thyrotropin (thyroid-stimulating hormone [TSH]) concentrations are associated with an increased risk of differentiated thyroid cancers in patients with nodular goiter. Therefore, the measurement of TSH concentrations might support the clinical estimation of cancer risk, especially in patients with thyroid nodules that are too small for fine-needle aspiration biopsies. Thus, the objective of this study was to compare preoperative serum TSH concentrations in patients with papillary thyroid microcarcinoma (PTMC) and individuals in whom the presence of even small differentiated thyroid cancers was excluded by thorough histological examination of the thyroid after total thyroidectomy because of medullary thyroid carcinoma or c-cell hyperplasia.

METHODS

The study was a retrospective cross-sectional analysis. Thirty-three patients with PTMC who had undergone a hemi- or total thyroidectomy and 54 subjects with medullary thyroid carcinoma or c-cell hyperplasia in whom a total thyroidectomy had been performed between 1994 and 2008 were included. Exclusion criteria were the intake of medication that might affect thyroid function and previous thyroid cancer or thyroid surgery.

RESULTS

The mean TSH value was comparable between patients with PTMCs (1.40 +/- 0.92 mLU/L, 95% CI = 1.07-1.72) and the control group (1.43 +/- 1.44 mLU/L; 95% CI = 1.04-1.82, p = 0.912). There was a positive trend in correlation between nodule size and TSH levels in patients with PTMC (p = 0.066).

CONCLUSIONS

TSH is not elevated in subjects with PTMCs, indicating that it is not likely involved in the de novo oncogenesis of these small cancers. However, TSH might rather play a role in the progression of preexisting PTMCs.