Subjects who regularly inhale cannabis smoke possess no greater risk of contracting lung cancer than do those who consume it occasionally or not at all, according to data published online ahead of print in the International Journal of Cancer.
An international team of investigators from Canada, New Zealand, the United Kingdom, and the United States analyzed data from six case-control studies involving over 5,000 subjects (2,159 cases and 2,985 controls) from around the world.
Authors concluded, “Results from our pooled analyses provide little evidence for an increased risk of lung cancer among habitual or long-term cannabis smokers.”
Investigators had previously presented their data at the 2013 annual meeting of the American Academy for Cancer Research.
Their findings are similar to those of a 2013 review published in the journal Annals of the American Thoracic Society, which concluded: “[H]abitual use of marijuana alone does not appear to lead to significant abnormalities in lung function. … Overall, the risks of pulmonary complications of regular use of marijuana appear to be relatively small and far lower than those of tobacco smoking.”
An accompanying commentary in the same journal affirmed, “[C]annabis smoking does not seem to increase risk of chronic obstructive pulmonary disease (COPD) or airway cancers. In fact, there is even a suggestion that at low doses cannabis may be protective for both conditions.”
Preclinical studies have documented that cannabinoids possess potent anti-cancer properties, including the inhibition of lung cancer cell growth. To date, however, scientists have yet to conduct controlled clinical trials replicating these results in human subjects.
The abstract of the study, “Cannabis smoking and lung cancer risk: Pooled analysis in the International Lung Cancer Consortium,” appears online here.
Study: Marijuana Smoking Not Associated With Airway Cancers, COPD, Emphysema, Or Other Tobacco-Related Pulmonary ComplicationsJuly 9, 2013
Pulmonary complications associated with the regular smoking of cannabis are “relatively small” and far lower than those associated with tobacco smoking, according to a recent review published in the June edition of the scientific journal Annals of the American Thoracic Society.
The paper – authored by Donald P. Tashkin, MD, emeritus professor of medicine and medical director of the Pulmonary Function Laboratory at the David Geffen School of Medicine at University of California, Los Angeles – is “the most comprehensive and authoritative review of the subject ever published,” according to an accompanying commentary. Donald Tashkin conducted US-government sponsored studies of marijuana and lung function for over 30 years.
His review finds that although smoking cannabis may be associated with symptoms of chronic bronchitis, studies do not substantiate claims that it is positively associated with the development of lung cancer, chronic obstructive pulmonary disease (COPD), emphysema, or bullous lung disease.
“[H]abitual use of marijuana alone does not appear to lead to significant abnormalities in lung function,” Tashkin writes. “[F]indings from a limited number of well-designed epidemiological studies do not suggest an increased risk of either lung or upper airway cancer from light or moderate use. … Overall, the risks of pulmonary complications of regular use of marijuana appear to be relatively small and far lower than those of tobacco smoking.”
Writing in an accompanying commentary, McGill University’s Dr. Mark Ware concludes: “Cannabis smoking is not equivalent to tobacco smoking in terms of respiratory risk. … [C]annabis smoking does not seem to increase risk of chronic obstructive pulmonary disease (COPD) or airway cancers. In fact, there is even a suggestion that at low doses cannabis may be protective for both conditions. … This conclusion will affect the way health professionals interact with patients, parents with teenagers, and policy makers with their constituents. … Efforts to develop cleaner cannabinoid delivery systems can and should continue, but at least for now, [those] who smoke small amounts of cannabis for medical or recreational purposes can breathe a little bit easier.”
Full text of the study, “Effects of marijuana smoking on the lung,” appears in Annals of the American Thoracic Society.
Study: No Association Between The Cumulative Consumption Of Cannabis Smoke And The Risk Of Lung CancerMay 10, 2013
In a recent presentation given at the annual meeting of the American Association of Cancer Research, investigators from the university of California, Los Angeles provided the latest data reaffirming that cannabis consumption is not associated with an elevated risk of lung cancer. Below is a summary of the findings from The Oncology Report:
The study included data from six case-control studies conducted from 1999 to 2012 in the United States, Canada, the United Kingdom, and New Zealand, with a subject pool of 2,159 lung cancer cases and 2,985 controls. All of the studies were part of the International Lung Cancer Consortium (ILCCO), an international group of lung cancer researchers with the aim of sharing comparable data from ongoing and recently completed lung cancer studies from different geographical areas and ethnicities.
Dr. Zhang of the University of California, Los Angeles, performed two analyses. One compared all lung cancer cases and all controls, regardless of concurrent or past tobacco use. Then, to reduce confounding by tobacco, she restricted the analysis to those who had never smoked tobacco.
… When compared with cannabis smokers who also used tobacco, habitual pot smokers had no significant increase in cancer risk. In an analysis of marijuana smokers that excluded tobacco smokers, there were no significant differences in any of the comparisons, including habitual vs. nonhabitual use; number of joints smoked per day; duration of up to 20 years or duration of more than 20 years.
The abstract of the presentation, which concludes “Our pooled results showed no significant association between the intensity, duration, or cumulative consumption of cannabis smoke and the risk of lung cancer overall or in never smokers,” is available online here.
It is with great sadness I report on the death of one of the most outstanding activists in the NORML family – Ben Masel has passed away at age 56 following his battle with lung cancer.
Friends are leaving tribute on Ben’s Facebook page.
I met Ben at the 2009 Great Midwest Harvest Fest. He and Gary Storck flew me out to speak to the crowd of thousands on the campus of University of Wisconsin and the statehouse steps. I quickly found him to be exceptionally brilliant (he was just shy of “grand master” in chess) and loaded with fabulous stories of his past activism with the Yippies.
Ben had hoped to make it out to the NORML Conference last week, but obviously his health had taken a turn for the worse. The NORML Board presented to him a special award for his lifetime of work. My own tribute to Ben appears in the August 2011 issue of HIGH TIMES Magazine where we named him “Freedom Fighter of the Month”… unfortunately too late for him to read it. It will be one of my bigger disappointments that Ben never received the recognition he deserved while he was alive to enjoy it.
Following is the article for HIGH TIMES with my sincere condolences to family and friends who had the privilege of knowing and loving him more than I.
If you watched the TV news coverage of the Wisconsin labor protests in Madison last February, you may have seen this month’s Freedom Fighter Ben Masel. A longtime activist with Madison NORML, Ben was instrumental in creating the vibrant cannabis community in the state, including organizing Weedstock and the Great Midwest Harvest Fest that celebrates its fortieth anniversary this October 1-3 (see madisonhempfest.com). He’s currently been fighting over the past few legislative sessions to get Wisconsin to pass the Jacki Rickert Medical Marijuana Act.
While Ben fights for the end of marijuana prohibition, his activism also extends into mainstream politics as well. He’s a passionate civil libertarian, advocating equally for free speech and gun rights, personal privacy and a return to stronger congressional control of war powers. Ben has run many times for elective office, from a challenge to Governor Tommy Thompson in 1990 to his current candidacy for the US Senate seat held by Herb Kohl. He first caught attention for his radicalism when at age 17 he became the youngest person placed on President Nixon’s infamous “enemies list” and “the man” has kept his eye on Ben ever since.
This March at the age of 56, Ben received the horrible news that he’d been stricken by lung cancer. Speaking to the Wisconsin State Journal, Ben said, “I’m feeling pretty upbeat about stuff. Not about having (cancer), but overall. I’m definitely not in the ‘Oh, no, poor me, I’ve got cancer’ mode.” In reviewing our records, we’re stunned and embarrassed that Ben had not been listed among the 206 activists who’ve won the award since 1990. Everyone at NORML and HIGH TIMES extends our highest hopes for Ben’s good health.
UPDATED: NORMLtv is now streaming the presentation of Ben’s award from this year’s conference in his honor:
It must have been a slow news day.
According to Google News, more than 750 media outlets — that’s 7-5-0, folks — have now weighed in on this week’s pot scare story du jour: “Smoking marijuana causes testicular cancer.”
So is there any truth behind the provocative headline? Some, but hardly enough to justify the media’s feeding frenzy.
Researchers at the Fred Hutchinson Cancer Research in Seattle matched 369 men with of testicular germ cell tumors (TGCTs) with 979 healthy controls. Here’s what they found.
Men who self-reported having “ever used” marijuana had no statistically significant risk of testicular cancer compared to healthy controls who never used pot.
Men who reported currently using marijuana at least once per week, and who had started smoking pot prior to age 18, had an elevated risk compared to controls of contracting a type of testicular cancer known as nonseminoma.
Sounds scary, huh? Well here’s the catch.
According to the federal government, millions of people smoke marijuana regularly. By contrast, diagnoses of nonseminoma, which typically affects males between the ages of 15 and 34, are extremely rare.
Nonseminomas account for fewer than one half of one percent of all cancers among American men.
Further undermining the study’s hypothesis is this: Since the 1970s, the percentage of American males smoking pot has climbed dramatically. By contrast, incidences of nonseminoma have risen only nominally during this same time period.
Of course, this is hardly the first time the mainstream media has jumped ugly on cannabis. Around this same time last year, news outlets from Reuters to Fox News declared that marijuana posed a greater cancer risk than cigarettes. Only problem was that the study they were reporting on actually demonstrated the opposite.
So why does the mainstream media continue to get the story wrong when it comes to pot? Good question. You can read my abbreviated answer here. And while you’re on NORML’s site, get the skinny on what the scientific literature really has to say about any potential links between marijuana and cancer here, here, and here.