Table 2.

Subgroup analysis by defining HER2 status by Hoffman validation criteria

Not fit Hoffman criteria						Fit Hoffman criteria
Clinicopathological parameters	Number of studies	OR/RR(95% CI)	P	Heterogeneity		Number of studies	OR/RR(95%CI)	P	Heterogeneity
				I 2 (%)	P value				I 2 (%)	P value
Sex	18	1.34(1.15, 1.56)	<0.001	0.0	0.716	15	1.63(1.41, 1.89)	<0.001	42.4	0.042
Age	13	1.01(0.72, 1.41)	0.976	72.0	0.000	14	0.78(0.62, 0.99)	0.038	45.6	0.032
Tumor size	7	0.94(0.70, 1.26)	0.692	0.0	0.486	4	0.55(0.32, 0.96)	0.070	12.6	0.330
Tumor site	10	1.06(0.83, 1.37)	0.632	25.3	0.211	14	1.40(1.14, 1.71)	0.001	25.2	0.182
Lauren’s classification	17	3.67(2.47, 5.47)	<0.001	76.2	<0.001	13	3.03(1.95,4.70)	<0.001	73.4	<0.001
Differentiation grade	16	1.24(0.76, 2.05)	0.390	74.8	<0.001	12	2.71(1.66, 4.44)	<0.001	76.8	<0.001
TNM stage (III+IV vs I+II)	14	1.53(1.05,2.23)	0.026	77.4	<0.001	10	1.23(1.04,1.46)	0.014	0.0	0.939
Lymph node metastasis	13	1.15(1.00, 1.33)	0.057	0.0	0.500	14	1.40(1.19, 1.64)	<0.001	0.0	0.847
Distant metastasis	5	2.58(1.00, 6.67)	0.050	64.8	0.023	4	1.52(1.18, 1.95)	0.001	0.0	0.617
Lymphovascular invasion	6	1.18(0.75, 1.85)	0.468	74.1	0.002	4	2.16(0.87, 5.35)	0.096	0.0	0.421
Overall survival	4	1.95(1.38, 2.51)	<0.001	0.0	0.583	6	1.11(0.68, 1.53)	<0.001	70.8	0.004

OR odds ratio, CI confidence interval, TNM tumor, node, metastasis