Expression of estrogen and androgen receptors in differentiated thyroid cancer: an additional criterion to assess the patient's risk.

Estrogen (ER) and androgen (AR) receptors may be expressed in thyroid tumors, but their prognostic role is controversial. We investigated whether ERs and AR expression could confer a more aggressive phenotype to thyroid tumors. We enrolled 91 patients (13 males and 78 females, mean age 49.3 ± 14.8) bearing small (T1 in the 2006 TNM system) differentiated thyroid cancers. Thirty-eight tumors were incidental histologic findings. Using immuno-histochemistry we evaluated ER-alpha, ER-beta and AR expression in tumors and in correspondent extra-tumor parenchyma. In tumors, 13 (16.7%) women and 1 (7.7%) man expressed ER-alpha; 42 (53.8%) women and 6 (46%) men expressed ER-beta; 16 (20.5%) women and 3 (23.1%) men expressed AR. In normal thyroid parenchymas, ER-beta was expressed in 52 (66.7%) women and in 9 (69.2%) men; ER-alpha in 3 (3.8%) women, and AR in 13 (16.7 %) women. Compared with normal thyroid parenchyma, tumors gained ER-alpha and lost ER-beta expression. Incidental cancers were more commonly ER-alpha(+) than ER-alpha(-) (47.7% vs 14.3% p=0.037). In ER-alpha(+) tumors, post-surgical serum thyroglobulin was higher than in the ER-alpha(-) ones (p=0.04). ER-beta(-) tumors showed vascular invasion more frequently than the ER-beta(+) ones (26.2% vs. 4.1%, p=0.005). AR (+) tumors showed capsular invasion more frequently than the AR (-) ones (77.8% vs 46.6%, p=0.014). In conclusion, ER-alpha positivity, ER-beta negativity and AR expression are associated with a more aggressive phenotype of small T1 differentiated thyroid cancers. ERs and ARs expression may represent an additional criterion in deciding whether to perform radioiodine ablation in these tumors.