Prostate cancer is the most frequently diagnosed cancer in American men and the second leading cause of cancer deaths. In some Western countries, it has become the leading cause of cancer deaths. As our population ages, the impact of prostate cancer on American men will increase; no other cancer rises in incidence and mortality rate with increasing age as rapidly as does prostate cancer.
It has been estimated that over 1 million American men now alive and over age 50 will eventually die of prostate cancer unless new treatments are developed to control this disease. Unfortunately, prostate cancer has a disproportionate impact on certain segments of our population. For example, African American men are more likely to develop prostate cancer and twice as likely to die from it than are other Americans.
Over the past decade, the incidence of prostate cancer has increased sharply as PSA testing has become widely available. With widespread awareness about prostate cancer and a greater willingness to discuss this disease publicly, more than 50 percent of men over the age of 50 report that they have been tested for prostate cancer within the past two years.
Much of the increased incidence, therefore, has been related to the identification through widespread screening of a large number of prevalent, but previously undetected, cases in the population. The gradual decline in the mortality rate seen in the past five years may be related, in part, to the remarkable sensitivity of PSA in detecting prostate cancer earlier, when it can be controlled with surgery or irradiation therapy.
Prostate cancer is common and primarily affects men older than 65. About 90 percent of men diagnosed with prostate cancer will have clinically localized disease (cancers confined to the prostate gland). Treatment approaches vary by geographic region and by physician specialty. The reasons for this variation are not clear and are not strongly linked to tumor grade (Gleason score) or PSA levels.
Cancer begins in cells, the building blocks that make up tissues. Tissues make up the organs of the body.
Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place.
Sometimes, this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor.
Tumors can be benign or malignant:
Benign tumors are not cancer:
- Benign tumors are rarely life-threatening.
- Generally, benign tumors can be removed. They usually do not grow back.
- Cells from benign tumors do not invade the tissues around them.
- Cells from benign tumors do not spread to other parts of the body.
Malignant tumors are cancer:
- Malignant tumors are generally more serious than benign tumors. They may be life-threatening.
- Malignant tumors often can be removed. But sometimes they grow back.
- Cells from malignant tumors can invade and damage nearby tissues and organs.
- Cells from malignant tumors can spread (metastasize) to other parts of the body. Cancer cells spread by breaking away from the original (primary) tumor and entering the bloodstream or lymphatic system. The cells invade other organs and form new tumors that damage these organs. The spread of cancer is called metastasis.
When prostate cancer spreads, cancer is often found in nearby lymph nodes. If cancer has reached these nodes, it also may have spread to other lymph nodes, the bones, or other organs.
When cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if prostate cancer spreads to bones, the cancer cells in the bones are actually prostate cancer cells. The disease is metastatic prostate cancer, not bone cancer. For that reason, it is treated as prostate cancer, not bone cancer. Doctors call the new tumor "distant" or metastatic disease.