Contrarily, thyroid cancer had an increased prevalence in patients with GH-secreting pituitary adenomas (aOR 3.17, 95% CI 1.67–6.02), PRL-secreting pituitary adenomas (aOR 3.66, 95% CI 1.45–9.28), and TSH-secreting pituitary adenomas (aOR 6.28, 95% CI 1.34–29.36) (Figure 2). This evidence concerns the gene GH1 and thyroid cancer.