K-ras Mutational Status in Cytohistological Tissue as a Molecular Marker for the Diagnosis of Pancreatic Cancer: A Systematic Review and Meta-Analysis

Table 1

Main characteristics of the studies included.

Study	Country	TP/FP/FN/TN	Number	Invasive	Assay type
Trümper et al., 1994 [14]	Germany	16/0/0/11	1	Moderate	PCR-SSCP + enriched PCR-RFLP
Watanabe et al., 1998 [15]	Japan	19/1/10/36	2	Moderate	PCR-HPA
		22/5/6/32	3	Very	PCR-RFLP
Mora et al., 1998 [16]	Spain	35/0/8/16	4	Minimal	Enriched RFLP-PCR + SSCP
Wenger et al., 1999 [17]	Germany	28/3/8/12	5	Very	PCR + hybridization
Castells et al., 1999 [18]	Spain	28/4/11/22	6	Minimal	PCR-RFLP + SSCP
Okai et al., 1999 [19]	Japan	14/2/5/15	7	Moderate	PCR-RFLP
Futakawa et al., 2000 [20]	Japan	8/4/10/24	8	Moderate	PCR-RFLP
Tada et al., 2002a [21]	Japan	20/0/6/8	9	Minimal	Enriched PCR and enzyme linked minisequence assay
		12/0/7/5	10	Moderate
Dianxu et al., 2002 [22]	China	33/1/3/13	11	Very	PCR-RFLP
Tada et al., 2002b [23]	Japan	10/5/28/57	12	Moderate	PCR-PHFA
		18/8/20/54	13	Moderate	PCR-ELMA
Zheng et al., 2003 [24]	China	45/0/9/12	14	Minimal	PCR-RFLP
Liu et al., 2003 [25]	China	14/1/6/14	15	Moderate	PCR-SSCP
Talar-Wojnarowska et al., 2005 [26]	Poland	20/8/6/15	16	Very	PCR-RFLP
Shi et al., 2008 [27]	USA	16/1/1/8	17	Moderate	LigAmp strategy
Parker et al., 2011 [28]	Spain	94/20/27/71	18	Very	PCR-RFLP
Ogura et al., 2012 [29]	Japan	266/0/40/47	19	Moderate	PCR-direct sequence assay

TP: true positive; FP: false positive; FN: false negative; and TN: true negative.
*According to how the material was obtained, the types of sample used for K-ras analysis were divided into three groups: fine needle aspiration (FNA) was considered minimally invasive, endoscopic retrograde cholangio-pancreatography (ERCP) moderately invasive, and surgery very invasive.