Table 1.

Summary of characteristics of studies in the meta-analysis

Study	Number of patients	Treatment approaches	Genotyping methods	Age	Male (%)
Z.H. Cao (2015)	186	Cisplatin-based chemotherapy	PCR-RFLP	19.2 ± 9.4	57.53
Z.F. Liu (2015)	115	Cisplatin-based chemotherapy	MALDI-TOF MS	–	56.52
Y.J. Sun (2015)	175	Chemotherapy	PCR-RFLP	17.8 ± 9.7	66.28
W.P. Ji (2015)	214	Cisplatin-based chemotherapy	PCR-RFLP	18.7 ± 11.5	62.15
Q. Zhang (2015)	260	Cisplatin-based chemotherapy	PCR-RFLP	18.4 ± 8.5	43.84
L.M. Yang(2012)	187	Neoadjuvant chemotherapy	PCR-RFLP	17.7 ± 9.6	56.68

PCR-RFLP polymerase chain reaction restriction fragment length polymorphism assay, MALDI-TOF MS matrix-assisted laser desorption/ionization time-of-flight mass spectrometry method, – unavailable