Hormonal therapy
Prostate cancer is highly sensitive to and dependent on the level of the male hormone testosterone, which drives the growth of prostate cancer cells in all but the very high-grade or poorly-differentiated forms of prostate cancer. Testosterone belongs to a family of hormones called androgens, and today front-line hormonal therapy for advanced and metastatic prostate cancer is called androgen deprivation therapy (ADT).
In the past, this was accomplished by surgical castration called bilateral orchiectomy. In that procedure, the testes were both removed. Today, doctors can block the function of the testes in a controllable and most often reversible fashion with drugs that prevent the production of testosterone (medical castration). These agents can result in shrinkage of the prostate gland, can stop prostate cancer cells from growing for up to several years, and can relieve pain caused by prostate cancer that has spread or metastasized into the bones by shrinking the cancer. The use of ADT does not produce a cure. Over time, the prostate cancer cells will develop an ability to grow despite the lack of hormones (castrate resistance). Another form of hormonal therapy is the use of androgen receptor blockers; these medications prevent testosterone from attaching (binding) to the prostate cancer cell and being absorbed into the cell where it can help the cell survive and grow.
Hormonal treatment today is primarily used in the treatment of locally advanced and metastatic prostate cancer. It may be used in conjunction with primary curative therapies (surgical and radiation based) to shrink the cancer/prostate to increase the likelihood of cure of the treatment, neoadjuvant therapy, and with radiation therapy for several years after treatment (adjuvant therapy). However, the primary role of ADT is in the treatment of widespread or metastatic prostate cancer. While it is not a curative treatment in that setting, it can both reduce symptoms and slow down the growth of the prostate cancer to prolong life.
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Talk to your doctor about increased risk of prostate cancer. Men with a high risk of prostate cancer may consider medications or other treatments to reduce their risk. Some studies suggest that taking 5-alpha reductase inhibitors, including finasteride (Propecia, Proscar) and dutasteride (Avodart), may reduce the overall risk of developing prostate cancer. These drugs are used to control prostate gland enlargement and hair loss in men.
However, some evidence indicates that men taking these medications may have an increased risk of getting a more serious form of prostate cancer (high-grade prostate cancer). If you're concerned about your risk of developing prostate cancer, talk with your doctor.
Treatments
Radiation therapy
Radiation therapy as with surgical therapy is a potentially curative treatment that uses radiation to kill cancer cells. Radiation therapy can be performed via external beam therapy (EBRT) or the placement of radioactive seeds into the prostate (prostate brachytherapy).
EBRT
An X-ray machine uses a low energy radiation beam to take a picture of a portion of the body. Radiation therapy machines put out high energy beams that can be focused very precisely to deliver treatment to a site. The radiation does not "burn out" the cancer, but damages the cells' DNA, which causes the cancer cells to die. This process can take some time to occur after the radiation treatments have been given.
The radiation passes directly through the tissues in EBRT. Radiation treatment used today delivers very little energy to normal tissues. It just passes through. Most of the energy is able to be focused and delivered directly to the area of the prostate gland containing cancer. This process minimizes damage to healthy tissue.
EBRT is appropriate for men who are candidates for radical prostatectomy but do not wish to undergo the surgery or who are not ideal surgical candidates.
EBRT may also be used to treat recurrent prostate cancer localized to the prostate bed (where the prostate was before it was removed surgically). It is also used to treat bone metastases (spread of the prostate cancer to the bone) to reduce pain or if the cancer is pressing on important structures, including the spinal cord.
Patients with a very large prostate or very small prostate, those with symptoms of bladder outlet obstruction, or who have had a previous transurethral resection of the prostate (TURP) are more difficult to treat and have a greater risk of side effects.
Focal therapy
Focal therapy involves ablation of the prostate cancer within the prostate with preservation of the surrounding healthy tissue. A number of focal therapies are being investigated, and a comparison of the efficacy of each of these therapies cannot be made given the limited data on many of these therapies. Focal therapies being investigated include cryotherapy, high-intensity focused ultrasound, laser ablation,
photo dynamic therapy, irreversible electroporation,
radio frequency ablation, and focal brachytherapy. As many of these are considered experimental, only cryotherapy will be briefly reviewed.
Cryotherapy (cryosurgery, cryoablation)
Cryotherapy is a minimally invasive therapy that damages tissue by local freezing.
Cryotherapy is most frequently used as a salvage treatment after failure of radiation therapy. As an outpatient, hollow needles are placed into the prostate through the perineum (the space between the scrotal sac and the anus) under image guidance. A gas is passed through the needles to freeze the prostate. Warm liquid is passed through the urethra at the same time to protect it. The needles are removed after the procedure. While potentially effective for local control of cancer in the prostate gland, the side effects can be significant and include pain and the inability to urinate. Potential long-term effects include tissue damage in needle-insertion areas, impotence, and incontinence. Cryotherapy is not currently recommend as a primary treatment for management of prostate cancer.
Chemotherapy
Chemotherapy or for prostate cancer involves the use of medications either in pill form or by injection into the veins, which can kill or at least slow the growth of metastatic prostate cancer cells. It does not presently have a role in the treatment of early stage prostate cancer except as part of
clinical trials/research studies. The use of chemotherapy in metastatic prostate cancer is presently not a potentially curative treatment, but it can relieve symptoms of prostate cancer, and can prolong life. It is usually used in the setting of castration- (medical or surgical) resistant prostate cancer.
Chemotherapy drugs work in many different ways. These drugs may damage the DNA of the cancer cells or disrupt the cells ability to divide (mitosis). These effects can cause cells to die. Not all prostate cancer cells may be sensitive to these drugs, but some may be. A tumor (a mass of cancer cells) will shrink if more cells are killed and removed than continue to grow and divide. As many normal tissues in the body also undergo the same patterns of growth and mitosis, these drugs have numerous side effects due to their effects on normal tissues.
