Table 2 Subgroup analysis of flavonoids intake and risk of esophageal, colocteral and gastric cancer.

From: Dietary flavonoid intake and the risk of digestive tract cancers: a systematic review and meta-analysis

Subgroups

Cancer site

No. of

cases

No. of

studies

OR (95% CI)

Heterogeneity test

I2 (%)

P

Geographic locations

 Europe

Esophageal

645

2

0.97 (0.71–1.33)

0

0.931

 America

Esophageal

4558

5

0.87 (0.68–1.11)

0

0.879

Cancer subtype

 ESCC

Esophageal

827

4

0.91 (0.66–1.24)

0

0.827

 EAC

Esophageal

435

2

0.86 (0.62–1.21)

0

0.520

Study design

 Cohort

Esophageal

341

1

0.96 (0.66–1.39)

N/A

N/A

 Case-control

Esophageal

1262

6

0.89 (0.71–1.11)

0

0.930

Geographic locations

 Europe

Colorectal

4847

7

0.96 (0.86–1.08)

34.5

0.165

 America

Colorectal

4112

2

1.14 (0.94–1.39)

0

0.480

Cancer subtype

 Colon

Colorectal

3005

4

0.92 (0.80–1.05)

46.6

0.132

 Rectum

Colorectal

1388

4

0.90 (0.75–1.08)

0

0.482

Study design

 Cohort

Colorectal

6609

7

1.05 (0.93–1.19)

16

0.308

 Case-control

Colorectal

2377

2

0.92 (0.78–1.09)

68.1

0.076

Geographic locations

 Europe

Gastric

1222

5

0.78 (0.62–0.97)

65.8

0.020

 America

Gastric

589

2

1.19 (0.89–1.57)

0

0.488

 Asia

Gastric

334

1

0.62 (0.38–1.08)

N/A

N/A

Study design

 Cohort

Gastric

1277

4

0.86 (0.67–1.09)

74.8

0.008

 Case-control

Gastric

868

4

090 (0.72–1.13)

58.4

0.065

  1. Abbreviations: OR, Odds Ratio; EAC, Esophageal Adenocarcinoma; ESCC, Esophageal Squamous Cell Cancer.