Table 3. Details of the immunoreactive scoring system.

		SI [0–3]
IRS [SI × PP]		Negative	Weak (1)	Moderate (2)	Strong (3)
PP [0–4]	Negative (0)	0	0	0	0
	≤10% (1)	0	1	2	3
	≥11%, ≤50% (2)	0	2	4	6
	≥51%,≤80% (3)	0	3	6	9
	≥81% (4)	0	4	8	12

IRS, immunoreactive score; SI, staining intensity; PP, the percentage of positive cells.