Prostate cancer treatment linked to cardiac death risk

An increased risk of dying from heart-related causes has been linked with a mainstay treatment of prostate cancer in a subgroup of men who have had prior heart attacks or congestive heart failure.

The authors say that the findings of their study should be carefully weighed against larger controlled trials that demonstrate benefits of ADT.

One of the main treatments for prostate cancer, androgen deprivation therapy (ADT) reduced male hormone levels in an effort to prevent them from stimulating cancer cells. 

However, previous studies have found some adverse effects to be associated with ADT, including increased risk of diabetes,coronary heart disease, heart attacks and sudden cardiac death.

To further investigate this link, a group of researchers from Brigham and Women's Cancer Center and Harvard Medical School - both in Boston, MA - analyzed data from 5,077 prostate cancer patients who were treated between 1997 and 2006. About 30% of the participants had been treated with ADT.

No link was found between ADT and heart-related deaths among men with no risk factors for heart problems after a median follow-up of 4.8 years.

However, among men with congestive heart failure or prior heart attacks, there was a 3.3-times increased risk of death from heart problems. Heart-related deaths occurred in 7.01% of men in this subgroup who were receiving ADT, compared with 2.01% of men not receiving ADT.

The researchers explain that this increased risk works out as one cardiac death for every 20 at-risk men who receive this therapy.

The researchers at Brigham and Women's Cancer Center said that while androgen deprivation therapy can be a life-saving drug for men with prostate cancer and [can] significantly increase the cure rates when used with radiation for aggressive disease, this study also raises the possibility that a small subgroup of men who have significant heart disease could experience increased cardiac death on ADT.

Further research should examine different types and durations of ADT

However, the researchers also warn that, as the study - which is published in the journal BJU International - was a retrospective analysis, its findings should be carefully weighed against larger controlled trials that demonstrate benefits of ADT.

It is also possible that changing the type or duration of ADT may reduce cardiac harm, and the researchers suggest that future studies should examine this.

The authors also consider that a longer follow-up period in future studies may reveal associations between ADT and cardiac harms in lower risk subgroups, such as among men with diabetes.

The researchers may still say that for men with significant heart problems, we should try to avoid ADT when it is not necessary - such as for men with low-risk disease or men receiving ADT only to shrink the prostate prior to radiation. However, for men with high-risk disease, in whom the prostate-cancer benefits of ADT likely outweigh any potential cardiac harms, ADT should be given even if they have heart problems, but the patient should be followed closely by a cardiologist to ensure that he is being carefully watched and optimized from a cardiac perspective.

In March, a study published in the Journal of Clinical Oncology found that prostate cancer patients who received ADT as their primary treatment instead of surgery or radiation therapy did not live any longer than patients who received no treatment.

The authors, from Georgetown Lombardi Comprehensive Cancer Center in Washington, DC, said that their study - which analyzed data from 15,170 patients - "mitigates against any clinical or policy rationale for use of primary androgen deprivation therapy in these men."