The association between serum TSH concentration and thyroid cancer.

There is mounting evidence that the serum concentration of TSH is an independent predictor for the diagnosis of thyroid malignancy in patients with nodular thyroid disease. Furthermore, preoperative serum TSH concentrations are higher in patients with more aggressive tumours, suggesting a potential role for TSH in the progression of differentiated thyroid cancer. Based on these observations, patients with higher serum TSH concentrations and borderline cytological results may require more aggressive investigation and treatment when compared with those with lower baseline TSH levels. The mechanisms underlying the finding of higher serum TSH in patients with thyroid cancer remain unexplained. In this issue of Endocrine-Related Cancer, Fiore et al. have analysed the relationship between serum TSH and diagnosis of papillary thyroid cancer in 10 178 patients with nodular thyroid disease who were investigated by fine-needle aspiration biopsy. They found significantly higher TSH concentrations in patients who were subsequently diagnosed with thyroid cancer compared with those with benign disease. In addition, they found that the development of autonomous thyroid function (TSH<0.4 muU/ml) was associated with a reduction in the risk of papillary thyroid carcinoma. In this commentary, the evidence regarding the association between serum TSH and thyroid cancer is discussed placing these new findings into context.