Study suggests smoking, but not nicotine, reduces risk for rare tumor
New research confirms an association between smoking and a reduced risk for a rare benign tumor near the brain, but the addition of smokeless tobacco to the analysis suggests nicotine is not the protective substance.
The study using Swedish data suggests that men who currently smoke are almost 60 percent less likely than people who have never smoked to develop this tumor, called an acoustic neuroma. But men in the study who used snuff, which produces roughly the same amount of nicotine in the blood as smoking, had no reduced risk of tumor development.
"We see this effect with current smokers but don't see it with current snuff users, so we think that maybe the protective effect has something to do with the combustion process or one of the other chemicals in cigarettes that are not in snuff," said Sadie Palmisano, a doctoral student in epidemiology at Ohio State University and lead author of the study. "We learned something from exclusion."
Acoustic neuroma is a tumor that grows on the vestibular cochlear nerve connecting the ear to the brain. It is not cancer, but it can cause nerve damage as well as symptoms that include vertigo, ringing in the ears and hearing loss. The only treatment for these slow-growing tumors is surgical removal or high-powered radiation that reduces their size. About one in 100,000 people per year develops these growths, which account for approximately 8 percent of all primary tumors inside the skull in the United States.
A few previous studies have found a similar link between smoking and lowered risk for development of these tumors, but did not take snuff use into account. Though the research is aimed at prevention of acoustic neuromas, the researchers emphasized that they do not endorse smoking as a way to avoid developing a tumor.
The findings suggested to the scientists that a lack of oxygen associated with smoking might help prevent the tumors by starving the cells whose overgrowth leads to the formation of an acoustic neuroma. These are called Schwann cells, and they produce the myelin coating on nerve cells in the peripheral nervous system outside the brain and spinal cord.
The research is published online and scheduled for future print publication in the American Journal of Epidemiology.
The scientists conducted a nationwide study of acoustic neuroma between 2002 and 2007, compiling data on Swedish patients between the ages of 20 and 69 years at the time of diagnosis with the tumors. These patients, as well as healthy Swedish control participants, also completed questionnaires about environmental exposures and lifestyle choices.
Palmisano and colleagues applied statistical analysis to these data to determine associations between smoking and snuff use and risk for acoustic neuroma. The analysis included data on 423 patients with tumors and 645 controls matched for age, sex and home location.
"We got practically all of the diagnosed cases in Sweden - there was an 84 percent participation rate. On top of that, a population-based registry served as the basis for the control sample. This made it incredibly representative of the population, and with the sample being this large, we make the case that the link between smoking and reduced risk for acoustic neuroma is there," Palmisano said.
The link was especially strong in men who were current smokers - a 59-percent reduction in risk for acoustic neuroma compared to people who had never smoked. In women current smokers, the association was smaller - a 30 percent reduced risk compared to never-smokers, with more statistical room for this link to be attributed to chance.
Current smokers were those who smoked at least one cigarette per day for six months or longer. For people who had smoked and then quit, including even longtime smokers, "we didn't find as much of an effect. It's like a puzzle," Palmisano said.
The researchers evaluated smokeless tobacco use among only men because too few women reported using snuff. The scientists found no difference in the risk for acoustic neuroma between current or past snuff users and people who had never used snuff.
These findings about snuff imply that nicotine is not providing the protection because habitual snuff users and smokers have similar levels of nicotine in their blood. By determining that snuff users reap no acoustic neuroma preventive benefits from the smokeless tobacco, the researchers determined that nicotine should probably be ruled out as a potentially protective compound in this context.
The Swedish and American forms of snuff differ substantially, so these findings do not translate to users of American smokeless tobacco, which is fermented and contains more chemicals than does Swedish snuff.
Many studies have also linked smoking with a reduced risk for Parkinson's disease, leading scientists to continue looking for clues about how tobacco can have this effect on nervous-system processes. Palmisano also will use the Swedish data to explore other potential causes of acoustic neuromas, including exposure to loud noises. The only known cause of the tumors is a genetic condition called neurofibromatosis. Two different sources of radiation also have been linked to increased risk for the tumors.
Journal reference: American Journal of Epidemiology
Provided by The Ohio State University
- Cigarettes, not Swedish snuff linked to increased risk of MS Aug 31, 2009 | not rated yet | 0
- Smokeless tobacco more effective than cigarettes for delivering dangerous carcinogens into the body Aug 09, 2007 | not rated yet | 0
- Study: Snuff users tend to obesity Aug 25, 2006 | not rated yet | 0
- Turn Down That Radio! Years Of Loud Noise May Lead To Tumor Jan 04, 2006 | not rated yet | 0
- Smokeless tobacco products not a safe option, won't help smokers quit Sep 13, 2010 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Why is zone 1 in liver more prone to ischemic injury?
May 23, 2013 Hi, Is it because around central vein, there is only deoxygenated blood from the vein where as in the periphery there is hepatic artery. Also why...
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013 As title suggest. Thanks :smile:
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
- More from Physics Forums - Medical Sciences
More news stories
Researchers from London's Kingston University have begun a two-year study which could help prolong the lives of people with colorectal tumours.
Cancer 2 hours ago | 5 / 5 (1) | 0
Transformative research from Western University has identified new hormones in the body which may suppress breast cancer and stimulate the regression of breast tumors.
Cancer 3 hours ago | 5 / 5 (1) | 0
(Medical Xpress)—Curtin University researchers have found evidence that targeting specific cells in the body can reverse the effects of cancer on the immune system.
Cancer 3 hours ago | 5 / 5 (2) | 0
A leading expert in childhood cancer at The University of Nottingham is spearheading a Europe-wide lobby of the European Parliament to try to make it easier for doctors to develop and test new treatments on children and young ...
Cancer 4 hours ago | not rated yet | 0
(AP)—Researchers examining the incidence of brain cancer at jet engine manufacturer Pratt & Whitney in Connecticut say they have found no statistically significant elevations in the rate of cancer among workers.
Cancer 5 hours ago | not rated yet | 0
Women at a particular stage in their monthly menstrual cycle may be more vulnerable to some of the psychological side-effects associated with stressful experiences, according to a study from UCL.
7 minutes ago | not rated yet | 0 |
Biological processes are generally based on events at the molecular and cellular level. To understand what happens in the course of infections, diseases or normal bodily functions, scientists would need to ...
37 minutes ago | not rated yet | 0 |
(HealthDay)—Menopausal hormone therapy should not be used for prevention of coronary heart disease, according to a Committee Opinion from the American College of Obstetricians and Gynecologists (ACOG) published ...
13 minutes ago | not rated yet | 0
The news about youth and diabetes keeps getting worse. The latest data from the national TODAY diabetes study shows that children who develop Type 2 diabetes are at high risk to develop heart, kidney and eye problems faster ...
36 minutes ago | not rated yet | 0
In Parkinson's disease, the protein "alpha-synuclein" aggregates and accumulates within neurons. Specific areas of the brain become progressively affected as the disease develops and advances. The mechanism underlying this ...
35 minutes ago | not rated yet | 0
After studying noise in one French Quarter neighborhood of New Orleans to determine whether or not noise levels exceeded municipal ordinances, Annette Hurley, PhD, Assistant Professor of Audiology at LSU Health Sciences Center ...
23 minutes ago | not rated yet | 0