Bilateral nerve-sparing RP: Who benefits most from procedure?

May 7, 2018
Andrew D. Bowser

The benefits of bilateral nerve-sparing procedures in men undergoing radical prostatectomy may be concentrated in those patients who have high sexual function at baseline.

The benefits of bilateral nerve-sparing procedures in men undergoing radical prostatectomy may be concentrated in those patients who have high sexual function at baseline, according to results of an analysis based on data from a prospective cohort study.

Overall, sexual and urinary function outcomes were better in men who underwent bilateral nerve sparing as compared with unilateral or non-nerve-sparing procedures, study authors reported in the Journal of Urology (2018; 199:1202-9).

However, further analysis showed that recovery in sexual function and incontinence scores reached statistical significance only in the group of men with high baseline sexual function and not in men with low baseline sexual function. These findings led investigators to conclude that bilateral nerve-sparing procedures may be “overperformed” in men with low sexual function at baseline.

In an interview with Urology Times, investigator Svetlana Avulova, MD, said that men with low sexual function should be appropriately counseled regarding realistic expectations of outcomes following such procedures.

“If you are counseling an older gentleman who has low baseline function, offering him a nerve-sparing procedure is not inappropriate, but probably is not beneficial,” said Dr. Avulova, of Vanderbilt University Medical Center, Nashville, TN, working with Daniel A. Barocas, MD, MPH, and co-authors.

The present analysis by Dr. Avulova and co-authors included data for men who had been enrolled in CEASAR (Comparative Effectiveness Analysis of Surgery and Radiation), an observational, population-based study. They included a total of 991 men who had undergone radical prostatectomy and had known nerve-sparing status. A total of 805 men in this analysis had bilateral nerve sparing procedures, while 111 had a unilateral procedure and 75 had a non-nerve-sparing procedure.

Investigators in CEASAR had used the Expanded Prostate Index Composite (EPIC) questionnaire to gather patient-reported sexual and urinary function outcomes data at baseline and again at 6, 12, and 36 months.

Next: What the authors foundLooking at EPIC scores for sexual function, Dr. Avulova and co-investigators found a significant overall benefit in favor of bilateral nerve sparing as compared to unilateral or no nerve sparing (6.1 points; 95% CI, 2.0-10.3; p=.004).

However, when baseline sexual function was considered, they found the benefit was attenuated in men with low baseline function (4.0 points; 95% CI, 0.6-8.7; p=.09) versus in men with high baseline function (8.2 points; 95% CI, 1.6-14.8; p=.014).

Similarly, they found that urinary incontinence scores were overall better for men who had undergone bilateral nerve sparing procedures, but again in sub-analysis, the difference in EPIC scores was significant only in the group of men with high baseline sexual function.

Based on these findings, Dr. Avulova said men with low baseline function might be expected to have minimal benefit from a nerve-sparing procedure.

“Offering patients nerve sparing, when they don't have excellent sexual function to begin with, I think may give them inflated hope in perceiving that the operation they're going to get is going to maintain their sexual function," Dr. Avulova added.

In addition, although CEASAR primary results showed there was no increased risk of a positive surgical margin, other studies have shown that this risk could be increased by nerve-sparing procedures, she added.

Findings of the current analysis of CAESAR data are in line with a few previous studies, including an analysis of the CaPSURE database showing that men with the highest-quartile baseline sexual function had a statistically significant benefit from bilateral nerve sparing, while the lowest quartile did not.

 

One major strength of the present study, according to authors, is that a large proportion of patients (80%) underwent contemporary robotic surgery. Previously, the effects of contemporary radical prostatectomy on sexual function and urinary incontinence had not been studied thoroughly with respect to baseline sexual function, they said.

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