Predicting sexual function after first-line treatment for prostate cancer

A newly published report in the Journal of the American Medical Association provides data (from two large cohorts of patients) on the quality of sexual function among men undergoing first-line treatment for localized prostate cancer. Alemozaffar et al. initially used data on patient characteristics before treatment, sexual health-related quality of life (HRQOL), and treatment details from men enrolled in the Prostate Cancer Outcomes and Satisfaction With Treatment Quality Assessment study (between 2003 through 2006) to develop models predicting erectile function 2 years after treatment. They then used data from men in the community-based Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) to carry out validation of the performance of their predictive model.

The following links offer free access to more information about this study (as of this morning):

Given the variety of information already available about this study, we shall keep our comments relatively brief.

The authors were able to use data from 1,027 patients, all with early stage, localized prostate cancer (clinical stages T1 and T2) to develop their predictive models. They were able to show that, at 2 years of follow-up post-treatment:

  • 37 percent of all evaluable patients reported functional erections.
  • 48 percent of evaluable patients with functional erections prior to treatment reported functional erections.
  • 53 percent of patients without penile prostheses reported use of medications or other devices for erectile dysfunction.
  • Pretreatment sexual HRQOL score, age, serum PSA level, race/ethnicity, body mass index, and intended treatment details were all associated with functional erections 2 years after treatment.

The models performed well in predicting erections in external validation among the CaPSURE cohort patients after radical prostatectomy, external beam radiation therapy, and brachytherapy. Unfortunately the study did not include a cohort of patients managed with active surveillance that would have allowed comparision. It should also be noted that the majority of the men undergoing radical prostatectomy and enrolled between 2003 and 206 did not receive robot-assisted laparoscopic prostatectomy (RALP). Whether this actually would make a difference to sexual function at up to 2 years post-surgery is therefore unknown.

It is to be hoped that the authors are planning to make this predictive tool available on line as a “plug and play” system that will allow patients to enter their relevant personal data and gain an individualized projection of their sexual function outcome.

The article in the Washington Post gives examples of the ability of the models to project individual patient outcomes, as follows:

  • For a 50-year-old man with good sexual function before treatment who has a radical prostatectomy, the probability of having good sexual function 2 years post-surgery ranges from 21 to 70 percent depending on his pre-treatment PSA level and whether a nerve-sparing technique was used.
  • For men of any age with good sexual function before treatment who have external beam radiation therapy, the probability of having food sexual function 2 years post-radiation ranges from 53 to 92 percent depending on pre-treatment PSA level and whether hormones were used along with radiation.
  • For a 60-year-old men with good sexual function before treatment who has permanent radioactive seed implants (brachytherapy), the probability of having good sexual function 2 years post-surgery ranges from 58 to 98 percent depending on race and body mass index. Apparently African-Americans and slimmer patients had better chances of retaining higher levels of sexual function.

3 Responses

  1. As with all studies, definition is everything.

    The defining point in this study is “Patient-reported functional erections suitable for intercourse 2 years following prostate cancer treatment.”

    What on earth is a “functional erection suitable for intercourse”? Where does it fit on the Glen Leslie scale?

    I’m not being critical — we’ve had many a discussion about how difficult it is to define a functional erection, but ….

  2. Terry:

    You can see the sexual assessment portion of the Expanded Prostate Cancer Index Composite (EPIC) questionnaire that was used in this study if you click here.

    If you look at question 2, you will see that this is a very simple measure based entirely on the patient’s perception of his sexual capability. It is focused exclusively on whether the patient has an erection “firm enough for intercourse.” Depending on the patient’s personal perception this would need to be at least a 4 on the Glen Leslie scale … but could also include a 5 or a 6.

  3. There is a good article by Tara Parker Pope in the New York Times Well blog dealing with post-surgical ED and with this article in particular.

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