Nomogram of Nakanishi et al for Predicting a Low Grade and Low Volume Prostate Cancer

 

Patient selection: man with a single core biopsy positive out of 10-13 cores (extended biopsy scheme)

 

Low volume prostate cancer is defined as both of the following:

(1) volume < 0.5 mL

(2) no Gleason Grade 4 or 5 tumor

 

Parameters:

(1) age in years

(2) PSA density in ng/mL/cc (ranges from 0 to 1)

(3) tumor length in mm

 

points for age =

= MAX(0,(-1.155 * (age in years)) + 86.625)

 

points for PSA density =

= (-100 * (density)) + 100

 

points for tumor length =

= MAX(0,(-6.825 * (length in mm)) + 81.9)

 

total score =

= SUM(points for all 3 parameters)

 

Interpretation:

• minimum score: 0

• maximum score: 240+

• The higher the score the greater the chances that the tumor is small and low grade.

Total Score	Probability Low Grade and Low Volume
< 68.4	< 1%
68.4 -103.3	((0.000039 * ((points)^3)) - (0.006983 * ((points)^2)) + (0.4278 * (points)) - 8.137) / 100
103.3 - 136.7	((0.005158 * ((points)^2)) - (0.783 * (points)) + 30.48) / 100
136.7 - 184.5	((0.00231 * ((points)^2)) + (0.3161 * (points)) - 66.75) / 100
184.5 - 229.5	((-0.008509 * ((points)^2)) + (4.074 * (points)) - 391.9) / 100
> 229.5	> 95%