Association between Ras association domain family 1A promoter methylation and hepatocellular carcinoma: A meta-analysis

Table 1 Characteristics of included studies in meta-analysis

Author	Year	Country/area	Race	Sample	Method	Case type	Cases (n)	Control type	Controls (n)
Chan et al[22]	2008	Hong Kong	Asian	Serum	MSRE-qPCR	HCC	63	HBV infection	63
Chang et al[23]	2008	China	Asian	Plasma	MSP	HCC	26	Liver cirrhosis	16
Maurizio et al[24]	2011	Italy	Caucasian	Whole blood	MSP	HCC	31	Liver cirrhosis/chronic hepatitis C	33/30
Mohamed et al[25]	2012	Egypt	Caucasian	Plasma	QMSP	HCC	40	HCV infection	40
Azab et al[26]	2011	Egypt	Caucasian	Whole blood	MSP	HCC	20	Liver cirrhosis	14
Zhang et al[27]	2007	Taiwan	Asian	Serum	MSP	HCC	50	HBV infection/HCV infection/coinfection	9/6/2
Huang et al[28]	2011	China	Asian	Plasma	MSRE-qPCR	HCC	72	Liver cirrhosis/chronic inactive hepatitis	25/12

MSP: Methylation-specific polymerase chain reaction (PCR); QMSP: Quantitative methylation-specific PCR; MSRE-qPCR: Methylation-sensitive endonuclease-qPCR; HCC: Hepatocellular carcinoma.

Table 2 Primer sequences used in included studies for detection of Ras association domain family 1A methylation

Author	Year	Method	Forward	Reverse	Annealing T (°C)
Chan et al[22]	2008	MSRE-qPCR	5'-AGCCTGAGCTCATTGAGCTG-3'	5'--ACCAGCTGCCGTGTGG-3'	60
Chang et al[23]	2008	MSP	M 5'-GTGTTAACGCGTTGCGTTGCGTATC-3'	M 5'-AACCCCGCGAACTAAAAACGA-3'	60
			U 5'-TTTGGTTGGAGTGTGTTAATGTG-3'	U 5'-CAAACCCCACAAACTAAAAACAA-3'
Maurizio et al[24]	2011	MSP	NA	NA	NA
Mohamed et al[25]	2012	QMSP	5'-AGCCTGAGCTCATTGAGCTG-3'	5'-ACCAGCTGCCGTGTGG-3'	60
Azab et al[26]	2011	MSP	M 5'-GTGTTAACGCGTTGCGTATC-3';	M 5'-AACCCCGCGAACTAAAAACGA-3';	54
			U 5'-TTTGGTTGGAGTGTGTTAATGTG-3'	U 5'-CAAACCCCACAAACTAAAAACAA-3'
Zhang et al[27]	2007	MSP	M 5'-GTGTTAACGCGTTGCGTATC-3'	M 5'-AACCCCGCGAACTAAAAACGA-3'	60
			U 5'-TTTGGTTGGAGTGTGTTAATGTG-3'	U 5'-CAAACCCCACAAACTAAAAACAA-3'
Huang et al[28]	2011	MSRE-qPCR	5'-AGCCTGAGCTCATTGAGCTG-3'	5'-ACCAGCTGCCGTGTGG-3'	58

M: Methylated sequence; NA: Not available; U: Unmethylated sequence; MSP: Methylation-specific polymerase chain reaction (PCR); QMSP: Quantitative methylation-specific PCR; MSRE-qPCR: Methylation-sensitive endonuclease-qPCR.

Table 3 Quality Assessment of Diagnostic Accuracy Studies-2 results of all included studies

Study	Risk of bias				Applicability concerns
	Patient selection	Index test	Reference standard	Flow and timing	Patient selection	Index test	Reference standard
Chan et al[22]	↑	?	↓	↓	↓	?	↓
Chang et al[23]	↑	?	↓	↓	↓	?	↓
Maurizio et al[24]	↑	?	↓	?	↓	?	↓
Mohamed et al[25]	↑	↓	↓	↓	↓	↓	↓
Azab et al[26]	↑	↓	↓	↓	↓	↓	↓
Zhang et al[27]	↑	↓	↓	↓	↓	↓	↓
Huang et al[28]	↑	?	↓	↓	↓	?	↓

↓: Low risk; ↑: High risk; ?: Unclear risk.

Table 4 Meta-regression results of meta-analysis

Sources	Coefficient (95%CI)	SE	T	P value	τ2	I2Res (%)	Adjusted R2 (%)
Method	1.09 (-0.55-2.73)	0.64	1.71	0.148	0.24	37.16	50.47
Race	0.83 (-1.00-2.66)	0.71	1.17	0.294	0.36	46.68	26.54
Sample	0.88 (-1.09-2.85)	0.77	1.87	0.301	0.36	45.96	26.46