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Model Predicts Sexual Function After Prostate Treatment

MedpageToday

Prostate cancer patients can obtain information on post-treatment sexual function from a nomogram that's based on a handful of easily assessed variables, investigators reported.

The combination of patient and treatment factors showed good correlation with two-year sexual-function outcomes for men treated with surgery or radiation therapy.

Depending on a patient's baseline characteristics and treatment details, the two-year probability of erectile function ranged from 10% to 70%, as reported in the Sept. 21 issue of JAMA.

"We have developed clinically applicable models to predict recovery of erectile function following prostatectomy, external radiotherapy, or brachytherapy for early-stage prostate cancer based on pretreatment sexual function, patient characteristics, and specific plan of treatment," Martin V. Sanda, MD, of Beth Israel Deaconess Medical Center in Boston, and co-authors wrote in conclusion.

Action Points

  • Explain that prostate cancer patients can obtain information on post-treatment sexual function from a nomogram that's based on a handful of easily assessed variables.
  • Point out that the combination of patient and treatment factors showed good correlation with two-year sexual-function outcomes for men treated with surgery or radiation therapy.

"External validation of this predictive model in a community-based cohort suggests that these findings are generalizable and may help physicians and patients to set personalized expectations regarding prospects for erectile function in the years following primary treatment for prostate cancer."

Health-related quality of life has emerged as a key factor in treatment decisions related to early prostate cancer, which most men survive after contemporary treatment. Urinary, bowel, vitality, and sexual domains of quality of life are most often affected by treatment for prostate cancer, the authors noted.

Among men who are sexually potent prior to surgery, sexual function is most often impaired after treatment and is closely related to patients' satisfaction with the outcome of treatment. Despite awareness of pretreatment factors that can affect post-treatment sexual function, few nomographic instruments exist to provide clinical guidance.

In an effort to inform patients and physicians about prostate cancer therapy and sexual function, Sanda and colleagues analyzed data from the Prostate Cancer Outcomes and Satisfaction with Treatment Quality Assessment (PROSTQA), a prospective, longitudinal, multicenter cohort study of men with previously untreated early-stage prostate cancer.

All of the men subsequently elected to undergo surgery, external radiation therapy, or brachytherapy. Details of the chosen treatment were collected in advance, including issues such as nerve-sparing versus non-nerve sparing surgery and neoadjuvant hormonal therapy with radiation.

The analysis also included patient-reported outcome measures and information regarding use of medication or devices for treatment of erectile dysfunction. The final analysis comprised 1,027 men who completed the 24-month post-treatment interview.

Investigators developed predictive models based on the surgical details and patient provided information. The models were subsequently validated in 1,655 men included in the Cancer of the Prostate Strategic Urologic Research Endeavor (CapSURE) registry.

Two-year follow-up data on the PROSTQA cohort showed that 368 (37%) men reported having functional erections, including 335 (48%) men who reported having functional erections prior to treatment. Additionally, 531 (53%) men without penile prostheses reported using medication or devices for erectile dysfunction.

Analysis of potential contributing factors identified six factors associated with post-treatment erectile function at 24 months:

  • Pretreatment score on the health-related quality-of-life sexual domain
  • Age
  • Serum PSA value
  • Race/ethnicity
  • Body mass index
  • Details of the intended treatment

The validation analysis of the CapSURE cohort yielded the following receiver-operating characteristic curve values for the different forms of treatment:

  • Prostatectomy -- 0.77, 95% CI 0.74 to 0.80
  • External radiotherapy -- 0.87, 95% CI 0.80 to 0.94
  • Brachytherapy -- 0.90, 95% CI 0.85 to 0.95

"The ability to inform individual patients how likely they are to develop erectile dysfunction based on their personal baseline sexual function, cancer severity, individual clinical characteristics, and treatment plan has been elusive," the authors wrote in their discussion of the findings.

"Our findings address this need by providing a validated, broadly applicable framework to predict the probability of long-term, post-treatment erectile dysfunction for individual patients."

In an accompanying editorial, Michael J. Barry, MD, of Massachusetts General Hospital in Boston, said that objective collection of subjective patient-reported information should become routine for usual care.

"More importantly, better ways of ensuring that patients are informed about their choices and invited to participate in making decisions need to be identified and disseminated," Barry wrote. "Outcomes data for all important options and outcomes need to be integrated in a useful synthesis for the broad spectrum of men facing this decision."

"The promise of patient-centered outcomes research will be realized not only when high-quality outcomes data are available for all common medical problems but also when patients are routinely informed and invited to participate in their healthcare decisions," Barry added.

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    Charles Bankhead is senior editor for oncology and also covers urology, dermatology, and ophthalmology. He joined ֱ in 2007.

Disclosures

The study was supported by NIH.

The authors had no relevant disclosures.

Primary Source

Journal of the American Medical Association

Alemozaffar M, et al "Prediction of erectile function following treatment for prostate cancer" JAMA 2011; 306: 1205-1214.