BERKELEY, CA (UroToday.com) - Prostate cancer is unique among the most common visceral cancers affecting the U.S. population in that it has a high incidence and a low mortality. This fact has spawned debate over issues that are seldom encountered with other malignancies.
Two of the most commonly debated topics are the need to screen for the prostate cancer and the need to treat those diagnosed with the disease. Regardless of the outcome of those debates, some prostate cancer patients will be treated, and arguably should be treated. When counseling a prostate cancer patient about the treatment options available, a physician needs to focus on both efficacy and toxicity.
| When counseling a prostate cancer patient about the treatment options available, a physician needs to focus on both efficacy and toxicity. |
Most studies have demonstrated that, with rare exception, efficacy among the three major treatment modalities (prostatectomy, external beam radiotherapy, and brachytherapy) is equivalent. It has been know for decades that the toxicity profiles of these treatments differ. These differences were highlighted in the PROST-QA trial. The PROST-QA investigators have only been able to report on their 2-year data due to the current lack of long-term follow-up. While follow up for this trial is ongoing, physicians are currently hampered by the fact that the literature is scant with long-term data on toxicity. That which does exist in the literature is typically single-modality reports, usually with only 5 years of follow-up. Because of this deficiency, we examined our institutional data on patients with a potential for a minimum of 10 years of follow-up after treatment with prostatectomy, external beam radiotherapy, or brachytherapy.
These patients are part of an inception cohort study at our institution in which all prostate cancer patients treated since 1986 are recorded and followed. We specifically looked at patients treated in 1999. At the time of analysis, these patients met the criterion of having a potential for a minimum of 10 years of follow-up. We graded the toxicity experienced by the patients and correlated the outcomes with treatment-related and pre-treatment characteristics. We found that patients treated with external beam radiotherapy and those with pre-existing diabetes mellitus were independently at greater risk of developing gastrointestinal or genitourinary toxicity.
We were not too surprised by the findings. The risk of poor healing after medical intervention that is borne by patients with diabetes mellitus is well described. The inability of any external beam modality (in this study it consisted of high-energy photon therapy using intensity modulated techniques) to avoid the adjacent, relatively radiation-intolerant organs like the bladder and the rectum easily explains the association of toxicity with external beam radiotherapy.
Since efficacy is equivalent among modalities, we feel that counseling patients about the toxicities of therapy is very important during consultation. Our study had led us to inform patients of the risk of long-term toxicity associated with external beam radiotherapy and diabetes mellitus.
Written by:
Jay P .Ciezki,1 MD, Chandana A. Reddy, MS,1 and Eric A. Klein, MD2 as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
1Cleveland Clinic Department of Radiation Oncology, 9500 Euclid Avenue, Cleveland, OH 44195, USA
2Cleveland Clinic GlickmanUrological and Kidney Institute, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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