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Prostate specific antigen doubling time predicts response to deferred antiandrogen therapy in men with androgen independent prostate cancer
Prostate Specific Antigen Doubling Time Predicts Response to Deferred Antiandrogen Therapy in Men with Androgen Independent Prostate Cancer Michael J. Shulman, M.D., Jose A. Karam, M.D., and Elie A. Benaim, M.D. Departments of Urology, University of Texas Southwestern Dallas Veterans Administration Hospital, Dallas, TX
Medical Center and
Introduction: To identify pretreatment variables predictive of response and duration of response to deferred antiandrogen therapy in men with androgen independent prostate cancer (AIPC). Materials
and Methods:
375 patients receiving androgen deprivation therapy (ADT) for advanced prostate cancer between 1977 and 2002 had medical records available for retrospective review. Inclusion criteria included: (1) diagnosis of AIPC; and (2) treatment with deferred antiandrogen therapy. AIPC was biochemically defined as two consecutive rises in prostate-specific antigen (PSA) levels during ADT. Treatment response to deferred antiandrogen therapy was defined as a greater than or equal to a 50% decline in the pretreatment PSA level. The prognostic value of various pretreatment parameters was determined with the appropriate statistical methods and tested with a Cox proportional hazards model. Results: 36 patients developed AIPC during follow up and were treated with deferred antiandrogen therapy. 12 patients (33.3%) experienced a PSA response. Median PSA failure-free survival was 9.0 months (95% Cl, 5.2 to 12.9). The only pretreatment variable predictive of a PSA response was PSA doubling time (PSADT). The mean PSADT in responders was 12.7 months versus 7.5 months in nonresponders (p = 0.037). Moreover, PSADT was the only statistically significant variable on univariate analysis of PSA failure-free survival in responders (HR 0.202, 95% Cl 0.041 to 0.990, p=O.O49). There was no statistically significant difference in cancer-specific survival between responders and non-responders (p=O. 1501). Conclusion: PSADT predicted both response and duration of response to deferred antiandrogen therapy in patients diagnosed with androgen independent prostate cancer.
Medical Center and
Introduction: To identify pretreatment variables predictive of response and duration of response to deferred antiandrogen therapy in men with androgen independent prostate cancer (AIPC). Materials
and Methods:
375 patients receiving androgen deprivation therapy (ADT) for advanced prostate cancer between 1977 and 2002 had medical records available for retrospective review. Inclusion criteria included: (1) diagnosis of AIPC; and (2) treatment with deferred antiandrogen therapy. AIPC was biochemically defined as two consecutive rises in prostate-specific antigen (PSA) levels during ADT. Treatment response to deferred antiandrogen therapy was defined as a greater than or equal to a 50% decline in the pretreatment PSA level. The prognostic value of various pretreatment parameters was determined with the appropriate statistical methods and tested with a Cox proportional hazards model. Results: 36 patients developed AIPC during follow up and were treated with deferred antiandrogen therapy. 12 patients (33.3%) experienced a PSA response. Median PSA failure-free survival was 9.0 months (95% Cl, 5.2 to 12.9). The only pretreatment variable predictive of a PSA response was PSA doubling time (PSADT). The mean PSADT in responders was 12.7 months versus 7.5 months in nonresponders (p = 0.037). Moreover, PSADT was the only statistically significant variable on univariate analysis of PSA failure-free survival in responders (HR 0.202, 95% Cl 0.041 to 0.990, p=O.O49). There was no statistically significant difference in cancer-specific survival between responders and non-responders (p=O. 1501). Conclusion: PSADT predicted both response and duration of response to deferred antiandrogen therapy in patients diagnosed with androgen independent prostate cancer.