incretins and Thyroid-Neoplasms

Incretin-based therapies, including the use of incretin mimetics of glucagon-like peptide-1 receptor (GLP-1R) agonists and incretin enhancers of dipeptidyl-peptidase 4 (DPP-4) inhibitors, are widely used by clinicians for glucose lowering in patients with type 2 diabetes mellitus. These agents have benefits of a lower risk of hypoglycemia, being neutral for body weight for DPP-4 inhibitors and having a potential for weight reduction with GLP-1R agonists. They may also have a neutral or beneficial cardiovascular effect. Despite these benefits, an increased risk of cancer (especially pancreatic cancer and thyroid cancer) associated with incretin-based therapies has been reported. In this article, we reviewed related literature of experimental animal and observational human studies, clinical trials, and meta-analyses published until December 15, 2014. Current studies suggested a probable role of GLP-1R activation on the development of pancreatic cancer and thyroid cancer in rodents, but such an effect in humans is not remarkable due to the lower or lack of expression of GLP-1R on human pancreatic ductal cells and thyroid tissues. Findings in human studies are controversial and inconclusive. In the analyses of the US Food and Drug Administration adverse events reporting system, a significantly higher risk of pancreatic cancer was observed for GLP-1R agonists and DPP-4 inhibitors, but a significantly higher risk of thyroid cancer was only observed for GLP-1R agonists. Such a higher risk of pancreatic cancer or thyroid cancer could not be similarly demonstrated in other human observational studies or analyses of data from clinical trials. With regards to cancers other than pancreatic cancer and thyroid cancer, available studies supported a neutral association in humans. Some preliminary studies even suggested a potentially beneficial effect on the development of other cancers with the use of incretins. Based on current evidence, continuous monitoring of the cancer issues related to incretin-based therapies is required, even though the benefits may outweigh the potential cancer risk in the general patients with type 2 diabetes mellitus.

Topics: Diabetes Mellitus, Type 2; Humans; Hypoglycemic Agents; Incretins; Neoplasms; Pancreatic Neoplasms; Risk Factors; Thyroid Neoplasms

Glucagon-like peptide-1 receptor agonists (GLP-1ra) are a new group of drugs with a glucose-lowering action due to their incretin effect. The GLP-1 receptor is expressed in various human tissues, which could be related to the pleiotropic effects of human GLP-1, as well as to the adverse effects described in patients treated with GLP-1ra. The risk of hypoglycaemia is low, which is one of the main considerations in the safety of this family of compounds and is also important to patients with diabetes. The most frequent adverse effect is nausea, which usually occurs at the start of treatment and is transient in 20-60% of affected patients. This article also reviews the information available on antibody formation, the potential effect on the thyroid gland, and the controversial association between this group of drugs with pancreatitis and cancer.

Topics: Cardiovascular Diseases; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Nausea; Pancreatic Neoplasms; Pancreatitis; Thyroid Neoplasms

Glucagon-like peptide-1 receptor agonists (GLP-1ra) are a new group of drugs with a glucose-lowering action due to their incretin effect. The GLP-1 receptor is expressed in various human tissues, which could be related to the pleiotropic effects of human GLP-1, as well as to the adverse effects described in patients treated with GLP-1ra. The risk of hypoglycaemia is low, which is one of the main considerations in the safety of this family of compounds and is also important to patients with diabetes. The most frequent adverse effect is nausea, which usually occurs at the start of treatment and is transient in 20-60% of affected patients. This article also reviews the information available on antibody formation, the potential effect on the thyroid gland, and the controversial association between this group of drugs with pancreatitis and cancer.

Topics: Animals; Antibody Formation; Blood Pressure; Carcinoma, Medullary; Cardiotonic Agents; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Gastrointestinal Motility; Glucagon-Like Peptide-1 Receptor; Heart; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Lipids; Meta-Analysis as Topic; Nausea; Pancreatitis; Receptors, Glucagon; Rodentia; Species Specificity; Thyroid Neoplasms; Vomiting

A retrospective cohort study, supplemented with a nested case-control study, was performed using two administrative databases from commercial health plans in the United States to compare the incidence of pancreatic and thyroid cancer among users of exenatide versus other antidiabetic drugs (OADs). Patients with type 2 diabetes who initiated exenatide or OADs between 1 June 2005 and 30 June 2015 were included. Pancreatic and thyroid cancers were identified using chart-validated algorithms in the cohort study. Cases in the nested case-control study were chart-confirmed pancreatic or thyroid cancers, and controls were sampled using risk-set sampling. The time-fixed analyses comparing 33 629 exenatide initiators with 49 317 propensity-score-matched OAD initiators yielded hazard ratios of 0.76 (95% confidence interval [CI] 0.47-1.21) for pancreatic cancer and 1.46 (95% CI 0.98-2.19) for thyroid cancer. Results in the time-dependent analyses by cumulative duration or dose were similar. Nested case-control analyses yielded rate ratios of 0.61 (95%CI, 0.37-1.00) for pancreatic cancer and 0.89 (95% CI, 0.64-1.24) for thyroid cancer. This observational study suggested exenatide use was not associated with an increased risk of pancreatic or thyroid cancer.

Topics: Adult; Aged; Cohort Studies; Databases, Factual; Diabetes Mellitus, Type 2; Exenatide; Female; Humans; Hypoglycemic Agents; Incidence; Incretins; Male; Middle Aged; Pancreatic Neoplasms; Propensity Score; Proportional Hazards Models; Retrospective Studies; Thyroid Neoplasms; United States

Topics: Diabetes Mellitus, Type 2; England; Female; Humans; Hypoglycemic Agents; Incretins; Male; Pancreatic Neoplasms; Pancreatitis; Product Surveillance, Postmarketing; Thyroid Neoplasms; United States; United States Food and Drug Administration

While incretins are of great interest for the therapy of diabetes 2, the focus has recently been brought to the thyroid, since rodents treated with glucagon-like peptide-1 (GLP-1) analogs were found to occasionally develop medullary thyroid carcinomas. Incretin receptors for GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) were therefore measured in various rodent and human thyroid conditions. In vitro GLP-1 and GIP receptor autoradiography were performed in normal thyroids, C-cell hyperplasia and medullary thyroid carcinomas in rodents. Receptor incidence and density were assessed and compared with the receptor expression in human thyroids, medullary thyroid carcinomas, and TT cells. GLP-1 receptors are expressed in C cells of normal rat and mice thyroids. Their density is markedly increased in rat C-cell hyperplasia and medullary thyroid carcinomas, where their incidence amounts to 100%. GIP receptors are neither detected in normal rodent thyroids nor in C-cell hyperplasia, but are present in all rat medullary thyroid carcinomas. No GLP-1 or GIP receptors are detected in normal human thyroids. Whereas only 27% of all human medullary thyroid carcinomas express GLP-1 receptors, up to 89% express GIP receptors in a high density. TT cells lack GLP-1 receptors but express GIP receptors. GLP-1 receptors are frequently expressed in non-neoplastic and neoplastic C cells in rodents while they are rarely detected in human C-cell neoplasia, suggesting species differences. Conversely, GIP receptors appear to be massively overexpressed in neoplastic C cells in both species. The presence of incretin receptors in thyroid C cell lesions suggests that this organ should be monitored before and during incretin-based therapy of diabetes.

Topics: Animals; Carcinoma, Neuroendocrine; Cells, Cultured; Diabetes Mellitus, Type 2; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Rats; Rats, Sprague-Dawley; Rats, Wistar; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Thyroid Gland; Thyroid Neoplasms; Tumor Cells, Cultured