Prostate Cancer Treatment Options
There are a number of prostate cancer treatment options available today. There is no "one size fits all" treatment for prostate cancer, so each man must learn as much as he can about various treatment options and, in conjunction with his physicians, make his own decision about what is best for him.
For most men, the decision will rest on a combination of clinical and psychological factors. Men diagnosed with localized prostate cancer today will likely live for many years, so any decision that is made now will likely reverberate for a long time. Careful consideration of the different options is an important first step in deciding on the best treatment course.
Consultation with all three types of prostate cancer specialists—a urologist, a radiation oncologist and a medical oncologist—will offer the most comprehensive assessment of the available treatments and expected outcomes.
The concept of active surveillance, or watchful waiting, has increasingly emerged in the past years as a viable option for men who, for one reason or another, have decided not to undergo immediate surgery or radiation therapy. During active surveillance, the cancer is carefully monitored for signs of progression. A PSA blood test and DRE are usually administered every six months along with a yearly biopsy of the prostate. If symptoms develop, or if tests indicate that the cancer is growing, treatment might be warranted.
Active surveillance might be a good choice for men who have very slow growing or very early cancers, or for men who have other serious medical conditions that affect the way they live their lives, especially if these other conditions are likely to shorten their lifespan.
Also, many of the treatment options for prostate cancer can be difficult to endure, and better outcomes are seen in men who are otherwise healthy. If a man is currently battling other disorders or diseases, such as heart disease, long-standing high blood pressure, or poorly controlled diabetes, his doctors might feel that it is in his best interest to hold off on therapy and avoid its potential complications.
Radiation TherapyRadiation involves the killing of cancer cells and surrounding tissues with directed radioactive exposure. (Review the roles of the prostate and the surrounding organs in the About the Prostate section.)
The use of radiation therapy as an initial treatment for prostate cancer is described below. Some forms of radiation therapy can also be used in men with advanced or recurrent prostate cancer.
External Beam Radiation Therapy
The most common type of radiation therapy is external beam radiotherapy. CT scans and MRIs are used to map out the location of the tumor cells, and x-rays are targeted to those areas. With 3D conformal radiotherapy, a computerized program maps out the exact location of the prostate tumors so that the highest dose of radiation can reach the cancer cells within the gland.
Intensity-modulated radiation therapy
(IMRT) allows oncologists to modulate, or change, the intensity of the doses and radiation beams to better target the radiation delivered to the prostate, while at the same time delivering lower doses to the tumor cells that are immediately adjacent to the bladder and rectal tissue.
Because the treatment planning with these types of radiation therapy are far more precise, higher—and more effective—doses of radiation can be used with less chance of damaging surrounding tissue.
Regardless of the form of external radiation therapy, treatment courses usually run five days a week for about seven or eight weeks, and are typically done on an outpatient basis.
While X-rays are currently the main method of treating tumors with radiation therapy, facilities that perform proton therapy are slowly becoming more commonplace. Worldwide, says Alfred R. Smith of the M. D. Anderson Cancer Center in Houston, there are more than six medical institutions with proton machines in the United States, and five more are in the planning or construction stages.
The advantage of using protons over other external beam sources is the precision with which protons of energetic particles are aimed at a targeted prostate cancer tumor while not affecting surrounding tissue. This direct attack on cancerous cells ultimately causes their death as the cell is particularly vulnerable to attack due to their rapid cell division. Proton treatment is notably valuable for treating localized, isolated, solid tumors before they spread to other tissues and to the rest of the body.
However, issues of cost and access have hampered wider use. Today’s proton-therapy machines take up a considerable amount of room owing to the large magnets that create the energetic particles and the concrete walls that are needed to shield the radiation. These machines also come with a hefty cost—between $25 and $150 million—allowing only a handful of cancer centers the ability to purchasing such equipment.
As efforts are made to reduce the size of these machines, the cost to build them and the price tag for treatment should also fall—giving cancer patients more accessibility to this treatment option. A machine now being developed by researchers at Lawrence Livermore National Laboratory is expected to be a fifth of the size and cost of the proton-therapy machines that are currently found at six specialized medical centers in the United States. Five more centers are currently under construction in the U.S.
With brachytherapy, tiny little metal pellets containing radioactive iodine or palladium are inserted into the prostate via needles that enter through the skin behind the testicles. As with 3D conformal radiation therapy, careful and precise maps are used to ensure that the seeds are placed in the proper locations.
Over the course of several months, the seeds give off radiation to the immediate surrounding area, killing the prostate cancer cells. By the end of the year, the radioactive material degrades, and the seeds that remains are harmless.
Compared with external radiation therapy, brachytherapy is less commonly used, but it is rapidly gaining ground, primarily because it doesn’t require daily visits to the treatment center.
The Importance of Dose Planning
Just as surgical skill can play an important role in determining outcomes from prostatectomy, technical skill and manual dexterity can play an important role in determining outcomes from radiation therapy. The use of computer software to assist with the dose planning and target prostate tissue helps greatly, but, in the end, the skill and experience of the radiation oncologist will make the biggest difference.
When choosing a radiation oncologist, at a minimum, make sure he or she has broad experience with an assortment of approaches and can objectively help to decide on the best course of treatment.
