A Radiation Oncologist Answers Treatment Questions About Prostate Cancer

Did you know that prostate cancer is the second-most common cancer in Oklahoma? A prostate cancer diagnosis can be devastating to men and their families.

September is Prostate Cancer Awareness Month. To help bring prostate cancer to the forefront as a serious health issue for Oklahomans, we collected questions about prostate cancer treatments and asked Gary Larson, M.D. to answer them. Dr. Larson has been practicing radiation oncology at INTEGRIS Health since 1990.

What are my chances of becoming impotent or incontinent? If that does happen can it be treated?

With surgery - Men who have surgery (called a prostatectomy) have about a 50 percent risk of becoming impotent. There is about a five percent risk of incontinence (continually dribbling urine for the rest of your life).

With radiation therapy - Radiation therapy carries about a 30-40 percent risk of losing erectile function. There is essentially no risk of incontinence.

While there is no foolproof treatment for incontinence, there are a variety of methods for restoring erectile function. Almost every man can have his potency restored after treatment. Taking a pill before sex, injecting medicine into the penis or surgical implantation of various mechanical devices are possible solutions to poor erectile function.

My doctor wants to try what he calls “watchful waiting.” Is this something you recommend?

Some men are candidates for active surveillance (also known as "watchful waiting") but for others, this is too risky, and they should be treated instead. I always discuss active surveillance as an option when consulting with any newly diagnosed prostate cancer patient, although I never recommend ignoring prostate (or any other) cancer.

By active surveillance, I mean doing a prostate-specific antigen test, or PSA, every three months and repeating an annual biopsy. Based on those results, I might recommend considering that option. If someone's PSA is less than 10, the likelihood that the cancer has spread beyond the immediate vicinity of the gland is very small, but I tell men that active surveillance ends when the PSA approaches 10.

There is a system of grading prostate cancer tissue based on how it looks under a microscope. This is called the Gleason score, and the grading ranges from 2 to 10 to indicate how likely it is that a tumor will spread.

For someone with low-risk prostate cancer (for example, a 75-year-old man with a lower Gleason score, and with a PSA of 4.5), I recommend active surveillance. However, if this patient has anxiety about his prostate cancer, he might want to go ahead and treat it, just so he can stop worrying. His chances for cure are greater than 90 percent. But again, for most men in this situation, active surveillance is fine.

If someone with similar tumor characteristics is only 60 years old, I tell him active surveillance may be fine for the time being, but he will most likely need treatment at some point. Since any curative treatment has the potential for at least some side effects, he might at least put off treatment for a few years before having to deal with them.

What are my treatment options if I have prostate cancer? There seems to be a lot of different treatments out there.

The short answer is there are several ways to successfully treat prostate cancer (curing it so it doesn't kill you, or even cause much in the way of symptoms). Your decision about which treatment to have will depend on which side effects you can best tolerate while undergoing treatment.

The American Urological Association periodically reviews all the published studies reporting treatment results for prostate cancer and it always comes to the same conclusion: taken as a whole, there is no difference in the likelihood of cure whether one has surgery or radiation therapy. Since cure rates are equivalent, however, men must consider their options and decide which treatment they want (or more realistically, which treatment they would least mind having).

Before going further, there are a few things to keep in mind.       

1. Not everyone with prostate cancer needs to be treated. As discussed above, active surveillance is appropriate for many men, sometimes for a short time and perhaps for a lifetime.            
2. There are only two methods of curing prostate cancer - surgery and radiation therapy. Different specialists have differing opinions about surgery vs. radiation, and surgery AND radiation, and the timing of each of these treatments. But remember, prostate cancer is generally slow-growing. Don't let anyone rush you into making a decision that will have consequences for the rest of your life.         
3. Things like cryotherapy, high intensity focused ultrasound, microwave heating, laser ablation and a few other methods may be appropriate for prostate cancer that recurs after primary treatment, but these are not curative by themselves.      
4. Androgen suppression (hormone therapy) will stop the progression of most prostate cancers, will make the PSA drop to almost zero and make masses or bone metastasis shrink away, but the effect is only temporary and lasts only a few months to a few years. It is not a curative treatment by itself, although it may be combined with radiation therapy to increase the likelihood of cure.
5. Androgen suppression has its own set of side effects including fatigue, loss of muscle mass, weight gain, loss of libido, impotence, osteoporosis and depression.

