Parker et al reported a nomogram for predicting recurrent prostate cancer with extrapelvic extension. This can help to identify a patient who may require more aggressive management. The authors are from the Mayo Clinic.
Patient selection: prostate cancer treated with primary radiation therapy
Outcome: extrapelvic disease
Parameters:
(1) change in PSA in ng/mL from nadir after radiation therapy
(2) time since radiation therapy in years
(3) NCCN risk group
points for delta PSA =
= 6.36 * (change in PSA)
points for time since radiation therapy =
= 105.263 - (5.263 * (time))
NCCN Risk Group
Points
low
0
intermediate
7.8
high
45.8
total score =
= SUM(points for all 3 parameters)
Interpretation:
• minimum score: 0
• maximum score: 241.2
• The higher the score the greater the risk of extrapelvic disease.
Score
Probability of Extrapelvic Disease
< 67.3
< 5%
>= 67.3
X = (0.033705 * (score)) - 5.1844;
probability = 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.79.
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