Background
Methods
Search strategy
Inclusion and exclusion criteria
Data extraction
Quality assessment
Study | Adequate definition of cases | Representativeness of cases | Selection of control | Definition of control | Control for important factor or additional factor2
| Exposure assessment | Same method of ascertainment for cases and controls | Nonresponse rate3
| Total quality scores |
---|---|---|---|---|---|---|---|---|---|
Kuper et al. [11], 2000 | ★ | ★ | - | ★ | ★ | - | ★ | - | 5 |
Gallus et al. [12], 2002 | ★ | ★ | - | ★ | ★ | - | ★ | - | 6 |
Gelatti et al. [13], 2005 | ★ | ★ | - | ★ | ★★ | ★ | ★ | - | 7 |
Ohfuji et al. [14], 2006 | ★ | ★ | - | ★ | ★★ | - | ★ | - | 6 |
Tanaka et al. [15], 2007 | ★ | ★ | ★ | ★ | ★ | - | ★ | - | 6 |
Montella et al. [16], 2007 | ★ | ★ | - | ★ | ★★ | - | ★ | - | 6 |
Wakai et al. [17], 2007 | ★ | ★ | ★ | ★ | ★ | - | ★ | - | 6 |
Ohish et al. [18], 2008 | ★ | ★ | ★ | ★ | ★★ | - | ★ | - | 7 |
Leung et al. [19], 2011 | ★ | ★ | - | ★ | - | ★ | ★ | - | 5 |
Study | Representativeness of the exposed cohort | Selection of the unexposed cohort | Ascertainment of exposure | Outcome of interest not present at start of study | Control for important factor or additional factor2
| Outcome assessment | Follow-up long enough for outcomes to occur3
| Adequacy of follow-up of cohorts4
| Total quality scores |
---|---|---|---|---|---|---|---|---|---|
Shimazu et al. [20], 2005 | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
Shimazu et al. [20], 2005 | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
Inoue et al. [21], 2005 | - | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 |
Kurozawa et al. [22], 2005 | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | - | 8 |
Hu et al. [23], 2008 | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
Inoue et al. [24], 2009 | - | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 8 |
Johnson et al. [25], 2011 | - | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 |
Statistical analysis
Results
Study characteristics
Author | Design | Study population | Study period and outcome | Case/Control | Coffee consumption | Risk estimate (95% CI) | Covariate adjustments |
---|---|---|---|---|---|---|---|
Kuper et al. [11], 2000 | HCCS | Greece | 1995–1998 HCC incidence | 333/360 | Nondrinkers | 1 | Age, gender, years of schooling, HBsAg and/or anti-HCV status |
<20 cups/week | 1.1 (0.5–2.6) | ||||||
≥20 cups/week | 0.9 (0.4–2.5) | ||||||
Gallus et al. [12], 2002 | HCCS | Greece Italy | 1995–1998 | 834/1912 | Nondrinkers | 1.0 | Age, sex, smoking, alcohol drinking, history of diabetes or hepatitis, education, BMI |
1984–1997 HCC incidence | 1 cup/day | 1.2 (0.9–1.6) | |||||
2 cup/day | 1.0 (0.7–1.3) | ||||||
≥3 cups/day | 0.7 (0.5–1.0) | ||||||
Shimazu et al. [20], 2005 | CS1 | Japan | 1984–1992 Primary liver cancer incidence | 70/22404 | Nondrinkers | 1.0 | Age, sex, smoking, alcohol drinking, history of liver disease |
occasionally | 0.56 (0.33–0.97) | ||||||
≥1 cups/day | 0.53 (0.28–1.00) | ||||||
Shimazu et al. [20], 2005 | CS2 | Japan | 1990–1997 Primary liver cancer incidence | 47/38703 | Nondrinkers | 1.0 | Age, sex, smoking, alcohol drinking, history of liver disease |
