Table 1.
Total fiber intake and its change after diagnosis in relation to mortality among colorectal cancer patients (n=1,575)*
| Post-diagnostic total fiber intake | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | HR (95% CI) per 5 g/day |
P for trend |
|---|---|---|---|---|---|---|
| Colorectal cancer-specific mortality | ||||||
| Median intake (interquartile range), g/day | 14.4 (12.8 to 15.8) | 18.2 (16.9 to 20.8) | 22.2 (20.1 to 24.8) | 28.9 (25.2 to 32.2) | ||
| No. of events (n=174) | 56 | 40 | 40 | 38 | ||
| No. of person-years (n=14,210) | 3,335 | 3,614 | 3,475 | 3,786 | ||
| Mortality rate (per 1,000 person-years) | 16.8 | 11.1 | 11.5 | 10.0 | ||
| Age, sex, stage-adjusted HR (95% CI) † | 1 (referent) | 0.68 (0.49-0.96) | 0.55 (0.39-0.78) | 0.63 (0.45-0.89) | 0.83 (0.72-0.95) | 0.006 |
| Multivariable-adjusted HR (95% CI) ‡ | 1 (referent) | 0.72 (0.50-1.03) | 0.48 (0.32-0.71) | 0.54 (0.35-0.85) | 0.78 (0.65-0.93) | 0.006 |
| All-cause mortality | ||||||
| No. of events (n=773) | 223 | 185 | 180 | 185 | ||
| Mortality rate (per 1,000 person-years) | 66.9 | 51.2 | 51.8 | 48.9 | ||
| Age, sex, stage-adjusted HR (95% CI) † | 1 (referent) | 0.76 (0.65-0.90) | 0.69 (0.58-0.82) | 0.66 (0.56-0.78) | 0.87 (0.82-0.92) | <0.001 |
| Multivariable-adjusted HR (95% CI) ‡ | 1 (referent) | 0.76 (0.63-0.91) | 0.71 (0.58-0.87) | 0.64 (0.51-0.80) | 0.86 (0.79-0.93) | <0.001 |
|
| ||||||
| Change in total fiber intake after diagnosis | Decrease of ≥2.0 g/day | Change of <2.0 g/day | Increase of 2.0-4.9 g/day | Increase of ≥5 g/day | HR (95% CI) per 5 g/day | P for trend |
|
| ||||||
| Colorectal cancer-specific mortality | ||||||
| Median intake (interquartile range), g/day | −4.9 (-7.2 to -3.1) | 0.1 (-0.9 to 1.1) | 3.2 (2.5 to 4.1) | 7.7 (6.0 to 10.0) | ||
| No. of events (n=174) | 52 | 64 | 29 | 29 | ||
| No. of person-years (n=14,209) | 4,322 | 3,873 | 3,087 | 2,927 | ||
| Mortality rate (per 1,000 person-years) | 12.0 | 16.5 | 9.4 | 9.9 | ||
| Age, sex, stage-adjusted HR (95% CI) † | 1.36 (1.00-1.84) | 1 (referent) | 1.02 (0.70-1.49) | 0.99 (0.68-1.44) | 0.88 (0.80-0.98) | 0.02 |
| Multivariable-adjusted HR (95% CI) ‡ | 1.65 (1.17-2.34) | 1 (referent) | 1.08 (0.73-1.61) | 0.91 (0.60-1.38) | 0.82 (0.72-0.93) | 0.002 |
| All-cause mortality | ||||||
| No. of events (n=773) | 230 | 257 | 160 | 126 | ||
| Mortality rate (per 1,000 person-years) | 53.2 | 66.4 | 51.8 | 43.0 | ||
| Age, sex, stage-adjusted HR (95% CI) † | 1.10 (0.95-1.29) | 1 (referent) | 1.07 (0.90-1.28) | 0.77 (0.64-0.93) | 0.92 (0.88-0.97) | 0.001 |
| Multivariable-adjusted HR (95% CI) ‡ | 1.17 (0.99-1.39) | 1 (referent) | 1.04 (0.87-1.24) | 0.67 (0.55-0.83) | 0.86 (0.81-0.92) | <0.001 |
Abbreviation: CI, confidence interval; HR, hazard ratio.
Post-diagnostic intake was assessed at least 6 months but no more than 4 years after diagnosis to minimize the influence of active treatment.
Cox proportional hazards regression model stratified by age groups at diagnosis (<60, 60-64, 65-69, 70-74, and ≥75 years), sex, and cancer stage (I, II, III, and unspecified), with additional adjustment for age at diagnosis (continuous).
Further adjusted for year of diagnosis (continuous), tumor grade of differentiation (1-3 and unspecified), subsite (proximal colon, distal colon, rectum and unspecified), pre-diagnostic fiber intake (in quartiles), post-diagnostic alcohol consumption (<0.15, 0.15-1.9, 2.0-7.4, ≥7.5 g/d), pack-years of smoking (0, 1-15, 16-25, 26-45, >45), BMI (<23, 23-24.9, 25-27.4, 27.5-29.9, ≥30 kg/m2), physical activity (women: <5, 5-11.4, 11.5-21.9, ≥22 MET-hours/week; men: <7, 7-14.9, 15-24.9, ≥25 MET-hours/week), regular use of aspirin (≥2 tablets per week), glycemic load (in quartiles), and consumption of total fat, folate, calcium, and vitamin D (in quartiles).