Table 4.

Marijuana smoking and the risk of HNC stratified by subsite of cancer

Oral cavity
Pharynx*,
Larynx
CasesControlsOR (95% CI)CasesControlsOR (95% CI)CasesControlsOR (95% CI)
Total9815,0151,3975,0151,1594,408
Marijuana smoking
    Never8774,1991.00 (reference)1,1774,1991.00 (reference)1,0633,7011.00 (reference)
    Ever777360.74 (0.55-1.00)1927361.13 (0.76-1.68)726340.98 (0.69-1.39)
    Missing278028802473
    P for heterogeneity0.330.030.62
Frequency of marijuana smoking (times per day)
    Never8774,1991.00 (reference)9882,8211.00 (reference)1,0633,7011.00 (reference)
    0-1596310.76 (0.54-1.07)1135341.05 (0.49-2.22)475350.88 (0.57-1.34)
    >1-310610.63 (0.30-1.30)22561.01 (0.28-3.64)11561.08 (0.54-2.18)
    >37430.64 (0.27-1.52)14410.82 (0.19-3.61)12421.05 (0.51-2.15)
    Missing288124592674
    P for trend0.040.710.99
    P for heterogeneity0.85<0.010.55
Duration of marijuana smoking (in years)
    Never8774,1991.00 (reference)1,1243,3191.00 (reference)1,0633,7011.00 (reference)
    >0-5293190.64 (0.42-0.99)753191.08 (0.63-1.85)202780.65 (0.38-1.11)
    >5-10161290.83 (0.46-1.50)281291.01 (0.46-2.24)121111.10 (0.56-2.14)
    >10-20181450.80 (0.46-1.40)361451.07 (0.51-2.26)101110.85 (0.41-1.76)
    >20131430.74 (0.39-1.39)451401.31 (0.62-2.76)281341.42 (0.84-2.38)
    Missing288026662673
    P for trend0.150.660.32
    P for heterogeneity0.930.230.69
Cumulative exposure (joint-year)
    Never8774,1991.00 (reference)1,1243,3191.00 (reference)1,0633,7011.00 (reference)
    >0-2414760.73 (0.50-1.08)974761.15 (0.68-1.94)314060.84 (0.52-1.36)
    >2-59770.68 (0.32-1.46)21771.29 (0.45-3.75)3660.31 (0.09-1.07)
    >5261820.73 (0.46-1.16)661801.03 (0.47-2.26)361611.20 (0.77-1.85)
    Missing288126662674
    P for trend0.070.760.75
    P for heterogeneity0.460.080.21
  • NOTE: Adjusted for age (categorical), study, race, sex, education level, pack-year (continuous), alcohol duration (continuous), duration of smoking pipe (continuous), and duration of smoking cigar (continuous).

  • * Random-effects estimates.

  • The Seattle study was not included in the analysis for duration and cumulative consumption of marijuana. The Tampa and Seattle studies were not included in the analysis on frequency of marijuana consumption.

  • No laryngeal cases in Seattle (the number of controls for laryngeal cancer is different because the Seattle study is not included in the laryngeal cancer analysis).