Prostate Cancer
Overview
Prostate cancer is the most common cancer in men and the second most common cause of cancer death in men. It is a cancer which is curable if detected early through digital rectal examinations or PSA blood testing.
Symptoms
Prostate cancer initially causes no symptoms. As the tumor enlarges within the prostate, obstruction of the urine channel can result. This will result in a decreased strength of the urinary stream and more frequent urination. These same symptoms are more commonly seen in the non-cancerous enlargement of the prostate, benign prostatic hyperplasia.
Later, prostate cancer spreads to the lymph nodes and bones. Spread to the lymph nodes usually produces no symptoms. Bone metastases typically develop in the larger bones in the body such as the spine, hips and pelvis. Pain from metastases tends to be continuous and in the bone itself. Arthritic pain on the other hand is usually associated with physical activity and located in a joint or back.
Diagnosis
Prostate cancer is diagnosed through the combination of a digital rectal examination and a blood test to measure prostate specific antigen (PSA). PSA is an enzyme produced in large quantities by the prostate secretory glands. The function of this enzyme is to break down seminal proteins and convert semen from an initial gel form into a liquid. A small amount of PSA leaks out of the prostate and can be measured in the blood. The concentration of PSA in the semen is approximately a million times the level in the bloodstream. All men with a prostate produce PSA. PSA can be elevated by several conditions, including an enlarged prostate, infection or inflammation, trauma and recent sexual activity. An elevated PSA does not confirm the diagnosis of prostate cancer, Similarly, a low PSA does not rule out the presence of prostate cancer. The PSA test is used to assess cancer risk, and may prompt a prostate needle biopsy (link).
Modifications of the PSA test may improve cancer risk assessment. PSA velocity looks at the rate of PSA increase over several years. Men with more rapidly rising levels are more likely to have prostate cancer. Free PSA is enzymatically inactive PSA produced primarily by non-cancerous prostate tissue. A high percentage of free PSA is suggestive of an enlarged prostate, while a low free PSA fraction raises the concern for prostate cancer.
Prostate cancer screening with PSA and a digital rectal examination is recommended for men all men starting at age 50. For men with a family history of prostate cancer or African-Americans, screening should start at age 40. Screening should be discontinued at when the one’s expectancy is less than 10-15 years.
Treatment
Localized Disease
There are a number of options for men with prostate cancer prostate cancer available. Treatments have improved over the past 15-20 years, but there is no perfect comparison to state which is the best treatment. For elderly men one very reasonable option is watchful waiting, with the use of hormonal manipulation in the future if the cancer becomes more active. We also have ongoing studies using active surveillance, initial close monitoring with aggressive treatment later if the cancer becomes more active. The aggressive treatment options when indicated include radiation or surgical removal. Although hotly debated, there does not appear to be one type of radiation that is superior to another, and the same is true for the various types of surgery (Standard and Robot-assisted). It is more important the skills of the treating physician rather than the actual technique being utilized. We offer all the various treatment types here at the University of Washington.
Advanced disease
Hormone therapy
The prostate gland is a male sex gland and susceptible to hormonal manipulation. Prostate cancer cells retain this sensitivity to hormone manipulation. Cutting off the supply of the male hormone testosterone to the tumor cells will cause death of most, but not all prostate cancer cells. Typically, after a period of several years the prostate cells will lose their dependence on testosterone and begin to grow again in the absence of testosterone.
Hormone therapy can be performed in a variety of ways. An orchiectomy is an outpatient surgical procedure in which the testicles are removed. More commonly, injections of LHRH agonists are administered at intervals ranging from monthly to yearly. These hormones signal the testicles decrease testosterone production.
Chemotherapy
In the past chemotherapy was not effective for the treatment of prostate cancer. Now, there are modern chemotherapy treatments which are effective in delaying disease progression. These treatments are usually administered after hormonal manipulation no longer is effective.
Immunotherapy
We are actively pursuing plans for the appropriate use of the newest therapy with some effectiveness against prostate cancer, Provenge. At present it is approved for use similar to chemotherapy.
Clinical Trials
Through our multi-disciplinary clinic and in collaboration with the Seattle Cancer Care Alliance we offer numerous clinical trials for men with prostate cancer. These trials attempt to answer questions as to how best to treat prostate cancer. Some trials involve standard therapies. Other trials evaluate investigational treatments, or combinations of standard therapy with additional investigational treatments.
Self Care
Additional Reading
A Guide to Surviving Prostate Cancer by Patrick Walsh, The Prostate Book by Peter Scardino, The Seattle Cancer Care Alliance Prostate Cancer Website
