Hormone therapy for prostate cancer may raise type 2 diabetes risk

Androgen deprivation therapy (ADT) is a common treatment for men with aggressive forms of prostate cancer and has saved countless lives. However, a new study from a team of Philippine researchers suggests that the treatment may also raise a man's risk of type 2 diabetes.

Testosterone is known to fuel the growth of prostate tumors. In men who have cancer that has spread beyond their prostate to other areas of their body, ADT is considered an invaluable method for shutting down the production of new tumor cells by stopping the body from producing more of the hormone.

However, the treatment has been associated with a number of side effects. The new study, which was presented at the Annual Meeting of the Endocrine Society, adds type 2 diabetes to the list of potential treatment complications. The findings confirm similar results attained in a 2009 study published in the journal Cancer.

For the present study, researchers from the Philippine General Hospital examined medical data from 38 men with advanced prostate cancer who were treated with ADT, comparing the information to the records of 36 individuals with less invasive tumors who were not treated with the hormone therapy.

The results showed that men who were given ADT were roughly twice as likely to develop type 2 diabetes, compared to those who received more conservative therapies. A total of 42 percent of those in the hormone treatment group developed the metabolic condition.

Maria Luisa Cecilia Rivera-Arkoncel, MD, the lead researcher on the study, said that the results raise important questions about the way prostate cancer is treated. While ADT may be effective at slowing tumor growth, the increased risk of type 2 diabetes may make the therapy inappropriate for some men.

However, she said that this is still a decision that doctors should make on an individual basis after discussing all the risk factors with their patients.

"These patients may benefit from counseling, screening and closer monitoring for the development of these complications," Rivera-Arkoncel said.

Additionally, further research will need to be conducted to confirm the results of the investigation. Rivera-Arkoncel acknowledged that the study had a relatively small sample size and that it was unable to conclusively determine that ADT was the cause of the higher rate of type 2 diabetes in the treatment group.