Prostate cancer is a disease in which cancer develops in the prostate, a gland in the male reproductive system. It occurs when cells of the prostate mutate and begin to multiply out of control. These cells may spread (metastasize) from the prostate to other parts of the body, especially the bones and lymph nodes. Prostate cancer may cause pain, difficulty in urinating, erectile dysfunction and other symptoms.
About the Prostate
The prostate gland, a key part of the male reproductive system, is linked closely with the urinary system. It is a small gland that secretes much of the liquid portion of semen,the milky fluid that transports sperm through the penis during ejaculation.
The prostate is located just beneath the bladder, where urine is stored, and in front of the rectum. It encircles, like a donut, a section of the urethra. The urethra is the tube that carries urine from the bladder out through the penis. During ejaculation, semen is secreted by the prostate through small pores of the urethra's walls.
The prostate is made up of three lobes encased in an outer covering, or capsule. It is flanked on either side by the seminal vesicles, a pair of pouch-like glands that contribute secretions to the semen. Next to the seminal vesicles run the two vas deferens, tubes that carry sperm from the testicles. The testicles, in addition to manufacturing sperm, produce testosterone, a male sex hormone that controls the prostate's growth and function.
Diagnosis of Prostate Cancer
Prostate cancer is most often discovered by physical examination or by screening blood tests, such as the PSA (prostate specific antigen) test. Suspected prostate cancer is typically confirmed by removing a piece of the prostate (biopsy) and examining it under a microscope. However, blind needle biopsies spread cancer cells and only yield a 25 % success rate in finding cancer. Recent advancements in imaging technology, such as a multi-parametric prostate MRI, allow physicians to locate suspicious areas of disease and then performed targeted biopsies improving diagnostic outcomes by up to 40%. In addition to locating suspicious lesions, a multi-parametric prostate MRI can determine whether prostate cancer has spread beyond the capsule.
Treatment of Prostate Cancer
There's more than one way to treat prostate cancer. For some men a combination of treatments — such as surgery followed by radiation or radiation paired with hormone therapy — works best. The treatment that is best for each man depends on several factors. These include how fast your cancer is growing, how much it has spread, your age and life expectancy, as well as the benefits and the potential side effects of the treatment.
You can receive radiation therapy via external beams or radioactive implants:
External-beam radiation therapy (EBRT). External beam radiation treatment makes use of high-powered X-rays to kill cancer cells, using a machine to deliver the radiation beam. This type of radiation is effective at destroying cancerous cells, but it can also scar adjacent healthy tissue.
The first step in radiation therapy is to map the precise area of your body that needs to receive radiation. Doctors often use three-dimensional scans to determine the exact location of your prostate and surrounding structures. Computer-imaging software gives the radiation oncologist the ability to find the best angles to aim the beams of radiation. By using new techniques — which allow for more precise focusing of the radiation beams with concentration of the radiation dose to the targeted area — greater doses of radiation can be administered to your prostate without harming surrounding tissue.
A body supporter holds you in the same position for each treatment. You'll also be asked to arrive for therapy with a full bladder . This will push most of your bladder out of the path of the radiation beam. Ink marks on your skin help to guide the radiation beam, and small gold markers may be placed in your prostate to ensure the radiation hits the same targets each time. Custom-designed shields help protect nearby normal tissue, such as your bladder, erectile tissues, anus, and rectal wall.
Treatments are generally given five days a week for about eight weeks. Each treatment appointment takes about 10 minutes. However, much of this is preparation time — radiation is received for only about 1 minute. You don't need anesthesia with external-beam radiation, because the treatment isn't painful.
Most men have mild side effects from this type of treatment, but most of the side effects disappear shortly after treatment is completed. Most men don't have problems with erections or intercourse immediately after radiation therapy. However, radiation can cause sexual side effects in some men later in life. Most of these men respond to medications used for ED. The younger you are, the better your chance of retaining normal sexual function.
During treatment some men experience urinary problems. The most common signs and symptoms are urgency to urinate and frequent urination. These problems usually are temporary and gradually diminish in a few weeks after completing treatment. Long-term problems are uncommon.
Rectal problems — including loose stools, rectal bleeding, discomfort during bowel movements and a sense that you have to have a bowel movement (rectal urgency) — may arise during treatment. Once the treatment course is complete, these problems generally subside. However, a few men may continue to experience rectal problems months after treatment, but these improve on their own in most men. Most long-term rectal symptoms are controlled with medications. Rarely, people develop persistent bleeding or a rectal ulcer after radiation. Surgery may be necessary to alleviate these problems.
Radioactive seed implants
Radioactive seeds implanted into the prostate have gained popularity in recent years as a treatment for prostate cancer. The implants, also known as brachytherapy, deliver a higher dose of radiation than do external beams, but over a substantially longer period of time.
During the implant procedure — which typically lasts about one to two hours, done under general anesthesia on an outpatient basis — between 40 and 100 rice-sized radioactive seeds are placed in your prostate through ultrasound-guided needles. The exact number of seeds inserted depends on the size of your prostate. The therapy is generally used in men with smaller or moderate-sized prostates with small and lower-grade cancers. Sometimes, hormone therapy is used for a few months to shrink the size of the prostate before seeds are implanted.
