 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
What is Prostate Cancer?Prostate cancer affects the prostate, a male reproductive gland located just below the bladder and in front of the rectum. About the size of a walnut, the prostate surrounds the bladder neck and part of the urethra, the tube that carries urine from the bladder to the outside of the body. The prostate's primary function is producing fluid for semen, a substance that carries sperm through the urethra as part of the reproduction process. Like other organs in the body, the prostate consists of cells that normally reproduce by dividing in an orderly, controlled way. But when those cells divide in an abnormal, uncontrolled way, they can form a non-cancerous (benign) or cancerous (malignant) growth. In benign growth, the cells do not spread to other parts of the body. This kind of excess growth in the prostate is called benign prostatic hyperplasia, or BPH, an enlargement that affects most older men. In malignant growth, the cells can spread to nearby healthy cells and destroy them, then destructively invade other parts of the body. How Does Prostate Cancer Spread? Most new cases of prostate cancer are detected when the disease is "localized," or still confined to the prostate. These cases are much easier to treat than cases in which the cancer has spread. But if left untreated, localized prostate cancer can spread to almost any organ in the body. Prostate cancer typically migrates first through the lymphatic system to nearby lymph nodes in the pelvis. (Lymph nodes are small masses of tissue distributed throughout the body to combat foreign or infectious agents.) Prostate cancer can also spread through the lymphatic system to more distant lymph nodes, or it can travel through the bloodstream to bones and other tissues. It might spread directly through the prostate to reach surrounding tissue. It could also turn inward, impeding the flow of urine. Tumor Grading/Staging Once prostate cancer has been confirmed, it is "graded" to indicate its level of aggression: how fast it may grow and spread. Tumor aggression is commonly graded by a Gleason score ranging from 2 to 10. A score of 2-4 signifies low aggression, 5-6 denotes moderate aggression, and 7-10 indicates high aggression - the most dangerous types of tumors. Tumors are classified by "stages" to indicate their size and how much they have already spread. Through staging, a physician can determine the most appropriate treatment. There are several staging techniques, some of which are the same methods used to detect prostate cancer. The most common staging system is TNM where T stands for tumor size, N for the degree of spread to the lymph nodes, and M for the presence of metastasis. A number is added to each of these letters to indicate degrees of size and spread.
Risk Factors Men over age 65 are at the greatest risk -- they account for more than 80 percent of all prostate cancer diagnoses. African American men have the highest rate of prostate cancer in the world. According to the American Cancer Society, the incidence rates for prostate cancer are 32 percent higher in African American men than in Caucasian men. Because prostate cancer occurs more often in some families, scientists believe that genetic factors play a strong role in determining the risk for this disease. Numerous studies indicate an increased risk of prostate cancer for men who have a close relative with the disease. Men whose fathers or brothers have had prostate cancer are clearly at risk. Men who have uncles or grandfathers who have had the disease are also at risk. Men who've had both fathers/brothers and uncles/grandfathers with prostate cancer are at the most risk of developing the disease. Studies show that environmental factors also contribute to prostate cancer incidence. And, rates are generally higher in countries where more animal fat is consumed. Prevention tips:
Detecting Prostate Cancer Since prostate cancer in its early, and most treatable, stage often shows no outward signs or symptoms, screening tests are very important. Physicians who are specialists in urology commonly use two tests to help detect the disease. Experts recommend that men begin getting at least one of these at age 40; African American men and men with a positive family history of prostate cancer should begin getting both tests at age 40. Signs and symptoms of prostate cancer can include:
Men who experience any of these symptoms should visit a urologist. Any of these symptoms may also be due to a non-cancerous prostate or unrelated condition. Still, it is important to see a doctor if any of these problems exist. Because prostate cancer has so few symptoms, regular screenings are the best way to detect it in the early stages. If the tumors are found when they are still localized in the prostate, the survival rate is 91 percent, according to the American Cancer Society. In the past 30 years, the survival rates for any stage of this disease have steadily improved, increasing from 50 to 80 percent -- due to more men getting regular screenings. Beginning at age 40, all men should have a digital rectal exam as part of an annual visit to their doctor. In this exam, the doctor inserts a gloved, lubricated finger into the rectum to check for hardness or lumps. The test is simple, quick, and relatively painless. For men age 50 and over, the American Cancer Society recommends a yearly prostate-specific antigen (PSA) blood test. If the results of either the digital rectal exam or the PSA are suspicious, further tests will be done. These tests alone cannot diagnose prostate cancer. If tests indicate that cancer may be present in the prostate, the patient needs a biopsy. A biopsy is a test in which some cells are removed from the abnormal growth, usually with a needle. These cells are then examined under a microscope to check for cancer. Even if the tests do not show cancer, the urologist may recommend surgery or other treatment to relieve urinary difficulties. Important Questions to Ask When a patient is diagnosed with
