Steyerberg et al developed a model with nomogram for predicting the likelihood of a male with prostate cancer having indolent disease. This can help identify a man who may be able to have less aggressive management. The authors are from Erasmus University in Rotterdam and the Cleveland Clinic.
Parameters:
(1) local prevalence of indolent prostate cancer (over range 20 - 50%)
(2) serum PSA in ng/mL (over range of 1 to 20 ng/mL)
(3) ultrasound prostate volume in cc (over range 20 to 80 cc)
(4) biopsy Gleason score
(5) total mm of cancer tissue in biopsy cores (over range 1 to 20)
(6) total mm of non-cancer tissue in biopsy cores (over range of 40 to 80)
total length of cores in mm =
= (total length of cancer tissue in mm) + (total length of noncancer tissue)
Parameter |
Finding |
Points |
---|---|---|
local prevalence |
20% |
-6 |
|
50% |
0 |
Gleason score |
2 + 2 |
0 |
|
2 + 3 |
1 |
|
3 + 3 |
4 |
points for local prevalence =
= (20 * (local percent) / 100) - 10
PSA |
Points |
---|---|
1 to 6 |
(0.1186 * ((PSA)^2)) - (2.843 * (PSA)) + 17.33 |
6 to 20 |
(-0.2818 * (PSA)) + 5.632 |
points for ultrasound volume =
= (0.1 * (volume in cc)) - 2
Tumor Length |
Points |
---|---|
1 to 5 |
(0.1237 * ((length)^2)) - (1.945 * (length)) + 10.67 |
5 to 20 |
(0.01778 * ((length)^2)) - (0.7408 * (length)) + 7.701 |
points for nontumor length =
= (0.1 * (length)) - 4
total score =
= SUM(points for all 6 parameters)
Total Score |
Probability of Indolent Cancer |
---|---|
< 9 |
< 13% |
9 to 17 |
(0.2933 * ((score)^2)) - (2.742 * (score)) + 13.91 |
17 to 25 |
(-0.2338 * ((score)^2)) + (14.48 * (score)) - 126.9 |
> 25 |
> 90% |
Alternatively:
X =
= (0.25 * (total score)) - 4.196
probability of indolent cancer =
= 1 / (1 + EXP((-1) * X))
Alternatively:
The data can be entered into the formula given in the footnote to Table 4 on page 110.
Purpose: To evaluate a male with prostate cancer for the likelihood of indolent disease using the model of Steyerberg et al.
Specialty: Hematology Oncology, Surgery, general, Urology
Objective: risk factors, severity, prognosis, stage
ICD-10: C61,