The seeds may contain one of several radioactive isotopes — including iodine and palladium. These seeds don't have to be removed after they stop emitting radiation.
Iodine and palladium seeds generally emit radiation that extends only a few millimeters beyond their location. This type of radiation isn't likely to escape your body in significant doses. However, doctors recommend that for the first few months you stay at least six feet away from children and pregnant women, who are especially sensitive to radiation. All radiation inside the pellets is generally exhausted within a year.
Side effects of seed implants are somewhat different from that of external-beam radiation. Seed implants deliver a higher dose of radiation to your urethra, causing urinary signs and symptoms such as frequent, slower and painful urination to occur in nearly all men. You may require medication to treat these signs and symptoms, and some men require medications or the use of intermittent self-catheterization to help them urinate.
Urinary symptoms tend to be more severe and longer lasting with seed implants than with external-beam radiation. Rectal symptoms, however, may be less frequent and less severe. Some men experience impotence due to radioactive seed implants.
Hormone Therapy for Prostate Cancer
When you have prostate cancer, male sex hormones (androgens) can stimulate the growth of cancer cells. The main type of androgen is testosterone. Hormone therapy either uses drugs to try to stop your body from producing male sex hormones, or involves surgery to remove your testicles, which produce most of your testosterone. This type of therapy can also block hormones from getting into cancer cells. Sometimes doctors use a combination of drugs to achieve both.
In most men with advanced prostate cancer, this form of treatment is effective in helping to slow the growth of tumors. Because it's effective at shrinking tumors, doctors use hormone therapy in some early-stage cancers — often in combination with radiation and sometimes with surgery. Hormones shrink large tumors so that surgery or radiation can remove or destroy them more easily. After these treatments, the drugs can inhibit the growth of stray cells left behind.
Some drugs used in hormone therapy decrease your body's production of testosterone. The hormones — known as luteinizing hormone-releasing hormone (LH-RH) agonists — can set up a chemical blockade. This blockade prevents the testicles from receiving messages to make testosterone. Drugs typically used in this type of hormone therapy include leuprolide (Lupron, Viadur) and goserelin (Zoladex). They're injected into a muscle or under your skin once every three or four months. You can receive them for a few months, a few years, or the rest of your life, depending on your situation.
Other drugs used in hormone therapy block your body's ability to use testosterone. A small amount of testosterone comes from the adrenal glands and won't be suppressed by leuprolide or goserelin. Certain medications — known as anti-androgens — can prevent testosterone from reaching your cancer cells. Drugs typically used for this type of therapy include flutamide (Eulexin), bicalutamide (Casodex) and nilutamide (Nilandron). They come in tablet form and, depending on the particular brand of drug, are taken orally one to three times a day. These drugs typically are given with an LH-RH agonist.
Simply depriving prostate cancer of testosterone usually doesn't kill all of the cancer cells. Within a few years, the cancer often learns to thrive without testosterone. Once this happens, hormone therapy is less likely to be effective. However, several treatment options still exist.
To avoid such resistance, intermittent hormone therapy programs have been developed. During this type of therapy, the hormonal drugs are stopped after your PSA drops to a low level and remains steady. You resume taking the drugs if your PSA level rises again.
Side effects of hormone therapy may include breast enlargement, reduced sex drive, impotence, hot flashes, weight gain and reduction in muscle and bone mass. Some of these drugs can also cause nausea, diarrhea, fatigue and liver damage.
Because most testosterone is produced in your testicles, surgical removal of your testicles (castration) also can be an effective form of therapy — especially for advanced prostate cancer. The procedure can be performed on an outpatient basis using a local anesthetic.
Surgical removal of your prostate gland, called radical prostatectomy, is another option to treat cancer that's confined to your prostate gland. During this procedure, your surgeon uses special techniques to completely remove your prostate and local lymph nodes, while trying to spare muscles and nerves that control urination and sexual function.
Two surgical approaches are available for a prostatectomy — retropubic surgery and perineal surgery:
In this approach, the gland is taken out through an incision in your lower abdomen that typically runs from just below your navel to an inch above the base of your penis. It's the most commonly used form of prostate removal for two reasons. First, your surgeon can use the same incision to remove pelvic lymph nodes, which are tested to determine if the cancer has spread. Secondly, the procedure gives your surgeon good access to your prostate, making it easy to save the nerves that help control bladder function and erections.
Perineal surgery. With the perineal approach, an incision is made between your anus and scrotum. There's generally less bleeding with perineal surgery, and recovery time may be shorter, especially if you're overweight. With this procedure, your surgeon isn't able to remove nearby lymph nodes.
During your operation, a catheter is inserted into your bladder through your penis to drain urine from the bladder during your recovery. The catheter will likely remain in place for one to two weeks after the operation while the urinary tract heals.
