Prostate Cancer
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When should I see my physician for a PSA (Prostate-Specific Antigen) test? PSA and digital rectal exam of the prostate should begin at age 50. In high-risk groups, such as African Americans, men with a family history (i.e. father, grandfather, brother) should begin screening at age 40 or sooner. Check with your physician to determine what is best for you.
Prostate cancer is second only to skin cancer as the most common male cancer in the United States. Each year more than 200,000 men are affected by this disease. Fortunately, most prostate cancers are slow growing and can be detected at an early stage, when most can be cured or watched safely. Risk Factors that may increase your risk of prostate cancer include:
An enlarged prostate (benign prostatic hyperplasia or BPH) does not increase your risk of prostate cancer. Symptoms and Screening Early stage prostate cancer often has no warning signs, making regular screening tests such as PSA and digital rectal exams critically important. Men are more likely to detect prostate cancer early when they have two simple screening tests - a digital rectal exam (DRE) and a prostate-specific antigen (PSA) blood test. During the DRE, your physician will insert a gloved finger into your rectum to feel the size, shape and texture of your prostate. The PSA test determines the level of PSA in a blood sample; high levels may indicate prostate cancer, an enlarged prostate or prostate infection. Men with normal levels of PSA also may have prostate cancer. Prostate specific antigen The PSA test measures the blood level of prostate-specific antigen, an enzyme produced by the prostate. Specifically, PSA is a protease whose normal function is to liquify gelatinous semen after ejaculation, allowing spermatazoa to more easily "swim" through the cervix. PSA levels under 4 ng/mL (nanograms per milliliter) are generally considered normal, while levels over 4 ng/mL are considered abnormal. This is a very generalized guideline as PSA levels can vary widely in men of different ages and with different prostate size etc. In men over 65 levels up to 6.5 ng/mL may be acceptable, depending upon each laboratory's reference ranges. PSA levels between 4 and 10 ng/mL indicate a risk of prostate cancer higher than normal, but the risk does not seem to rise within this six-point range. When the PSA level is above 10 ng/mL, the association with cancer becomes stronger. However, PSA is not a perfect test. Some men with prostate cancer do not have an elevated PSA, and most men with an elevated PSA do not have prostate cancer. PSA levels can change for many reasons other than cancer. Two common causes of high PSA levels are enlargement of the prostate (benign prostatic hypertrophy (BPH)) and infection in the prostate (prostatitis). It can also be raised for several weeks after ejaculation and after catheterization. PSA levels are lowered in men who use medications used to treat BPH or baldness. These medications, finasteride (marketed as Proscar or Propecia) and dutasteride (marketed as Avodart), may decrease the PSA levels by 50% or more. Diagnosis and Staging If further evaluation is needed after the screening tests, a prostate biopsy may be recommended. A biopsy is a procedure in which a sample of prostate tissue is removed and then looked at under a microscope. A core needle biopsy is the main method used to diagnose prostate cancer. The biopsy itself takes about 10 minutes and is usually done in the doctor's office. You will likely be given antibiotics to take before the biopsy and for a few days after to reduce the risk of infection. For a few days after the procedure, you may feel some soreness in the area and will likely notice blood in your urine. You may also have some light bleeding from your rectum, especially if you have hemorrhoids. Many men also see some blood in their semen or have rust colored semen, which can last for several weeks after the biopsy, depending on how frequently you ejaculate. Your biopsy samples will be sent to a pathology lab. There, a pathologist will see if there are cancer cells in your biopsy by looking at the samples under the microscope. If cancer is present, the pathologist will also assign it a grade. Getting the results usually takes at least 10 to 14 days, but it can take longer. In its early stages (T1 and T2), prostate cancer is usually confined to the prostate itself. As the cancer advances, it may move outside the prostate to surrounding tissues, lymph nodes, bones or other parts of the body (Stage T3 or T4). Your tissues also will receive a "Gleason Score" that helps predict how aggressive the cancer is. Gleason Score Grading The Gleason Grading system is used to help evaluate the prognosis of men with prostate cancer. Together with other parameters, it is incorporated into a strategy of prostate cancer staging which predicts prognosis and helps guide therapy. A Gleason score is given to prostate cancer based upon its microscopic appearance. Cancers with a higher Gleason score are more aggressive and have a worse prognosis. Assigning Grades Cancers with Gleason scores of 6 or less are called low-grade or well-differentiated Cancers with Gleason scores of 7 may be called moderately-differentiated or intermediate-grade. Cancers with Gleason scores of 8 to 10 may be called poorly-differentiated or high-grade. Prostate Cancer Staging The stage or the extent of prostate cancer is one of the most important factors in choosing treatment options and predicting a patient's outlook. If a prostate biopsy confirms cancer, more tests will be done to determine how far it has spread within the prostate, to nearby tissues, or to other parts of the body. Common testing used for staging are CT scans of the abdomen and pelvis, bone scans and chest imaging. Treatment of Prostate Cancer Many effective treatments for prostate cancer exist today. With early detection, many patients can be cured. The most appropriate treatment will depend on factors such as age, health, lifestyle and the characteristics of your cancer. :
