Table 4.
Marijuana smoking and the risk of head and neck cancer stratified by subsite of cancer
| Oral cavity | Pharynx#* | Larynx~ | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases | Controls | OR | 95% CI | Cases | Controls | OR | 95% CI | Cases | Controls | OR | 95% CI | |
| Total | 981 | 5015 | 1397 | 5015 | 1159 | 4408 | ||||||
| Marijuana smoking | ||||||||||||
| Never | 877 | 4199 | 1.00 | Ref | 1177 | 4199 | 1.00 | Ref | 1063 | 3701 | 1.00 | Ref |
| Ever | 77 | 736 | 0.74 | (0.55, 1.00) | 192 | 736 | 1.13 | ( 0.76, 1.68) | 72 | 634 | 0.98 | (0.69, 1.39) |
| Missing | 27 | 80 | 28 | 80 | 24 | 73 | ||||||
| p for heterogeneity | 0.33 | 0.03 | 0.62 | |||||||||
| Frequency of marijuana smoking (times per day) | ||||||||||||
| Never | 877 | 4199 | 1.00 | Ref | 988 | 2821 | 1.00 | Ref | 1063 | 3701 | 1.00 | Ref |
| 0–1 | 59 | 631 | 0.76 | (0.54, 1.07) | 113 | 534 | 1.05 | (0.49, 2.22) | 47 | 535 | 0.88 | (0.57, 1.34) |
| >1–3 | 10 | 61 | 0.63 | (0.30, 1.30) | 22 | 56 | 1.01 | (0.28, 3.64) | 11 | 56 | 1.08 | (0.54, 2.18) |
| >3 | 7 | 43 | 0.64 | (0.27, 1.52) | 14 | 41 | 0.82 | (0.19, 3.61) | 12 | 42 | 1.05 | (0.51, 2.15) |
| Missing | 28 | 81 | 24 | 59 | 26 | 74 | ||||||
| p for trend | 0.04 | 0.71 | 0.99 | |||||||||
| p for heterogeneity | 0.85 | <0.01 | 0.55 | |||||||||
| Duration of marijuana smoking (in years) | ||||||||||||
| Never | 877 | 4199 | 1.00 | Ref | 1124 | 3319 | 1.00 | Ref | 1063 | 3701 | 1.00 | Ref |
| >0–5 | 29 | 319 | 0.64 | (0.42, 0.99) | 75 | 319 | 1.08 | (0.63, 1.85) | 20 | 278 | 0.65 | (0.38, 1.11) |
| >5–10 | 16 | 129 | 0.83 | (0.46, 1.50) | 28 | 129 | 1.01 | (0.46, 2.24) | 12 | 111 | 1.10 | (0.56, 2.14) |
| >10–20 | 18 | 145 | 0.80 | (0.46, 1.40) | 36 | 145 | 1.07 | (0.51, 2.26) | 10 | 111 | 0.85 | (0.41, 1.76) |
| >20 | 13 | 143 | 0.74 | (0.39, 1.39) | 45 | 140 | 1.31 | (0.62, 2.76) | 28 | 134 | 1.42 | (0.84, 2.38) |
| Missing | 28 | 80 | 26 | 66 | 26 | 73 | ||||||
| p for trend | 0.15 | 0.66 | 0.32 | |||||||||
| p for heterogeneity | 0.93 | 0.23 | 0.69 | |||||||||
| Cumulative exposure (joint-year) | ||||||||||||
| Never | 877 | 4199 | 1.00 | Ref | 1124 | 3319 | 1.00 | Ref | 1063 | 3701 | 1.00 | Ref |
| >0–2 | 41 | 476 | 0.73 | (0.50, 1.08) | 97 | 476 | 1.15 | (0.68, 1.94) | 31 | 406 | 0.84 | (0.52, 1.36) |
| >2–5 | 9 | 77 | 0.68 | (0.32, 1.46) | 21 | 77 | 1.29 | (0.45, 3.75) | 3 | 66 | 0.31 | (0.09, 1.07) |
| >5 | 26 | 182 | 0.73 | (0.46, 1.16) | 66 | 180 | 1.03 | (0.47, 2.26) | 36 | 161 | 1.20 | (0.77, 1.85) |
| Missing | 28 | 81 | 26 | 66 | 26 | 74 | ||||||
| p for trend | 0.07 | 0.76 | 0.75 | |||||||||
| p for heterogeneity | 0.46 | 0.08 | 0.21 | |||||||||
Adjusted for age (categorical) study, race, sex, education level, packyear (continuous), alcohol duration (continuous), duration of smoking pipe (continuous) and duration of smoking cigar (continuous)
#
Random effect 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)