Hello. I am Dr Gerald Chodak, for Medscape. This week I want to talk about brachytherapy for treating prostate cancer.
Stone and Stock reported a large cohort study, published in the Journal of Urology, of more than 1700 men treated for prostate cancer between 1990 and 2007, with a 10-year mean follow-up. The study included a mixture of patients and treatments: Some men received brachytherapy with iodine alone, and some received brachytherapy with palladium, with or without hormone therapy, or with or without external beam radiation. Thus, it is not a pure study of patients treated with a single method.
The results are particularly good for men with low-risk disease who had only iodine-125 seed implantation. The cancer-specific survival at 10 years was 99.3%. The authors compared their results with other treatments, such as radical prostatectomy, citing SEER data. Unfortunately, that kind of comparison is not very valid because SEER looks at the pathology on radical prostatectomy, whereas Stone's paper looked at the pathology based on biopsy alone.
The authors also concluded that androgen deprivation therapy not only did not improve survival but that prolonged use may have actually reduced overall survival. That analysis is problematic for several reasons: The study was not prospective and randomized, and it goes against other prospective randomized trials that have consistently shown a survival benefit of androgen deprivation therapy for men getting external radiation. There has not been a prospective randomized trial of men who received brachytherapy to determine whether the addition of androgen deprivation therapy affects survival. I believe we cannot use this paper to assess the impact of androgen deprivation therapy in the management of localized disease.
Another problem is that the results clearly look excellent for men with low-risk disease, but active surveillance results reported by Klotz showed a very similar 10-year overall or cause-specific survival, and that study included men with intermediate-risk disease in addition to men with low-risk disease. We are left with an inability to determine whether brachytherapy offers men a clear advantage.
The report does not discuss the side effects, but these same authors have reported a prospective analysis showing very good comparisons with men who had brachytherapy; their long-term results found good quality-of-life outcomes. Nonetheless, it would be useful in this larger cohort to have seen some of that data.
Brachytherapy is one of the options for men with prostate cancer. For men with low-risk disease who do not want to accept active surveillance, brachytherapy may, indeed, be the best of the options in terms of overall quality of life. But until we have a prospective randomized trial, we will never know if that is truly the case. The ongoing ProtecT study in the United Kingdom is comparing several different treatments, and although brachytherapy is not part of that, it will at least give us a prospective randomized analysis of the relative merits of surgery, radiation, and active surveillance.
For now, we have gained some information from this analysis but are left with too many unanswered questions. Without randomized trials, it is very difficult to make strong conclusions about the relative merits of brachytherapy compared with the other options.
I look forward to your comments. Thank you.
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Cite this: Prostate Brachytherapy Has Good Long-term Outcomes - Medscape - Oct 17, 2014.