What are the warning signs of prostate cancer?
Prostate cancer gives no typical warning signs that it is present in your body. It often grows very slowly, and some of the symptoms related to enlargement of the prostate are typical of noncancerous enlargement of the prostate, known as benign prostatic hyperplasia (BPH).
With more advanced disease, you may have fatigue, weight loss, and generalized aches and pains.
When the disease has spread to the bones, it may cause pain in the area. Bone pain may present in different ways. In some men, it may cause continuous pain, while in others, the pain may be intermittent. It may be confined to a particular area of the body or move around the body; it may be variable during the day and respond differently to rest and activity. If there is significant weakening of the bone(s), fractures may occur. More common sites of bone metastases include the hips, back, ribs, and shoulders. Some of these sites are also common locations for arthritis, so the presence of pain in any of these areas is not definitive for prostate cancer.
If prostate cancer spreads locally to the lymph nodes, it often does not cause any symptoms. Rarely, if there is extensive lymph node involvement, leg swelling may occur.
In patients with advanced cancer that has spread to the spine, paralysis can occur if the nerves are compressed because of either collapse of the spine or tumor growing into the spine.
If the prostate cancer grows into the floor (bottom) of the bladder, or if a large amount of cancer is present in the pelvic lymph nodes, one or both ureters can be obstructed. Signs and symptoms of ureteral obstruction include decreased urine volume, no urine volume if both ureters are blocked, back pain, nausea, vomiting, and possibly fevers if infections occur.
Blood in the urine and blood in the ejaculate are usually not related to prostate cancer; however, if these are present, you should seek urologic evaluation.
In individuals with widespread metastatic disease, bleeding problems can occur. In addition, patients with prostate cancer may develop anemia. The anemia may be related to extensive tumor in the bone, hormonal therapy, or the length of time you have had the cancer. Because the blood count tends to drop slowly, you may not have any symptoms of anemia. Some individuals with very significant anemia may have weakness, orthostatic hypotension (lowering of the blood pressure when you stand up), dizziness, shortness of breath, and the feeling of being ill and tired. Symptoms of advanced disease and their treatments are listed in Table 4.
What causes prostate cancer? What causes prostate cancer to grow?
The exact causes of prostate cancer are not known. Prostate cancer may develop because of changes in genes. Alterations in androgen (male hormone) related genes have been associated with an increased risk of cancer. Alterations in genes may be caused by environmental factors, such as diet. The more abnormal the gene, the higher is the likelihood of developing prostate cancer. In rare cases, prostate cancer may be inherited. In such cases, 88% of the individuals will have prostate cancer by the age of 85 years. Males who have a particular gene, the breast cancer mutation (BRCA1), have a threefold higher risk of developing prostate cancer than do other men. Changes in a certain chromosome, p53, in prostate cancer are associated with high-grade aggressive prostate cancer.
Table 4. Common Symptom-Directed Treatment Strategies in Advanced Prostate Cancer
EACA, epsilon aminocaproic acid; NSAIDs, nonsteroidal anti-inflammatory drugs.
From Smith JA et al. Urology 1999; 54(suppl 6A):8—14. Reprinted with permission from Elsevier Science.
Prostate cancer, similar to breast cancer, is hormone sensitive. Prostate cancer growth is stimulated by the male hormones testosterone and dihydrotestosterone (a chemical that the body makes from testosterone). Testosterone is responsible for many normal changes, both physical and behavioral, that occur in a man's life, such as voice change and hair growth. The testis makes almost 90% of the testosterone in the body. A small amount of testosterone is made by the adrenal glands (a paired set of glands found above the kidneys that produce a variety of substances and hormones that are essential for daily living). In the bones, a chemical called transferrin, which is made by the liver and stored in the bones, also appears to stimulate the growth of prostate cancer cells. When cancers develop, they secrete chemicals that cause blood vessels to grow into the cancer and bring nutrients to the cancer so that it can grow.