Table 3.

Associations of serum concentrations of retinol and carotenoids with total, low-grade, and high-grade cancers by treatment arm, in the PCPTa

Total prostate cancerGleason 2–6Gleason 7–10
Case/controlOR (95% CI)Case/controlOR (95% CI)Case/controlOR (95% CI)
Retinol
Placebo
 Q1b205/260Ref.153/260Ref.42/260Ref.
 Q2236/2561.11 (0.86–1.44)178/2561.11 (0.84–1.47)49/2561.18 (0.75–1.85)
 Q3259/2521.18 (0.91–1.53)207/2521.23 (0.93–1.63)44/2521.07 (0.68–1.71)
 Q4275/2411.30 (1.00–1.68)197/2411.21 (0.91–1.60)69/2411.74 (1.14–2.68)
P trend0.040.140.02
Finasteride
 Q1164/179Ref.89/179Ref.67/179Ref.
 Q2165/1830.88 (0.64–1.20)96/1830.94 (0.65–1.35)61/1830.81 (0.53–1.22)
 Q3183/1830.94 (0.69–1.28)115/1831.09 (0.76–1.56)63/1830.80 (0.53–1.20)
 Q4196/1980.95 (0.70–1.30)122/1981.08 (0.75–1.54)66/1980.81 (0.53–1.22)
P trend0.900.500.33
P interactionc0.200.720.03
α-Carotene
Placebo
 Q1196/256Ref.145/256Ref.45/256Ref.
 Q2245/2561.16 (0.90–1.51)190/2561.20 (0.91–1.60)48/2561.04 (0.66–1.63)
 Q3263/2491.28 (0.99–1.67)197/2491.27 (0.95–1.68)55/2491.24 (0.80–1.93)
 Q4271/2481.32 (1.01–1.73)203/2481.29 (0.96–1.72)56/2481.36 (0.86–2.14)
P trend0.030.100.13
Finasteride
 Q1164/184Ref.95/184Ref.64/184Ref.
 Q2168/1800.95 (0.69–1.29)93/1800.92 (0.64–1.32)68/1800.96 (0.64–1.45)
 Q3198/1901.06 (0.78–1.44)119/1901.08 (0.76–1.54)67/1900.94 (0.62–1.42)
 Q4178/1890.95 (0.69–1.30)115/1891.04 (0.72–1.49)58/1890.81 (0.53–1.25)
P trend0.920.630.35
P interaction0.170.530.16
β-Carotene
Placebo
 Q1196/245Ref.143/245Ref.46/245Ref.
 Q2255/2661.13 (0.87–1.46)192/2661.15 (0.87–1.53)50/2660.99 (0.64–1.54)
 Q3274/2531.28 (0.98–1.66)205/2531.27 (0.96–1.69)61/2531.35 (0.87–2.08)
 Q4250/2451.18 (0.90–1.55)195/2451.22 (0.91–1.64)47/2451.07 (0.67–1.71)
P-trend0.160.150.46
Finasteride
 Q1159/193Ref.92/193Ref.59/193Ref.
 Q2170/1721.09 (0.80–1.49)106/1721.18 (0.82–1.69)60/1721.03 (0.68–1.58)
 Q3201/1861.15 (0.85–1.57)112/1861.10 (0.77–1.57)78/1861.24 (0.82–1.87)
 Q4178/1921.07 (0.78–1.47)112/1921.15 (0.80–1.65)60/1920.99 (0.64–1.53)
P trend0.600.560.79
P interaction0.610.640.93
β-Cryptoxanthin
Placebo
 Q1249/251Ref.187/251Ref.51/251Ref.
 Q2221/2570.84 (0.65–1.09)171/2570.86 (0.65–1.13)44/2570.85 (0.54–1.32)
 Q3274/2501.08 (0.84–1.38)202/2501.05 (0.80–1.38)64/2501.25 (0.83–1.89)
 Q4231/2510.90 (0.69–1.17)175/2510.89 (0.67–1.17)45/2510.95 (0.60–1.49)
P trend0.890.740.70
Finasteride
 Q1168/188Ref.99/188Ref.65/188Ref.
 Q2179/1811.07 (0.79–1.44)102/1811.03 (0.73–1.47)67/1811.03 (0.68–1.54)
 Q3196/1861.27 (0.94–1.72)119/1861.32 (0.93–1.87)68/1861.12 (0.75–1.69)
 Q4165/1881.09 (0.79–1.49)102/1881.13 (0.78–1.62)57/1880.98 (0.64–1.50)
P trend0.380.290.95
P interaction0.650.430.77
  • aAssociations were adjusted for age, race, BMI, family history of prostate cancer, and serum cholesterol.

  • bQuartiles of serum concentration of retinol and carotenoids were defined based on values in all controls (finasteride and placebo arms combined). Quartiles 1, 2, 3, and 4, respectively, were defined using the following stratum-specific cutoffs. Retinol: <0.58 μg/dL, 0.58 to <0.67 μg/dL, 0.67 to <0.77 μg/dL, >0.77 μg/dL; α-carotene: <0.03 μg/dL, 0.03 to <0.04 μg/dL, 0.04 to <0.7 μg/dL, >0.7 μg/dL; β-carotene: <0.14 μg/dL, 0.14 to <0.23 μg/dL, 0.23 to <0.37 μg/dL, >0.37 μg/dL; β-cryptoxanthin: <0.06 μg/dL, 0.06 to <0.09 μg/dL, 0.09 to <0.12 μg/dL, >0.12 μg/dL.

  • cP value tests for interaction between serum quartile (as a trend ordinal value) and stratification factor.