At What Point Are Prostate Cancer Patients Cured?
Nov. 1, 1999 (Cleveland) -- Patients with prostate cancer whose prostate-specific antigen (PSA) blood levels return to normal range and stay there for at least 5 years after radiation therapy have a high likelihood of being cured of their cancer, according to this study that appears in the Oct. 15 issue of Cancer, a journal published by the American Cancer Society.
Prostate cancer is the most common cancer in men, and the second most fatal. According to figures from the American Cancer Society, 179,300 men will be diagnosed with prostate cancer in 1999, and 37,000 will die from the disease. Although prostate cancer has few, if any, symptoms in its early stages, it is highly treatable. Therefore, the American Cancer Society recommends annual PSA screening and digital rectal examinations in all men aged 50 and older.
In patients who are diagnosed with prostate cancer and undergo treatment, including surgery or radiation therapy, PSA testing is used to determine the effectiveness of treatment. PSA levels below 4.0 are considered normal.
These authors found that patients have a high likelihood of cure if their PSA levels remain normal for about three and a half years following treatment, and rarely have treatment failure if they do well for four years after radiation therapy. In those patients in whom radiation treatment failed, 95% had increasing PSA levels during the first four years after treatment.
"When we treated patients for prostate cancer in the past, we were not able to tell them whether or not they were cured. We could tell them, at treatment initiation, how effective the treatment could be, but we never really knew at what point we could tell them that they were cured," says study co-author Frank A. Vicini, MD, who is at the William Beaumont Hospital in Royal Oak, Michigan, where he performed this study with his colleagues.
But before confirming that treatment has been completely successful, physicians must follow these patients for a sufficient time, Vicini cautions WebMD, especially those with lower PSA levels. Surprisingly, patients with higher PSA levels, which are associated with more advanced cancer, showed treatment failures sooner than those with lower levels, which are associated with cancers that are not as advanced. The authors, therefore, recommend longer follow-up for patients who have a more favorable outlook before radiation therapy to make sure the cancer does not recur.
"[If patients] started out with a very aggressive cancer (high PSA), it will take less time to determine whether they are cured. Conversely, if they have a less aggressive cancer (a lower PSA), it may take a little bit longer before we can say to them that we're 95% certain that they are cured," Vicini tells WebMD.