Featured Research

from universities, journals, and other organizations

Researchers At UCLA's Jonsson Cancer Center Report Smoking Marijuana May Increase Risk Of Head And Neck Cancers

Date:
December 20, 1999
Source:
University Of California, Los Angeles Health Sciences
Summary:
Researchers at UCLA's Jonsson Cancer Center are reporting, for the first time, that smoking marijuana may increase the risk of head and neck cancers. Previous laboratory and clinical studies have indicated that marijuana use may be related to molecular alterations in the respiratory tract, changes that may lead to cancer.

Researchers at UCLA's Jonsson Cancer Center are reporting, for the first time, that smoking marijuana may increase the risk of head and neck cancers.

Results of an epidemiological study of more than 340 people are outlined in an article published in today's (Dec. 17) edition of the peer-reviewed journal Cancer Epidemiology Biomarker and Prevention.

Previous laboratory and clinical studies have indicated that marijuana use may be related to molecular alterations in the respiratory tract, changes that may lead to cancer. This is the first study to examine whether smoking marijuana increases risk of head and neck cancers, said Dr. Zuo-Feng Zhang of UCLA's Jonsson Cancer Center, a professor in the Department of Epidemiology in the UCLA School of Public Health and director of the cancer epidemiology training program at UCLA.

"Most people don't think about marijuana in relationship to cancer," said Zhang, lead author of the journal article. "The carcinogens in marijuana are much stronger than those in tobacco. The big message here is that marijuana, like tobacco, can cause cancer."

Zhang studied the relationship between marijuana use and head and neck cancers in 173 patients diagnosed with those diseases. He compared those findings to 176 cancer-free control patients, and found that those who habitually smoked marijuana were at higher risk for head and neck cancers.

The epidemiological data was collected using a structured questionnaire, which queried patients about their histories of tobacco smoking, marijuana smoking and alcohol use. Zhang said researchers were able to evaluate the data on marijuana smoking independently from data on tobacco smoking and alcohol use, which also increase the risk of certain cancers.

The results of the study are particularly important now, Zhang said, as habitual marijuana smokers from the 1960s reach older ages. Because head and neck cancers -- cancers of the mouth, tongue, larynx and pharynx -- take many years to develop, people who smoked large amounts of marijuana in the 1960s may just now be contracting head and neck cancers, Zhang said.

"In the '60s, we had very high numbers of people in their 20s smoking marijuana," Zhang said. "These people are just now getting to the ages at which they will get head and neck cancers. This is the time to study a risk like this."

The more times per day a person smokes marijuana, the greater his or her risk of head and neck cancers, according to the study. Additionally, people who use marijuana habitually for many years also increase their risk of head and neck cancers, Zhang said.

"If you smoke a little, your risk increases a little," Zhang said. "If you smoke a lot, your risk increases a lot."

Marijuana is the most commonly used illegal drug in the United States, Zhang said. It is estimated that about 31 percent of the U.S. population 12 years or older has used marijuana, according to the journal article.

Zhang's research builds on previous studies of marijuana and cancer risk. An article by UCLA cancer researchers published in the Aug. 19, 1998, issue of the Journal of the National Cancer Institute stated that habitual smoking of marijuana and crack cocaine causes the same kinds of molecular changes that precede the development of lung cancer in cigarette smokers.

"Now we have evidence that may link marijuana smoking to head and neck cancers," Zhang said. "Many people may think marijuana is harmless, but it's not."

In addition, the epidemiological study and the subsequent journal article also touch on the interplay between marijuana smoking and the genetic defect that prevents DNA from repairing itself. Some marijuana smokers with this genetic defect might not have the ability to repair DNA damage prompted by the habit. Zhang said these people are about 16 times more likely to develop head and neck cancers than non-marijuana smokers whose DNA repair function is operating normally.

Zhang said larger epidemiological studies are needed to replicate the results obtained by UCLA cancer researchers. One such study, funded by the National Institutes of Health, is being conducted now at UCLA.


Story Source:

The above story is based on materials provided by University Of California, Los Angeles Health Sciences. Note: Materials may be edited for content and length.


Cite This Page:

University Of California, Los Angeles Health Sciences. "Researchers At UCLA's Jonsson Cancer Center Report Smoking Marijuana May Increase Risk Of Head And Neck Cancers." ScienceDaily. ScienceDaily, 20 December 1999. <www.sciencedaily.com/releases/1999/12/991220082058.htm>.
University Of California, Los Angeles Health Sciences. (1999, December 20). Researchers At UCLA's Jonsson Cancer Center Report Smoking Marijuana May Increase Risk Of Head And Neck Cancers. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/1999/12/991220082058.htm
University Of California, Los Angeles Health Sciences. "Researchers At UCLA's Jonsson Cancer Center Report Smoking Marijuana May Increase Risk Of Head And Neck Cancers." ScienceDaily. www.sciencedaily.com/releases/1999/12/991220082058.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins