SAN ANTONIO (Reuters Health) — Smoking increases the risk of impotence in patients who receive radiation treatment for prostate cancer, according to a report from the Fox Chase Cancer Center in Philadelphia, Pennsylvania.
“A history of current or past tobacco use impacted significantly on the potency rate,” Dr. James C. Wurzer said during his presentation of the Fox Chase data at this year’s annual meeting of the American Society for Therapeutic Radiology and Oncology.
The study was small, involving only 34 men treated with radiation for localized prostate cancer, but the progress of these men was studied for 6 years. The men were 65 years of age or younger when they were treated with 3D conformal radiation, an improved form of radiation delivery that is more precise than older forms and has a lower risk of irradiating healthy tissues around the tumor, Wurzer noted.
None of the men who smoked at the time of treatment were sexually potent 6 years after treatment. In contrast, 66% of the men who never smoked said they could still have an erection.
For comparison purposes, Wurzer noted that 78% of a group of 18 men of the same age who did not have prostate cancer could still have erections.
Radiation therapy can cure prostate cancer in men with early stage tumors that are confined to the prostate gland. But the radiation must pass close to or through bundles of nerves that control erectile function, Wurzer pointed out. The healthier the nerves are before radiation therapy to the prostate, the better the chance a man has to maintain or recover sexual function afterwards.
Smoking is a risk factor for impotence because it closes off microscopic blood vessels that supply the nerve bundles.
Wurzer and colleagues also asked study subjects about urinary incontinence, but there was no difference between the treated and the untreated patients. There was also no difference in rectal urgency or persistent diarrhea, two potential side effects of radiation therapy.
Other potential risk factors examined were high blood pressure, diabetes, heart disease, history of stroke, or consumption of more than 8 ounces of alcohol per day, but none of these made a significant difference in sexual potency the way tobacco use did, Wurzer concluded.