The impact of serial prostate biopsies on sexual function in men on active surveillance for prostate cancer.
OBJECTIVE
NCCN Guidelines® recommend annual prostate biopsies for men with low risk prostate cancer on active surveillance. We determined whether erectile function decreases with the number of biopsies experienced.


METHODS
During a median 3.2-year followup after prostate cancer diagnosis in 2003 to 2010 at our institution 427 men on active surveillance underwent a total of 1,197 biopsies and provided 1,398 erectile function evaluations via the Sexual Health Inventory for Men questionnaire. For analysis we decomposed the 25-point questionnaire responses into a 5-point erectile function score and a 3-level sexual activity status. We used separate models adjusted for patient characteristics to determine whether either outcome varied with biopsy exposure.


RESULTS
At diagnosis the median age was 61 years and median prostate specific antigen was 5.3 ng/ml. Of the cases 70% were clinical stage cT1 and 93% were Gleason score less than 7. Of biopsies followed by evaluations 40% were the first undergone by the patient and 9% were the fifth to ninth. At the first erectile function evaluation 15% of men were inactive, 8% engage in stimulation and 77% engaged in intercourse. Sexual activity level changed in greater than 20% of respondents between evaluations. Adjusted erectile function scores were not associated with biopsy exposure cross-sectionally or longitudinally but they corresponded with the 50th, 63rd and 80th percentiles of erectile function by increasing sexual activity level. Similarly, sexual activity was not associated with biopsy exposure. Separated outcomes were more accurate and informative than Sexual Health Inventory for Men scores.


CONCLUSIONS
Our study had high power to detect erectile function-biopsy associations but it estimated that the effects were negligible. We recommend erectile function scores over Sexual Health Inventory for Men scores to avoid biased assessment of erectile function.
Department of Epidemiology and Biostatistics, University of California-San Francisco, San Francisco, California 94107-1762, USA. joan@biostat.ucsf.edu
Joan F
JF
Hilton
Sarah D
SD
Blaschko
Jared M
JM
Whitson
Janet E
JE
Cowan
Peter R
PR
Carroll
D001706:Biopsy / Q000009:adverse effects / Q000706:statistics & numerical data; D007172:Erectile Dysfunction / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology; D011471:Prostatic Neoplasms / Q000473:pathology*; D057832:Watchful Waiting