|Reviewer: Courtney Lewis, MD|
|The Abramson Cancer Center of the University of Pennsylvania|
Authors: Zietman AL, Chung CS, Coen JJ, Shipley U
Localized prostate cancer is currently treated with either surgery or radiation, and the optimal treatment strategy remains controversial. Prostate cancer is a slow-growing in most men, and published data often lack the long-term follow-up to determine differences in treatment outcome. The ASTRO consensus definition for biochemical failure after definitive radiation stresses that the PSA may continue to decline for up to two year post treatment, and requires three consecutive rises in PSA for a failure. This process could take four to five years to determine failure, whereas after radical prostatectomy, any rise in PSA post-operatively is considered failure. The authors stress that in order to compare radiation versus surgery in this situation; the follow-up period must be long enough such that most failures have had a chance to occur. Thus in this study, the authors review the outcome after definitive radiation for patients with a follow-up of almost ten years.
Materials and Methods
The authors state that these results can be used as a benchmark with which to compare newer radiation techniques. In this series, most of the patients were too old for surgery, and only 8% died of prostate cancer. However, almost half had biochemical evidence of recurrence at 10 years. None of these patients were treated with conformal therapy and the median dose of 68.4 Gy is lower than the 70-78Gy we use today.
Also, the authors do not indicate the studies used for staging, but by Gleason score and PSA alone, almost 62% had intermediate or high risk features (Gleason > 6 or PSA > 10), and thus were at higher risk for recurrence. An analysis of biochemical failure by Gleason score or PSA was not included in the study.
In summary, these results provide baseline for determining the efficacy of newer radiation techniques. We should also discuss the issue of biochemical recurrence with patients when advising a definitive treatment strategy for early stage prostate cancer.