Can you give more information on the two methods of curing prostate cancer - surgery and radiation therapy?

1. Surgery

There are basically two methods of performing a prostatectomy.

Open - Where the surgeon makes an incision from just above the pubic bone to the belly button and dissects out the prostate (and some lymph nodes), then connects the neck of the bladder to the remaining urethra (since the intervening prostatic urethra is no longer there) and leaves a catheter in place for a few weeks to allow everything to heal back together.

Robotic - Which is basically the same operation but is performed through small incisions using remotely controlled robotic arms and stereoscopic visualization. Dissection is more precise (in experienced hands) and in-hospital stays are shorter. Publications report the potential for a reduced incidence of side effects like infection and bleeding, but it's difficult to tell if the major long-term complications like impotence and incontinence are any less.

Side effects of surgery:

• The major side effect that surgery has (and radiation therapy doesn't) is incontinence.
• For men who become incontinent after surgery, most require one or two months to regain continence.
• Overall, about five percent never regain urine control (wearing a diaper the rest of their lives).
• Impotence is more common with surgery than with radiation therapy.
• Some studies report potency preservation rates after surgery above 50 percent, but the studies define potency as the "ability to obtain an erection sufficient for vaginal penetration." So, if you can have sex for 30 seconds, you are counted as being potent.

Overall, in my experience, men do better with sexual function and infinitely better with incontinence if they are treated with radiation therapy as opposed to surgery.

2. Radiation therapy

You might be wondering, "So, what's the down side of radiation therapy?" It depends on the various ways radiation therapy may be given.

For patients with low-risk, localized prostate cancer I recommend brachytherapy. 

Brachytherapy involves the insertion of radioactive implants directly into the issue.

• The patient usually goes home in a few hours and may have a catheter overnight.
• Men usually have voiding symptoms (frequency, urgency, decreased stream force) for the next month, which resolve over time.
• Men may have some irritative rectal symptoms for a few weeks and can develop a rectal ulcer a year or two after the procedure.
• If someone has higher risk factors, then brachytherapy alone does not result in a sufficiently high cure rate. 

For patients with intermediate- or high-risk prostate cancer, I recommend external beam radiation therapy. 

External beam radiation therapy treatment can be given using one of two techniques:

• Intensity-modulated radiation therapy (IMRT) given with X-rays
• Proton therapy

By the way, the cyberknife, tomotherapy and other accelerators all deliver IMRT treatment with X-rays. There is no difference in the end result, just the machines being used to deliver it.

You may also hear the term IGRT which stands for image-guided radiation therapy. This simply means that some sort of imaging (stereoscopic X-rays, CT, portal imaging) is performed with the patient on the treatment table just before the treatment is delivered. IGRT is used with all forms of IMRT treatment as well as with proton therapy treatment.

For IMRT (X-rays) treatment, side effects may include:

• Extreme fatigue.
• Rectal irritation - A few weeks into treatment rectal irritation may happen, which can range from mild diarrhea to pain, bleeding and a continual feeling of needing to have a bowel movement, even though there may be nothing besides a little mucous in the stool.              
• Urinary irritation - A few weeks into treatment, urinary irritative symptoms may happen, such as frequency, urgency and slow bladder emptying, which last until a few weeks after treatment is finished.        
• Long-term risks include the development of radiation-induced cancers.
• Most side effects (besides the development of secondary cancers) resolve within a few months to a year after the radiation therapy is over.

For proton therapy treatment, side effects may include:   

• Fatigue is minimal.          
• Rectal symptoms are infrequent because such a small volume of the rectum is receiving radiation (just the part immediately adjacent to the prostate).   
• Urinary irritation may occur, although the symptoms are generally less severe than with X-rays.
• Studies have shown there is only a minimal increase in the risk of radiation-induced cancers with protons compared X-rays, likely due to the smaller volume of tissue receiving any radiation dose. Up to 60 percent less radiation generally can be delivered to the normal tissues around the tumor, which lowers the risk of radiation damage to healthy tissues.
• The side effects usually resolve within a few weeks after proton therapy is over.

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For more information about the surgical treatment of prostate cancer, and the types of radiation therapy used to treat prostate cancer, please visit the website of the American Cancer Society.