Subgroup

Studies

Total participants

Odds ratio (95% CI)

P value

Model

Heterogeneity (I²)

Age

7

479

1.44 (0.94 - 2.22)

0.09

Random

6%

Sex

8

519

1.06 (0.72 - 1.57)

0.77

Random

0%

Tumor size

6

397

4.38 (2.65 - 7.25)

0.0001

Random

0%

Clinical stage

6

397

5.33 (3.10 - 9.16)

0.00001

Random

0%

LNM stage

3

290

2.89 (1.62 - 5.11)

0.003

Random

0%

DM

2

232

2.09 (1.01 - 4.32)

0.05

Random

0%

Histology Grade

3

258

1.75 (0.52 - 5.93)

0.37

Random

73%