Smaletz et al developed a nomogram for predicting survival in a patient with progressive metastatic prostate carcinoma who has been treated with castration. This can help the patient reach an informed decision about treatment options. The authors are from Memorial Sloan-Kettering Hospital, Cornell University and UCSF-Mount Sinai Cancer Center (San Francisco).
Parameters:
(1) age of the patient
(2) Karnofsky Performance Scale (KPS)
(3) hemoglobin in g/dL
(4) PSA in ng/mL
(5) LDH in U/L
(6) alkaline phosphatase in U/L
(7) serum albumin in g/dL
Data from the nomogram on page 3979 was extracted and analyzed in JMP. As recommended in the text, PSA, LDH and alkaline phosphatase were analyzed after taking the natural logarithm of the serum value.
points for age =
= (-0.009485 * ((age in years)^2)) + (1.62826 * (age in years)) – 50.383
points for KPS from 50 to 90 =
= (1.39 * (KPS)) – 70.2
where:
• A KPS < 50 indicates a poor prognosis.
• A patient with progressive metastatic prostate cancer is unlikely to have a KPS of 100.
points for hemoglobin =
= (0.2733 * ((hemoglobin)^2)) + (2.73189 * (hemoglobin)) – 25.2261
points for PSA =
= (1.549816 * (LN(serum PSA))) + 0.28684
points for LDH =
= (2.5593 * ((LN(LDH))^2)) - (56.3312 * (LN(LDH))) + 280.7511
points for alkaline phosphatase with value <= 99 U/L =
= (-16.0695 * (LN(alk phos))) + 80.80554
points for alkaline phosphatase with value > 99 U/L =
= (-2.04082 * (LN(alk phos))) + 16.387755
points for albumin from 4.2 to 5.2 g/dL =
= (-10.625 * ((albumin)^2)) + (84.875 * (albumin)) – 127.05
points for albumin from 2.6 to 4.2 g/dL =
= (-4.893 * ((albumin)^2)) + (59.8063 * (albumin)) – 122.6675
total points =
= SUM(points for all 7 parameters)
Interpretation:
• minimum score: 0
• maximum score: > 300
• The higher the score the greater the survival.
|
Score
|
Probability of 1 Year Survival
|
|
< 100
|
< 1%
|
|
100 - 164
|
(0.0000491 * ((points)^2)) - (0.01001 * (points)) + 0.51996
|
|
164 - 200
|
(0.00839 * (points)) – 1.181066
|
|
200 – 287
|
(-0.000057 * ((points)^2)) + (0.033316 * (points)) – 3.88043
|
|
> 287
|
> 98%
|
|
Score
|
Probability of 2 Year Survival
|
|
< 142
|
< 1%
|
|
142 - 208
|
(0.0000433 * ((points)^2)) - (0.01228 * (points)) + 0.881066
|
|
208 - 242
|
(0.0088565 * (points)) – 1.644619
|
|
242 - 292
|
(-0.000053 * ((points)^2)) + (0.036 * (points)) – 5.10183
|
|
> 292
|
> 88%
|
|
Score
|
Median Survival in Months
|
|
< 48
|
< 1
|
|
48 - 156
|
(0.0003499 * ((points)^2)) - (0.02576 * (points)) + 1.44633
|
|
156 - 287
|
(0.0025169 * ((points)^2)) - (0.7926 * (points)) + 69.30957
|
|
> 287
|
> 50
|
Limitations:
• The reference ranges for PSA, LDH, and alkaline phosphatase are not specified.
