Kattan et al developed a nomogram for predicting the 5 year probability of metastatic disease in a patient with localized prostate cancer treated with three dimensional conformal radiation therapy (CRT). The data required for the calculation is available at the time of treatment and can aid decision making for the individual patient. the authors are from Memorial Sloan-Kettering Cancer Center in New York.
Parameters:
(1) clinical stage
(2) biopsy Gleason score (from 2 to 10)
(3) pretreatment PSA in ng/mL
|
Clinical Stage |
Points |
|
T1C |
6 |
|
T2A |
0 |
|
T2B |
34 |
|
T2C |
47 |
|
T3A |
74 |
|
T3B |
75 |
|
T3C |
100 |
|
Gleason Score |
Points |
|
2 |
0 |
|
3 |
0.4 |
|
4 |
0.8 |
|
5 |
1.2 |
|
6 |
3.6 |
|
7 |
14 |
|
8 |
32 |
|
9 |
50 |
|
10 |
68 |
|
Pretreatment PSA |
Points |
|
0.3 |
0 |
|
1 |
5 |
|
3 |
11 |
|
7 |
15 |
|
12 |
20 |
|
18 |
27 |
|
25 |
32 |
|
35 |
38 |
|
50 |
45 |
|
70 |
51 |
|
100 |
57 |
This data can be approximated by 2 equations derived from JMP:
|
PSA in ng/mL |
Points |
|
< 18 |
(-0.047965 * ((PSA)^2)) + (2.21776 * (PSA)) + 1.94811 |
|
>= 18 |
(-0.003623 * ((PSA)^2)) + (0.7853 * (PSA)) + 14.4811 |
total score =
= SUM(points for all 3 parameters)
The total score is then converted to a probability of metastasis within 5 years.
|
Points |
Probability |
|
10.5 |
0.03 |
|
40 |
0.05 |
|
60 |
0.07 |
|
80 |
0.10 |
|
105.4 |
0.15 |
|
122.5 |
0.20 |
|
148.9 |
0.30 |
|
168.6 |
0.40 |
|
185.7 |
0.50 |
|
205.5 |
0.63 |
This data can be approximated by the equation derived from JMP:
probability of metastasis =
= ((0.0000046 * ((points)^3)) + (0.0003334 * ((points)^2)) + (0.0333222 * (points)) + 2.715348) / 100 * 100%
Specialty: Hematology Oncology, Surgery, general, Urology
