Hormone Therapy for Prostate Cancer Linked to Higher Risk of Diabetes
A new study presented by researchers at the Philippine General Hospital in Manila finds that men who are diagnosed with prostate cancer and receiving androgen deprivation therapy (ADT) are at a higher risk of diabetes and metabolic syndrome than those not on hormonal therapy.
Androgen deprivation therapy or androgen suppression therapy aims to reduce the levels of male hormones, testosterone and dihydrotestosterone (DHT), produced mainly in the testicles which stimulate prostate cancers to grow. This type of medication is typically used when prostate cancer patients are unable to undergo surgery or radiation or if their cancer is advanced beyond the prostate gland.
There are several types of hormone therapy used to treat prostate cancer. Luteinizing hormone-releasing hormone (LHRH) analogs such as leuprolide (Lupron, Viadur, and Eligard), goserelin (Zoladex), triptorelin (Trelstar), and histrelin (Vantas) lower the amount of testosterone made by the testicles. Several of these drugs are also known as gonadotropin-releasing hormone (GnRH) agonists.
A newer class of drugs being used is called luteinizing hormone-releasing hormone (LHRH) antagonists such as degarelix (Firmagon). These work similarly to LHRH analogs but reduce testosterone more quickly. Anti-androgens such as flutamide (Eulexin), bicalutamide (Casodex), and nilutamide (Nilandron) may be added to another type of therapy if it is no longer working by itself.
For the study, lead author Maria Luisa Cecilia Rivera-Arkoncel MD, a fellow at the Philippine General Hospital, compared 38 men with prostate cancer who received ADT and 36 men with less advanced cancer that did not receive the hormone therapy. Men in the ADT group either underwent bilateral orchiectomy (removal of testicles) at least six months earlier or received six or more months of treatment with injects of GnRH agonists.
The two groups of men were similar in terms of diabetes risk factors at the beginning of the study.
According to the data, the prevalence of diabetes was 42% in the ADT group compared to 19% of men in the non-ADT group. The men also had a higher prevalence of metabolic syndrome, a cluster of cardiovascular risk factors such as high blood sugar, high blood pressure and high cholesterol, than those not taking hormonal therapy.
Dr. Rivera-Arkoncel cautioned that the study findings suggest, but cannot prove, that ADT is the cause of the increased prevalence of diabetes, but does state that the patients “may benefit from counseling, screening and closer monitoring for the development of these complications.”
Reference: The Endocrine Society (2011, June 6). Hormone deprivation therapy for prostate cancer may raise diabetes risk. ScienceDaily. Retrieved June 22, 2011.