Papillary Thyroid Carcinoma in Patients with Acromegaly from a Single Center in China

An increased risk of thyroid cancers in patients with acromegaly has been addressed by numerous studies. However, the differences between patients with papillary thyroid cancer (PTC) with and without acromegaly remain to be clarified. We compared the clinical-pathologic data and genetic alterations of PTC between the 2 groups.

Four patients with PTC and acromegaly and 32 age-matched patients with PTC without acromegaly were retrieved retrospectively from the hospital recordings. Mutational analysis was determined by direct sequencing. Insulin-like growth factor-1 receptor and insulin Rβ expression were analyzed by immunohistochemistry in acromegaly group.

The prevalence of multifocality involved in bilateral lobes in the acromegaly group was significantly increased (P = 0.017). The presence of bilateral lymph node metastasis showed the increasing trend even though without a significant difference because of the limited number of PTC patients in acromegaly group (P = 0.053). There was no significant difference in other factors, such as sex, tumor size in maximum diameter, lymph node metastasis, extrathyroidal extension, and TNM stage. Two (50%) PTCs in acromegalic group and 25 (78.12%) PTCs in the nonacromegalic group were detected to harbor BRAF^600E mutation, and no patient was identified to have NRAS codon 61, KRAS codon 61/12/13 mutation. Insulin-like growth factor-1 receptor and insulin Rβ immunostaining showed low positive to positive in PTC cells and negative in adjacent normal tissues in patients with acromegaly.

Multifocality involved in 2 lobes is more common in patients with PTC and acromegaly, which shows more aggressive behaviors. BRAF mutation is not uncommon in patients with PTC and acromegaly.