Table 2.

Epidemiologic studies on marijuana use and lung cancer

Study location, period, author, referenceCharacteristics of casesCharacteristic of controls or cohortExposure assessmentExposure categoriesRR or OR (95% CI)Adjustment for potential confounders and other notes
Tunisia, 1988–1989, Hsairi et al. (23)110 cases diagnosed in a hospital, 70.0% have histological confirmation, 97.3% male. Response rate: N/A110 residents in Tunisia, individually matched on age, sex, and average number of cigarettes/day Response rate: N/AFace-to-face interviews with questionnaireCannabis use8.2 (1.3–15.5)
  • Adjusted for age, sex, number of cigarettes/day, water pipe use, and snuff use

  • “Cannabis use” was not defined. Assessment of dose–response relations not reported

Los Angeles, CA, 1999–2004, Hashibe et al. (16)611 lung cancer cases from the cancer registry Response rate: 39%1,040 cancer-free controls matched to cases on age, gender, and neighborhood. LA residents age 18 to 65. Response rate: 72%Subjects were interviewed face-to-face with a standardized questionnaireNever
≥ 0 to 1 joint-years
≥1 joint years
Never smokers
0.44 (0.21–0.92)
1.1 (0.48–2.6)
  • Adjusted for age, gender, race/ethnicity, educational level, and alcohol consumption

  • Estimates shown are for never smokers

  • Included in the Zhang et al. pooled analysis (27)

Tunisia, Morocco, Algeria, 1996–2004, Berthiller et al. (24)430 cases from hospitals from 3 studies
 Response rate:
N/A
755 hospital-based controls
 Response rate:
N/A
Pooled self-reported questionnaire dataEver cannabis use
Joint years
Never
>0 to <2 joint-years
≥2 joint-years
2.4 (1.5–3.7)

1.00
1.76 (0.81–3.82)
3.44 (1.51–7.86)
  • Adjusted on age, occupational exposure, country, years of tobacco smoking

  • Estimates by frequency and duration did not show any dose response (not presented in paper)

  • Includes data from Voirin et al. (45) and Sasco et al. (46)

New Zealand, 2001–2005, Aldington et al. (25)79 cases identified from the New Zealand Cancer Registry and hospital database. Age < 55 years. Response rate: 77%324 controls matched in 5-year age groups and district health boards Response rate: 66%Interviewer-administered questionnairesCannabis use
Joint-years
Nonsmoker
First tertile (<1.39)
Second tertile (1.39–10.5)
Third tertile (>10.5)


1.0
0.3 (0.1–1.7)
0.5 (0.1–2.0)

5.7 (1.5–21.6)
  • Adjusted for age, sex ethnicity, pack-years of cigarette smoking, and family history of lung cancer

  • For ever joint-year increase, RR = 1.08 (95% CI = 1.02–1.15)

  • Included in the Zhang et al. pooled analysis (27)

Sweden, 1969–2009, Callaghan et al. (26)179 lung cancer casesCohort of 49,321 young men age 18 to 20 years old in military conscriptionSelf-reported questionnaires. The 1969 to 1970 conscription collected information about alcohol and drug useEver Cannabis
 smoking
Lifetime frequency
Never
Once
2–4 times
5–10 times
11–50 times
> 50 times
1.25 (0.84–1.87)


1.00
1.52 (0.77–3.01)
0.66 (0.27–1.62)
0.68 (0.21–2.16)
1.68 (0.77–3.66)
2.12 (1.08–4.14)
  • Adjusted for cigarette smoking (frequency), alcohol consumption, respiratory conditions, socioeconomic status

  • Duration of use was not available

US, Canada, UK, and New Zealand, 2010, Zhang et al. (27)2,159 cases from 6 case–control studies in the lung cancer (ILCCO) consortium
Response rate:
N/A
2,985 controls from 6 case–control studies in the lung cancer (ILCCO) Consortium
Response rate:
N/A
Pooled self-reported questionnaire dataNever-tobacco
 smokers
Nonhabitual cannabis smoker
Habitual
Joint-years
<1 joint-years
1 to <10 joint-years
≥10 joint-years
Continuous joint-years


1.00

1.03 (0.51–2.08)

1.00
1.26 (0.57–2.75)

0.54 (0.12–2.55)
1.00 (0.93–1.07)
  • Adjusted for age, sex, race, highest education, and study

  • Estimates presented are for never-tobacco smokers

  • Included the published studies from Los Angeles (16) and New Zealand (25)