Table 3. Epidemiologic studies on marijuana use and testicular cancer.

Study location, period, author, reference	Characteristics of cases	Characteristic of controls or cohort	Exposure assessment	Exposure categories	RR or OR (95% CI)	Adjustment for potential confounders and other notes
Washington State, 1999 –2006, Daling et al. (28)	369 cases ages 18 to 44 years Response rate: 67.5%	979 age-matched controls who resided in the same 3 countries Response rate: 52.2%	Interviewer-administered questionnaires	Frequency		Adjusted for age, reference year, alcohol use, current smoking, history of cryptorchidism
				Daily or >=1 d/per week	2.0 (1.3-3.2)
				Less than once/per week	1.4 (0.9-2.3)
				Duration
				<10 years	1.8 (1.0-3.3)
				≥10 years	1.6 (1.1-2.5)
Texas, Louisiana, Arkansas, or Oklahoma, 1990- 1996, Trabert et al. (29)	187 cases from hospital-based cased-control study at University of Texas M.D. Anderson Cancer Center. Age 18-50 Response rate: N/A	148 controls from hospital-based cased-control study at University of Texas M.D. Anderson Cancer Center Response rate: N/A	A self-administered questionnaire ascertaining demographics, lifestyle habits medical history, and diet.	Frequency		Adjusted for age, race, alcohol use, cigarette smoking, and history of cryptorchidism
				Never	1.0
				<1/day	0.5 (0.3-0.9)
				Daily or >1/day	2.2 (1.0-5.1)
				Duration
				<10 years	0.6 (0.3-1.0)
				≥10 years	1.2 (0.6-2.8)
Los Angeles, 1986-1991 Lacson et al. (30)	163 cases identified in the Los Angeles Cancer Registry, age 18-35 Response rate: 81%	292 controls matched on age, race/ethnicity, and neighborhood Response rate: 78.7%.	An interview using structured questionnaires	Frequency		Adjusted on cryptorchidism, education, religiosity, and reported use of cocaine, and amyl nitrite Crude ORs did not show any associations Duration among former users appeared to show the strongest associations with marijuana use
				<1 per week	2.10 (1.09-4.03)
				≥1 per week	1.53 (0.73-3.24)
				Duration
				<10 years	2.09 (1.09-3.98)
				≥10 years	1.51 (0.66-3.47)