Abstract LB-394: Marijuana use and testicular germ cell tumors

Abstract

Abstract Introduction: Since the early 1970's the incidence of testicular germ cell tumors (TGCT) in the U.S. has been increasing, however, environmental exposures accounting for this rise have not been identified. Trends in marijuana use have also increased during this period. Chronic marijuana use has been shown to produce adverse effects on the human endocrine and reproductive systems. A prior study of marijuana use and TGCT reported a significant association among frequent and long-term current users. We aimed to evaluate the relationship of marijuana use and TGCT in an existing hospital-based case-control study conducted at the University of Texas M. D. Anderson Cancer Center. Methods: TGCT cases diagnosed between January 1990 and October 1996 (n=187) and male friend controls (n=148) matched on age, race and state of residence were enrolled in the study. Associations of marijuana use and TGCT were estimated using unconditional logistic regression adjusting for age, race, prior cryptorchidism, cigarette smoking and alcohol intake. Associations stratified on histology (seminoma, nonseminoma) were also examined. Results: Overall, TGCT cases were more likely to be frequent marijuana users (daily or >1 day per week) than were controls [OR: 2.2, 95% CI: 1.0, 5.2]. In the analysis limited to nonseminomas, cases were significantly more likely than controls to be frequent users [OR: 3.3, 95% CI: 1.3, 8.6] and to be long-term users (10+ years) [OR: 2.3, 95% CI: 1.0, 5.8]. As the use of friend controls can bias the results of retrospective studies, we evaluated the extent to which reporting of marijuana use among the controls was consistent with data from the 1996 population-based National Survey on Drug Use and Health (NSDUH). We compared the observed number of controls who reported ever using marijuana with the expected number based on age- and race-specific proportions in the NSDUH and found no significant difference [O/E ratio: 0.96; 95% CI: 0.74, 1.22], suggesting selection or reporting bias was not an explanation for the observed associations. Discussion: Our finding of an association between frequent marijuana use and TGCT, particularly among men with nonseminoma is consistent with the findings of a previous report. Marijuana use may be related to nonseminoma due to activation of the cannabinoid receptors during a critical time period in pubertal development; however it is also plausible that biologically active components of marijuana may function through pathways other than the endocannabinoid system. Additional studies of marijuana use and TGCT are warranted, especially studies evaluating the role of endocannabinoid signaling and cannabinoid receptors in TGCT. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-394.