Seattle, WA: The results of a recent Fred Hutchinson Cancer Research study reporting that heavy, long-term cannabis use is associated with an elevated risk of a rare form of testicular cancer are preliminary and should be interpreted cautiously, NORML Deputy Director Paul Armentano said today.
The widely reported study, published online on the website of the journal Cancer, assessed the relative risk of testicular germ cell tumors (TGCTs) in 369 men and 979 age-matched controls. Of the 369 cases, 268 reported having smoked cannabis and 97 were current users.
Investigators did not find a statistically significant risk among men diagnosed with TGCT who had “ever used” compared to healthy controls. By contrast, authors did observe an elevated risk of cancer among men who were current weekly use of cannabis, particularly if their use began before eighteen years of age.
Researchers said that this observed association was specific to nonseminoma tumors, a less common type of testicular cancer. Overall, nonseminomas account for fewer than one half of one percent of all cancers among American men.
Investigators cautioned that their findings are preliminary, and argued that “additional studies of TGCTs will be needed to test this hypothesis.”
They also acknowledged that incidences of nonseminomas have not risen in the general public at rates that correspond with the climbing popularity cannabis use.
Previous studies have generally failed to find a causal association between marijuana use and cancer. Most recently, a UCLA study of more than 2,200 subjects (1,212 cases and 1,040 controls) reported that marijuana smoking was not positively associated with cancers of the lung or upper aerodigestive tract – even among individuals who reported smoking more than 22,000 joints during their lifetime.
A 1997 Kaiser Permanente retrospective cohort study examining the relationship of marijuana use and cancer incidence in 65,171 men and women in California found that cannabis use was not associated with increased risks of developing tobacco-use related cancers – including lung cancer, breast cancer, prostate cancer, colorectal cancer, or melanoma.
Commenting on this latest study, NORML Deputy Director Paul Armentano said: “Advocates for marijuana law reform have never claimed that cannabis is a harmless substance. This premise is neither accurate, nor is it the standard society uses – or should use – to determine the licit or illicit nature of controlled substances. Many substances have links to cancer, including tobacco, alcohol, and caffeine. In all three cases, the public’s understanding of these risks has led consumers to voluntarily reduce their intake of these products. By contrast, the acknowledgement of these potential risks has not led to a criminal ban on the use of these substances, nor should it.
“In short, if scientists confirm these preliminary findings in a larger, population-based study, then groups like NORML and others that represent the cannabis using community will no doubt be among the first to alert their constituency. Nevertheless, even if these potential risks are substantiated, it remains true that by any objective scientific measure cannabis remains safer – both to the user and to the public – than the use of alcohol or tobacco.”
For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “Association of marijuana use and the incidence of testicular germ cell tumors,” will appear in the March 15 issue of Cancer. Additional information of marijuana use and cancer risk is available in the NORML white paper, Cannabis Smoke and Cancer: Assessing the Risk,” available online at: http://norml.org/index.cfm?Group_ID=6891.