The Role of Different Molecular Markers in Papillary Thyroid Cancer Patients with Acromegaly

Prevalence of papillary thyroid cancer (PTC) is increased in patients with acromegaly. We aimed to determine the protein expression of BRAF, RAS, RET, insulin like growth factor 1(IGF1), Galectine 3, CD56 in patients with PTC related acromegaly and to compare the extensity of these expressions with normal PTC patients and benign thyroid nodules.

We studied 313 patients with acromegaly followed in Cerrahpasa Medical Faculty, Endocrinology and Metabolism Clinic between 1998 and 2015. On the basis of availability of pathological specimen of thyroid tissues, thyroid samples of 13 patients from 19 with acromegaly related PTC (APTC), 20 normal PTC and 20 patients with multinodulary goiter (MNG) were histopathologically evaluated. Protein expressions were determined via immunohistochemical staining in ex-vivo tumor samples and benign nodules.

The incidence of PTC in acromegaly patients were 6% (n=19). Among patients with PTC, APTC and MNG, all the immunohistochemical protein expressions we have studied were higher in papillary thyroid cancer groups (p<0.01, for all). Between PTC group without acromegaly and APTC, galectin 3 and IGF1 expression was significantly higher in acromegalic patients (p<0.01 for all) while RAS was predominantly higher in PTC patients without acromegaly (p<0.01).

BRAF expression was not higher in PTC with acromegaly patients compared to PTC patients without acromegaly. Galectine 3 and IGF1 were expressed more intensively in APTC. These positive protein expressions may have more influence on determining malign nodules among acromegaly patients.