Equation of Flanagan et al for Approximating the Oncotype™ Recurrence Score (Original Magee Score)

 

Patient selection: woman with invasive breast cancer (types not specified), ideally lymph node negative and ER-positive

 

Paramters:

(1) nuclear grade

(2) mitotic count in 10 high power fields with 0.55 mm high power field diameter (Nikon eclipse 50i scope) or 0.238 square mm

(3) H score for estrogen receptor (from 0 to 300)

(4) H score for progesterone receptor (from 0 to 300)

(5) HER2/neu status

 

H score =

= (percent of cells staining 1+) + (2 * (percent of cells staining 2+)) + (3 * (percent of cells staining 3+))

 

Parameter	Finding	Points
nuclear grade	well-differentiated	1
	moderately differentiated	2
	poorly differenitated	3
mitotic count in 10 hpf	<= 8	1
	9 to 18	2
	>= 19	3
HER2/neu	negative	0
	equivocal	0
	positive (amplified)	1

 

where:

• The cutoffs for the mitotic count would need to be adjusted for different field areas at high power.

 

estimated recurrence score =

= (5.538 * (points for mitotic count)) + (9.486 * (points for HER2 status)) + (5.42 * (points for nuclear grade)) – (0.045 * (H score for ER)) – (0.03 * (H score for PR)) + 13.424

 

Recurrence Score	Risk of Recurrence
<= 17	low
18 to 30	intermediate
>= 31	high

 

Performance:

• The approximated score performed well for Nottingham Grade 1 and 3 tumors. The Oncotype™ score may be helpful in Nottingham Grade 2 or equivocal tumors.