General Information - What is Prostate Cancer?
What is Prostate Cancer?
- Prostate Cancer Statistics
- The Prostate Gland
- What is Cancer?
- What is Prostate Cancer?
- Signs & Symptoms
- Treatment Options
Prostate Cancer Statistics
Prostate cancer is the second most common cancer in American men. The American Cancer Society estimates that:
- About 1 man in 7 will be diagnosed with prostate cancer during his lifetime.
- About 233,000 new cases of prostate cancer will be diagnosed in 2014.
Prostate cancer is the second leading cause of cancer death in American men, behind only lung cancer. The American Cancer Society estimates that:
- About 1 man in 36 will die of prostate cancer.
- About 29,480 men will die of prostate cancer in 2014
Prostate cancer occurs mainly in older men:
- Although prostate cancer is sometimes diagnosed in men in their 30s and 40s, it is usually found after the age of 50.
Prostate cancers exhibit the entire spectrum of cancer aggressiveness:
- Many prostate cancers progress slowly.
- Others can progress rapidly and be lethal.
In the PSA screening era, there has been:
- An 80% decrease in the proportion of patients who have metastatic prostate cancer at diagnosis
- A 45% decrease in the prostate cancer-specific mortality rate
The Prostate Gland
The prostate gland is part of the male reproductive system. It consists of millions of microscopic glands that drain into the urinary channel, called the urethra. The prostate is located just below the bladder and in front of the rectum. The urethra passes through it and into the penis. The prostate is about the size of a walnut.
The prostate's main function is to produce prostate-specific antigen (PSA), which is necessary to liquefy the semen so that sperm can swim out to fertilize the egg.
What is Cancer?
Cancer is a group of many different diseases that all affect cells, the body's basic unit of life. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process helps keep the body healthy.
Malignant tissue is cancer:
- The cancer cells divide out of control.
- They can invade and destroy nearby healthy tissue.
- Cancer cells can break away from the tumor they form and enter the bloodstream and lymphatic system. This is how cancer spreads from the original (primary) tumor to form new tumors in other parts of the body.
The spread of cancer is called metastasis. Most cancers are named for the type of cell or organ in which they begin. When cancer spreads to other parts of the body, the new tumor has the same malignant cells and the same name as the primary tumor. For example, if prostate cancer spreads to the bones, the cancer cells in the new tumor are prostate cancer cells. The disease is metastatic prostate cancer; it is not bone cancer.
Benign tissue is not cancer:
- The cells do not invade nearby tissue or spread to other parts of the body.
Benign Prostatic Hyperplasia
Benign prostatic hyperplasia (BPH) is the abnormal growth of benign prostate cells. In BPH, the prostate grows larger and pushes against the urethra and bladder, blocking the normal flow of urine. Although this condition is seldom life-threatening, it may require treatment to relieve symptoms.
What is Prostate Cancer?
Prostate cancer occurs when the lining cells of the microscopic prostate glands transform from being normal to become frankly malignant and invade into the remaining prostate tissue. Prostate cancer can remain in the prostate gland, or it may spread to nearby lymph nodes. It may also spread to the bones, bladder, rectum, and other organs.
Pre-cancerous changes can also occur in the prostate. These are called prostatic intraepithelial neoplasia (PIN) or, more worrisome, atypical small acinar proliferation (ASAP). These conditions need to be monitored closely, as they may be associated with or turn into prostate cancer in the future.
There are four stages of prostate cancer:
- Stage one: the cancer is confined to the prostate and has not grown large enough to produce a lump that the doctor can feel when performing a digital rectal examination.
- Stage two: the cancer is more advanced and can be felt on digital rectal examination, but it has not spread outside the prostate gland.
- Stage three: the cancer has spread locally beyond the prostate but not to distant sites, such as the bones or lymph nodes.
- Stage four: the cancer has spread to organs in other parts of the body
Signs & Symptoms
In the early stages of prostate cancer:
- There are usually no signs or symptoms.
In its more advanced forms, the symptoms of prostate cancer can include:
- A weakened urine flow
- Frequent or sudden urges to urinate
- Difficulty urinating or emptying the bladder
- Blood in the urine
- Inability to have an erection
If the cancer is very advanced, men may experience symptoms such as:
- Persistent pain in the back or pelvis
- Unexplained weight loss
- Swelling or weakness in the lower body
Many milder symptoms are similar to symptoms of other conditions, such as benign prostatic hyperplasia (BPH) or a urinary tract infection. A physician can help you understand your symptoms and determine if further testing is necessary.
One or more of the following tests can be used to determine if you have prostate cancer and, if so, how aggressive it might be.
Digital Rectal Exam
One of the first tests will likely be a digital rectal exam. During this examination, the doctor inserts a lubricated, gloved finger into the rectum to feel for any abnormalities on the prostate gland, such as hardness or irregularity.