prostate cancer, he will likely have many questions for his doctor. Here are some of the
most important ones to ask: Is the cancer still confined to the
prostate (localized)? How do you know? At what stage is the cancer? What is its grade; how quickly is
it likely to spread? Are further tests necessary? Why? Should I get a second opinion? Do I need a radical prostatectomy,
or should I consider radiation or another form of treatment? Please define in detail my
treatment options and their projected effectiveness. Why is one treatment or another
best for me? Should I have a combination of treatments? If so, in what sequence? What are the advantages and
disadvantages of each treatment option? What are the risks of complications or side
effects? How are complications such as
impotence and incontinence treated? Is my surgeon a board-certified
urologist with experience in my kind of operation? Does my surgeon belong to a
multidisciplinary team that can accurately explain the treatment options? What will happen if, for the time
being, I choose no treatment other than observation or "watchful waiting"? How
often will I need to be examined? After my treatment, what are the
chances that cancer will recur, and how would we deal with
The options that you and your physician choose for treating your prostate cancer will depend on the tumor's size, amount of spread, aggressiveness, and your own age and general health. Each treatment option has advantages and disadvantages. To help you decide which may be best for you, the following explains in some detail each option, its effectiveness and possible side effects. Surgery The most common method for treating localized prostate cancer in the United States is radical prostatectomy, an inpatient surgical procedure in which the entire prostate and nearby tissue are removed while the patient is under general anesthesia. The prostate may be removed with or without sparing the nerves - one or both of the nearby neurovascular bundles that are essential for sexual potence in most men. Sparing the nerves could allow patients to recover full potency, although there are no pre-surgery guarantees that the nerves can be spared or that sparing them will produce the desired effect. If the prostate cancer truly is localized, prostatectomy - with or without sparing the nerves - may well rid the patient of the disease for the rest of his life. Sometimes during the operation the surgeon will examine nearby lymph nodes with a laparoscope. If cancer is detected in the nodes, indicating that it has spread, the prostate usually will not be removed since there would be little benefit to the patient. To proceed with prostate removal, the surgeon makes an incision either in the abdomen (retropubic approach) or between the scrotum and anus (perineal approach). In the retropubic approach, the surgeon can sample lymph nodes and remove the prostate in one step, saving surgery time. By either method, radical prostatectomy results in impotence in many patients and incontinence (leaking of urine) in some. The risk of impotence - inability to achieve or maintain an erect penis - varies among patients depending on their age and general health, the stage of their cancer and the skill of their surgeon. A number of options are available for treating impotence. Less than 5 percent of radical prostatectomy patients experience severe incontinence (nearly continuous leakage of urine) after surgery, however, up to 30 percent report occasional leakage. For most, leaking eventually stops without treatment. Incontinence can also be treated. Patients undergoing radical prostatectomy generally stay in the hospital three days and leave with a catheter tube in their bladder to drain urine. The catheter usually can be removed after several days. External Beam Radiation Therapy In this non-invasive (no incision) procedure, a linear X-ray machine delivers a beam of well-focused radiation to the prostate in an effort to kill cancer cells. This procedure requires several 15-minute treatments five times a week for seven to eight weeks. It can be done on an outpatient basis; no hospital stay or anesthesia are necessary. Most patients tolerate this procedure very well, although frequent trips to the hospital may be difficult for the elderly. Also, the risks of impotence and incontinence with this treatment are lower than with radical prostatectomy, and there is no risk from surgical bleeding or transfusion. However, there are other risks. Some potential for radiation damage to nearby organs such as the bladder and rectum exists despite modern