- Prostate cancer is cancer that occurs in the prostate — a small walnut-shaped gland in men that produces the seminal fluid that nourishes and transports sperm.
- Prostate cancer is one of the most common types of cancer in men. Usually prostate cancer grows slowly and is initially confined to the prostate gland, where it may not cause serious harm.
- However, while some types of prostate cancer grow slowly and may need minimal or even no treatment, other types are aggressive and can spread quickly.
- Prostate cancer that's detected early — when it's still confined to the prostate gland— has a better chance of successful treatment.
- It's not clear what causes prostate cancer.
- Doctors know that prostate cancer begins when some cells in your prostate become abnormal.
- Mutations in the abnormal cells' DNA cause the cells to grow and divide more rapidly than normal cells do.
- The abnormal cells continue living, when other cells would die.
- The accumulating abnormal cells form a tumor that can grow to invade nearby tissue. Some abnormal cells can also break off and spread (metastasize) to other parts of the body.
Prostate cancer may cause no signs or symptoms in its early stages.
Prostate cancer that's more advanced may cause signs and symptoms such as:
- Trouble urinating
- Decreased force in the stream of urine
- Blood in semen
- Discomfort in the pelvic area
- Bone pain
- Erectile dysfunction
Surgery involves the removal of the prostate and some surrounding healthy tissue during an operation. A surgical oncologist is a doctor who specializes in treating cancer using surgery. For prostate cancer, a urologist or urologic oncologist is the surgical oncologist involved in treatment. The type of surgery depends on the stage of the disease, the man’s overall health, and other factors.
Surgical options include:
- Radical (open) prostatectomy. A radical prostatectomy is the surgical removal of the entire prostate and the seminal vesicles. Lymph nodes in the pelvic area may also be removed. This operation has the risk of affecting sexual function. Nerve-sparing surgery, when possible, increases the chance that a man can maintain his sexual function after surgery by avoiding surgical damage to the nerves that allow erections and orgasm to occur. Orgasm can occur even if some nerves are cut because these are 2 separate processes. Urinary incontinence is also a possible side effect of radical prostatectomy. To help resume normal sexual function, men can receive drugs, penile implants, or injections. Sometimes, another surgery can fix urinary incontinence.
- Robotic or laparoscopic prostatectomy surgery is possibly much less invasive than a radical prostatectomy and may shorten recovery time. A camera and instruments are inserted through small keyhole incisions in the patient’s abdomen. The surgeon then directs the robotic instruments to remove the prostate gland and some surrounding healthy tissue. In general, robotic prostatectomy causes less bleeding and less pain, but the sexual and urinary side effects can be similar to those of a radical (open) prostatectomy. Talk with your doctor about whether your treatment center offers this procedure and how it compares with the results of the radical (open) prostatectomy.
- Bilateral orchiectomy is the surgical removal of both testicles. It is described in detail in “Systemic treatments” below.
- Before surgery, talk with your health care team about the possible side effects from the specific surgery you will have. Typically, younger or healthier men may benefit more from a prostatectomy. Younger men are also less likely to develop permanent erectile dysfunction and urinary incontinence after a prostatectomy than older men.
- Radiation therapy Radiation therapy is the use of high-energy rays to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time.
The types of radiation therapy used to treat prostate cancer include:
- External-Beam Radiation Therapy is the most common type of radiation treatment. The radiation oncologist uses a machine located outside the body to focus a beam of x-rays on the area with the cancer. Some cancer centers use conformal radiation therapy (CRT), in which computers help precisely map the location and shape of the cancer. CRT reduces radiation damage to healthy tissues and organs around the tumor by directing the radiation therapy beam from different directions to focus the dose on the tumor.
- Brachytherapy or Internal Radiation Therapy is the insertion of radioactive sources directly into the prostate. These sources, called seeds, give off radiation just around the area where they are inserted and may be left for a short time (high-dose rate) or for a longer time (low-dose rate). Low-dose-rate seeds are left in the prostate permanently and work for up to 1 year after they are inserted. However, how long they work depends on the source of radiation. High-dose-rate brachytherapy is usually left in the body for less than 30 minutes, but it may need to be given more than once.
- Intensity-Modulated Radiation Therapy (IMRT) is a type of external-beam radiation therapy that uses CT scans to form a 3D picture of the prostate before treatment. A computer uses this information about the size, shape, and location of the prostate cancer to determine how much radiation is needed to destroy it. With IMRT, high doses of radiation can be directed at the prostate without increasing the risk of damaging nearby organs.
- Proton Therapy also called proton beam therapy, is a type of external-beam radiation therapy that uses protons rather than x-rays. At high energy, protons can destroy cancer cells. Current research has not shown that proton therapy provides any more benefit to men with prostate cancer than traditional radiation therapy. It is also more expensive.
- Focal Therapies are less-invasive treatments that destroy small prostate tumors without treating the rest of the prostate gland. These treatments use heat, cold, and other methods to treat cancer, primarily for men with low-risk or intermediate-risk prostate cancer. They are being studied and most have not been endorsed as standard treatment options. Focal therapies are usually done as part of clinical trials.
