Table 1.

The immunoreactive score (IRS) calculation (IRS: A × B = 0–12).

A (Percentage of Positive Cells)	B (Intensity of Staining)	IRS Score (A × B)
0 = no positive cells	0 = no color reaction	0–1 = negative
1 = <10% of positive cells	1 = mild reaction	2–3 = mild
2 = 10%–50% positive cells	2 = moderate reaction	4–8 = moderate
3 = 51%–80% positive cells	3 = intense reaction	9–12 = strongly positive
4 = >80% positive cells