Urologists continue to face a controversial, challenging question: Which course of treatment is best for low- to intermediate-risk prostate cancer? In recent years, 90% of newly diagnosed prostate cancer patients have this level of disease, so the question is increasingly relevant to clinical practice.
Conclusive, well-controlled studies comparing outcomes of radical prostatectomy, brachytherapy, and external beam radiation therapy have been lacking. However, new data-both published and unpublished-have provided some answers about differences in outcomes of these treatments, according to Eric A. Klein, MD, head of the section of urologic oncology at Cleveland Clinic's Glickman Urological and Kidney Institute.
At the International Prostate Cancer Update here, Dr. Klein reviewed data from the Cleveland Clinic Localized Prostate Cancer Registry established in 1996 that included all prostate cancer patients diagnosed with low- to intermediate-risk prostate cancer who were treated with radical prostatectomy, brachytherapy, or external beam radiation therapy. Low-risk prostate cancer was defined as T1c disease, PSA <10.0 ng/mL, and a Gleason score <6. Intermediate-risk disease was defined as cT2b or cT2c disease, PSA of 10.1 to 20 ng/mL, and a Gleason score of 7. All men had at least 2 years of follow-up and four serum PSA tests; none received androgen deprivation or adjuvant therapy.
"I can tell you that there is absolutely no difference in these endpoints in any of these treatment modalities for low-risk patients," said Dr. Klein, the primary author of the unpublished data. "This is primarily due to the low rate of events in these early-stage patients, who might have done just as well with no active therapy."
"For patients with intermediate-risk disease, there are some short-term differences in biochemical failure and overall survival that favor brachytherapy, but there are fewer local recurrences after radical prostatectomy. When looking at the big picture, the overall survival rates and the prostate cancer-specific mortality rates are so low that there isn't any clear winner."
AUA clinical practice guidelines on localized prostate cancer tell a similar story. The guidelines, released in 2007, state that "there is a paucity of high-quality evidence to favor particular treatment modalities for men with localized prostate cancer." According to the guidelines: "Active surveillance, interstitial prostate brachytherapy, external beam radiotherapy, and radical prostatectomy are appropriate monotherapy treatment options for the patient with low-risk localized prostate cancer."
With outcomes of the different modalities essentially being equal, the focus turns to treatment side effects and their impact on quality of life.