The prostate is a walnut-sized glandular (secretory) component of the male reproductive system. It is located just below the bladder and in front of the rectum. The urethra runs through the prostate much like the hole through a donut. Surrounding the prostate is a fibrous layer called the prostatic capsule. The function of the prostate is to lubricate the urethra with secretions just prior to ejaculation. This fluid is a small contribution to the semen, which nourishes and protects sperm. After reproductive age, a man's prostate does not serve a useful function, but often causes bothersome urinary symptoms due to BPH and is high-risk for developing into cancer.
Prostate Cancer Epidemiology (statistics)
According to American Cancer Society and government estimates, in 2009 approximately 192,000 new cases of prostate cancer were diagnosed with and 27,000 men died of prostate cancer.
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 arises from the secretory tissue of the prostate. With loss of the normal regulation of cell growth and division, tumor formation results. Prostate cancer is the most common non-skin malignancy in men and is responsible for more deaths than any other cancer except lung cancer. Approximately 16% of American men are diagnosed with prostate cancer during their lifetime.
Age is the strongest predictor of prostate cancer. Over 2/3 of all prostate cancers are diagnosed in men 65 and older. If a man lives long enough, it is almost certain he will develop prostate cancer. Determining if that cancer represents a real threat to life is another issue. Autopsies performed on elderly men often reveal prostate cancer that was not diagnosed during life. This means that many men die with prostate cancer, not from it. Race is another risk factor for developing prostate cancer with African Americans having the highest risk, followed by caucasians, Hispanics, and Asians.
After being told of the diagnosis of prostate cancer, a man and his family should consider the available treatment options. Before selecting 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.
Prognosis and Choice of Treatment 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. Although far from perfect, PSA is currently the best-available marker for prostate cancer screening. PSA usually rises as prostate cancer progresses to more aggressive or higher volume of disease. But it can also be elevated due to non-malignant conditions, including benign prostate enlargement, infection, and trauma.
- Tumor Grade - describes how aggressive the cancer appears under a microscope. The pathologist evaluates prostate tissue specimens according to the standardized Gleason 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 - describes where the tumor is. Prostate cancer identified by screening tests is generally low stage. If the PSA is less than 10 and the grade is Gleason 6 or less, no evaluation for metastatic disease is indicated. Imaging studies are used to stage higher risk prostate cancer, such as when the PSA is greater than 10 or the grade is Gleason 7 or higher. These studies include bone scans, CT scans, and MRIs.
- 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 there is likely more risk than possible benefit in screening for, diagnosing, or treating 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 prostate cancer to be detected earlier and allowing patients live active and productive lives after prostate cancer treatment.