October 10, 2005

PSA increase predicts prostate cancer outcome

By David Douglas

NEW YORK (Reuters Health) - The time it takes for
prostate-specific antigen (PSA) levels to double can help
predict the clinical outcome of patients with prostate cancer
who have been treated with combined radiation and hormone
therapy, researchers report in the International Journal of
Radiation Oncology, Biology, Physics.

"Since patients with PSA recurrences after treatment for
prostate cancer have significant variability in subsequent
clinical outcomes, other parameters such as PSA kinetics have
been used to better predict those patients who may develop
symptomatic recurrences or decreased survival," lead
investigator Dr. Andrew K. Lee told Reuters Health.

"Brief PSA doubling time," he continued, "has been shown to
be significant for predicting clinically apparent recurrences."

In the current study, Lee and colleagues at the University
of Texas M. D. Anderson Cancer Center, Houston reviewed data on
621 men with prostate cancer that had not spread to other areas
of the body. Overall, 62 men experienced some degree of
clinical failure and 22 had true clinical failure.

Tumor grade and PSA doubling time of 8 months or less were
independently associated with time to any clinical failure.
This was not true of tumor stage, hormone therapy duration or
radiation dose.

Only hormone therapy duration and a doubling time of 8
months or less were significantly associated with time to true
clinical failure.

The estimated 5-year rate of any clinical failure was 9.4
percent for men with a doubling time of more than 8 months and
60.4 percent for those with a shorter doubling time.
Corresponding values for true clinical failure were 6.5 percent
and 68.5 percent. For estimated 6-year overall survival after
PSA failure, the proportions were 79.1 percent and 29.7

These results, Lee concluded, "further define the role of
using PSA doubling time in predicting which men may have worse
clinical outcomes, including decreased survival, after
combination treatment with radiation and hormonal therapy, and
aid in the selection of patients for more rigorous monitoring
and more aggressive...therapies."

SOURCE: International Journal of Radiation, Biology,
Physics, October 1, 2005.