Fox Chase Cancer Center Study: PSA Nadir Predicts Cancer Recurrence and Death
PHILADELPHIA (November 7, 2001) — A Fox Chase Cancer Center study shows a strong link between post-treatment PSA nadir values and prostate cancer recurrence and death following radiotherapy. The study will be presented at the American Society for Therapeutic Radiology and Oncology Annual Meeting in San Francisco, Ca., on Tuesday, November 6 at 2:55 p.m. PT by Alexandra L. Hanlon, Ph.D., senior statistician at Fox Chase Cancer Center.
Following prostate cancer treatment, a PSA test is administered repeatedly over a period of several months and should drop from its pre-treatment level. The nadir is the lowest value post-treatment. A consensus definition of disease relapse is three rises in the PSA value following treatment.
The study examines the outcomes of 615 men treated at Fox Chase Cancer Center between April 1989 and December 1995 with three-dimensional conformal radiation therapy (3DCRT). Predictors of distant metastasis and death due to prostate cancer were evaluated.
"To our knowledge, this is the first study to demonstrate the overwhelming predictive power of post-treatment PSA nadir and PSADT for distant failure and death due to prostate cancer following external beam irradiation," said Hanlon.
With a median follow-up of 64 months, 186 of the 615 patients experienced PSA relapse, 40 developed distant metastasis, and 18 died of prostate cancer. 48 of the patients who experienced PSA relapse were treated with androgen deprivation.
Ten-year rates of freedom from distant metastasis were 96%, 89%, and 49% for PSA nadir values <1.0, 1.1-2.0, and >2.0 ng/mL. Ten-year survival rates were 96%, 96%, and 78% for post-treatment nadir values <1.0, 1.1-2.0, and >2.0 ng/mL.
Multivariate analysis demonstrated that nadir, tumor stage and grade, radiation dose and androgen deprivation use upon PSA failure were predictive of distant metastasis. For patients with sufficient PSA follow-up for PSA doubling time (PSADT) calculations, multivariate analysis of distant failure from time of biochemical failure demonstrated that PSADT, nadir, and androgen deprivation were independent predictors of distant metastasis.
Multivariate analysis of death due to prostate cancer demonstrated that nadir and palpation stage were the only predictors of death from prostate cancer. "This study has the potential to have an immediate impact on how we treat prostate cancer," said Hanlon. "In particular, physicians will have an earlier indication that the disease may have recurred or that the treatment failed. In addition, these results may be used for the early identification of patients at high risk for distant metastasis who may be directed to applicable Phase III clinical trials."
The other authors on this Fox Chase Cancer Center study are Hasmik Diratzouian and Gerald E. Hanks.
Fox Chase Cancer Center, one of the nation's first comprehensive cancer centers designated by the National Cancer Institute in 1974, conducts basic and clinical research; programs of prevention, detection and treatment of cancer; and community outreach. For more information about Fox Chase activities, visit the Center's web site at www.fccc.edu.
Fox Chase Cancer Center, part of Temple University Health System, is one of the leading cancer research and treatment centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase also was among the first institutions to receive the National Cancer Institute’s prestigious comprehensive cancer center designation in 1974. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are routinely recognized in national rankings, and the Center’s nursing program has achieved Magnet status for excellence three consecutive times. Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research and oversees programs in cancer prevention, detection, survivorship, and community outreach. For more information, call 1-888-FOX-CHASE (1-888-369-2427).