What is Prostate Cancer?
More Common Than You Think.
According to the American Cancer Society, prostate cancer is the most common form of cancer in adult males. Not surprisingly, it is the second leading cause of cancer-related deaths in men, trailing only lung cancer in its deadliness. If you are an adult male, you have a one-in-six chance of developing prostate cancer during your lifetime.
The prostate is a walnut-sized gland that sits below the bladder and surrounds the upper part of the male urethra. The prostate produces nutrients for sperm and typically enlarges as men age.
Prostate cancer usually affects men over 65 and is rarely seen in men under 40. The disease occurs in African-American males at a higher rate than others. Public awareness of prostate cancer is more important than ever considering that the number of men aged 50 or over in the U.S. will have increased by some 30% from 1995 to 2005.
In its early stages, prostate cancer shows no symptoms. Once they appear, symptoms include weak or interrupted urine flow, difficulty controlling urination, frequent urination, especially at night, painful urination, blood in the urine, and persistent lower back or pelvic pain.
Because symptoms are silent early on, around 20% of prostate cancers are detected after the disease has spread beyond the prostate gland into other tissues or organs, which dramatically impacts a patient's long-term survival. If the cancer is caught while still in the prostate gland, it can be effectively treated, especially with brachytherapy.
How is Prostate Cancer Diagnosed?
Several techniques detect and confirm the presence of prostate cancer. Two basic tests—a DRE and a PSA—determine the presence of abnormalities in your prostate. If the tests uncover abnormalities, a biopsy and an imaging test are usually performed to confirm the presence of cancer and to accurately locate it within the prostate. Once the cancer is identified and localized, a process called cancer staging helps physicians characterize the cancer and how far it has advanced into the body.
DREs and PSAs
There are two ways to initially detect prostate cancer. The first is a digital rectal exam (DRE), which can be performed during your annual physical check-up. The doctor inserts a gloved finger into the rectum to feel the surface of the prostate for abnormalities. The second method, a Prostate Specific Antigen (PSA) test, is a simple blood test that checks your blood for elevated PSA levels, which would suggest an enlarged prostate and the possibility of prostate cancer. The PSA is measured in ng/mL.
PSA Scoring
0-4 Low cancer risk
4-10 Slightly elevated risk
10+ Abnormally Elevated risk
Your doctor may be using a different scoring scale depending upon your age, ethnicity or family history.
Biopsies
If either the DRE or the PSA tests show abnormalities, physicians will generally conduct a biopsy of the prostate, during which the physician will remove a small piece of tissue from the prostate and have it checked for cancer. Biopsies are scored on a scale of 2 to 10. The score is a measure of how quickly the tumor is growing. The higher the score the more aggressive the tumor.
Gleason Scoring for prostate biopsies
2-4 Low Aggressiveness
5-6 Moderate Aggressiveness
7-10 High Aggressiveness
Gleason Grades Diagram (PDF)
Once the biopsy is completed and scored, imaging tests like an MRI, CT scan or ultrasound are used to determine the exact location of the tumor.
Cancer Staging
After the prostate cancer is confirmed and located, the cancer is staged. Cancer staging defines how far the cancer has spread and whether it has moved beyond the prostate. There are four stages.
Stage 1: Cancer in its earliest stage; confined inside the prostate gland.
Stage 2: Cancer is still localized in the prostate, in the form of a hard nodule.
Stage 3: Tumor has spread outside the prostate to surrounding tissues.
Stage 4: Cancer has spread outside to other tissues and possibly other organs.
Most physicians stage prostate cancer with a system called the TNM staging system. The TNM is internationally recognized and essentially describes the stages of prostate cancer and corresponding treatment methods. Another equally effective system is the ABCD/Whitmore-Jewitt system. In either case, your physician will use the system to tell you the stage of your disease and explain the treatment options.
TNM and ABCD Staging Systems Diagrams (PDF)
