Association Between Type 2 Diabetes Mellitus and Thyroid Cancer?
Posted: Wednesday, September 2, 2020
Although patients with type 2 diabetes generally experience a higher incidence of cancer, there does not seem to be any increased risk for thyroid cancer specifically in patients with diabetes or in those considered to have prediabetes (higher than normal blood sugar levels). There does seem to be an association, however, between diabetes and structural or benign changes, according to a case-control prospective study published in Endocrine Connections by Martin Hill, PhD, DSc, of the Institute of Endocrinology in Narodni, Prague.
Researchers screened 722 patients for type 2 diabetes mellitus and prediabetes; then patients underwent both thyroid ultrasonography and biochemical tests. Of this cohort, 55 were found to have prediabetes, 79 had diabetes, and 588 did not have diabetes. The diagnosis of diabetes was new for 6.5% of the patients with diabetes, whereas 72% of those with prediabetes received this as a new diagnosis. In addition, fine-needle aspiration of the thyroid was conducted in 263 patients, with an additional 109 undergoing thyroid surgery. In all, 52 benign tumors and 57 malignant tumors were found.
Patients with type 2 diabetes had larger thyroid gland volume as well as higher levels of free T4 in comparison with patients without diabetes. Thyroid nodules or multinodular thyroid glands were noted in 66% of patients with prediabetes, 62% of those with diabetes, and 50% of those without diabetes.
The percentage of patients with thyroid cancers did not change significantly between the groups (P = .794). However, positive predictors of diabetes or prediabetes included thyroid volume, multinodular thyroid gland, thyroid nodule volume, body mass index, age, history of smoking, and non-thyroid cancer. Of note, 30% of patients with type 2 diabetes compared with 10% of those with prediabetes and 8.4% of those without diabetes had a history of cancer (not thyroid). The most common types of cancers included colon, prostate, breast, melanoma, and urothelial.
Disclosure: The authors reported no conflicts of interest.