Prognosis of papillary thyroid carcinoma in relation to preoperative subclinical hypothyroidism

Introduction It has been established that thyroid-stimulating hormone (TSH) stimulates the growth and development of thyroid malignancy, and a higher serum TSH level is associated with the incidence of thyroid cancer and an advanced tumour stage. This study aimed to evaluate the association of preoperative subclinical hypothyroidism with the prognosis of papillary thyroid cancer (PTC). Methods A total of 466 patients who underwent surgery for PTC between December 2006 and June 2009 were enrolled. Among them, 44 patients had subclinical hypothyroidism, while 422 did not have subclinical hypothyroidism, as diagnosed using the preoperative thyroid function test. We compared the recurrence rate and association with clinicopathological features in the two groups. Results The median patient age was 46.9 years (17-74 years). There were 420 female and 46 male patients. The median follow-up duration was 81.4 months. There were no statistical differences between the two groups with respect to age, sex, tumour size, extrathyroidal extension, multifocality, lymph node metastasis, TNM stages, recurrence and disease-free survival, despite a significant difference in the average TSH concentrations of the two groups. Conclusions Our results suggest that preoperative subclinical hypothyroidism was not associated with tumour aggressiveness and recurrence in PTC.