Table 2.

Multivariate RRs and 95% CIs of prostate cancer, according to categories of dairy food consumption in the PLCO study

Dairy product intake (servings/day)*Ptrend†
Total dairy≤0.980.99-1.671.68-2.74≥2.75
    Total cases434451521504
        RR (95% CI)‡1.00 (referent)0.99 (0.86-1.13)1.13 (0.99-1.30)1.12 (0.97-1.30)0.06
        RR (95% CI)‡ + diet calcium1.00 (referent)0.98 (0.85-1.13)1.11 (0.95-1.30)1.06 (0.88-1.30)0.44
    Nonaggressive cases§236238305310
        RR (95% CI)‡1.00 (referent)0.94 (0.78-1.13)1.17 (0.98-1.40)1.20 (0.99-1.46)0.01
        RR (95% CI)‡ + diet calcium1.00 (referent)0.93 (0.77-1.12)1.14 (0.92-1.40)1.06 (0.82-1.38)0.48
    Aggressive cases190207207187
        RR (95% CI)‡1.00 (referent)1.07 (0.87-1.31)1.08 (0.88-1.33)1.02 (0.81-1.28)0.99
        RR (95% CI)‡ + diet calcium1.00 (referent)1.06 (0.86-1.31)1.08 (0.85-1.38)1.07 (0.79-1.45)0.73
Low-fat dairy≤0.080.09-0.410.42-0.99≥1.00
    Total cases424483478525
        RR (95% CI)‡1.00 (referent)1.14 (1.00-1.30)1.12 (0.98-1.28)1.23 (1.07-1.41)0.02
        RR (95% CI)‡ + diet calcium1.00 (referent)1.14 (1.00-1.30)1.11 (0.96-1.28)1.19 (1.00-1.41)0.13
    Nonaggressive cases§239263259328
        RR (95% CI)‡1.00 (referent)1.08 (0.90-1.29)1.04 (0.87-1.25)1.30 (1.09-1.55)0.003
        RR (95% CI)‡ + diet calcium1.00 (referent)1.08 (0.90-1.29)1.03 (0.85-1.24)1.20 (0.96-1.50)0.12
    Aggressive cases177213211190
        RR (95% CI)‡1.00 (referent)1.23 (1.01-1.51)1.22 (0.99-1.49)1.12 (0.90-1.39)0.93
        RR (95% CI)‡ + diet calcium1.00 (referent)1.23 (1.00-1.51)1.22 (0.98-1.51)1.17 (0.90-1.53)0.66
High-fat dairy≤0.100.11-0.250.26-0.52≥0.53
    Total cases466496478470
        RR (95% CI)‡1.00 (referent)1.09 (0.96-1.24)1.04 (0.91-1.20)1.07 (0.92-1.23)0.65
        RR (95% CI)‡ + diet calcium1.00 (referent)1.09 (0.95-1.24)1.04 (0.91-1.19)1.05 (0.91-1.21)0.82
    Nonaggressive cases§262282274271
        RR (95% CI)‡1.00 (referent)1.06 (0.89-1.26)1.01 (0.84-1.20)1.03 (0.85-1.24)0.99
        RR (95% CI)‡ + diet calcium1.00 (referent)1.06 (0.89-1.26)1.00 (0.84-1.20)1.00 (0.83-1.21)0.80
    Aggressive cases198205195193
        RR (95% CI)‡1.00 (referent)1.11 (0.91-1.36)1.08 (0.88-1.34)1.13 (0.91-1.42)0.42
        RR (95% CI)‡ + diet calcium1.00 (referent)1.11 (0.91-1.36)1.08 (0.88-1.33)1.13 (0.91-1.42)0.43

  • ↵* Dairy food consumption categorized as quartiles.

  • ↵† P trend was based on the medians of the categories.

  • ↵‡ RRs adjusted for age, race, study center, family history of prostate cancer, body mass index, smoking status, physical activity, history of diabetes, red meat intake, total energy intake, education, and number of screening examinations during the follow-up period.

  • ↵§ Nonaggressive cases were defined as Gleason score <7 and stage I/II. Thirty cases were deleted due to missing data on Gleason sum or tumor stage. Aggresive cases were defined as Gleason score ≥7 or stage ≥ III