Daily marijuana use linked to increased risk of deadly head and neck cancers, study finds

Sandee LaMotte, CNN

(CNN) — Using marijuana daily for years whitethorn raise nan wide consequence of head and cervix cancers three- to five-fold, according to a caller study that analyzed millions of aesculapian records.

“Our investigation shows that group who usage cannabis, peculiarly those pinch a cannabis usage disorder, are importantly much apt to create caput and cervix cancers compared to those who do not usage cannabis,” said elder study writer Dr. Niels Kokot, a professor of objective otolaryngology-head and cervix room astatine nan Keck School of Medicine astatine nan University of Southern California successful Los Angeles.

Cannabis usage disorder is diagnosed erstwhile a personification has 2 aliases much of specified symptoms arsenic craving weed, becoming tolerant to its effects, utilizing much than intended, utilizing marijuana moreover though it causes problems successful life, utilizing it successful high-risk situations, experiencing withdrawal and being incapable to quit, according to the US Centers for Disease Control and Prevention.

“While our study did not differentiate betwixt methods of cannabis consumption, cannabis is astir commonly consumed by smoking,” Kokot said successful an email. “The relation we recovered apt pertains chiefly to smoked cannabis.”

Some 69% of group pinch a test of oral aliases pharynx cancer will survive 5 years aliases longer after their diagnosis, according to nan National Cancer Institute. If nan crab metastasizes, however, that complaint drops to 14%. About 61% of group diagnosed pinch cancer of the larynx will beryllium live 5 years later — a complaint that drops to 16% if nan crab spreads.

The study utilized security information to look astatine nan relation of cannabis usage upset pinch caput and cervix cancers, said Dr. Joseph Califano, nan Iris and Matthew Strauss Chancellor’s Endowed Chair successful Head and Neck Surgery astatine nan University of California, San Diego. He was not progressive successful nan study.

“The researchers utilized a huge, immense dataset, which is really extraordinary, and location is tremendous powerfulness successful looking astatine numbers this ample erstwhile we typically only spot mini studies,” said Califano, who is besides nan head of UC San Diego’s Hanna and Mark Gleiberman Head and Neck Cancer Center.

“On average, group pinch cannabis usage upset fume astir a associated coming and do truthful for astatine slightest a mates years, if not longer,” said Califano, who coauthored an editorial published Thursday successful JAMA Otolaryngology–Head & Neck Surgery successful conjunction pinch nan caller study.

However, he added, nan study does not find an relation betwixt “the occasional recreational usage of marijuana and caput and cervix cancer.”

Causes of caput and cervix cancers

In nan United States, caput and cervix cancers dress up 4% of each cancers, pinch much than 71,000 caller cases and much than 16,000 deaths expected successful 2024, according to nan National Foundation for Cancer Research.

Tobacco use, which includes smoking cigarettes, cigars, pipes and smokeless tobacco, and nan usage of intoxicant are nan 2 astir communal causes of caput and cervix cancers, experts say. Other consequence factors see mediocre oral hygiene; gastroesophageal reflux disease, aliases GERD; a weakened immune system; and a fare debased successful fruits and vegetables. Occupational consequence factors see vulnerability to asbestos and wood dust.

A increasing number of caput and cervix cancers are owed to infection pinch nan quality papillomavirus aliases HPV, aliases nan Epstein-Barr virus, aliases EBV, which are DNA viruses that impact genes, making them susceptible to malignancies.

Epstein-Barr microorganism is linked to infectious mononucleosis, besides called nan “kissing disease,” arsenic good arsenic various cancers. Researchers estimate that 90% of nan world’s organization is infected pinch EBV.  A vaccine is disposable for HPV, which is linked to a precocious consequence of processing cervical crab and immoderate non-Hodgkin lymphomas.

It’s imaginable to beryllium infected pinch some viruses astatine once, and that operation is responsible for 38% of each virus-associated cancers, according to research.

How mightiness cannabis origin cancers?

The study, published Thursday successful JAMA Otolaryngology–Head & Neck Surgery, analyzed a database of 4 cardinal physics wellness records and recovered much than 116,000 diagnoses of cannabis usage upset among group pinch caput and cervix cancers. Those men and women, whose mean property was 46, were past matched pinch group who besides had caput and cervix cancers but were not diagnosed pinch cannabis usage disorder.

The study showed that group pinch cannabis usage upset were astir 2.5 times much apt to create an oral cancer; astir 5 times much apt to create oropharyngeal cancer, which is crab of nan soft palate, tonsils and backmost of nan throat; and complete 8 times much apt to create crab of nan larynx. The findings held existent for each property groups, according to nan study.

Smoke is 1 cardinal logic for nan relation betwixt smoking weed and caput and cervix cancers, experts say. Smoking baccy doubles nan risk of processing caput and cervix squamous compartment carcinoma, which makes up 90% of each caput and cervix cancers.  Heavier baccy usage leads to moreover higher risk, and erstwhile intoxicant is added, nan consequence is moreover greater.

Due to nan measurement marijuana is smoked — unfiltered and breathed successful profoundly and held successful nan lungs and pharynx for a fewer seconds — nan consequence from cannabis fume could beryllium moreover greater, experts say.

Another cardinal to nan puzzle of really cannabis causes cancer: Research has recovered a nexus betwixt various cannabinoids and tumor growth. There are more than 100 cannabinoids — biologic compounds successful nan cannabis works that hindrance to cannabinoid receptors successful nan quality body, according to nan National Center for Complementary and Integrative Health. All told, location are astir 540 chemicals successful each marijuana plant.

Tetrahydrocannabinol, aliases THC, is nan constituent that makes 1 euphoric, while cannabidiol, aliases CBD, has been shown to person medicinal uses for puerility seizures and epilepsy.

“Part of nan investigation we person already published shows that THC aliases THC-like compounds tin surely accelerate tumor growth,” Califano said. “We besides person immoderate information to show that cannabinoids heighten nan maturation of HPV-related pharynx cancers.”

With nan usage of marijuana rising, location is interest that diagnoses of caput and cervix cancers could summation successful coming years, Kokot said.

“Especially arsenic (marijuana) becomes much wide legalized and socially accepted, we whitethorn spot a corresponding emergence successful caput and cervix crab cases if nan relation is confirmed,” he said.

“This underscores nan value to pass group astir nan imaginable risks and behaviour further investigation to understand nan semipermanent impacts of cannabis usage connected crab development.”