Table 3.
Adjusted hazard ratios and 95% confidence intervals for associations of alcohol consumption with biliary tract cancer risk by anatomic site in the Biliary Tract Cancers Pooling Project–summary risk estimates from the random-effects meta-analysis*
| Alcohol consumption | No. of noncases†,‡ | Gallbladder cancer |
Intrahepatic bile duct cancer |
Extrahepatic bile duct cancer |
Ampulla of Vater cancer |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of cases‡ | HR (95% CI) | I2, % | No. of cases‡ | HR (95% CI) | I2, % | No. of cases‡ | HR (95% CI) | I2, % | No. of cases‡ | HR (95% CI) | I2, % | ||
| Alcoholic drinks/day | |||||||||||||
| 0 | 716 188 | 456 | (Referent) | 230 | (Referent) | 326 | (Referent) | 161 | (Referent) | ||||
| >0–0.5 | 865 648 | 408 | 1.07 (0.91 to 1.26) | 0.0 | 173 | 0.79 (0.62 to 1.00) | 0.0 | 292 | 0.87 (0.68 to 1.12) | 30.8 | 181 | 1.08 (0.80 to 1.45) | 13.7 |
| >0.5–<1 | 269 152 | 99 | 1.10 (0.87 to 1.39) | 0.0 | 59 | 0.91 (0.65 to 1.26) | 0.0 | 103 | 1.14 (0.82 to 1.58) | 28.4 | 52 | 0.99 (0.69 to 1.41) | 0.0 |
| 1–<3 | 338 965 | 112 | 0.94 (0.74 to 1.21) | 0.0 | 95 | 0.98 (0.73 to 1.31) | 0.0 | 140 | 1.08 (0.74 to 1.58) | 48.3 | 95 | 1.33 (0.99 to 1.80) | 0.0 |
| 3–<5 | 68 509 | 20 | 1.16 (0.69 to 1.94) | 0.0 | 32 | 1.25 (0.77 to 2.02) | 8.5 | 45 | 1.82 (0.98 to 3.39) | 57.2 | 18 | 1.16 (0.66 to 2.01) | 0.0 |
| ≥5 | 42 166 | 9 | 2.39 (0.63 to 9.12) | 64.9 | 24 | 2.35 (1.46 to 3.78) | 0.0 | 22 | 1.02 (0.64 to 1.62) | 0.0 | 14 | 1.59 (0.85 to 2.98) | 0.0 |
| P trend § | .31 | .04 | .84 | .35 | |||||||||
| Continuous per 1 drink | — | — | 0.98 (0.92 to 1.05) | 12.0 | — | 1.03 (1.01 to 1.06) | 0.0 | — | 1.03 (0.98 to 1.08) | 25.3 | — | 1.00 (0.95 to 1.04) | 0.0 |
Adjusted for sex (male, female), race (white, black, Asian and Pacific Islander, other), education (less than high school graduate, high school graduate, some college or post-high school training), body mass index in kg per m2 (<18.5, 18.5–<25, 25–<30, ≥30), history of diabetes (ever vs never diagnosed), birth cohort (1870–1899, 1900–1909, 1910–1919, 1920–1929, 1930–1939, 1940–1949, 1950–1959, 1960–1982), and smoking status (never, former, current). CI = confidence interval; HR = hazard ratio.
No. of noncases: The same noncase group was used for all analyses, except for analyses of intrahepatic bile duct cancer. The Radiation Effects Research Foundation Life Span Study (RERF) did not provide information on intrahepatic bile duct cancer diagnoses, so this study was excluded from these analyses and the maximum noncase group was thus n = 2 267 501.
No. of noncases and No. of cases: Some counts do not add to totals because of missing data. Numbers represent the maximum possible number of participants included in each analysis.
P trend: Two-sided P value for the ordinal variable, calculated using the Wald test.