occasionally | 1.05 (0.52~2.16) | ||||||
≥1 cups/day | 0.68 (0.31~1.51) | ||||||
Kurozawa et al. [22], 2005 | CS | Japan | 1988–1999 HCC mortality | 258/83966 | Total | Age, sex, smoking, alcohol habits, history of diabetes or liver disease, education | |
Nondrinkers | 1.0 | ||||||
<1 cup/day | 0.83 (0.54–1.25) | ||||||
≥1 cup/day | 0.50 (0.31–0.79) | ||||||
Men | |||||||
Nondrinkers | 1.0 | ||||||
<1 cup/day | 0.91(0.57–1.45) | ||||||
≥1 cup/day | 0.49(0.28–0.85) | ||||||
Women | |||||||
Nondrinkers | 1.0 | ||||||
<1 cup/day | 0.64 (0.27–1.51) | ||||||
≥1 cup/day | 0.51 (0.20–1.31) | ||||||
Inoue et al. [21], 2005 | CS | Japan | 1990–2001 HCC incidence | 334/90452 | Men and women | Age, sex, study area, ethanol intake, green vegetable, green tea and smoking | |
Almost never | 1.0 | ||||||
1–2 day/week | 0.75 (0.56–1.01) | ||||||
3–4 day/week | 0.79 (0.55–1.14) | ||||||
1–2 cups/day | 0.52 (0.38–0.73) | ||||||
3–4 cups/day | 0.48 (0.28–0.83) | ||||||
≥5 cups/day | 0.24 (0.08–0.77) | ||||||
Men | |||||||
Almost never | 1.0 | ||||||
1–2 day/week | 0.74 (0.52–1.05) | ||||||
3–4 day/week | 0.76 (0.50–1.16) | ||||||
1–2 cups/day | 0.55 (0.38–0.80) | ||||||
3–4 cups/day | 0.41 (0.21–0.77) | ||||||
≥5 cups/day | 0.27 (0.09–0.87) | ||||||
women | |||||||
Almost never | 1.0 | ||||||
1–2 day/week | 0.77 (0.43–1.37) | ||||||
3–4 day/week | 0.89 (0.43–1.84) | ||||||
1–2 cups/day | 0.43 (0.20–0.90) | ||||||
3–4 cups/day | 0.89 (0.31–2.59) | ||||||
≥5 cups/day | ----- | ||||||
Gelatti et al. [13], 2005 | HCCS | Italy | 1994–2003 HCC incidence | 250/500 | Nondrinkers | 1.0 | Age, sex, alcohol drinking, HBV and/or HCV infection |
1–2 cups/day | 0.8 (0.4–1.3) | ||||||
3–4 cups/day | 0.4 (0.2–0.8) | ||||||
≥5 cups/day | 0.3 (0.1–0.7) | ||||||
Ohfuji et al. [14], 2006 | HCCS | Japan | 2001–2002 HCC incidence | 73/253 | Nondrinkers | 1.0 | Age, sex, smoking, alcohol drinking, time since first identification of liver disease, BMI, disease severity, family history of liver disease, interferon therapy |
<1 cup/day | 0.61 (0.18–2.03) | ||||||
≥1 cup/day | 0.38 (0.13–1.12) | ||||||
Tanaka et al. [15], 2007 | PCCS | Japan | 2001–2004 HCC incidence | 209/1253 | Nondrinkers | 1.0 | Age, sex, smoking status, heavy alcohol drinking, |
occasionally | 0.33 (0.22~0.48) | ||||||
1–2 cups/day | 0.27 (0.15~0.48) | ||||||
≥3 cups/day | 0.22 (0.11~0.43) | ||||||
Montella et al. [16], 2007 | HCCS | Italy | 1999–2002 HCC incidence | 185/412 | Abstainers | 2.28 (0.99–5.24) | Age, sex, alcohol drinking, HBV and/or HCV infection, education, smoking, alcohol drinking |
<14 cups/week | 1.0 | ||||||
14–20 cups/week | 0.54 (0.27–1.07) | ||||||
21–27 cups/week | 0.57 (0.25–1.32) | ||||||
≥28 cups/week | 0.43 (0.16–1.13) | ||||||
Wakai et al. [17], 2007 | NCCS | Japan | 1988–1990 HCC incidence | 96/3444 | Nondrinkers | 1.0 | Age, sex, smoking, alcohol drinking, consumption of areca,educational levels, ethnicity,source of hospital |
<1 cup/day | 0.77 (0.45–1.32) | ||||||
≥1 cup/day | 0.49 (0.25–0.96) | ||||||
Hu et al. [23], 2008 | CS | Finland | 1997–2002 HCC incidence | 128/60323 | Total | Age, sex, smoking, alcohol drinking, education, study year, diabetes and chronic liver disease BMI and during follow up. | |
