Researchers found an association between increased levels of prostate-specific antigen (PSA) — known as PSA failure — and a high risk of mortality in healthy patients who had previously received treatment for prostate cancer. But in patients who had another disease, such as history of heart attack or stroke, PSA failure no longer appeared to predict the risk of death.
Because physicians sometimes recommend a given treatment based on whether it reduces the rise in PSA levels without knowing whether this is associated with mortality, this finding shows the importance of informing patients of the results of clinical trials, as well as the risks and benefits of a given treatment, before recommending it.
The study, “Prostate-Specific Antigen Failure and Risk of Death Within Comorbidity Subgroups Among Men With Unfavorable-Risk Prostate Cancer Treated in a Randomized Trial,” was published by Dr. Nicholas Giacalone, MD, and his colleagues from Brigham and Women’s Hospital in Boston, in the Journal of Clinical Oncology.
An increase in PSA levels has been widely used as a marker for disease progression in prostate cancer and should decrease after surgery. But in some cases, PSA blood levels increase again, signaling that the cancer has not been cured or that it has returned (recurrence), which prompts patients to look for possible treatments.
“Many studies have reported on PSA results after prostate cancer treatment, but they are not mature enough yet to determine if these results translate into prolonged survival,” Giacalone said in a news release. “We wanted to see if we could identify whether or not published randomized studies that show a benefit in the reduced risk of return of disease, as measured by PSA, will translate into higher rates of cure based on a man’s overall health.”
In their study, researchers analyzed data from nearly 200 men over the course of 16 years with intermediate- and high-risk prostate cancer. These men were randomly assigned to receive radiation therapy with or without six months of hormonal therapy to treat PSA recurrence after surgery for prostate cancer.
The researchers found that of the 156 men who died during that period, 29 were due to prostate cancer. They observed that PSA failure (increased levels of PSA) after surgery was associated with a 1.6-fold increase in mortality risk among patients with no significant health problems, but not among men with other moderate or severe medical conditions.
“Recommending treatment on the basis of reduced PSA failure observed from early results of [clinical trials] is unlikely to prolong survival in men with moderate-to-severe comorbidity but may prolong survival in men with no or minimal comorbidity, providing evidence to support discussing the early results with these men,” the authors wrote in their report.