Sept. 20, 2011 -- The better a man's erections before prostate cancer treatment, the more likely he is to recover the ability to have erections later.
Martin G. Sanda, MD, and colleagues followed 1,027 men for two years after prostate cancer treatment. The researchers focused on the men's ability to have erections. They evaluated which factors helped to predict that.
''The key factor influencing how men did long term is how men did before treatment," Sanda says. He is director of the Prostate Care Center at Beth Israel Deaconess Medical Center and associate professor of surgery at Harvard Medical School.
"That may seem like a no-brainer," he tells WebMD.
However, he says his new study is one of the first to help predict, scientifically, what men can expect in terms of sexual recovery after prostate cancer treatment.
By evaluating different treatments and characteristics, Sanda has developed a prediction model. It can be used by doctors and patients to help predict sexual recovery.
Besides pretreatment erections, he found that age, treatment type, and other factors affect sexual recovery.
About 240,000 men will get a prostate cancer diagnosis this year, according to the American Cancer Society. About 34,000 men will die this year from prostate cancer.
The study was funded by the National Institutes of Health. It is published in the Journal of the American Medical Association.
Evaluating Sexual Function
The researchers evaluated men with prostate cancer who sought care from 2003 to 2006 at nine hospitals in the U.S.
The men were enrolled in the Prostate Cancer Outcomes and Satisfaction With Treatment Quality Assessment (PROSTQA).
In all, 1,027 completed the 24-month study. The men responded to telephone interviews and questionnaires at four different times during the two years.
The main outcome the researchers looked at were erections adequate for intercourse. The men answered such questions as: "How would you describe the usual quality of your erection during the last four weeks?"
Most of these men (524) had their prostate removed, called a prostatectomy. Another 241 had external beam radiation, and 262 had implantation of radioactive ''seeds" or brachytherapy.
Sexual Ability After Treatment
Two years after treatment, the researchers found that 37% of the men, overall, reported good erections. The men's ability to sustain an erection adequate for intercourse varied by the type of treatment. Overall, considering both the men who could and could not get a good erection before treatment, the researchers found:
- 35% of men who had prostate removal reported good erections two years later.
- 37% of men who had external radiation did.
- 43% of men who had radioactive seeds did.
When the researchers focused only on the men who reported having functional erections before treatment, they found that 48% of those men overall recovered that ability two years later.
By treatment, considering only those potent before:
- 40% of men who had surgery had erections again.
- 58% of men who had radiation did.
- 63% of men who had seeds did.
Younger men, those who had a better sexual functioning score before treatment, and those who had ''nerve-sparing" surgery (meant to help maintain the ability to keep an erection) were more likely to have adequate erections.
Those with lower levels of prostate specific antigen (PSA) were also more likely to report good erections, Sanda found. The higher the PSA level, the more likely cancer is present. However, there are reasons other than prostate cancer for an increased PSA level.
It could be that men with lower PSA levels had less extensive cancer and were thus more likely to be able to get the ''nerve-sparing'' surgery, Sanda says.
The outlook could be better, he says, if more men would take advantage of medications and devices to help with erections. "We found that a surprisingly substantial number of patients who did have trouble with erections after treatment weren't using any medication or devices," Sanda says.
Those who did were helped, he says. For instance, 74% of those who used penile injections were helped.
Sanda says it's important to remember that the numbers he found for sexual recovery are just that. "Those numbers are averages, overall, for the group," he says.
Doctors can access the questionnaire he used, he says, and help patients know what to expect.
The prediction model is best used after treatment decisions, Sanda says. "There are bigger issues in deciding treatment, such as cancer control."
Choose Treatment First
While there have been other predictive studies, the new one is ''one of the strongest to date," says Michael J. Barry, MD, medical director of the John D. Stoeckle Center for Primary Care Innovation at Massachusetts General Hospital. He discloses that he serves as president of the Foundation for Informed Medical Decision Making.
He wrote an editorial to accompany the study.
One strength of the new study, he tells WebMD, is that the researchers looked at men treated at nine different hospitals.
If doctors use the approach, he says, it will give men an idea of what to expect based on their characteristics.
He agrees with the researchers that the prediction model is best used after a man has chosen a treatment.
Sanda reports a lecture honorarium from Eli Lily, but not for this study.