Effect of Repeat Prostate Biopsies on Erectile Function

Selezionata da Pietro Cazzola

Erectile DysfunctionMen diagnosed with low-risk prostate cancer have various management options. Active surveillance (AS) is one consideration, while standard treatments include radical prostatectomy (RP), radiotherapy (RT), and even cryotherapy. These treatments, while often curative, are associated with significant potential side effects. Men inquiring specifically about erectile function (EF) are told that, while RP is deleterious in the short-term, nerve-sparing approaches allow for the restoration of potency in most men. Men who elect RT (or brachytherapy) typically suffer less precipitous declines in EF, but typically lose potency much more rapidly than occurs with the natural aging process. Whole-gland cryotherapy, meanwhile, carries with it a near guarantee of near total impotence. But what about AS and loss of EF?
At most North American centers, and as supported by recent guidelines, AS patients undergo protocol prostate biopsies every 12 to 18 months. We know that surgery and radiation are deleterious to EF, but what is known about the risks serial prostate biopsies pose to EF?
We first investigated this question in 2009, and published a study wherein men in our AS cohort (mean age 68) were mailed a validated five-item EF questionnaire (Sexual Health Inventory for Men [SHIM]), and their self-reported scores were compared with their scores at protocol entry.1

We found a statistical correlation between increasing biopsy number and decreasing EF that held up on multivariable analyses controlling for age and other factors. In this cohort of elderly men, those without pre-existing erectile dysfunction (ED) trended toward even steeper declines in EF with repeat biopsies.
Since our hypothesis-generating publication, two studies using other AS cohorts have systematically explored the same issue. In these analyses, declines in EF with serial biopsies were found to be more modest.2,3 In fact, declines in EF have appeared to correlate less with increasing biopsy number than with number of years on AS and with advancing age. In the most recent publication, Braun and colleagues3 studied a younger set of men (mean age 64) and noted annual decreases in EF of 1 point/year on the International Index of Erectile Function (IIEF-6) scale while on AS, as well as a fivefold increase in the use of phosphodiesterase type 5 (PDE-5) inhibitors while on AS for 5 years. Such high rates of PDE-5 inhibitor adoption undoubtedly diminish any questionnaire-based assessments of EF, which suggests that, even in this younger cohort, the effects on EF of being on AS and of receiving serial prostate biopsies are not negligible. Hilton and colleagues studied an even younger cohort of men on AS (median age 61) and found little effect on EF that was related to prostate biopsies.
To truly tease out the effects of repeat biopsies alone would require an age-matched control group of men with low-risk prostate cancer who did not undergo repeat biopsies over time, a limitation common to the three aforementioned studies. More important, however, is to put the cumulative findings from these studies into perspective: EF in older men declines on AS, particularly after three or more protocol biopsies, but it does not decline nearly as much as after definitive therapy.4

References

  1. Fujita K, Landis P, McNeil BK, Pavlovich CP. Serial prostate biopsies are associated with an increased risk of erectile dysfunction in men with prostate cancer on active surveillance. J Urol. 2009;182(6):2664-2669.
  2. Hilton JF, Blaschko SD, Whitson JM, et al. The impact of serial prostate biopsies on sexual function in men on active surveillance for prostate cancer. J Urol. 2012;188(4):1252-1258.
  3. Braun K, Ahallal Y, Sjoberg DD, et al. Effect of repeated prostate biopsies on erectile function in men on active surveillance for prostate cancer. J Urol. 2014;191(3):744-749.
  4. van den Bergh RC, Korfage IJ, Roobol MJ, et al. Sexual function with localized prostate cancer: active surveillance vs radical therapy. BJU Int. 2012;110(7):1032-1039.

Christian Pavlovich, MD