Prostate Cancer
(Cancer of the Prostate; Prostatic Carcinoma)
Definition
Prostate cancer is a disease in which cancer cells grow in the prostate gland. The prostate is a walnut-sized gland in men. It surrounds the urethra. The prostate makes a fluid that is part of semen. This disease occurs in men.
Prostate Cancer
Cancer occurs when cells in the body (in this case prostate cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissue and spread to other parts of the body. A benign tumor does not invade or spread.
The sooner prostate cancer is treated, the better the outcome. Call your doctor right away if you think you have this condition.
Causes
The cause of prostate cancer is unknown. However, research shows that certain risk factors are linked to the disease.
Risk Factors
These factors increase your chance of developing prostate cancer. Tell your doctor if you have any of these risk factors:
- Age: 55 or older
- Race: Black
- Family history of prostate cancer, especially father or brother
- Family history of prostate cancer diagnosed at a young age
- A high-fat diet
Symptoms
If you have any of these symptoms do not assume it is due to prostate cancer. These symptoms may also be caused by other, less serious health conditions, such as benign prostatic hyperplasia (BPH) or an infection. Tell your doctor if you have any of these:
- A need to urinate frequently, especially at night
- Difficulty starting urination or holding back urine
- Not able to urinate
- Weak or interrupted urine flow
- Painful or burning urination
- Difficulty having an erection
- Painful ejaculation
- Blood in urine or semen
- Frequent pain or stiffness in the lower back, hips, or upper thighs
Diagnosis
Your doctor will ask about symptoms and medical history, and perform a physical exam.
Tests:
- Digital rectal exam—examination of the rectum with the doctor's gloved finger inserted into your rectum
- Urine test—to check for blood or infection
- Blood test—to measure prostate specific antigen (PSA) and prostatic acid phosphatase (PAP)
Other tests to learn more about the cause of your symptoms are:
- Transrectal ultrasonography—a test that uses sound waves and a probe inserted into the rectum to find tumors
- Intravenous pyelogram —series of x-rays of the organs of the urinary tract
- Cystoscopy —the doctor looks into the urethra and bladder through a thin, lighted tube
- Biopsy —removal of a sample of prostate tissue to test for cancer cells
Treatment
Once prostate cancer is found, tests are done to find out if the cancer has spread and, if so, to what extent. Treatment depends on how far the cancer has spread. Talk to a radiation oncologist and urologist. They can help you decide the best treatment plan. Discuss the benefits and risks of each treatment option.
Standard treatment options:
Watchful Waiting
There is no treatment with watchful waiting. Your doctor will do tests to see if the cancer is growing. Watchful waiting is for:
- Early stage prostate cancer that seems to be growing slowly
- Older prostate cancer patients or those with serious medical problems that may make the treatment risks outweigh the possible benefits
Surgery
Surgery involves removing the cancerous tumor and nearby tissues, and possibly nearby lymph nodes. Surgery is offered to patients who are in good health and are younger than 70 years old. Types of surgery:
-
Pelvic lymphadenectomy—removal of lymph nodes in the pelvis to determine if they contain cancer
- If they do, removal of the prostate and other treatment may be recommended.
- Radical retropubic prostatectomy —removal of the entire prostate and nearby lymph nodes through an incision in the abdomen
- Radical perineal prostatectomy
—removal of the entire prostate through an incision between the scrotum and the anus
- Nearby lymph nodes are sometimes removed through a separate incision in the abdomen.
- Transurethral resection of the prostate (TURP)
—removal of part of the prostate with an instrument inserted through the urethra
- TURP is not a cancer surgery, but can be used to relieve the symptoms if you have either prostate cancer or an enlarged gland due to other reasons.
Prostate cancer surgery can cause impotence . It can also cause leakage of urine from the bladder or stool from the rectum. Nerve-sparing surgery may reduce these risks. But this kind of surgery may not effectively treat very large tumors or tumors that are very close to nerves.
Robotic surgery and laparoscopic surgery may be other options. These minimally invasive techniques can reduce side effects, blood loss, and recovery time.
Radiation Therapy
Radiation therapy involves the use of radiation to kill cancer cells and shrink tumors. Radiation may be:
- External radiation therapy—radiation is directed at the tumor from a source outside the body
- Internal radiation therapy—radioactive materials placed into the body near the cancer cells
Internal radiation therapy is often used for treating earlier stage cancers. Radiation therapy for prostate cancer may cause impotence and urinary problems. However, most studies show that impotence rates are less for radiation therapy than for standard prostatectomy and slightly less than that for nerve-sparing procedures. Rates of incontinence following radiation therapy are also less than following prostatectomy. But, there is an increased risk of cystitis due to radiation.
Hormone Therapy
Hormone therapy is used for patients whose prostate cancer has spread beyond the prostate or has recurred after treatment. The goal of hormone therapy is to lower levels of the male hormones, called androgens. The main androgen is testosterone. Lowering androgen levels can cause prostate cancers to shrink or grow more slowly, but does not cure cancer. Methods of hormone therapy include:
-
Orchiectomy—a surgical procedure to remove one or both of the testicles, which are the main source of male hormones
- Orchiectomy decreases hormone production. This can shrink or slow the growth of most prostate cancers.
