Prevalência e fatores de risco associados ao carcinoma diferenciado da tireoide em pacientes com tumores neuroendócrinos da hipófise

Abstract

It is postulated that patients with different subtypes of pituitary neuroendocrine tumors (PitNETs) may present a higher prevalence of cancer. Factors underlying individuals becoming overweight, such as insulin resistance, hyperleptinemia, and low-grade inflammation, may play a role in the risk of differentiated thyroid carcinoma (DTC) in such patients. This study aimed to investigate the prevalence of and obesity-related risk factors associated with DTC in patients with PitNETs. This cross-sectional study involved 149 patients with nonacromegalic PitNETs (AG group), 71 patients with acromegaly (ACRO group), and 156 controls (CG group). All participants underwent insulin and blood glucose measurements with the determination of the homeostatic model assessment - insulin resistance (HOMA-IR) index, leptin, and high-sensitivity C-reactive protein (hsCRP), and they also underwent thyroid ultrasound. Clinically significant nodules were biopsied for subsequent cytopathological evaluation, and participants were operated on when indicated. Patients in the AG and CG groups had high levels of insulin resistance and a significantly higher frequency of hyperleptinemia and subclinical inflammation compared with those of patients in the ACRO group. There were no cases of DTC in the AG group; two findings, 1 incidental, of DTC occurred in the CG group, and 3 cases of DTC were present in the ACRO group. Acromegaly was associated with DTC after adjusted analysis. Our findings in patients with nonacromegalic PitNETs do not indicate a high risk for DTC despite the presence of metabolic and inflammatory risk factors for neoplastic events. In contrast, acromegaly promotes a greater risk of DTC.