Table 2 Results of subgroup and meta-regression analyses

From: The prognostic value of phosphorylated Akt in breast cancer: a systematic review

Outcomes, factors and subgroups

No. of studies

No. of patients

Summary HR (95% CI)

Heterogeneity

Meta-regression P-value

Overall survival:

20

6349

1.52 (1.29–1.78)

I2 = 58.4%, P = 0.001

 

1. Population

     

Asian

9

2089

1.71 (1.30–2.26)

I2 = 77.4%, P = 0.000

0.430

Non-Asian

11

4260

1.39 (1.20–1.61)

I2 = 0.0%, P = 0.515

 

2. Sample size

     

<142

11

1078

1.72 (1.35–2.20)

I2 = 38.8%, P = 0.090

0.183

≥142

9

5271

1.36 (1.13–1.64)

I2 = 60.3%, P = 0.010

 

3. ER-positive patients

     

<50%

5

518

1.68 (1.16–2.44)

I2 = 45.9%, P = 0.116

0.353

≥50%

12

5370

1.37 (1.14–1.64)

I2 = 55.1%, P = 0.011

 

4. PR-positive patients

     

<50%

6

1473

1.48 (1.02–2.15)

I2 = 53.4%, P = 0.057

0.680

≥50%

5

2495

1.61 (1.21–2.16)

I2 = 39.0%, P = 0.161

 

5. HER2-positive patients

     

<50%

10

5198

1.50 (1.20–1.88)

I2 = 67.4%, P = 0.001

0.557

≥50%

5

486

1.74 (1.27–2.39)

I2 = 0.0%, P = 0.500

 

6. pAkt overexpression rate

     

<50.4%

11

3741

1.69 (1.33–2.14)

I2 = 61.5%, P = 0.004

0.690

≥50.4%

8

2330

1.50 (1.27–1.77)

I2 = 0.0%, P = 0.793

 

7. Hormonal treatment

     

Yes

1

130

2.17 (1.01–4.68)

NA

0.452

No

19

6219

1.50 (1.28–1.76)

I2 = 59.0%, P = 0.001

 

8. Trastuzumab

     

Yes

3

261

1.63 (0.94–2.81)

I2 = 20.4%, P = 0.285

0.801

No

17

6088

1.51 (1.21–1.78)

I2 = 62.1%, P = 0.000

 

9. Follow-up length

     

<5 years

5

441

1.78 (1.22–2.61)

I2 = 22.5%, P = 0.271

0.398

≥5 years

15

5908

1.47 (1.24–1.74)

I2 = 61.9%, P = 0.001

 

10. Effect measure

     

Hazard ratio

18

6171

1.51 (1.27–1.81)

I2 = 60.1%, P = 0.001

0.766

Risk ratio

2

178

1.56 (1.24–1.97)

I2 = 0.0%, P = 0.523

 

11. Analyzing method

     

Univariate

14

2960

1.56 (1.26–1.93)

I2 = 66.7%, P = 0.000

0.861

Multivariate

6

3389

1.40 (1.12–1.74)

I2 = 24.1%, P = 0.253

 

12. Study quality score

     

<7

12

2594

1.37 (1.13–1.66)

I2 = 54.5%, P = 0.012

0.159

≥7

8

3755

1.81 (1.36–2.42)

I2 = 61.0%, P = 0.012

 

Disease-free survival:

24

8683

1.28 (1.13–1.45)

I2 = 74.2%, P = 0.000

 

1. Population

     

Asian

13

3272

1.36 (1.09–1.69)

I2 = 75.2%, P = 0.000

0.796

Non-Asian

11

5411

1.24 (1.05–1.47)

I2 = 71.2%, P = 0.000

 

2. Sample size

     

<142

11

1095

1.70 (1.28–2.26)

I2 = 58.5%, P = 0.007

0.061

≥142

13

7588

1.13 (1.01–1.28)

I2 = 70.6%, P = 0.000

 

3. ER-positive patients

     

<50%

2

154

1.32 (0.47–3.69)

I2 = 78.8%, P = 0.030

0.796

≥50%

19

7907

1.18 (1.05–1.33)

I2 = 68.5%, P = 0.000

 

4. PR-positive patients

     

<50%

6

2086

1.07 (0.82–1.40)

I2 = 57.8%, P = 0.037

0.315

≥50%

8

4210

1.45 (1.03–2.04)

I2 = 74.2%, P = 0.000

 

5. HER2-positive patients

     

<50%

16

7679

1.21 (1.05–1.40)

I2 = 73.2%, P = 0.000

0.569

≥50%

3

264

1.08 (0.60–1.95)

I2 = 26.8%, P = 0.255

 

6. pAkt overexpression rate

    

<50.4%

13

4438

1.38 (1.14–1.67)

I2 = 66.6%, P = 0.000

0.575

≥50.4%

10

3967

1.27 (0.98–1.63)

I2 = 77.0%, P = 0.000

 

7. Hormonal treatment

     

Yes

3

295

2.74 (1.16–6.52)

I2 = 74.4%, P = 0.020

0.067

No

21

8388

1.21 (1.07–1.36)

I2 = 69.4%, P = 0.000

 

8. Trastuzumab

     

Yes

1

44

0.77 (0.38–1.58)

NA

0.322

No

23

8639

1.30 (1.14–1.47)

I2 = 75.1%, P = 0.000

 

9. Follow-up length

     

<5 years

6

1479

1.60 (0.88–2.89)

I2 = 78.5%, P = 0.000

0.572

≥5 years

18

7204

1.24 (1.10–1.41)

I2 = 73.4%, P = 0.000

 

10. Effect measure

     

Hazard ratio

18

5998

1.42 (1.14–1.75)

I2 = 71.2%, P = 0.000

0.435

Risk ratio

6

2685

1.21 (1.03–1.42)

I2 = 71.3%, P = 0.000

 

11. Analyzing method

     

Univariate

12

3886

1.16 (1.02–1.31)

I2 = 68.8%, P = 0.000

0.106

Multivariate

12

4797

1.65 (1.22–2.22)

I2 = 76.1%, P = 0.000

 

12. Study quality score

     

<7

9

2397

1.14 (1.00–1.31)

I2 = 33.1%, P = 0.153

0.403

≥7

15

6286

1.41 (1.15–1.71)

I2 = 81.4%, P = 0.000

 
  1. Abbreviations: HR = hazard ratio; CI = confidence interval; ER = estrogen receptor; PR = progesterone receptor; HER2 = human epi-dermal growth factor receptor 2; NA = not applicable.