Prostate Cancer: Latest Treatments and Emerging Therapies
How does active surveillance or expectant management of early-stage prostate cancer work? continued...
When selecting men for active surveillance, doctors screen out men whose tumors have features that could be signs of faster-growing or more extensive disease. Then they follow the men on active surveillance very closely. If a man has any evidence of disease progression in tissue samples taken during annual biopsies, then treatment will be recommended.
Researchers in Sweden followed a population of men with early-stage prostate cancer for an average of 12.5 years. They found that men with tumors that were small, confined within the prostate, and not of an aggressive type had "excellent" survival. That finding was valid regardless of what age the man was diagnosed. None of the men in the study had cancer that was detected by prostate-specific antigen (PSA) testing. PSA testing is a relatively recent and controversial method for screening for prostate cancer. Part of the controversy stems from the fact it may pick up very early cancers that might not otherwise cause problems.
In a second study, the same group of men were followed even longer. After an average follow-up of 21 years, 91% of the men had died. Sixteen percent of the deaths could be attributed to prostate cancer. Most of the cancers grew slowly for the first 10 to 15 years of the study. But after 15 years of watchful waiting, there was a substantial increase in the number of men who had progression of their cancers. In addition, more of the men developed metastatic prostate cancer. Also, more died from the prostate cancer itself than in the earlier years of the study. The researchers said that the findings support early treatment of prostate cancer. Early treatment is especially beneficial for men who at the time of diagnosis have an estimated life expectancy of 15 years or longer.
Does hormonal therapy or androgen deprivation have a role in localized prostate cancer?
Hormonal therapy, or androgen deprivation, uses drugs or surgery to block the action of testosterone and other hormones on prostate cancer. There is new evidence to suggest it does not offer any survival advantage for men with disease that is confined to the prostate gland. It may, in fact, be harmful compared with expectant management alone.
Androgen deprivation does, however, play an important role in treating men with locally advanced and metastatic prostate cancer. This is the focus of the next section of this article.
What are the options for locally advanced, recurrent, or metastatic prostate cancer?
Locally advanced cancer is called stage III cancer. It refers to cancer that has spread beyond the margins of the prostate gland into the seminal vesicles and/or nearby lymph nodes. Recurrent cancer refers to a previously treated cancer that has returned in the previously treated area. The return is usually signaled by a rise in prostate-specific antigen in the bloodstream after radical prostatectomy or radiation therapy. Metastatic or stage IV cancer refers to the spread of prostate cancer cells through the lymphatic system or bloodstream to other parts of the body. For instance, it might spread through the bloodstream into the bones.