- Luteinizing hormone-releasing hormone (LHRH) agonists—injections that can decrease the amount of testosterone made by the testicles
-
Anti-androgens (eg,
flutamide
,
bicalutamide
)—medications that can block the action of androgens
- These medications are used in combination with orchiectomy or LHRH agonists, a combination called total androgen blockade.
- Drugs that prevent adrenal glands from making androgens (eg, ketoconazole , aminoglutethimide )
-
Estrogens—drugs that prevent the production of testosterone in the testicles
- Estrogens are rarely used today because of the risk of serious side effects.
Hormone therapy for prostate cancer may cause:
- Hot flashes
- Impaired sexual function
- Loss of sexual desire
- Weakened bones
Other Treatment Options
Other treatments are being tested. Patients may want to consider taking part in a clinical trial when weighing treatment options. The treatments that are currently being tested include:
Cryosurgery
Cryosurgery uses an instrument to freeze and destroy prostate cancer cells.
Chemotherapy
Chemotherapy is the use of drugs to kill cancer cells. It may be given in many forms, including: pill, injection, and via a catheter. The drugs enter the bloodstream and travel through the body, killing mostly cancer cells, but also some healthy cells.
One type of chemotherapy is docetaxel (Taxotere). This drug was found to prolong life in men with hormone refractory prostate (HRPC) cancer. (In HRPC, PSA levels continue to rise or the tumor continues to grow despite hormone therapy.)
Biological Therapy
Biological therapy is the use of medications or substances made by the body to increase or restore the body’s natural defenses against cancer. It is also called biological response modifier (BRM) therapy.
High-intensity Focused Ultrasound
This treatment uses an endorectal probe that makes ultrasound (high-energy sound waves). This can destroy cancer cells.
Conformal Radiation Therapy
Conformal radiation therapy uses three-dimensional radiation beams that are conformed into the shape of the diseased prostate. This treatment spares nearby tissue the damaging effects of radiation.
Intensity-Modulated Radiation Therapy (IMRT)
IMRT uses radiation beams of different intensities to deliver higher doses of radiation therapy to the tumor and lower doses to nearby tissues at the same time.
Prevention
Beginning at 50 years old, men should be offered a digital rectal exam and PSA blood test to screen for prostate cancer. Many, but not all professional organizations, recommend a yearly PSA blood test for men over 50 years old. Black men and men with close family members who have had prostate cancer diagnosed at a young age should begin screening at 45 years old. All men should discuss PSA testing with their doctor.
RESOURCES:
American Cancer Society
http://www.cancer.org/
National Cancer Institute
http://www.cancer.gov/
National Prostate Cancer Coalition
http://www.pcacoalition.org/
CANADIAN RESOURCES:
The Canadian Prostate Cancer Network
http://www.cpcn.org/
Prostate Cancer Research Foundation
http://www.prostatecancer.ca/english/home/
References:
All about prostate cancer. American Cancer Society website. Available at: http://www.cancer.org/docroot/CRI/CRI_2x.asp?sitearea=LRN&dt=36 . Accessed June 17, 2008.
Berthold DR, Pond G, DeWit R, et al. Docetaxel plus prednisone or mitoxantrone for advanced prostate cancer: updated survival of the TAX 327 study (abstract). J Clin Oncol . 2007;25:236s.
Definition of HRPC. Hormone Refractory Prostate Cancer website. Available at: http://www.hrpca.org/definitionofhrpc.html . Accessed February 7, 2008.
Know your options: a prostate cancer education program. National Cancer Institute website. Available at: http://www.cancer.gov/PDF/d00d7731-d7a9-4219-aff1-16d62b8cbe96/knowyouroptions.pdf . Accessed November 10, 2005.
Prostate cancer. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated May 2009. Accessed May 6, 2009.
Prostate cancer. National Cancer Institute website. Available at: http://www.cancer.gov/cancertopics/types/prostate . Accessed June 17, 2008.
Prostate cancer (PDQ): treatment. National Cancer Institute website. Available at: http://www.cancer.gov/cancertopics/pdq/treatment/prostate/patient . Accessed November 10, 2005.
Radiation therapy for cancer: questions and answers. National Cancer Institute website. Available at: http://www.cancer.gov/cancertopics/factsheet/Therapy/radiation . Accessed November 10, 2005.
Schröder FH, Hugosson J, Roobol MJ, et al. Screening and prostate-cancer mortality in a randomized European study. N Engl J Med. 2009;360:1320-1328.
Tannock IF, de Wit R, Berry WR, et al. Docetaxel plus prednisone or mitoxantrone plus prednisone for advanced prostate cancer. N Engl J Med . 2004;351:1502.
Last reviewed March 2009 by Rosalyn Carson-DeWitt, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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