Immunotherapy/vaccine therapy
The immune system works by trying to very specifically target infections or to attack and kill cells which are either cancerous or are not our own. The immune system attempts to eliminate these invading problems using antibodies and cells called T-lymphocytes; in cases of cancer the immune system still struggles to control the problem for many reasons. The cancer seems often to either depress or overwhelm the immune system. Immune therapies (immunotherapy) attempt to boost the capability of our immune system.
Provenge (Sipuleucel-T) is a form of immunotherapy, a vaccine therapy, used to treat prostate cancer that has metastasized. It is appropriate in patients whose cancer is no longer responding to hormonal therapy but who are asymptomatic or minimally symptomatic. These patients may be showing a rise in PSA level after previous hormonal treatment has kept the PSA down for a long time.
Bone-targeted therapy
Bone health is an essential component of prostate cancer treatment. Both the disease itself, as well as the treatment of the disease with androgen deprivation therapy, can have a significant impact on bone health. Several bone-targeted therapies have been approved.
Bisphosphonates
The bisphosphonates are a group of drugs used to treat several conditions people can get. They also can lower elevated blood levels of calcium in people with cancer. They work by affecting cells in the bones called osteoclasts, which work to remove bone. These drugs encourage the death of the osteoclasts. In prostate cancer they impact the course of skeletal-related events including reducing pain in the bones, and delaying the progression of bone metastases associated problems including the appearance of fractures (breaks in bones). While the bisphosphonates can affect the growth of prostate cells in the laboratory, they are presently not considered a targeted or direct-acting drug like a chemotherapy or hormonal treatment. They have also not been shown to prevent the appearance of bone metastases in prostate cancer patients. Nonetheless, they are an important part of the treatment of prostate cancer patients with bone metastases.
. It is given intravenously. Its side effects are primarily reactions to the drug infusion. The dose of Zometa may need to be adjusted if the patient's blood tests show signs of deterioration in the function of the patient's kidneys. In addition, its use can predispose patients to serious dental conditions , which can result in breakdown of the bone of the jaw after dental extractions. It is advised that you see your dentist.
Radio pharmaceuticals
The use of substances that are radioactive as a treatment for bone metastases has been tried for years. Strontium-89 and samarium-153 have been used in the past. They decrease pain in patients with prostate cancer with bone metastases but they do not prolong life; these medications lower levels of healthy blood cells in patients who receive them.
Radium is like calcium and it migrates to bone where it acts locally. As an alpha emitter, radiation from radium does not travel far enough in the body to damage other healthy tissues. Unlike the bisphosphonates, the use of this agent reduces pain and can prolong survival. It is administered by an injection into a vein. It can cause nausea, diarrhea, and low blood counts.
Research techniques
High-intensity focused ultrasound (HIFU) is an approach to therapy that is presently approved for use in Europe, and is under study in the U.S. It uses high intensity sound waves focused on the prostate gland to heat and thereby kill cancer cells. It should only be used as part of a research study (a clinical trial). The safety, side effects, and comparative effectiveness to surgery and radiation therapy must be established.
Clinical trials are research studies being conducted to evaluate new treatments for prostate cancer. These include approaches such as HIFU, as well as modifications of surgical and radiation techniques, and new drugs and immune therapy approaches. The National Comprehensive Cancer Network, a group assembled from the major comprehensive cancer centers of the U.S., considers that the best care of a cancer patient is afforded by their participation in a clinical trial. Patients with prostate cancer should always ask if there is a clinical trial option for them at any point in their therapy. Clinical trial participation assures you that your treatment has been considered by numerous cancer experts and is at least as good as a standard treatment that you may receive off of a clinical trial. In addition, the results of your treatment will be carefully analyzed in anonymous fashion, and results can be used to help others.
Complementary and alternative care approaches
In addition to standard types of prostate cancer treatments, there are other approaches that patients may choose during their treatment for their disease.
Some of these treatments are called complementary treatments and may help with control of symptoms or problems the patient may be experiencing. Examples of these include
acupuncture for pain control, yoga
and meditation for relaxation, as well as guided imagery, aromatherapy, and other techniques. Tell your doctors about all treatment approaches you are engaged in. These approaches usually will be of no harm to you, and may be very beneficial. Knowing what you are doing may help your doctor to better understand and coordinate your treatments and medications. Herbal therapies have been demonstrated in the lab to affect prostate cancer cells, but in many cases, have not been proven to be clinically effective. PC-SPES is an herbal therapy that has been used in the past for prostate cancer. It was associated with an increased risk of blood clots. Thus, prior to taking this or other herbal therapies, discuss these therapies with your doctor.
Be very careful about alternative treatments. The vast majority of medical professionals keep up-to-date on the latest advances, or are willing to research them for patients when asked. No truly effective treatments are being withheld from patients, though alternative care providers often say they are in an attempt to sell patients on their types of treatment. Such alternative therapies can do harm to patients, and can interfere with conventional treatment. Alternative care providers can be reasonably said to be preying on the desperation of cancer patients.
If nutritional supplements
are suggested in addition to conventional therapy by an alternative care professional, tell all your doctors what you are taking. Some nutritional substances can interfere with the effectiveness of some conventional cancer treatments. Some "natural" substances can be toxic and can result in side effects or problems your regular doctor may not recognize unless they know what you are taking.
Prostate cancer patients, like all cancer patients, are frightened. Discuss your anxiety
and concerns with your primary care doctor, urologist, and radiation and medical oncologists. They have many ways to help
