Prostate Cancer: Latest Treatments and Emerging Therapies
What's involved with radiation for early-stage prostate cancer? continued...
Modern radiation therapy is often done with a conformal technique. That's a technique in which three-dimensional imaging systems map out the shape of the prostate tumor. That allows for more precise delivery of high-dose radiation directly to the tumor. At the same time, it minimizes exposure to nearby healthy structures such as the bowel or urinary tract. A refinement of conformal radiation therapy is called intensity-modulated radiation therapy (IMRT). IMRT allows more precise delivery of high-energy radiation to the tumor with lower exposure of healthy tissues. Doing so often results in a lower incidence of side effects in the urinary tract or bowel.
For low-risk prostate cancers, good treatment options include radiation in the form of brachytherapy or external beam radiation treatment such as IMRT or proton therapy. Cure rates for radiation compare favorably to those of prostatectomy. There have been no major head-to-head studies that compare the effectiveness of surgery and radiation therapy for low-risk prostate cancer. But there is general agreement that patients should not select a therapy based on comparative cure rates. Rather, men should consider the possibility of side effects and the impact they may have on their quality of life.
What are the complications and side effects of radiation?
Common complications of radiation therapy include erectile dysfunction and urinary incontinence. Erectile dysfunction after radiation tends to improve more gradually than after surgery. But newer radiation techniques have lowered the risk of long-term erectile dysfunction.
Other complications may include short-term bladder infections and irritation or discomfort during voiding. Men who have radiation therapy are often given a short-term course of alpha-blockers. Those are drugs commonly prescribed to treat voiding problems caused by benign enlargement of the prostate. Drugs in this category include Flomax and Hytrin.
Radiation therapy may also cause infections of the lining of the anus and intestinal infections. The incidence of these complications, though, is significantly lower with the use of conformal or IMRT techniques than with conventional external beam radiation. Some men also experience fatigue after multiple radiation sessions. The fatigue usually resolves over time.
How does active surveillance or expectant management of early-stage prostate cancer work?
It seems counterintuitive. But active surveillance or "watchful waiting" may be a good option for many older men who have early-stage, nonaggressive disease without bothersome symptoms. Active surveillance may also be a suitable option for some men with other illnesses. That's because the illness may be complicated by surgery or radiation.
With active surveillance, men with small volume, low-grade, early-stage cancers can have regular follow-up visits every six months. The visits include a digital rectal examination of the prostate and blood tests. In addition, the men receive annual prostate biopsies. This routine is an alternative to immediate radical prostatectomy.
Currently about half of all men diagnosed with prostate cancer will have low-risk disease at the time of diagnosis. This is based on several different criteria, including:
- A prostate-specific antigen (PSA) level of less than 10
- A Gleason (tumor aggressiveness scale) score of 6 or less on a scale of 2-10
- Stage T1c disease, meaning that the tumor cannot be felt on digital rectal exam and is detected only on needle biopsy, or
- Stage T2a disease, meaning minimal detectable disease in one half lobe of the prostate or less