Researchers at Johns Hopkins and The Brady Urological Institute have identified three risk factors and developed a simple reference tool that doctors can use to determine who is at high risk of death after prostate cancer recurrence following surgery.
The new tool - a set of tables that assess a combination of blood tests, the surgical pathology results and time following surgery - can be used to tell which men with recurring cancer after surgery are most likely to die from their renewed disease and would benefit from further treatment.
"We identified three risk factors associated with death from prostate cancer after recurrence that may allow doctors to distinguish early on between those who need further treatment versus those who are relatively safe and can be carefully watched," says Stephen J. Freedland, M.D., instructor of urology at Johns Hopkins and lead investigator of the report published in the July 27, 2005, issue of the Journal of the American Medical Association.
If discovered early through screening, prostate cancer is treatable and is often cured by a surgical procedure called radical prostatectomy. However, as many as one-third of those who undergo surgery will eventually show signs that the cancer has recurred, said Freedland.
The risk factors are based on:
- The amount of time, in months, it takes the level of prostate-specific antigen (PSA) in the blood to double after surgery. The shorter the time, the higher the risk.
- The elapsed time, in years, from surgery to recurrence as measured by the PSA test. Again, the shorter the time the higher the risk.
- The Gleason score (2-10), a microscopic measurement of prostate cancer aggressiveness when viewed under a microscope. Higher scores reflect more aggressive tumors.
An additional finding was that time to death after recurrence for patients in the low-risk group was quite long -- often much longer than 16 years, added Freedland.
To identify the risk factors, the researchers studied 379 patients treated with radical prostatectomy at Johns Hopkins between 1982 and 2000 who had a biochemical (PSA) recurrence - signs of prostate cancer revealed in blood tests - and had at least two PSA tests after recurrence that were separated by at least three months. The researchers found that the time for the PSA to double, the time from surgery to recurrence, and the Gleason score were significant risk factors for predicting time to death from prostate cancer recurrence and that patients could be divided into either a high-risk or a low-risk group. The categories include PSA doubling time (less then three months versus three to 8.9 months versus nine to 14.9 months versus 15 or more months), Gleason score, (seven or lower versus eight to 10), and time from surgery to biochemical recurrence (three years or under versus more than three years).
For example, patients with a PSA doubling time of less then three months (23 patients) had a median survival of six years. Patients with a PSA doubling time of less than three months, biochemical recurrence three or fewer years after surgery, and a Gleason score of eight to 10 (15 patients) had a median survival of three years. However, patients with a PSA doubling time of 15 months or more and a biochemical recurrence more than three years after surgery (82 patients) had a 100 percent survival. Using these three risk factors, the researchers then constructed tables to estimate the risk of prostate cancer-specific survival at five, 10, and 15 years after biochemical recurrence.
"We hope the tables will be useful to patients and their physicians for assessing the risk of death from prostate cancer following recurrence after surgery and guide the need for additional treatments," said Freedland.