techniques that allow radiation to be targeted precisely to the tumor. And since the prostate is left in place with this procedure, there is a chance that some cancer may linger and show up again in later years. In addition, several weeks of radiation can cause moderate to heavy fatigue, rectal pains with diarrhea and spasms, and frequent and/or painful urination. And even though the impotence rate is lower than with radical prostatectomy, it still ranges from 30-50 percent. Overall, reports in medical literature show that external beam radiation therapy is effective for treating prostate cancer. Results are especially favorable in the first 10 years after treatment, and some more recent reports reflect good results for 20 years or more. Conformal Radiation Therapy Conformal radiation therapy for prostate cancer is an ultra precise way to deliver radiation to the prostate with maximum sparing of normal tissue. The radiation therapy plan is based on information from CT scanning which is transformed into three dimensional images for planning. This planning allows the treatment planning team to view the tumor in the context of the normal tissues surrounding it. Thus, they are able to conform the high dose volume to the shape of the tumor or target volume, thus offering maximum sparing of normal tissues. This technique thus optimizes the advantages of external beam radiation and is expected to produce less side effect. True conformal treatment delivery requires high technical sophistication in the acquisition and manipulation of diagnostic images and treatment delivery and depends on the multidisciplinary interaction of a team of radiation therapists, dosimetrists, physicists and radiation oncologists. Brachytherapy (Radioactive Seed Implantation) Also a non-invasive outpatient procedure, brachytherapy involves planting tiny radioactive seeds containing Iodine-125 or Palladium-103 into the prostate through specially designed needles guided by ultrasound and X-ray. The seeds slowly emit radiation that kills cancer cells. Brachytherapy is a one-time procedure in which patients are under local spinal anesthesia (epidural) - numb from the waist down. It works like this: After a CT scan confirms that the prostate is suitable for implantation, the doctor uses ultrasound and X-ray to locate it, then inserts 15 to 20 needles between the scrotum and rectum and guides them into the prostate. Through these needles, 90 to 120 radioactive seeds are implanted in the prostate and remain there forever, slowly emitting radiation for about two months. After the implant, the patient goes to the recovery room. X-rays and CT scans are taken, the catheter is removed, and the patient can go home after recovering from the anesthesia. Most can resume normal activities in a few days. Generally, brachytherapy is well tolerated by older patients in poor medical condition, it causes minimal bleeding, and it has relatively few side effects. The most common one is urinary irritation that can last a few months. Medication can prevent or minimize these symptoms. Some patients feel soreness after implantation that may require pain medication. Blood in the urine may occur for several days. There is also a small chance for long-term damage of the bladder or rectum. About 20 to 30 percent of patients experience impotence at one to three years after treatment; however, many patients maintain sexual potency. Of all the methods for treating prostate cancer, brachytherapy has been in use the shortest time. Available data show that it produces good results over six or seven years, but as yet no data is available to draw conclusions about long-term results. Brachytherapy is sometimes combined with external beam radiation therapy or with short-term hormone therapy. Cryosurgery Cryosurgery is an experimental technique that involves freezing the prostate and adjacent tissues at extremely low temperatures with liquid nitrogen in an effort to kill cancer cells. This technique eliminates the risks associated with invasive surgery. In theory it could have a rapid effect, cause little pain and potentially eradicate localized prostate cancer. It requires only brief hospitalization, and chances are good that the patient will retain full urinary continence soon after treatment. However, side effects that have been observed include impotence (in about 80 percent of patients), scarring of the urethra and urinary dysfunction, and irritation of the bladder, urethra, rectal wall and genitalia. Because there are many unanswered questions about this method's effectiveness and side effects, cryosurgery is not yet a widely accepted technique for treating prostate cancer. Observation The behavior of prostate cancer is variable. In many patients, it can grow very slowly and cause no problems in the patient's lifetime. Hence, patients with early-stage, low-grade, localized prostate cancer may restrict their care to regular observation and accept treatment only if the cancer progresses. This "watchful waiting" is an especially common choice among older patients and those with other life-threatening illnesses. Evidence from medical literature indicates that such patients have a reasonably high probability of surviving the cancer for at least 10 years. In general, men younger than 70 and in good health are the best