0–1 cup/day | 1.0 | ||||||
2–3 cups/day | 0.66 (0.37–1.16) | ||||||
4–5 cups/day | 0.44 (0.25–0.77) | ||||||
6–7 cups/day | 0.38 (0.21–0.69) | ||||||
≥8 cups/day | 0.32 (0.16~0.62) | ||||||
Men | |||||||
0–1 cup/day | 1.0 | ||||||
2–3 cups/day | 0.68 (0.35–1.31) | ||||||
4–5 cups/day | 0.35 (0.18–0.71) | ||||||
6–7 cups/day | 0.31 (0.15–0.63) | ||||||
≥8 cups/day | 0.28 (0.13–0.61) | ||||||
Women | |||||||
0–1 cup/day | 1.0 | ||||||
2–3 cups/day | 0.62 (0.19–2.04) | ||||||
4–5 cups/day | 0.60 (0.20–1.82) | ||||||
6–7 cups/day | 0.58 (0.19–1.82) | ||||||
≥8 cups/day | 0.41 (0.10–1.70) | ||||||
Ohishi et al. [18], 2008 | NCCS | Japan | 1999–2002 HCC incidence | 224/644 | Nondrinkers | 1.0 | Hepatitis virus infection, alcohol consumption, smoking habits, BMI, diabetes mellitus, and radiation dose to the liver |
Daily | 0.40 (0.16–1.02) | ||||||
Inoue et al. [24], 2009 | CS | Japan | 1993–1994 HCC incidence | 110/18815 | Total | Age, sex, area, smoking, alcohol drinking, BMI, diabetes mellitus, green tea consumption, serum ALTlevel, and HBV and HCV infection status | |
Almost never | 1.0 | ||||||
<1 cup/day | 0.67 (0.42–1.07) | ||||||
1–2 cups/day | 0.49 (0.27–0.91) | ||||||
≥3 cups/day | 0.54 (0.21–1.39) | ||||||
Men | |||||||
Almost never | 1.0 | ||||||
<1 cup/day | 0.79 (0.46–1.37) | ||||||
1–2 cups/day | 0.37 (0.17–0.81) | ||||||
≥3 cups/day | 0.32 (0.10–1.10) | ||||||
Women | |||||||
Almost never | 1.0 | ||||||
<1 cup/day | 0.39 (0.15–1.03) | ||||||
1–2 cups/day | 0.92 (0.36–2.38) | ||||||
≥3 cups/day | 0.69 (0.11–4.22) | ||||||
Johnson et al. [25], 2011 | CS | Chinese | 1993–2006 HCC incidence | 362/61321 | Nondrinkers | 1.0 | Age at recruitment, sex, dialect group, year of recruitment, BMI, level of education, consumption of alcoholic beverages, smoking, black tea and green tea intake, and history of diabetes. |
0-<1 drinkers/day | 0.94 (0.63–1.40) | ||||||
1-<2 drinkers/day | 1.17 (0.87–1.56) | ||||||
2-<3 drinkers/day | 0.78 (0.56–1.07) | ||||||
≥3 drinkers/day | 0.56 (0.31–1.00) | ||||||
Leung et al. [19], 2011 | HCCS | HongKong | 2007–2008 HCC incidence | 109/125 | <1 time/week | 1.0 | Age, sex, alcohol drinking, cigarette smoking, tea consumption and physical activity |
1–3 times/week | 0.58 (0.24–1.36) | ||||||
≥4 times/week | 0.41 (0.19–0.89) |
High vsNon/Almost never drinkers
Study | No. of studies | No. of cases | Relative risk (95% CI) | Heterogeneity | ||
---|---|---|---|---|---|---|
Q |
P
| I2(%) | ||||
High versus non/almost never intake | ||||||
All studies | 16 | 3,622 | 0.50 (0.42–0.59) | 16.71 | 0.337 | 10.2% |
Study design | ||||||
Cohort studies | 7 | 1,309 | 0.48 (0.38–0.62) | 2.47 | 0.676 | 0.0% |
Case–control studies | 9 | 2,313 | 0.50 (0.40–0.63) | 12.38 | 0.125 | 36.8% |
Study region | ||||||
Asia | 11 | 1,892 | 0.45 (0.36–0.56) | 7.86 | 0.642 | 0.0% |
Europe | 5 | 1,730 | 0.57 (0.44–0.75) | 7.09 | 0.131 | 43.6% |
Study gender | ||||||
Male | 4 | 583 | 0.38 (0.25–0.56) | 1.83 | 0.609 | 0.0% |
Female | 4 | 247 | 0.60 (0.33–1.10) | 0.94 | 0.815 | 0.0% |
Adjustment for main confoundersa
| ||||||
Adjusted | 11 | 2,512 | 0.54 (0.46–0.66) | 8.5 | 0.581 | 0.0% |
Unadjusted | 5 | 1,110 | 0.39 (0.28–0.54) | 5.34 | 0.254 | 25.1% |