After the catheter is removed, you'll likely experience some bladder control problems (urinary incontinence) that may last for weeks or even months. Most men eventually regain control. Many men experience stress incontinence, meaning they're unable to hold urine flow when their bladders are under increased pressure, as happens when they sneeze, cough, laugh or lift. In some men, major urinary leakage persists, and secondary surgical procedures may be needed in an attempt to correct the problem.
Impotence is another common side effect of radical prostatectomy, because nerves on both sides of your prostate that control erections may be damaged or removed during surgery. Most men younger than age 50 who have nerve-sparing surgery are able to achieve normal erections afterward, and some men in their 70s are able to maintain normal sexual functioning. Men who had trouble achieving or maintaining an erection before surgery have a higher risk of being impotent after the surgery.
Chemotherapy for Prostate Cancer
This type of treatment uses chemicals that destroy rapidly growing cells. Chemotherapy can be quite effective in treating prostate cancer, but it can't cure it. Because it has more side effects than hormone therapy does, chemotherapy often is reserved for men who have hormone-resistant prostate cancer, especially if their cancer is causing problems.
As new chemotherapy drugs are developed, trials continue using single-drug chemotherapy, multiple combinations of chemotherapy, and combinations of chemotherapy and hormone therapy. Early results are positive, but extensive experience with newer drug agents is pending. In the future, gene therapy or immune therapy may be more successful in treating metastasized tumors of the prostate. Current technology limits the use of these experimental treatments to a small number of centers.
Cryotherapy for Prostate Cancer
This treatment is used to destroy cells by freezing tissue. Original attempts to treat prostate cancer with cryotherapy involved inserting a probe into the prostate through the skin between the rectum and the scrotum (perineum). Using a rectal microwave probe to monitor the procedure, the prostate was frozen in an attempt to destroy cancer cells. Poor precision in monitoring the extent of the freezing process often resulted in damage to tissue around the bladder and long-term complications such as injury to the rectum or the muscles that control urination.
More recently, smaller probes and more precise methods of monitoring the temperature in and around the prostate have been developed. These advances may decrease the complications associated with cryotherapy, making it a more effective treatment for prostate cancer. Although progress continues, more time is needed to determine how successful cryotherapy may be as a treatment for prostate cancer.
The PSA blood test can help detect prostate cancer at a very early stage. This allows many men to choose watchful waiting as a treatment option. In watchful waiting (also known as observation, expectant therapy or deferred therapy), regular follow-up blood tests, rectal exams and possibly biopsies may be performed to monitor progression of your cancer.
During watchful waiting no medical treatment is provided. Medications, radiation and surgery aren't used. Watchful waiting may be an option if your cancer isn't causing symptoms, is expected to grow very slowly, and is small and confined to one area of your prostate.
Watchful waiting may be particularly appropriate if you're elderly, in poor health or both. Many such men will live out their normal life spans without treatment and without the cancer spreading or causing other problems. But watchful waiting can also be a rational option for a younger man as long as you know the facts, are willing to be vigilant, and accept the risk of a tumor spreading during the observation period, rendering your cancer incurable.
HIFU (High Intensity Focused Ultrasound)
HIFU is a state-of-the-art technology acoustic ablation technique that utilizes the power of ultrasound to destroy deep-seated prostate cancer tissue with pinpoint accuracy. HIFU focuses sound waves in a targeted area which rapidly increases the temperature in the focal zone causing tissue destruction.
The control and precision of HIFU reduces the risk of common prostate cancer treatmet side effects such as impotence and incontinence. HIFU is a 2-3 hour, one-time procedure preformed on an out-patient basis under spinal or epidural anesthesia. Unlike radiation, HIFU is non-ionizing so it can be repeated if necessary without damaging healthy tissue. This means that HIFU can also be used as a salvage technique if other prostate cancer treatments fail.
Similar to what happens when sunlight is focused through a magnifying lens, precise focusing of ultrasound energy during HIFU therapy elevates the temperature of the tissue in the focal zone very rapidly while intervening tissue between the transducer and the focal zone is kept at a safe temperature. The result is an accurate and repeatable lesion at the target sites that are monitored in real time by the treating physician. All the afected zones are preplanned and checked by the physician prior to starting the HIFU therapy. The imaging capabilities of the technology allow for identification of vital structures such as the prostate capsule, seminal vesicles, rectal wall and physiological location of the neurovascular bundles.
Dr. Wheeler is considered a HIFU expert and performs the treatment on many patients who choose this non-invasive state-of-the-art treatment. For more information on HIFU, please visit his HIFU website www.panamhifu.com to learn more.
In a study published by the journal of the National Cancer Institute. African American men were found to be nearly twice the risk of prostate cancer compared to white men even after an adjustment of number of known and suspected cancer risk factors. African American men have the highest rate of prostate cancer in the U.S. In addition, a Ropel Starks service showed that African American men are significantly more likely than white men to experience side effects from prostate cancer treatments including incontinence. They are also more likely than white men to be disatisfied with their doctors support. Dr. Ronald E. Wheeler will discuss diagnosis and treatments for prostate cancer in these videos.