Anti-EGFR treatment resistance in patients with wild-type RAS metastatic colorectal cancer: Three case reports

Table 2 Summary of literature on acquired resistance to anti-EGFR therapy

Resistance mechanism	Detection source	Number of cases (%)	Ref.
KRAS gene mutation	Tissue	1/10 (10)	Montagut et al[5]
	Serum	9/24 (37.5)	Diaz et al[6]
	Tissue and Serum	5/11 (45.5)	Misale et al[7]
	Tissue and Serum	3/7 (42.9)	Bardelli et al[8]
	Serum	22/24 (91.7)	Bettegowda et al[9]
	Serum	3/4 (75)	Misale et al[10]
NRAS gene mutation	Serum	9/24 (37.5)	Bettegowda et al[9]
	Serum	2/4 (50)	Misale et al[10]
EGFR gene mutation	Tissue	2/10 (20)	Montagut et al[5]
	Serum	2/24 (8.3)	Bettegowda et al[9]
KRAS gene amplification	Tissue and Serum	1/11 (9.1)	Misale et al[7]
	Serum	4/10 (40)	Mohan et al[11]
HER-2 gene amplification	Tissue	2/2 (100)	Yonesaka et al[12]
MET gene amplification	Tissue and Serum	3/7 (42.9)	Bardelli et al[8]
	Serum	1/10 (10)	Mohan et al[11]