Higher TSH Is Not Associated With Thyroid Cancer Risk in the Presence of Thyroid Autoimmunity

Abstract

Background Higher-but-within-normal thyrotropin (thyroid-stimulating hormone, TSH) is associated with higher risk for differentiated thyroid cancer (DTC) in surgical series. Our recent clinical observations suggest that this is not the case in the presence of autoimmune thyroid disease (AITD). We designed the present study to clarify this controversy. Methods We analyzed our prospectively collected database of patients referred for thyroid surgery at 2 tertiary care referral centers in Greece and the United States. We collected data for preoperative TSH, postoperative pathology, and thyroid peroxidase (TPO) antibodies titers. Subjects were subdivided into 2 groups, those with AITD (i.e., lymphocytic thyroiditis) and non-AITD. We excluded subjects with Graves disease, abnormal TSH (< 0.40 or > 4.50 mIU/mL), or recent use of levothyroxine. We compared the serum TSH among different groups using the Mann-Whitney test. Results A total of 3973 subjects were screened; 1357 met exclusion criteria. After all exclusions, data from 1731 non-AITD subjects and 329 AITD subjects were included in the analysis. AITD subjects had higher TSH than non-AITD subjects (2.09 vs 1.48; P < 0.0001). TSH values were higher in DTC compared with benign histology only in non-AITD subjects (1.65 vs 1.40; P < 0.0001). Progressively higher TSH was associated with higher incidence of DTC only in non-AITD subjects (P < 0.0001). In AITD subjects, TSH was similar between groups with or without DTC (2.02 vs 2.14; P = 0.21). Conclusions TSH concentrations are not associated with the risk of developing DTC in the presence of thyroid autoimmunity, even though this seems to be the case for all other patients.

The relationship between papillary thyroid carcinoma and preoperative TSH level: A cross-sectional study from Syria

“…[4,7] Thirdly, the improved survival rate and decreased recurrence rate in thyroid cancer patients treated with suppressive doses of levothyroxine supports TSH tropic effect on thyroid tissue promoting neoplasia and carcinogenesis along with oncogenes and other growth factors such as IGF1. [7,8] Albeit many previous studies confirmed an increased risk of malignancy in the thyroid nodules with higher TSH values, even at normal TSH levels, the relationship between TSH levels and PTC is still controversial. [4,8,9] The authors have no funding and conflicts of interest to disclose.…”

“…[ 5 , 6 ] Secondly, data on other thyroid cancer risk factors and early diagnosis strategies are still insufficient and sometimes expensive and their impact on patient management is still debated. [ 4 , 7 ] Thirdly, the improved survival rate and decreased recurrence rate in thyroid cancer patients treated with suppressive doses of levothyroxine supports TSH tropic effect on thyroid tissue promoting neoplasia and carcinogenesis along with oncogenes and other growth factors such as IGF1. [ 7 , 8 ]…”

“…[ 4 , 7 ] Thirdly, the improved survival rate and decreased recurrence rate in thyroid cancer patients treated with suppressive doses of levothyroxine supports TSH tropic effect on thyroid tissue promoting neoplasia and carcinogenesis along with oncogenes and other growth factors such as IGF1. [ 7 , 8 ]…”

Autoimmune thyroid disease correlates to islet autoimmunity on zinc transporter 8 autoantibody

“…According to previous study ( 28 , 29 ), we divided AITD patients into two subgroups according to the titer of TPOAb, namely the high-titer TPOAb (H-TPOAb) group (≥100 IU/mL) and the low-titer TPOAb (L-TPOAb ) group (<100 IU/mL). There were 217 H-TPOAb and 129 L-TPOAb subjects in the GD group, while 197 H-TPOAb and 93 L-TPOAb subjects in the HT group respectively.…”

Stress, Thyroid Dysregulation, and Thyroid Cancer in Children and Adolescents: Proposed Impending Mechanisms

“…Studies in children with HT have shown that persistently elevated TSH levels are associated with increased risk of TC [52, 53]. However, a recent study from adult cases showed that in thyroid autoimmunity, TSH concentrations are not associated with the risk of developing differentiated TC [54]. Further studies are needed to address the role of TSH in TC both in the pediatric and adult population.…”