Table 4. Sensitivity and specificity of nine top mutated genes between tumor DNA and cfDNA of stage IV GC patients.

	TP53		ARID1A		KMT2C		KMT2D		FAT4		LRP1B		MACF1		CDH1		PLB1
	Tumor DNA mutation		Tumor DNA mutation		Tumor DNA mutation		Tumor DNA mutation		Tumor DNA mutation		Tumor DNA mutation		Tumor DNA mutation		Tumor DNA mutation		Tumor DNA mutation
	Yes	No	Yes	Yes	Yes	No	Yes	No	Yes	No	Yes	No	Yes	No	Yes	No	Yes	No
cfDNA mutation
Yes	3	0	5	0	6	0	8	0	8	0	5	0	4	0	3	0	3	0
No	19	34	15	36	9	41	3	45	1	47	2	49	1	51	1	52	1	52
Sensitivity	13.6%		25%		40%		72.7%		88.9%		71.4%		80%		75%		75%
Specificity	100%		100%		100%		100%		100%		100%		100%		100%		100%

Abbreviations: cfDNA: cell-free DNA; GC: gastric cancer.