- Cryosurgery also called cryotherapy or cryoablation, is a type of focal therapy. It is the freezing of cancer cells with a metal probe inserted through a small incision in the area between the rectum and the scrotum, the skin sac that contains the testicles. It is not an established therapy or standard of care for men newly diagnosed with prostate cancer. Cryosurgery has not been compared with radical prostatectomy or radiation therapy, so doctors do not know if it is a comparable treatment option. Its effects on urinary and sexual function are also not well known.
- High-intensity focused ultrasound (HIFU) is a heat-based type of focal therapy. During HIFU treatment, an ultrasound probe is inserted into the rectum and then sound waves are directed at cancerous parts of the prostate gland. This treatment is designed to destroy cancer cells while limiting damage to the rest of the prostate gland. The FDA approved HIFU for the treatment of prostate tissue in 2015. HIFU may be an attractive option for some patients, but knowing who may benefit most from this treatment is still unknown. Similarly, HIFU should only be performed by a specialist with extensive expertise. You will need to carefully discuss with your doctor if HIFU is the best treatment for you.
- Doctors use treatments such as ADT, chemotherapy, and novel agents to reach cancer cells throughout the body. This is called systemic treatment.
- ADT is used to treat prostate cancer in different situations, including locally advanced, recurrent prostate cancer, and metastatic prostate cancer. Some of the situations in which ADT may be used include:
- Men with NCCN-based intermediate-risk and high-risk prostate cancer who are having definitive therapy with radiation therapy are candidates for ADT. Definitive therapy is a treatment given with the intent to cure the cancer. Men with intermediate-risk prostate cancer should receive ADT for at least 4 to 6 months. Those with high-risk prostate cancer should receive ADT for 24 to 36 months.
- ADT may also be given to men who have had surgery and microscopic cancer cells were found in the removed lymph nodes. ADT is done to eliminate any remaining cancer cells and reduce the chance the cancer will return. This is known as adjuvant therapy. Although the use of adjuvant ADT is controversial, some specific patients appear to benefit from this approach.
Specific types of ADT
- Bilateral orchiectomy. Bilateral orchiectomy is the surgical removal of both testicles. It was the first treatment used for metastatic prostate cancer more than 70 years ago. Even though this is an operation, it is considered an ADT because it removes the main source of testosterone production, the testicles. The effects of this surgery are permanent and cannot be reversed.
- LHRH stands for Luteinizing Hormone-Releasing Hormone Medications known as LHRH agonists prevent the testicles from receiving messages sent by the body to make testosterone. By blocking these signals, LHRH agonists reduce a man’s testosterone level just as well as removing his testicles. Unlike surgical castration, the effects of LHRH agonists are often reversible, so testosterone production usually begins again once a patient stops treatment. However, testosterone recovery can take any time from 6 months to 24 months, and for a small proportion of patients, testosterone production does not return.
- LHRH Agonists are injected or placed as small implants under the skin. Depending on the drug used, they may be given once a month or once a year. When LHRH agonists are first given, testosterone levels briefly increase before falling to very low levels. This effect is known as a “flare.” Flares occur because the testicles temporarily release more testosterone in response to the way LHRH agonists work in the body. This flare may increase the activity of prostate cancer cells and cause symptoms and side effects, such as bone pain in men with cancer that has spread to the bone.
- LHRH Antagonist also called a gonadotropin-releasing hormone (GnRH) antagonist, stops the testicles from producing testosterone like LHRH agonists, but they reduce testosterone levels more quickly and do not cause a flare. The FDA has approved degarelix (Firmagon), given by monthly injection, to treat advanced prostate cancer. One side effect of this drug is that it may cause a severe allergic reaction.
- LHRH agonists and antagonists lower testosterone levels in the blood, anti-androgens block testosterone from binding to so-called “Androgen Receptors” which are chemical structures in cancer cells that allow testosterone and other male hormones to enter the cells. These drugs include bicalutamide (Casodex), flutamide (Eulexin), and nilutamide (Nilandron) and are taken as pills. Anti-androgens are usually given to men who have “hormone-sensitive” prostate cancer, which means that the prostate cancer still responds to testosterone suppression therapy. Anti-androgens are not usually used by themselves to treat prostate cancer.
- Combined androgen blockade Sometimes anti-androgens are combined with bilateral orchiectomy or LHRH agonist treatment to maximize the blockade of male hormones. This is because even after the testicles are no longer producing hormones, the adrenal glands still make small amounts of androgens. Many doctors also feel that this combined approach is the safest way to start ADT, as it prevents the possible flare that sometimes happens in response to LHRH agonist treatment. Some, but not all, research has shown that combined androgen blockade can help patients live longer than treatment with just ADT, surgery, or LHRH agonists or antagonists. Therefore, some doctors prefer to give combined drug treatment, while others may only give the combination early in the treatment to prevent the flare.
- Intermittent ADT was given for the patient’s lifetime or until it stopped controlling the cancer, and then other treatment options were considered. During the past 2 decades, researchers have studied the use of intermittent ADT, which is ADT that is given for specific times (most commonly 6 months) and then stopped temporarily to allow for testosterone levels to recover. For these patients, ADT is restarted when the PSA begins to rise again. When to restart therapy (that is, at which PSA levels) remains controversial. Using ADT in this way may lower the side effects related to the lack of testosterone and improve a patient’s quality of life. This approach most benefits patients who have no evidence of metastases. Intermittent ADT has not been shown to be as effective as or better than lifelong ADT in men with metastatic disease.