There is no "one size fits all" treatment for prostate cancer. You should learn as much as possible about the many treatment options available and, in conjunction with your physicians, make a decision about what's best for you. Because men diagnosed with localized prostate cancer today may live for many years, any decision made now will probably reverberate for a long time.
The suitability of prostate cancer treatment options must be based on a number of factors, including:
- Stage of prostate cancer
- Current state of health and age
- Personal preferences
- Side effects of the different treatment options
Your desire for a certain therapy based on risks, benefits, and your intuition. Consultation with all three types of prostate cancer specialists—a urologist, a radiation oncologist, and a medical oncologist—will give you the most comprehensive assessment of the available treatments and expected outcomes. Many hospitals and universities have multidisciplinary prostate cancer clinics that can provide this three-part consultation service.back to top
Prostatectomy is the most common prostate cancer treatment for early-stage localized cancer in the United States today. The most advanced form of prostate cancer surgery practiced today is robotic prostatectomy.back to top
Radiation involves the killing of cancer cells and surrounding tissues with directed radioactive exposure. 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.back to top
External Beam Radiation Therapy
This is the most common type of radiation therapy. CT scans and MRIs are used to map out the location of the tumor cells, and X-rays are targeted to those areas. With 3-D conformal radiotherapy, a computerized program maps out the exact location of the prostate tumors so the highest dose of radiation can reach the cancer cells within the gland.
Many studies have shown that while surgery results in a more immediate loss of erectile function followed by a period of recovery, radiation therapy results in a slower loss of erectile function over time in men who have good erectile function before treatment. By the end of five years, the risks of erectile dysfunction appear to be fairly similar in men who have chosen radiation or surgery.
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.
The advantage of using protons over other external beam sources is precision. Protons of energetic particles can hit a targeted prostate cancer tumor without affecting surrounding tissue. This direct attack on cancerous cells ultimately causes their death, as the cells are particularly vulnerable to attack due to their rapid division.
Proton treatment is suitable for treating localized, isolated, solid tumors before they spread to other tissues and the rest of the body. However, to date, proton beam therapy has never been compared directly to standard IMRT techniques, so we do not truly know if this offers an advantage over standard approaches.
With brachytherapy, tiny metal pellets containing radioactive iodine or palladium are inserted into the prostate via needles that enter through the skin behind the testicles. As with 3-D conformal radiation therapy, 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 remain are harmless.
Compared with external radiation therapy, brachytherapy is less commonly used, but it's rapidly gaining ground, primarily because it doesn't require daily visits to the treatment center. Side effects can include erectile dysfunction, urinary frequency and obstruction, and rarely rectal injury.
Prostate cancer cells are like 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's a common target for therapeutic intervention in men with the disease.
Hormone therapy, also known as androgen-deprivation therapy or ADT, is designed to stop testosterone from being released or to prevent it 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 remain unaffected by hormone therapy. As these hormone-independent cells continue to grow unchecked, hormone therapies have less and less of an effect on the growth of the tumor over time.
For this reason, hormone therapy is not a perfect strategy in the fight against prostate cancer, and it does not cure the disease. It also carries some unwanted toxicities. But it remains an important step in the process of managing advancing disease, and it will likely be a part of every man's therapeutic regimen at some point during his fight against recurrent or advanced 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.
In addition, several agents are approved or widely available for use in prostate cancer, including estramustine and mitoxantrone. Estramustine (Emcyt) is an oral medication with hormonal and chemotherapeutic properties that has anti-cancer activity, and can be safely combined with other chemotherapies. Mitoxantrone (Novatrone) is a chemotherapy agent given intravenously every three weeks and is known to delay and reduce pain from prostate cancer metastasis from earlier studies. It remains an effective weapon against prostate cancer.
In labs around the world, researchers are busy identifying new drugs, new regimens, and new treatment approaches that might prove beneficial to men with prostate cancer. Most of these investigational agents are being tested in men with advanced prostate cancer: Therapy options for men at this stage of disease are often not effective enough to halt progression of the disease, and men are typically affected by side effects from the disease and/or the medications that they're taking. It's therefore the perfect stage at which to test out new drugs because any improvement will likely be rapidly noticed and much appreciated.
The Goal of Targeted Therapies
Chemotherapy drugs can play an important role in improving the lives of men with advanced prostate cancer, but they often don't distinguish between tumor cells and healthy cells to a high degree and can kill off some normal cells along the way. So-called targeted therapies, by contrast, are drugs that are specifically designed to interfere with the way cancer cells grow, with the way cancer cells interact with each other, and/or with the way that the immune system interact with the cancer without damaging a man's normal cells.
There are a number of different kinds of targeted therapies being currently investigated for prostate cancer.
Interfering With Cancer Cell Growth
All cells in the body, including cancer cells, rely on a complex communication system to know when to grow, when to divide, and when to die. This system uses specialized proteins, fats, and other substances to tell the different cells or parts of cells how to act. Over the years, cancer researchers have been studying ways to interfere with the signaling system that regulates the growth of cancer cells.
Interfering With Cancer Cell Spread
As cancer cells divide and start to spread, new blood vessels sprout from the old ones to help supply the necessary nutrients to the new tumor site via a process called angiogenesis. If angiogenesis could be inhibited, researchers theorized, the new tumor cells would die and the cancer's growth would be halted.
In 2004, the angiogenesis inhibitor bevacizumab (Avastin) was approved by the FDA for use in colorectal cancer. Since then, it has been shown to improve outcomes in women with breast cancer, kidney cancer, and brain tumors, and is currently being studied in a number of other cancer types, including prostate cancer. A phase III trial of this agent have been completed and results are anticipated in 2010. Although no other drugs currently available were designed to specifically act as an angiogenesis inhibitor, researchers have found that the drug thalidomide (Thalomid) has some anti-angiogenic properties, and is also currently being tested in men with prostate cancer. Newer more potent analogs of thalidomide (Revlimid, or lenalidomide) are also in clinical trials for prostate cancer.
Harnessing the Immune System to Fight Off Cancer Cells
In order for the immune system to fight off foreign invaders, it has to learn to recognize what's normal and what's not normal. Unfortunately, because cancer cells start out as normal healthy cells, the immune system never has a chance to learn to distinguish between the normal cell and the cancer cell.
Unlike preventive vaccines, which are designed to teach the immune system to develop a way to fight off a specific virus should it come into contact with that same virus again, therapeutic vaccines stimulate the immune system to recognize and fight certain proteins specific to cancer cells. Each of the therapeutic vaccines currently being tested in men with advanced prostate cancer works in a slightly different fashion, but all are designed to harness the immune system's ability to fight off disease and teach it to fight off prostate cancer cells. One such vaccine, Provenge (sipuleucel-T) was recently approved by the FDA for prostate cancer.