(RxWiki News) In some prostate cancer patients, the disease is closely watched, rather than actively treated. A new study suggested that testosterone levels seen during this monitoring may hint at cancer progress.
This study focused on the testosterone levels of men who had prostate cancer but were not being actively treated for the condition.
The study found that men with lower levels of free testosterone were more likely to see a progression of their disease that required active treatment.
"Talk to your doctor about prostate cancer screening."
This study was led by Ignacio F. San Francisco, MD, of the Department of Urology at the Pontificia Universidad Católica de Chile in Santiago, Chile.
According to Dr. San Francisco and colleagues, for some men with low-risk prostate cancer, "active surveillance" can be a mainstay of their treatment — meaning the cancer is watched closely for any changes but not actively treated with medications, surgery or radiation.
In about one third of cases, the disease will progress and require active treatment. Dr. San Francisco and team aimed to examine if testosterone levels had any association with the disease progression in men with prostate cancer.
To do so, these researchers looked at the cases of 154 men who were on active surveillance for their prostate cancer between January 2000 and July 2012. The men had an average age of 62 and were followed for an average of three years and two months.
The patients' testosterone levels were tested when their active surveillance began. Both total testosterone (the overall level of the hormone in the blood) and free testosterone (the levels of testosterone not bound to a certain protein and thus able to enter prostate cells) were considered.
Over the course of the study, 54 of the men (35 percent) progressed from active surveillance to active treatment.
Dr. San Francisco and team found that men who saw a progression of their disease had significantly lower free testosterone levels than the men who did not progress to active treatment. The men who progressed to active treatment had an average free testosterone level of 0.75 nanograms per decilitre (ng/dL), compared with an average level of 1.02 ng/dL in the men who did not progress to active treatment.
The researchers noted that the men whose free testosterone levels were lower than 0.45 ng/dL had a higher risk for disease progression. Nine out of the 13 men (69.2 percent) with free testosterone levels below 0.45 ng/dL progressed to active treatment, while the same was true for 36 out of the 98 men (36.7 percent) with levels of 0.45 ng/dL or higher.
No relationship was seen between total testosterone levels and disease progression. The sample size examined in this study was fairly small, and further research is needed to confirm these findings.
"Further studies are indicated to validate free testosterone levels as a predictor of disease reclassification for men with [prostate cancer] undergoing [active surveillance]," wrote Dr. San Francisco and team.
In an interview with dailyRx News, E. David Crawford, Head of the Section of Urologic Oncology at the University of Colorado Anschutz Medical Campus, said other studies have examined the connection between testosterone levels and prostate cancer.
"We have known for years that there is a relationship to low testosterone levels and aggressiveness of prostate cancer in men with a diagnosis," said Dr. Crawford.
"These studies dealt with outcomes of men treated with radical prostatectomy and relating outcomes to baseline testosterone," explained Dr. Crawford. "This is the first review to relate low T to poor prognosis in men on active surveillance."
This study was published online May 4 in the journal BJU International. No conflicts of interest were reported.