Accuracy of the Kattan nomogram across prostate cancer risk-groups.
ABSTRACT • To investigate the predictive ability of nomograms at the extremes of preoperative clinical parameters by examining the predictive ability across all prostate cancer risk groups.
• The Columbia University Urologic Oncology Database was reviewed: 3663 patients underwent radical prostatectomy from 1988 to 2008. Patients who had received neoadjuvant or adjuvant therapy, or had insufficient clinical parameters for estimation of 5-year progression-free probability using the preoperative Kattan nomogram were excluded. • A total of 1877 patients were included and stratified by D'Amico risk criteria. Mean estimated nomogram progression rates were compared with actuarial Kaplan-Meier survival statistics. • A regression model to predict progression-free survival was fitted with estimated nomogram score and concordance indices were calculated for the entire model and subsequently for each risk group.
• Of 1877 patients, 857 (45.6%) were low risk, 704 (37.5%) were intermediate risk, and 316 (16.8%) were high risk by D'Amico criteria. • Mean estimated nomogram survival and actuarial Kaplan-Meier survival at 5 years were 90.5% and 92.2% (95% CI 89.2-94.3) for low-risk, 76.7% and 77.8% (73.3-81.7) for intermediate-risk, and 65.8% and 60.4% (52.0-67.7) for high-risk groups, respectively. Using nomogram score in the regression model, the c-index for the full model was 0.61. • For low-, intermediate- and high-risk patients independently the c-index was 0.60, 0.59 and 0.57, respectively. When low-, intermediate- and high-risk patients were independently removed from the model the c-index was 0.64, 0.65 and 0.55, respectively. • The c-index for the full model using the categorical nomogram risk scores was 0.67. Similar to the D'Amico model, the c-index improved to 0.69 when intermediate-risk patients were removed from the model.
• The study confirms the ability of preoperative nomograms to accurately predict actuarial survival across all risk groups. • The predictive ability of the nomogram varies by risk group, yet even at the extremes of high-risk and low-risk prostate cancer the nomogram accurately predicts outcome.
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ABSTRACT: Several preoperative prostate cancer nomograms have been developed that predict risk of progression using pretreatment prostate-specific antigen (PSA) level, clinical stage, and biopsy Gleason grade. We describe the development and performance of a new nomogram. The nomogram adds new markers to the standard clinical predictors that reflect the biologic behavior of prostate cancer: pretreatment plasma levels of interleukin-6 soluble receptor (IL6SR) and transforming growth factor beta1 (TGF-beta1). Between November 7, 1994 and December 22, 1997, 714 patients with stage cT1c to cT3a prostate cancer and no prior therapy were treated with radical prostatectomy at the Methodist Hospital, Houston TX. Plasma levels of IL6SR and TGF-beta1 were measured in banked preoperative plasma. With these data, a nomogram was developed to predict the probability of PSA progression within 5 years of surgery. The nomogram was validated with bootstrapping to assess its discrimination and calibration performance. In the multivariable Cox model, PSA (P =.004), IL6SR (P <.001), TGF-beta1 (P <.001), primary Gleason grade (P <.002), and secondary Gleason grade (P =.029) were associated with PSA progression, whereas clinical stage (P =.696) was not. The nomogram seemed to be well calibrated and had a bootstrap-corrected area under the receiver operating characteristic curve (ie, concordance index) of 0.83. For comparison, a nomogram that omitted IL6SR and TGF-beta1 achieved a concordance index of only 0.75. We found that pretreatment plasma levels of IL6SR and TGF-beta1 improved the ability to predict biochemical progression by a prognostically substantial margin. A nomogram including the pretreatment levels of these molecular markers, along with standard clinical markers, has been developed and internally validated.Journal of Clinical Oncology 10/2003; 21(19):3573-9. · 18.04 Impact Factor