Table 2.

Association (estimated OR and 95% CL) between cumulative marijuana use and cancer incidence, by type of cancer, amount of marijuana use, and covariate adjustment

Cancer type (marijuana use)Cases, NControls, NCrude OR (95% CL)Adjusted OR (95% CL)
Model 1Model 2Model 3
Oral cancer
    50 joint-years*2971,0231.7 (1.3, 2.2)1.5 (1.1, 2.0)1.2 (0.86, 1.6)1.1 (0.80, 1.5)
    P for trend*0.00020.00640.330.53
    Never1154731111
    >0 to <1 joint-years913211.2 (0.86, 1.6)1.1 (0.82, 1.6)1.1 (0.75, 1.5)1.1 (0.74, 1.5)
    1 to <10 joint-years401241.3 (0.88, 2.0)1.2 (0.81, 1.9)1.0 (0.65, 1.7)1.1 (0.65, 1.7)
    10 to <30 joint-years20571.4 (0.83, 2.5)1.3 (0.71, 2.2)0.90 (0.48, 1.7)0.92 (0.48, 1.7)
    30 to <60 joint-years12232.1 (1.0, 4.4)1.7 (0.80, 3.6)1.1 (0.49, 2.4)0.88 (0.38, 2.0)
    ≥60 joint-years24352.8 (1.6, 4.9)2.3 (1.3, 4.0)1.2 (0.61, 2.2)1.1 (0.56, 2.1)
Pharyngeal cancer
    50 joint-years*991,0231.0 (0.55, 1.8)0.96 (0.51, 1.8)0.68 (0.33, 1.4)0.75 (0.37, 1.5)
    P for trend*0.980.890.280.42
    Never604731111
    >0 to <1 joint-years213210.52 (0.31, 0.87)0.51 (0.30, 0.87)0.63 (0.35, 1.1)0.67 (0.37, 1.2)
    1 to <10 joint-years81240.51 (0.24, 1.1)0.54 (0.25, 1.2)0.66 (0.28, 1.5)0.71 (0.30, 1.7)
    10 to <30 joint-years5570.69 (0.27, 1.8)0.70 (0.26, 1.9)0.38 (0.10, 1.4)0.39 (0.10, 1.5)
    ≥30 joint-years6580.82 (0.34, 2.0)0.73 (0.29, 1.8)0.53 (0.19, 1.5)0.57 (0.20, 1.6)
Laryngeal cancer
    50 joint-years*871,0261.6 (1.0, 2.5)1.6 (1.0, 2.6)1.0 (0.55, 1.9)0.93 (0.50, 1.7)
    P for trend*0.0430.0520.990.81
    Never394751111
    >0 to <1 joint-years243220.91 (0.54, 1.5)0.94 (0.54, 1.6)1.0 (0.56, 2.0)0.81 (0.42, 1.6)
    1 to <10 joint-years71240.69 (0.30, 1.6)0.70 (0.30, 1.6)0.58 (0.22, 1.5)0.42 (0.15, 1.2)
    10 to <30 joint-years8571.7 (0.76, 3.8)1.7 (0.73, 4.0)1.3 (0.51, 3.4)0.91 (0.33, 2.5)
    30 to <60 joint-years5232.6 (0.96, 7.4)2.9 (0.98, 8.5)1.3 (0.34, 4.7)0.71 (0.19, 2.7)
    ≥60 joint-years7352.4 (1.0, 5.8)2.4 (0.95, 6.0)1.1 (0.37, 3.5)0.84 (0.28, 2.5)
Esophageal cancer
    50 joint-years*1071,0191.2 (0.75, 2.0)1.2 (0.70, 2.0)0.94 (0.52, 1.7)0.83 (0.44, 1.5)
    P for trend*0.410.540.850.55
    Never504721111
    >0 to <1 joint-years303180.89 (0.55, 1.4)0.92 (0.56, 1.5)0.84 (0.50, 1.4)0.71 (0.41, 1.2)
    1 to <10 joint-years131240.99 (0.52, 1.9)0.97 (0.50, 1.9)0.91 (0.44, 1.9)0.77 (0.36, 1.6)
    10 to <30 joint-years5570.83 (0.32, 2.2)0.73 (0.27, 2.0)0.57 (0.20, 1.6)0.44 (0.15, 1.3)
    ≥30 joint-years9581.5 (0.69, 3.1)1.3 (0.57, 2.8)0.79 (0.34, 1.9)0.53 (0.22, 1.3)
Lung cancer
    50 joint-years*6061,0161.4 (1.1, 1.8)1.7 (1.3, 2.3)1.4 (1.0, 1.9)1.0 (0.74, 1.4)
    P for trend*0.013<0.00010.0260.89
    Never2994701111
    >0 to <1 joint-years1613170.80 (0.63, 1.0)0.88 (0.68, 1.1)0.87 (0.66, 1.1)0.63 (0.46, 0.87)
    1 to <10 joint-years651240.82 (0.59, 1.2)1.0 (0.72, 1.5)1.0 (0.70, 1.5)0.71 (0.46, 1.1)
    10 to <30 joint-years32570.88 (0.56, 1.4)1.1 (0.71, 1.8)0.89 (0.53, 1.5)0.56 (0.31, 1.0)
    30 to <60 joint-years20231.4 (0.74, 2.5)2.0 (1.0, 3.8)1.5 (0.75, 2.9)0.82 (0.38, 1.7)
    ≥60 joint-years33351.5 (0.90, 2.4)2.2 (1.3, 3.7)1.5 (0.86, 2.6)0.62 (0.32, 1.2)
  • NOTE: Crude estimates are unadjusted for covariates. Model 1 is adjusted for age (15 categories) and gender. Model 2 is adjusted for age (15 categories), gender, race/ethnicity (4 categories), education (5 categories), and drink-years. Model 3 is adjusted for age (15 categories), gender, race/ethnicity (4 categories), education (5 categories), drink-years, tobacco use (ever/never), and pack-years.

  • * Treating cumulative marijuana use as a continuous variable; the estimated OR is for a difference of 50 joint-years. To minimize leveraging from outliers, these regressions exclude subjects reporting >200 joint-years of marijuana use.