How Marijuana Accelerates Growth of HPV-related Head and Neck Cancer Identified

January 13, 2020  |  Yadira Galindo

University of California San Diego School of Medicine researchers have identified the molecular mechanism activated by the presence of tetrahydrocannabinol (THC) — the ingredient that causes people to feel the euphoria or “high” associated with cannabis — in the bloodstream that accelerates cancer growth in patients with human papillomavirus (HPV)-positive head and neck squamous cell carcinoma. 

“We now have convincing scientific evidence that daily marijuana use can drive tumor growth in HPV-related head and neck cancer,” said Califano. “Marijuana and other cannabis products are often considered benign, but it is important to note that all drugs that have benefits can also have drawbacks. This is a cautionary tale.”

Together, a low HPV vaccination rate and an increase in marijuana use among youth has the makings of a storm, said Califano, physician-in-chief and director of the Head and Neck Cancer Center at Moores Cancer Center at UC San Diego Health.

Joseph A. Califano III, MD, professor and vice chief of the Division of Otolaryngology in the Department of Surgery at UC San Diego School of Medicine.

Dr. Mahmoud ElSohly: Part 15-Can Marijuana Cure Brain Cancer?

Mahmoud Elsohly, PhD, is a pharmacologist known for his work on marijuana. He is professor of pharmaceutics in the school of pharmacy at the University of Mississippi where he directs the Marijuana Project which grows pharmaceutical-grade marijuana for research. He is an expert in the processing, testing, and detection of drugs of abuse.

Key Points

  • Again, this is not something that has been shown.
  • Science has been preempted by anecdotal evidence
  • Education is key.
  • First time in history that a drug has been approved by popular vote
  • Marinol and Syndros are dronabinol (THC) approved by FDA. Clinical trials have shown what dose is needed.
  • Epidiolex (CBD) is latest drug to be approved by FDA to treat rare forms of epilepsy.
Cannabis use and incidence of testicular cancer: a 42-year follow-up of Swedish men between 1970 and 2011

No evidence was found of a significant relation between lifetime “ever” cannabis use and the subsequent development of testicular cancer [n = 45 250; 119 testicular cancer cases; adjusted hazard ratio (AHR) 1.42, 95% CI, 0.83, 2.45]. “Heavy” cannabis use (defined as usage of more than 50 times in lifetime, as measured at conscription) was associated with the incidence of testicular cancer (n = 45 250; 119 testicular cancer cases; AHR 2.57, 95% CI, 1.02, 6.50).


The current study provides additional evidence to the limited prior literature suggesting cannabis use may contribute to the development of testicular cancer.

THC Accelerates Head and Neck Cancer Growth

Researchers at the University of California San Diego School of Medicine have identified the molecular mechanism activated by the presence of tetrahydrocannabinol (THC) in the bloodstream that accelerates cancer growth in patients with HPV-positive head and neck squamous cell carcinoma. 

“HPV-related head and neck cancer is one of the fastest growing cancers in the United States, while at the same time, exposure to marijuana is accelerating. This is a huge public health problem,” said Joseph A. Califano III, MD, senior author and professor and vice chief of the Division of Otolaryngology in the school’s Department of Surgery. 

Head and neck squamous cell carcinoma is the sixth most common cancer worldwide, the school reports. These cancers begin in the cells that line the mucous membranes inside the mouth, nose, and throat. About 30% of cases are related to HPV infection, and these cases in particular are on the rise

Cannabis: Oral Health Effects

Topic last updated: August 24, 2020

Key Points

  • Cannabis smoking is associated with periodontal complications, xerostomia, and leukoplakia as well as increased risk of mouth and neck cancers.
  • Historically, cannabis has been smoked as marijuana, but is increasingly available in other forms, including edible and topically applied products.
  • Cannabis use has increased in recent years, along with state legalization, although it remains federally banned.

Cannabis in Medicine


Legalization of marijuana is becoming increasingly prominent in the United States and around the world. While there is some discussion of the relationship between marijuana and overall health, a comprehensive resource that outlines the medical literature for several organ systems, as well as non-medical societal effects, has yet to be seen. While all physicians strive to practice evidence-based medicine, many clinicians aren’t aware of the facts surrounding cannabis and are guided by public opinion.
This first of its kind book is a comprehensive compilation of multiple facets of cannabis recommendation, use and effects from a variety of different perspectives. Comprised of chapters dedicated to separate fields of medicine, this evidence-based guide outlines the current data, or lack thereof, as well as the need for further study. The book begins with a general overview of the neurobiology and pharmacology of THC and hemp. It then delves into various medical concerns that plague specific disciplines of medicine such as psychiatry, cardiology, gastrointestinal and neurology, among others. The end of the book focuses on non-medical concerns such as public health and safety, driving impairment and legal implications.

Comprised of case studies and meta-analyses, Cannabis in Medicine:  An Evidence-Based Approach provides clinicians with a concise, evidence-based guide to various health concerns related to the use of marijuana. By addressing non-medical concerns, this book is also a useful resource for professionals working in the public health and legal fields.

Is Marijuana A True Medicine?

True medicine approved by the FDA undergoes rigorous trials and research. Due to potential complications noted during those trials, many new medications do not make it to the market. A drug that becomes available for prescription purposes comes with a dosage guideline. 

Marijuana advocates put out many product claims of treatment and cures without adequate scientific proof. They also put out products without consistency in their chemicals or compounds.  In other words, dosing irregularities, chemical composition variations, and contaminants all exist within final products. Several studies have shown that many final products contain heavy metals, bacteria, fungus, insecticides, etc. (1,2) For the person who purchases these products, it is becomes a guessing game to know if your product is contaminated.