Genetic Alterations in Differentiated Thyroid Cancer Patients with Acromegaly

Area of Science:

• Endocrinology
• Oncology
• Molecular Biology

Background:

• Acromegaly, a condition of excess growth hormone, is linked to a higher risk of differentiated thyroid cancer (DTC).
• Understanding the molecular basis of DTC in acromegaly is crucial for risk stratification and management.

Purpose of the Study:

• To investigate the prevalence of specific genetic mutations (BRAF, RAS) and gene rearrangements (RET/PTC, PAX8/PPARγ) in acromegalic patients with DTC.
• To correlate these genetic alterations with clinical and histological features of DTC in acromegaly.
• To compare the genetic landscape of DTC in acromegaly with non-acromegalic DTC patients.

Main Methods:

• Analysis of BRAF V600E and NRAS codon 61 point mutations in 14 acromegalic patients with DTC.
• Screening for RET/PTC1, RET/PTC3, and PAX8/PPARγ gene rearrangements in tumor samples.
• Comparison with a control group of 14 non-acromegalic patients with DTC.

Main Results:

• NRAS codon 61 mutations were detected in 21.4% of acromegalic DTC patients, representing the most frequent genetic alteration.
• BRAF V600E mutations were found in 14.3% of acromegalic DTC patients, significantly less frequent than in non-acromegalic DTC (64.3%, p=0.02).
• No RET/PTC or PAX8/PPARγ rearrangements were observed. Mutations were associated with more aggressive histologic features, but no recurrences or metastases were noted.

Conclusions:

• NRAS codon 61 mutations are the predominant genetic finding in differentiated thyroid cancer associated with acromegaly.
• The lower prevalence of BRAF V600E mutations in acromegalic DTC suggests it may not be a primary driver of thyroid cancer in this condition.
• While BRAF and NRAS mutations correlate with aggressive histology, their prognostic impact in acromegaly-associated DTC requires further investigation.