Prostate-Specific Antigen (PSA) Test
The PSA test and the “free” PSA tests are commonly used to detect prostate cancer. PSA is a substance made by the prostate. An unusually high amount of PSA in the blood and a persistent rise in PSA value may be an indication of prostate cancer. If these two tests lead your doctor to believe cancer is present, he or she may recommend an imaging study and/or a prostate biopsy.
PHI and PCA3 Tests
The US Food and Drug Administration (FDA) recently approved these tests as aids to the early detection of prostate cancer. The Prostate Health Index (PHI) is a more accurate form of the PSA test. The PCA-3 test is a gene-based test performed on a urine sample collected after a digital rectal examination.
Prostate Imaging Tests
A trans-rectal ultrasound scan involves inserting a small, lubricated device into the rectum after instilling a local anesthetic. This test uses sound waves to create an image of the prostate gland. Its main role is to guide the biopsy needle during the biopsy procedure.
A multi-parametric MRI (magnetic resonance imaging) scan is an imaging test that can detect regions of the prostate gland that are suspicious for cancer and should be targeted during a biopsy. This test is based upon the principle that water diffuses more slowly through cancerous tissue than through normal tissue.
A biopsy uses a thin needle to remove tiny fragments of tissue so they can be checked for abnormalities. To check the prostate, a needle is inserted either through the ultrasound probe in the rectum or through the skin near the rectum.
The biopsy cores removed from the prostate look like a 1-inch piece of dental floss. A pathologist uses a microscope to check the cores for cancerous tissue.
If cancer is present, the biopsy information is useful in estimating the aggressiveness of the cancer and the likelihood that the cancer is completely confined to the prostate. The pathologist usually reports the grade of the tumor. The grade tells how closely the tumor resembles normal prostate tissue and suggests how fast the tumor is likely to grow. The Gleason system uses scores of 2 to 10. Another system uses G1 through G4. Tumors with lower scores are less likely to grow or spread than tumors with higher scores.
A range of possible treatments exists for men with prostate cancer. The type of treatment depends on factors such as:
- Your health
- Your age
- Your preferences in terms of the benefits risks of potential side effects of the treatments
- The stage of the cancer's progression
Your doctor may recommend active surveillance if the cancer has the microscopic features of a slowly progressing tumor (Gleason grade ≤ 6), the cancer is found in early stages, and you are an older man. Active surveillance monitors the condition with repeated PSA tests and biopsies until it shows evidence of changing. Delayed treatment may be offered if it appears that the tumor is more aggressive than initially suspected.
Surgery is usually the preferred treatment to remove the cancer for younger patients with a tumor that has not advanced beyond the prostate gland.
There are three kinds of surgery:
Radical prostatectomy, where the prostate is removed along with the nearby tissue and seminal vesicles. This may be performed as an “open” operation through a small incision in the lower abdomen or as a “robot-assisted laparoscopic” procedure though six small incisions.
The most concerning possible risks are the possibility of erectile dysfunction (impotency) and urinary incontinence. Northwestern surgeons are nationally and internationally recognized experts in performing “nerve-sparing” radical prostatectomy that preserves potency and urinary continence in the majority of patients. People come from around the US and from foreign countries to access this expertise at Northwestern.
Pelvic lymphadenectomy is used to remove the lymph nodes in the pelvic area. It can be performed in conjunction with either the open or robotic approaches. The lymph nodes are examined for cancer. If it is present, your doctor can determine how to move forward with treatment.
Transurethral resection of the prostate (TURP) is a surgery that removes tumor tissue from the gland that has obstructed the urinary channel. It is not a curative operation, but does serve to relieve urinary symptoms in patients who are not candidates for a radical prostatectomy.
Radiation therapy is used to kill cancer cells or keep the cells from growing. Whether radiation is used, and what type, depends on how far the cancer has progressed. Side effects also include risks for impotence and rectal or urinary problems.
The types of radiation are:
External therapy uses a machine to send radiation to the cancer from outside of the body. These include IMRT (intensity modified radiation therapy), proton beam therapy, and “cyber knife” radiotherapy.
Internal therapy, called seeds or brachytherapy, uses needles guided by ultrasound images to place radioactive seeds inside the body near the prostate.
Androgens (e.g., testosterone and dihydro-testosterone) are male sex hormones that can cause prostate cancer cells to grow. For patients with advanced prostate cancer, the doctor may choose to treat you with androgen-deprivation therapy that will remove the effects of these hormones (by surgically removing both testicles) or, alternatively, decrease their activity in the body with drug therapy.
Hormonal therapy may come with side effects such as loss of sexual desire, poor sexual function, hot flashes, weak bones (with long-term treatment), loss of body muscle, gain of body fat, low energy level, and anemia.
Other Drug Therapies
Other types of drugs may be used to treat prostate cancer. These include:
- Chemotherapy to stop the growth of cells
- Biologic therapy to restore the body's immune system
- Drug therapy to strengthen the bones
Clinical Trials (Investigational Therapy)
Northwestern University houses the National Cancer Institute Robert H. Lurie Comprehensive Cancer Center that participates in clinical trials of new investigational treatments for prostate cancer.