Table 2. Meta-analysis: HR value in lung cancer subgroups according to histology and stage.

	Nb	Patients	Combined HR (95% CI)	χ2heterogeneity test (P)
Overall	10	1695	1.68(1.42–1.93)	0.113
Asian	6	1041	1.33(1.62–1.70)	0.415
Caucasian	4	654	1.96(0.42–2.30)	0.348
Adenocarcinoma	3	560	1.75(1.38–2.52)	0.134
Stage I	4	315	2.51(1.23–3.79)	0.928

Abbreviations: HR: hazard ratio; Nb: number of studies; CIs: confidence intervals.