MONDAY, Oct. 29 (HealthDay News) -- Prostate cancer patients who received Viagra before and after their radiation therapy had improved sexual function, according to a new study.
Sexual woes, including erectile dysfunction, are a common side effect of prostate cancer care. The new study included patients with prostate cancer that had not spread who underwent external-beam radiation therapy and/or permanent implantation of radioactive "seeds."
The men were randomly assigned to take either a 50-milligram-a-day dose of Viagra (sildenafil citrate) or an inactive placebo during treatment and for six months after therapy.
The men completed sexual function questionnaires before their first radiation treatment and at six, 12 and 24 months after treatment. The questionnaires asked them about their erectile function, orgasmic function, sexual desire, intercourse satisfaction and overall sexual satisfaction.
"Men who received the drug showed significantly improved overall sexual function, including improved erectile function," said study lead author Dr. Michael Zelefsky, vice chair for clinical research programs in the department of radiation oncology at Memorial Sloan-Kettering's Cancer Center.
"Results like this are important because they demonstrate that drug therapy used before and after radiation treatment may lessen the risk of impotence, a common side effect of radiation therapy," Zelefsky said in an American Society for Radiation Oncology (ASTRO) news release. Future studies will be needed to further define the drug's role and the optimal duration to prevent loss of sexual function after treatment."
Pfizer, the maker of Viagra, provided partial funding for this study.
One expert said this type of study is valuable for patients.
"Since erectile dysfunction occurs as often with radiation as it does with surgery, this is an important study," said Dr. Warren Bromberg, a urologist at Northern Westchester Hospital in Mount Kisco, N.Y. However, he noted that "while [the researchers'] report an improvement with Viagra compared to placebo, the amount of benefit is not revealed."
Erectile dysfunction medications do have their own issues, Bromberg added, including "the expense of a daily dose of such oral medication, side effects such as facial flushing, headache, stuffy nose, and adverse interactions with other medications."
Still, many prostate cancer patients could benefit, depending on their individual case, Bromberg said. "One difference in how radiation may affect erections compared with surgery is that men who have undergone surgery may see a progressive improvement in their erections for up to 3 years after treatment, whereas men who have undergone radiation may see a progressive decline," he noted. "Therefore, the use of oral medications for men undergoing radiation may be more important in the long run."
The study was to be presented Monday at ASTRO's annual meeting in Boston. Findings presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.
The Prostate Cancer Foundation has more about erectile dysfunction after prostate cancer treatment.
-- Robert Preidt
SOURCES: Warren Bromberg, M.D., urologist, Northern Westchester Hospital, Mount Kisco, N.Y.; American Society for Radiation Oncology, news release, Oct. 29, 2012
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