Table 3.

Meta-analysis of the PD-1 rs2227981 C > T polymorphism and cancer risk

	No. of study	T vs. C			TT vs. CC			TT+CT vs. CC			TT vs. CT+CC
		OR (95% CI)	P	P (Q-test)	OR (95% CI)	P	P (Q-test)	OR (95% CI)	P	P (Q-test)	OR (95% CI)	P	P (Q-test)
Total	7	0.84 (0.71-1.00)	0.050	0.001	0.67 (0.50-0.91)	0.011	0.032	0.91 (0.74-1.12)	0.381	0.007	0.65 (0.47-0.90)	0.009	0.008
Ethnicity
Asians	2	0.74 (0.63-0.86)	< 0.001	0.647	0.56 (0.31-1.00)	0.051	0.154	0.71 (0.59-0.87)	0.001	0.510	0.61 (0.30-1.27)	0.188	0.073
Caucasians	5	0.90 (0.71-1.14)	0.367	0.001	0.73 (0.49-1.07)	0.101	0.032	1.03 (0.79-1.34)	0.843	0.015	0.66 (0.44-0.99)	0.047	0.009
Cancer type
Breast cancer	2	0.82 (0.71-0.95)	0.009	0.301	0.76 (0.53-1.10)	0.147	0.975	0.76 (0.63-0.92)	0.005	0.159	0.83 (0.59-1.17)	0.292	0.750
Other cancer	5	0.85 (0.66-1.11)	0.238	< 0.001	0.64 (0.41-1.01)	0.056	0.010	1.00 (0.75-1.33)	0.994	0.009	0.58 (0.36-0.92)	0.022	0.003
HWE
Yes	5	0.93 (0.79-1.10)	0.400	0.019	0.77 (0.63-0.93)	0.006	0.446	0.98 (0.74-1.29)	0.871	0.002	0.79 (0.66-0.94)	0.007	0.905
No	2	0.61 (0.45-0.84)	0.002	0.138	0.36 (0.24-0.56)	< 0.001	0.476	0.78 (0.60-1.01)	0.060	0.927	0.32 (0.21-0.49)	< 0.001	0.165

HWE: Hardy-Weinberg equilibrium. Bold values are statistically significant (P < 0.05).