Watchful waiting / Active Surveillance Watchful waiting, also called "active surveillance," refers to observation and regular monitoring without invasive treatment. Watchful waiting is often used when an early stage, slow-growing prostate cancer is found. Active surveillance may also be suggested when the risks of surgery, radiation therapy, or hormonal therapy outweigh the possible benefits. Other treatments can be started if symptoms develop, or if there are signs that the cancer growth is accelerating (e.g., rapidly rising PSA, increase in Gleason score on repeat biopsy, etc.). For younger men, a trial of active surveillance may not mean avoiding treatment altogether, but may reasonably allow a delay of a few years or more, during which time the quality of life impact of active treatment can be avoided. Published data to date suggest that carefully selected men will not miss a window for cure with this approach. Surgery Radical robotic prostatectomy is performed for aggressive tumors which have not spread beyond the prostate; cure rates depend on risk factors such as PSA level and Gleason grade. However, it may cause nerve damage that significantly alters the quality of life of the prostate cancer survivor. The most common serious complications are loss of urinary control and erectile dysfunction. Reported rates of both complications vary widely depending on how they are assessed, by whom, and how long after surgery, as well as the setting (e.g., academic series vs. community-based or population-based data). Although penile sensation and the ability to achieve orgasm usually remain intact, erection and ejaculation are often impaired. In the event of positive margins or locally advanced disease found on pathology, adjuvant radiation therapy may offer improved survival. Surgery may also be offered when a cancer is not responding to radiation therapy. Radiation therapy Radiation therapy uses ionizing radiation to kill prostate cancer cells. When absorbed in tissue, Ionizing radiation such as Gamma and x-rays damage the DNA in cells, which increases the probability of apoptosis (cell death). Two different kinds of radiation therapy are used in prostate cancer treatment: brachytherapy and external beam radiation therapy. External beam radiation therapy uses a linear accelerator to produce high-energy x-rays which are directed in a beam towards the prostate. A technique called Intensity Modulated Radiation Therapy (IMRT) may be used to adjust the radiation beam to conform with the shape of the tumor, allowing higher doses to be given to the prostate and seminal vesicles with less damage to the bladder and rectum. External beam radiation therapy is generally given over several weeks with daily visits to a radiation therapy center. Permanent implant brachytherapy is a popular treatment choice for patients with low to intermediate risk features, can be performed on an outpatient basis, and is associated with good 10-year outcomes with relatively low morbidity. It involves the placement of about 100 small "seeds" containing radioactive material (such as iodine-125 or palladium-103) with a needle through the skin of the perineum directly into the tumor while under spinal or general anesthetic. These seeds emit lower-energy X-rays which are only able to travel a short distance. Although the seeds eventually become inert, they remain in the prostate permanently. The risk of exposure to others from men with implanted seeds is generally accepted to be insignificant. Radiation therapy is commonly used in prostate cancer treatment. It may be used instead of surgery for early cancers, and it may also be used in advanced stages of prostate cancer to treat painful bone metastases. Radiation treatments also can be combined with hormonal therapy for intermediate risk disease, when radiation therapy alone is less likely to cure the cancer. Some radiation oncologists combine external beam radiation and brachytherapy for intermediate to high risk situations. One study found that the combination of six months of androgen suppressive therapy combined with external beam radiation had improved survival compared to radiation alone in patients with localized prostate cancer. Others use a "triple modality" combination of external beam radiation therapy, brachytherapy, and hormonal therapy. Cryosurgery Cryosurgery is another method of treating prostate cancer. Under ultrasound guidance, metal rods are inserted through the skin of the perineum into the prostate. Highly purified Argon gas is used to cool the rods, freezing the surrounding tissue at -196 °C (-320 °F). As the water within the prostate cells freeze, the cells die. The urethra is protected from freezing by a catheter filled with warm liquid. HIFU - High Intensity Frequency Ultrasound (HIFU) uses ultrasound energy to heat and destroy diseased tissue. Hormonal therapy Hormonal therapy uses antiandrogens to block prostate cancer cells from binding dihydrotestosterone (DHT), a hormone produced in the prostate and required for the growth and spread of most prostate cancer cells. Blocking DHT often causes prostate cancer to stop growing and even shrink. It may also be given to certain men undergoing radiation therapy or surgery to help shrink and prevent return of their cancer. Advanced Disease Treatment for advanced stage prostate cancer focuses on extending life and relieving the symptoms of metastatic disease. Chemotherapy may be offered to slow disease progression and postpone symptoms. Bisphosphonates such as zoledronic acid have been shown to delay skeletal complications such as fractures or the need for radiation therapy in patients with hormone-refractory metastatic prostate cancer. Bone pain due to metastatic disease is treated with opioid pain relievers such as morphine and oxycodone. External beam radiation therapy directed at bone metastases may provide pain relief. Injections of certain radioisotopes, such as strontium-89, phosphorus-32, or samarium-153, also target bone metastases and may help relieve pain. |
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