Prostate cancer cells are just like all other living organisms—they need fuel to grow and survive. Because the hormone testosterone serves as the main fuel for prostate cancer cell growth, it is a common target for therapeutic intervention in men with prostate cancer.
Hormone therapy, also known as androgen-deprivation therapy or ADT, is designed to stop testosterone from being released or to prevent the hormone from acting on the prostate cells. Although hormone therapy plays an important role in men with advancing prostate cancer, it is increasingly being used before, during, or after local treatment as well.
The majority of cells in prostate cancer tumors respond to the removal of testosterone. But some cells grow independent of testosterone, and therefore remain unaffected by hormone therapy. As these hormone-independent cells continue to grow unchecked, over time, hormone therapies have less and less of an effect on the growth of the tumor.
Hormone therapy is therefore not a perfect strategy in the fight against prostate cancer, and does not cure the disease. But it remains an important step in the process of managing advancing disease, and will likely be a part of every man’s therapeutic regimen at some point during his fight against recurrent or advanced prostate cancer.
The most common types of hormone therapy are described below. Although each of these therapeutic options is effective at controlling prostate cancer growth, the loss of testosterone confers significant side effects in nearly all men. (A review of how best to manage side effects from testosterone loss can be found in the Side Effects section.)
Because about 90% of testosterone is produced by the testicles, surgical removal of the testicles, or orchiectomy, is an effective solution to blocking testosterone release. This approach has been used successfully since the 1940s, but because it’s a permanent and irreversible surgical solution, most men opt for drug therapy instead.
For men who choose this option, the procedure is typically done on an outpatient basis in the urologist’s office. Recovery tends to be rather quick and no further hormone therapy is needed, making orchiectomy a very attractive choice for someone who prefers a low-cost, one-time procedure.
LHRH, or luteinizing-hormone releasing hormone, is one of the key hormones released by the body before testosterone is produced. (Note that LHRH is sometimes called GnRH, or gonadotropin-releasing hormone.) Blocking the release of LHRH through the use of LHRH agonists or LHRH analogues is one of the most common hormone therapies used in men with prostate cancer.
Drugs in this class, including leuprolide (Eligard, Lupron, and Viadur), goserelin (Zoladex), and triptorelin (Trelstar), are given in the form of regular shots: once a month, once every three months, once every four months, or once per year.
LHRH agonists cause what is known as a "flare" reaction because of an initial transient rise in testosterone. This can result in a variety of symptoms ranging from bone pain to urinary frequency or difficulty.
Antiandrogenssuch as bicalutamide (Casodex), flutamide (Eulexin), and nilutamide (Nilandron), help to block the action of testosterone in prostate cancer cells. They are therefore often added to the LHRH agonist for at least the first 4 weeks of therapy when the flare reaction typically occurs. In this setting, antiandrogens can be helpful in preventing the flare reaction.
Although the sexual side effects of the antiandrogens when given alone are typically far fewer compared with the LHRH agonists, antiandrogens might not be as effective as orchiectomy or LHRH agonists and are not the optimal choice for men with documented metastatic prostate cancer.
The term "chemotherapy" refers to any type of therapy that uses chemicals to kill or halt the growth of cancer cells. The drugs work in a variety of ways, but are all based on the same simple principle: stop the cells from dividing and you stop the growth and spread of the tumor.
Until recently, chemotherapy was used only to relieve symptoms associated with very advanced or metastatic disease. With the publication of two studies in 2004 showing that the use of docetaxel (Taxotere) can prolong the lives of men with prostate cancer that no longer responds to hormone therapy, more and more doctors are recognizing the potential benefits of chemotherapy for the men they treat with advanced prostate cancer.
Building on these successes, there are now dozens of clinical trials studying various combinations of chemotherapy drugs, some using new mixes of older drugs and some using newer drugs. Some trials are looking to find a chemotherapy regimen that’s more tolerable or more effective than docetaxel in men with metastatic disease, others are looking to find a chemotherapy regimen that can delay the onset of metastases, and still others are seeking to improve upon the results with docetaxel by adding to it other novel agents and testing the combination.
Paramount in all researchers’ minds is a way to maximize benefit while minimizing side effects. Chemotherapy, like all powerful drugs, can take a toll on the body. A review of how to best manage the side effects of chemotherapy can be found in the Side Effects section.
Off-Label Chemotherapy Use
Strictly speaking, few chemotherapy agents have been approved by the FDA for use in prostate cancer. But over the years, doctors have found that some medications that are regularly used in other types of cancers can be used rather effectively in men with prostate cancer.
Off label use of a drug means that the drug is approved by the FDA for use in one disease but is being used in another. The drug is known to be safe overall, and has been proven effective for the disease in which it’s approved. That doesn’t mean it’s not effective in prostate cancer as well; it just means that the drug hasn’t been rigorously tested in prostate cancer, so there’s no formal "proof" that it’s effective. Nevertheless, off-label use of chemotherapy is common, and its use is often found to be beneficial in men with prostate cancer.
Because very few drugs will score a home run in every person, second-line chemotherapy has a long and valued tradition in the treatment of cancer. In this setting, off-label drugs are common, and are chosen specifically because they work somewhat differently than what was used first, providing another chance to see a benefit.