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Could cell phones increase your risk of cancer?

A rather black sheep topic in the medical community is whether cell phones cause cancer.  The weak electromagnetic fields and transmission sent off by the devices are something that many users expose themselves to numerous times daily.  One difficulty in determining the amount of possible danger is that such effects would likely be long term and cell phone use has been around for two decades, with heavy use only coming in the late nineties.  With cell phones threatening to replace the land phone lines nationwide the issue is causing growing concern.

It does not help that the few early studies have shown seemingly contradictory results, some showing no risk, some showing significant risks, others showing specialized but less sweeping effects, which could be detrimental (ie. effects on only certain cancers, cancer characteristics).  Still the current evidence supporting the view that mobile phones may cause cancer, combined with the results of several unreleased studies were enough to convince top cancer doc, Dr. Ronald B. Herberman, director of the University of Pittsburgh Cancer Institute to warn his faculty and staff to limit their cell phone use because of cancer risks.

While the U.S. Food and Drug Administration (FDA) has remained unconcerned about the threat, Doctor Herberman feels the evidence is stacking up.  He says the possible threat, particularly to children is to serious to adopt a "wait and see" approach.  He states, "Really at the heart of my concern is that we shouldn't wait for a definitive study to come out but err on the side of being safe rather than sorry later."

Doctor Herberman's statement is the first time a head of a major academic cancer research institution has vocally supported the idea of a cell phone-cancer link.  Many think that it will have significant impacts at other institutions and in general public opinion.  In his memo he states that children should only use cell phones for emergencies due to greater risk on their developing brains.  The memo went out to his institution's over 3000 faculty and staff members.

In the memo Doctor Herberman suggests that there is evidence that keeping the cell phone away from the head or use of speakerphone or a wireless headset can help reduce users risk.  He also warns to avoid public use on public facilities like buses or subways as it exposes other to the EM radiation in a public health hazard analogous to, but perhaps not comparable to, secondhand smoke.

Despit the fact that the topic has not been widely discussed or addressed among brain specialists there have been a growing number of studies looking at the issue.  Most have concluded against there being a threat.  French and Norwegian studies, as well as a 2008 University of Utah analysis of nine U.S. studies all found no clear risk of brain cancer increases.  However as the University of Utah analysis points out, "The potential elevated risk of brain tumors after long-term cellular phone use awaits confirmation by future studies."

The FDA's website officially states, "If there is a risk from these products -- and at this point we do not know that there is -- it is probably very small."

However Doctor Herberman believes that there is a "growing body of literature linking long-term cell phone use to possible adverse health effects including cancer."  He continues, "Although the evidence is still controversial, I am convinced that there are sufficient data to warrant issuing an advisory to share some precautionary advice on cell phone use."

Devra Lee Davis, the director of the university's center for environmental oncology was a key advocate of the stance.  She states, "The question is, do you want to play Russian roulette with your brain?  I don't know that cell phones are dangerous. But I don't know that they are safe."

Both she and Doctor Herberman reference the results of Interphone, a massive ongoing research project involving 13 nations.  The research published to date in peer reviewed journals has been less alarming but cautionary, and Doctor Herberman believes more alarming results are surfacing.  However the research has come under fire by the National Research Council in the U.S. for its "selection bias", requiring brain tumor victims to recall how many times they used cell phones over certain periods, which is considered to be questionable in accuracy.

The largest fully completed study, from the Journal of the National Cancer Institute in 2006 tracked 420,000 Danish cell phone users and found no clear link between cell phones and cancer.  A more recent French study found no significant risk of three major types of nervous system tumors, but did find an increased risk for one type of brain tumor among heavy users that needed to be verified.

Dan Catena, a spokesman for the American Cancer Society is neutral on the topic stating, "By all means, if a person feels compelled that they should take precautions in reducing the amount of electromagnetic radio waves through their bodies, by all means they should do so.  But at the same time, we have to remember there's no conclusive evidence that links cell phones to cancer, whether it's brain tumors or other forms of cancer."

Joe Farren, a spokesman for the CTIA-The Wireless Association says that his organization is concerned that "misinformation" may be spread about cell phones.  He states, "When you look at the overwhelming majority of studies that have been peer reviewed and published in scientific journals around the world, you'll find no relationship between wireless usage and adverse health affects."

Some studies do support the conclusion, though. A study in Finland found that cell phone users of 10 years or more were 40 percent more likely to get a brain tumor on the side of the head they usually hold their phone.  A follow up study in Sweden indicate this risk to be closer to four times as great.

In February, DailyTech reported in a study appearing in a U.S. medical journal, which indicated that heavy cell phone use raised the risk of some tumors as much as 50 percent.  Cancers of the salivary gland in particular were found to be the most commonly induced type.  This study differed in that it looked at the effects of long term use.  Also it was among the first studies to examine cancer rates in other organs besides the brain.


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RE: Basic statistics
By Octoparrot on 7/26/2008 9:42:17 PM , Rating: 2
Point well taken, but I'd be interested to know if alterations in the DNA repair framework could alter the frequency of mutation. As you point out, causing errors of metabolism will not directly lead to DNA mutation.

1) There are a number of enzymes involved in DNA replication, which would be where it might be worth looking at these studies. What happens if exonuclease/proof-reading activity is impaired?

2) You must know more than me about such things as transposons, or the RNA interference pathway, as these have been more recently understood. Given external retroviruses that piggyback the RNA & DNA machinery of the cell--is it not plausible that such a virus could have reproduction enhanced slightly if certain enzyme activities are altered? What if the frequency of disruptions to cellular DNA is increased ever so slightly--including insertion into non-coding elements that control transcription, leading to a deregulation of growth factors in one line of cells? A long chain of low probability events to be sure...but not improbable. Interesting question though whether we could ever prove this is clinically insignificant or not.


RE: Basic statistics
By Complex Pants on 7/26/2008 10:37:05 PM , Rating: 2
1) Totally true and impairing proof reading could totally be an upstream cause of tumor development.

2) Transposons may be a cause, but then since they would be present in every other cell in the body, why would cancer be limited to the brain. In theory if this was the case then just basic sunlight exposure would provide enough EM radiation to stop all sorts of enzymes in your body and I would expect tumor formation would increase greatly. I am just starting medical school and I don't have hard facts on this, but it is my belief that the blood-brain barrier is pretty effect against most types of viruses, so it would seem unlikely to me that an external virus in conjunction with cell phone radiation would cause a tumor. But as you said, it could just be a long chain of low-probability events that have occurred, which in my view boils down to bad luck. I always like to remember that getting struck by lighting has about a 1:20,000 chance of happening. It gives me a healthy perspective on things.

I also want to know why cell phone always seem to give you brain tumors, but no tumors on your skin, either on your head or hand. It would seem to me that faster dividing, less protected cells would be more susceptible to EM radiation than the slower dividing glial cells.


RE: Basic statistics
By masher2 (blog) on 7/27/2008 11:14:26 AM , Rating: 3
quote:
I also want to know why cell phone always seem to give you brain tumors, but no tumors on your skin, either on your head or hand. It would seem to me that faster dividing, less protected cells would be more susceptible to EM radiation than the slower dividing glial cells.
Skin cancer is 20X as prevalent, making for a larger statistical base which is much more resistant to spurious random associations.

Rarer conditions like brain tumors show a much smaller number in any sample population, and thus are much more susceptible to chance variations.


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