Table 3. EGFR and K-Ras gene status, PTEN protein expression: correlation with clinical response to cetuximab.

	EGFR (FISH)			K-Ras		PTEN
	E	P	A	WT	Mut	Pos	Neg
Clinical response to PR	0	4	6	9	1	10	0
Cetuximab NR	3	12	2	8	9	6	11
Fisher exact test	P<0.05			P<0.05		P<0.001

Abbreviations: PR, partial response; NR, nonresponder; E, eusomy; P, chromosome 7 polysomy; A, EGFR gene amplification; WT, wild type; Mut, mutated; Pos, positive; Neg, negative.