(RxWiki News) Medications that have been used to treat advanced prostate cancers are now sometimes used to treat patients with earlier stages of the disease. A new study demonstrated that this practice may have some significant side effects. Newly diagnosed prostate cancer patients who were taking hormone blocking medications had higher risks of kidney failure than did patients not taking these medicines, according to this recent study.
Prostate cancer is fueled by male hormones called androgens. And the technique for blocking those hormones is called androgen deprivation therapy (ADT). Testosterone is the most common male hormone that’s involved in prostate cancer.
Traditionally, ADT has been used for men with advanced cases of prostate cancer. A dailyRx News contributing expert — Ralph de Vere White, MD, director of the University of California, Davis Comprehensive Cancer Center — noted that this study points out the problems of changing treatment plans.
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Francesco Lapi, PharmD, PhD, of Jewish General Hospital in Montreal, Canada, and colleagues conducted this study to determine whether the use of ADT was associated with an increased risk of acute kidney injury in patients newly diagnosed with prostate cancer.
Acute kidney injury results when the kidney stops functioning properly. The condition leads to death in about half the cases.
For this study, the researchers worked with 10,250 men who had been diagnosed with prostate cancer that had not yet spread beyond the prostate gland (metastasized), between January 1997 and December 2008. Participants were followed until December 2009.
According to the study's authors, "Androgen deprivation therapy is the mainstay treatment for patients with advanced prostate cancer. While this therapy has been traditionally reserved for patients with advanced disease, ADT is increasingly being used in patients with less severe forms of the cancer."
The researchers looked at various types of ADT, including gonadotropin-releasing hormone agonists (GnRH — sold under the brand names Lupron, Zoladex, Trelstar), oral antiandrogens (Cyprostat, Eulexin, Casodex, Nilandron), combined androgen blockade (GnRH agonist + oral antiandrogens), bilateral orchiectomy (the surgical removal of both testicles to stop the production of testosterone), estrogens (sold under a variety of brand names) and combinations of the above.
Compared to men who had never received ADT, men who were currently being treated with ADT had 2.5 times greater odds of developing kidney failure.
The link was seen mostly with combination therapies using GRHA and oral antiandrogenes, estrogens, GRHA alone and other combination therapies, according to the authors.
Dr. de Vere White, who is also a distinguished professor of urology at UC Davis, told dailyRx News, "This is an extremely thoughtful paper and raises the very interesting question — is this yet another unrecognized complication of androgen deprivation therapy? However, it is also interesting to note that the actual incidence of acute kidney impairment [of] 5.5 per 1,000 person years appears very small."
“Secondly," he continued, "the patients in the study getting androgen deprivation were newly diagnosed and did not have metastatic disease. Since at least 90 percent of these people should not be receiving androgen deprivation therapy, the easiest way to avoid risk of kidney impairment is to be treated appropriately."
The authors wrote that their study's results need to be further investigated and duplicated in other studies.
Findings from this research were published in the July 17 issue of JAMA.
This study was funded in part by Prostate Cancer Canada. Two of the authors disclosed financial relationships with a number of pharmaceutical companies.