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Accuracy of the Kattan nomogram across prostate cancer risk‐groups
Author(s) -
Korets Ruslan,
Motamedinia Piruz,
Yeshchina Olga,
Desai Manisha,
McKiernan James M.
Publication year - 2011
Publication title -
bju international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 1464-4096
DOI - 10.1111/j.1464-410x.2010.09838.x
Subject(s) - nomogram , medicine , prostatectomy , proportional hazards model , prostate cancer , risk assessment , urology , oncology , cancer , computer security , computer science
Study Type – Diagnostic (exploratory cohort)
Level of Evidence 2b What’s known on the subject? and What does the study add? The Kattan nomogram is one of the most commonly used preoperative prediction tools for estimating individualized risk of biochemical recurrence after radical prostatectomy. However, little is known about this nomogram’s accuracy for patients at the extremes of the risk spectra, as only a small fraction of such patients comprised the cohort used in its development. We examined the accuracy of the Kattan nomogram across various risk groups, and confirmed its ability to accurately estimate risk of recurrence, even for patients with high and low‐risk prostate cancer. OBJECTIVE • 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. PATIENTS AND METHODS • 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. RESULTS • 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. CONCLUSIONS • 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.