Impotence and Prostate Cancer Therapy

Impotence. Another study of 2,903 men (Speight/ UCSF: 2005) found that sexual function immediately after completing treatment was better with radiation than surgery but by 4 years the results were about the same for all combinations of treatment (see graph.) Another study showed external beam had the least effect on sexual function (go here). Two recent long review articles here and here

(See three recent literature reviews on impotence , table#1 , table#2, table#3, and a study on impotence treatment and review here). A recent study (Sildenafil citrate (Viagra) and erectile dysfunction following external beam radiotherapy for prostate cancer: a randomized, double-blind, placebo-controlled, cross-over study. Luca Incrocci International Journal of Radiation Oncology*Biology*Physics,2001:  51:5 : 1190-1195) found that Viagra was effective in 50 - 70% of men with impotence related to radiation but is usually required a 100mg dose (rather than 50 mg.) A large study from Sloan   Kettering with men who became impotent after external beam irradiation found that Viagra (dose of 50-100mg) was effective in 75% of the men and at 4 years was still working in 96% of the men (Zelefsky ASTRO 2003.)

A  recent study showed that Cialis was similarly effective in radiation patients. (A randomized, double-blind, placebo-controlled, cross-over study to assess the efficacy of tadalafil (Cialis) in the treatment of erectile dysfunction following three-dimensional conformal external-beam radiotherapy for prostatic carcinoma Sixty-seven percent of the patients reported an improvement of erectile function with tadalafil (placebo: 20%), and 48% reported successful intercourse with tadalafil (placebo: 9%) (p < 0.0001). Side effects were mild or moderate IJROBP 2006;66:439).

The RTOG trial (0215) will be comparing Viagra (50 - 100mg Sildenafil) with placebo for patients treated with radiation from RTOG 99-10. As background they make the following comparisons:

Health Outcomes After Prostatectomy or Radiotherapy for Prostate Cancer: Results From the Prostate Cancer Outcomes Study

Arnold L. Potosky, Julie Legler, Peter C. Albertsen, Janet L. Stanford, Frank D. Gilliland, Ann S. Hamilton, J. William Eley, Robert A. Stephenson, Linda C. Harlan   Journal of the National Cancer Institute, Vol. 92, No. 19, 1582-1592, October 4, 2000

Background: Radical prostatectomy and external beam radiotherapy are the two major therapeutic options for treating clinically localized prostate cancer. Because survival is often favorable regardless of therapy, treatment decisions may depend on other therapy-specific health outcomes. In this study, we compared the effects of two treatments on urinary, bowel, and sexual functions and on general health-related quality-of-life outcomes over a 2-year period following initial treatment. Methods: A diverse cohort of patients aged 55–74 years who were newly diagnosed with clinically localized prostate cancer and received either radical prostatectomy (n = 1156) or external beam radiotherapy (n = 435) were included in this study. A propensity score was used to balance the two treatment groups because they differed in some baseline characteristics. This score was used in multivariable cross-sectional and longitudinal regression analyses comparing the treatment groups. All statistical tests were two-sided. Results: Almost 2 years after treatment, men receiving radical prostatectomy were more likely than men receiving radiotherapy to be incontinent (9.6% versus 3.5%; P<.001) and to have higher rates of impotence (79.6% versus 61.5%; P<.001), although large, statistically significant declines in sexual function were observed in both treatment groups. In contrast, men receiving radiotherapy reported greater declines in bowel function than did men receiving radical prostatectomy. All of these differences remained after adjustments for propensity score. The treatment groups were similar in terms of general health-related quality of life. Conclusions: There are important differences in urinary, bowel, and sexual functions over 2 years after different treatments for clinically localized prostate cancer. In contrast to previous reports, these outcome differences reflect treatment delivered to a heterogeneous group of patients in diverse health care settings. These results provide comprehensive and representative information about long-term treatment complications to help guide and inform patients and clinicians about prostate cancer treatment decisions.