candidates for aggressive therapy. Men over 80 may best be treated with observation, which has low cost and no side effects, thus enabling them to maintain their quality of life. Men between 70 and 80 must make a decision based on their health, quality-of-life issues and aggressiveness of the tumor. The main disadvantage of observation is that, over time, the cancer could advance between check-ups and become incurable if it spreads beyond the prostate. Hormone Therapy Hormone therapy is designed to stop the production of the male hormone testosterone, which is produced in the testicles and stimulates the natural growth of both the prostate and prostate cancer. In general, hormone therapy is used when prostate cancer that has spread beyond the prostate and cannot be successfully treated with surgery or radiation, or when patients are not candidates for those methods because of other illness. This therapy is not a cure; rather, it slows the progress of cancer, eases symptoms, and boosts the patient's survival and quality of life. One form of hormone therapy is surgical removal of the testicles (orchiectomy) to stop production of testosterone at the source. This is a simple procedure that can be performed on an outpatient basis with the patient under local or general anesthesia. In this procedure, which erases the need for further hormone therapy, the scrotum is left intact, so a man's outward appearance changes little. Another therapy is administering hormonally active drugs such as estrogens to reduce testosterone levels in the bloodstream. Some side effects of estrogen are breast development, breast tenderness and a greater incidence of heart disease. Breast development can usually be prevented with a dose of radiotherapy to the breast area. There are newer hormones that have the same effect as orchiectomy and estrogen therapy without the likelihood of breast development or heart problems. However, these are expensive and must be injected regularly for life. In addition, patients may be given hormonal agents called antiandrogens that keep testosterone from helping cancer cells flourish. These also are not curative and may produce side effects, but they have also been shown to prolong life in certain patients. Nearly all patients will experience a remission of their prostate cancer when treated with hormones. However, hormone therapy is also associated with hot flashes, a loss of sex drive, and a loss of sexual capacity. When deciding which form of hormone is best, the patient must consider the cost of the treatment, its known effectiveness and safety, and its likely impact on quality of life. Sometimes various forms of hormone therapy are combined with each other, and sometimes hormone therapies are combined with more established treatments, such as radiation and surgery, to give patients with localized prostate cancer some extra help fighting it. Chemotherapy Some forms of chemotherapy, the use of anti-cancer drugs, may be employed for patients with advanced disease and for whom hormone therapy has failed. In the past it was thought that chemotherapy would do little good, but with earlier diagnosis of prostate cancer, patients are often not as sick when they reach the point of qualifying for this treatment, which can reduce pain and other symptoms of advanced disease, curb tumor growth and increase survival time. Common side effects of chemotherapy are nausea and vomiting, hair loss, anemia, and greater chances of infections and mouth sores. Side effects vary among individuals, but most side effects disappear after treatment stops. The advice of one or more medical oncologists should be sought by patients considering chemotherapy after other forms of treatment have failed. Follow-up Treatment Prostate-specific antigen (PSA) levels in the patient's bloodstream are monitored after prostate surgery and at regular intervals after all prostate cancer therapies. Patients for whom the disease has been eradicated will have no detectable PSA in their blood. Also performed at regular intervals to check for recurrence or spread of cancer are X-rays, bone scans and blood tests. One detection method that has been developed and is under review by the U.S. Food and Drug Administration (FDA) is Prostascint (capromab pendetide), a diagnostic imaging agent that can more accurately pinpoint the extent and location of prostate cancer. Developed by CYTOGEN, Prostascint has completed all three phases of human clinical studies conducted at more than 30 leading medical institutions in the U.S., including The James Cancer Hospital. Prostascint is a monoclonal antibody which, after being administered to the patient via intravenous infusion, locates and attaches to an antigen found on malignant tumors, no matter where they are located in the body. The Prostascint antibody contains an imaging isotope that emits rays detectable by an external gamma camera. This produces an image that reveals the location and extent of the cancer. Clinical studies with Prostascint, both in pre-surgical patients and patients with suspected cancer recurrence, have shown that the product can identify cancer that has spread beyond the prostate, especially in the lymph nodes. This would be a tremendous help to the physician and patient in determining the best surgical or non-surgical treatment.
|
