- About Prostate Cancer -
The Prostate
The prostate is part of the male reproductive system,
located just below the bladder and in front of the rectum.
Normally the size of a walnut, the prostate surrounds the urethra
(the tube that empties urine from the bladder) and is itself surrounded by a fibrous layer called the prostatic capsule. The glandular function of the prostate
is to lubricate the urethra just prior to ejaculation and contribute fluid to the semen, which nourishes sperm. After reproductive age, a man's prostate does not serve a useful function, but often causes urinary tract symptoms and has a high rate of cancer.
Prostate Cancer Epidemiology (statistics)
According to government estimates, approximately 186,000 new cases of prostate cancer will be diagnosed in 2008 in the United States and over 28,000 will die of the disease.
By age 50, about one-third of American men have microscopic
evidence of prostate cancer. By age 75, half to three-quarters
of men will have some cancerous changes in the prostate. Many of these cancers remain latent, producing no
signs of symptoms, or serious threat to health.
A smaller percentage of men will be diagnosed with and treated for
prostate cancer. About 16 percent of American men will be
diagnosed with prostate cancer during their lives; 8 percent
will develop significant symptoms; and 3 percent will die
of the disease. There is increasing evidence that screening for prostate cancer results in earlier diagnosis and treatment, thereby reducing the mortality rate from this disease.
About
Prostate Cancer
Prostate cancer is a disease in which
malignant (cancer) cells arise in the glandular (secretory) tissue of the prostate. Prostate cancer is the most common non-skin
malignancy in men and is responsible for more deaths than
any other cancer, with the exception of lung cancer. Approximately
16% of American men are diagnosed with prostate cancer during their lifetime.
After being diagnosed with prostate cancer, a man and his family face several choices regarding
treatment. Decisions involve multiple factors, personal as well
as medical. Before choosing a treatment, it is important
to learn about all the options available. With this knowledge,
a newly diagnosed prostate cancer patient can actively participate
with his doctor in planning his individualized
treatment.
Treatment options and prognosis depend
on several variables:
- PSA - "prostate specific antigen" is a protein made by the prostate and added to semen during ejaculation. A small amount of PSA is released into the blood stream and is a useful marker for certain prostate conditions. The blood test is currently the best-available surrogate marker for prostate cancer screening. It is elevated as prostate cancer reaches higher Grades and Stages, although it can be elevated due to non-malignant conditions, including benign prostate enlargement and infection.
- Tumor Grade - this is a description of how aggressive the cancer cells appear under the microscope. The pathologist evaluates prostate tissue specimens according to a standardized grading system. A score from 1-5 is assigned to the two most prevalent tumor areas identified, with the most common pattern listed first. These two scores are added together for the total Gleason score. Typically, the score is reported in the format "Gleason 3+4=7". Grades 2-6 are low grade cancers; grade 7 is intermediate; grades 8-10 are high grade. Grades 6 and 7 are the most common. The higher the score, the higher the risk of disease progression.
- Tumor Stage - this is a description of where the tumor is. If the cancer is identified by screening tests, and no metastatic disease is identified, then the tumor is described as low stage. For patients with PSA<10 and Gleason Grade 6 or less, no further evaluation is generally needed. Imaging studies often used to stage higher risk prostate cancer are bone scans, CT scans, and MRIs. There is a somewhat complex system (TNM system) that describes tumor stage precisely.
- Age, overall health, life expectancy. It is well-known that a large proportion of elderly men have prostate cancer when they die of something else. This implies there is a risk of overtreating some men, who would never become symptomatic from prostate cancer. If a man has multiple significant illnesses or a life expectancy less than 10 years, then it is of questionable benefit to screen for, diagnose, or treat prostate cancer.
With greater public awareness, screening has led to early
detection in a higher proportion of men and mortality rates are declining.
Additionally, new advances in medical technology are enabling
cancer patients to continue to live active and productive lives
after prostate cancer treatment.
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