Endocrine Abstracts

It is known that acromegaly is associated with increased risk of benign and malignant tumours. Previous studies show the prevalence of nodular thyroid disease in 40–70% of patients with acromegaly, and a 5–7% prevalence of thyroid cancer in these patients, which is higher compared to the general population.

Latvian Cancer Register data show an incidence of thyroid cancer of 7.5–7.7 per 100 000 inhabitants in 2007–2010.

We retrospectively studied our hospital acromegaly database of 60 patients. Only 10 patients (16%) had nodular goiter, 9 of them underwent thyroid surgery, and in 4 cases (two females and two males) histological examination revealed thyroid cancer (papillary carcinoma in all). It means 6.6% of acromegaly patients had thyroid cancer. Three of four patients with thyroid malignancy, and one of five patients with benign nodules had an active acromegaly at the time of thyroid surgery.

Genetic testing of four acromegaly patients with papillary thyroid cancer revealed the presence of SSTR5 gene polymorphism rs34037914 T alleles (genotypes TT and TG) in two patients, which is associated with increased risk of acromegaly.

Our results point to a certain association of thyroid cancer with acromegaly activity. The post-operative observation period is too short to allow evaluation of the rate of possible thyroid cancer relapse, especially in patients with consistenly increased GH and IGF1. Patients with acromegaly and nodular goiter should be often controled by thyroid ultrasound followed by fine needle aspiration biopsy as indicated.