Pre-treatment nomogram for disease-specific survival of patients with chemotherapy-naive androgen independent prostate cancer.
OBJECTIVE
Our objective was to develop a nomogram that predicts the probability of cancer-specific survival in men with untreated androgen-independent prostate cancer (AIPC).


METHODS
AIPC was diagnosed in 129 consecutive patients between 1989 and 2002. No patient received cytotoxic chemotherapy. Univariate and multivariate Cox regression models were used to test the association between prostate-specific antigen (PSA) level at initiation of androgen deprivation, PSA doubling time (PSADT), PSA nadir on androgen deprivation therapy (ADT), time from ADT to AIPC, and AIPC-specific mortality. Multivariate regression coefficients were then used to develop a nomogram predicting AIPC-specific survival at 12-60 mo after AIPC diagnosis. Two-hundred bootstrap resamples were used to internally validate the nomogram.


RESULTS
AIPC-specific mortality was recorded in 74 of 129 patients (57.4%). Other-cause mortality was recorded in 7 men (5.4%). Median overall survival was 52.0 mo (mean, 36.0 mo) and median AIPC-specific survival was 54.0 mo (mean, 35.0 mo). In univariate regression models, all variables were significant predictors of AIPC-specific survival (p < or = 0.02). In multivariate models, PSADT and time from androgen deprivation to AIPC remained statistically significant (p < or = 0.004). Bootstrap-corrected predictive accuracy of the nomogram was 80.9% versus 74.9% for our previous model.


CONCLUSIONS
A nomogram predicting AIPC-specific survival is between 13% and 14% more accurate than previous nomograms and 6% more accurate than tree regression-based predictions obtained from the same data. Moreover, a nomogram approach combines several advantages, such as user-friendly interface and precise estimation of individual recurrence probability at several time points after AIPC diagnosis, which all patients deserve to know and all treating physicians need to know.
Svatek
Robert
R
Department of Urology, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd. J8.112, Dallas, Texas 75390-9110, USA.
Karakiewicz
Pierre I
PI
Shulman
Michael
M
Karam
Jose
J
Perrotte
Paul
P
Benaim
Elie
E
D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use*; D019540:Area Under Curve; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049451:Nomograms; D011237:Predictive Value of Tests; D011336:Probability; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000401:mortality* / Q000473:pathology; D012372:ROC Curve; D012189:Retrospective Studies; D016019:Survival Analysis
D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen