NEAL CONAN, host:
This is TALK OF THE NATION. Im Neal Conan in Washington.
Almost everybody who owns a cell phone, and that's almost everybody, has wondered at some point or another whether using those things might lead to brain cancer. Decades' worth of research can't seem to come up with a definitive answer, and each inconclusive or contradictory result leads to more questions along the intersection of science, law and the media.
If you have questions about what you've heard concerning cell phones and brain cancer, give us a call, 800-989-8255. Email us, email@example.com. You can also join the conversation on our website. That's at npr.org. Just click on TALK OF THE NATION.
Later in the program, what would you say if one of your neighbors asked if he could sleep over? But first, cell phones and brain cancer, and we turn to Dr. Siddhartha Mukherjee, an assistant professor of medicine at Columbia University, a practicing physician who wrote a piece in this Sunday's New York Times Magazine. He's also the author of "The Emperor of All Maladies: A Biography of Cancer," which just yesterday received the Pulitzer Prize for general nonfiction. He joins us from our bureau in New York. Welcome, and congratulations.
Dr. SIDDHARTHA MUKHERJEE (Columbia University): Thank you so much. It's a real pleasure.
CONAN: In the New York Times piece, you start by telling us how all this came to public attention back in the early '90s, back before a lot of us had cell phones.
Dr. MUKHERJEE: Absolutely. I mean, the first cases, you know, started appearing in the public media, and probably the very first case was a case filed by David Reynard in Florida, and Reynard's wife, Susan, or Suzie Ellen Reynard, had developed brain cancer, astrocytoma, and the Reynards brought suit against NEC and GTE, the cell phone manufacturer and cell phone carrier, claiming that the use of the cell phone had caused the astrocytoma.
CONAN: And everybody, I think, remembers if not that case specifically, the claim that the brain tumor was in the exact shape of the antennae of the cell phone.
Dr. MUKHERJEE: That's right. So this is what David Reynard claimed. As I said, as I point out in the piece, it's very hard to - shapes of tumors are very hard - I'm actually - I haven't seen her particular MRI or CAT scan, but often patients will come to me and say: Look, doesn't this tumor resemble either the shape of a cell phone, or doesn't the tumor resemble the shape of something that I held close to my head? Usually it's a very hard thing to interpret, because like clouds, the tumors take the shape of our imaginations.
So this is what David Reynard certainly thought, that there was a relationship between the cell phone and her tumor.
CONAN: And you go through then a lot of the science involved in trying to determine whether there should be - whether scientists can discover a link between brain cancer and cell phones, and the first one would be simply the - well, everybody started using cell phones all of a sudden, at the same time. There ought to be - if there's a link, there ought to be a sudden spike in the number of brain cancers.
Dr. MUKHERJEE: Right. I mean, the point that I'm trying to make in this - that I try to make in this piece - and in fact it's a point that I also make in "The Emperor of All Maladies," my book, is that finding a causal agent for cancer is not like solving a mathematical equation.
It is not like there's a single magical formula that will allow us to find and define a cancer-causing agent or a carcinogen. In fact, the way it's defined or such the way such carcinogens are ever described or identified is through a process that really resembles a detective case, solving a detective case, in which you take one piece of evidence, you add another piece of evidence, and often you're looking for corroborative pieces of evidence.
And so the first piece of evidence that you might want to look for is, well: Is there a coincidence in usage? So in other words, as the usage of cell phones has accelerated, almost creating a natural experiment between the early - between the late '80s and 2011, has there been an increase in brain tumors? Because if the cell phones truly contain a carcinogen, then increasing cell phone use dramatically, as has happened, should increase the rate of the development of brain cancers in America.
CONAN: And yet when you go through the data, it doesn't show up.
Dr. MUKHERJEE: Absolutely. So the data, there have been several studies, but two major ones. One of them, an earlier study, showed that the rate has essentially remained flat from about - the first thing you have to remember is that these brain cancers are extremely rare. There are about six to seven cases diagnosed for 100,000 men and women in America. So the rates are very rare.
So it's very important to start this conversation by saying that we were looking at a phenomenon that already is an extremely rare phenomenon. You are vastly more likely, I suspect, to die of an accident because of the misuse of a cell phone while driving - by several, several fold.
The danger of brain cancer is vastly less than that. But that said, let's just concentrate for a second on brain cancer. The rate remained flat between 1992 and about 2000. In 2000 a subsequent study has updated that, and overall the rate remains flat as well, except there is a small increase, from 2.5 cases per 100,000 to 2.6 cases per 100,000, for tumors in the frontal lobe - only in women and not in men.
Now, that part of the brain is not a part of the brain that we typically think is associated with holding a cell phone. It's not near the ear. It's not near either of the ears. It actually is in the frontal(ph) lobe. And again, it's a change from 2.5 to 2.6 per 100,000 men and women.
I don't know what the cause of this is, but most scientists think that it's unlikely that phone use is what's causing it. It might even just be - it probably is just random fluctuations. You know, with such small numbers and such large denominators, it's very likely that you have small fluctuations like 2.5 to 2.6, as you can imagine.
CONAN: Sure, and there are other methods to determine whether something is a carcinogen or not. But one of the main ideas behind the - well, you know, the thing radiates. It sends out radiation. Isn't that carcinogenic? And you point out: Well, not the kind of radiation necessarily that a cell phone uses.
Dr. MUKHERJEE: That's right. So in fact it's very important - in order to have sophisticated and important conversations about cancer and carcinogens, we need to have - we need to define some terms.
The kind of radiation - the word radiation really means any radiant energy that's coming out of any source. So for instance, while I'm sitting here in the studio in New York, I'm being bombarded with radiation from electrical light, from an ordinary light.
There's also radiation that's coming through the window, and you know, for the most part these forms of radiation don't affect the way, they don't affect the DNA of the cell. They can't mutate genes and therefore are very unlikely to cause cancer because they don't really have any capacity to alter genes directly.
Cell phone radiation happens to belong to that part of the spectrum. It's the very low-energy part of the spectrum, in contrast to radiation from X-rays.
So even though we use the word radiation, it really is a huge range, ranging from very energic rays, such as X-rays, which can burrow through your tissues, break up DNA, cause mutations, and thereby increase cancer rates, on one end of that spectrum.
And on the other end of the spectrum are things like, you know, light, sunlight and other forms of radiation which don't really - which are much less energetic.
Of course, there are some forms of light that reach a kind of energy that's important, but for most radiant light, we don't have that kind of energy, and cellular phones lie in that spectrum.
CONAN: We should point out most of you listening to the radio, well, radio stations send out radiation too.
Dr. MUKHERJEE: Absolutely, therefore the word radio.
CONAN: Therefore the word radio. And it's also down at the lower end of the spectrum, and, well, I don't think there's ever been any questions about that.
But anyway, we want to get some callers in on the conversation. Our guest is Dr. Siddhartha Mukherjee, an assistant professor of medicine, in medical oncology, and celebrating his new Pulitzer Prize for "Emperor of All Maladies: A Biography of Cancer," which he received yesterday the Pulitzer Prize for general nonfiction.
We're talking today about the link or trying to establish the link or the search for the link between cell phones and brain cancer. Give us a call, 800-989-8255. Email firstname.lastname@example.org. We'll start with George and George with us from Charleston.
GEORGE (Caller): Yes.
CONAN: Go ahead, please, you're on the air.
GEORGE: Yeah, well, I'm interested in what his comment would be on the X-ray photograph that I saw that very, very exactly emulated the shape of a cell phone and that was exactly in the location that a cell phone would be when one is using it.
And the other question or the other comment I'd like him to make is: Is he aware of the radically reduced sensitivity that one would have to a cell phone if it were placed several feet away from the ear, as I saw many people using cell phones, especially Qualcomm cell phones, early on.
And I realize the reason for that was that these were contractor types, that they knew somehow that, you know, that the emitted radiation was harmful to them, and the company itself, Qualcomm, knew this as well, and so they had a feature that allowed users to hold the phone at a distance, and you know...
CONAN: Thereby reduce exposure, yeah.
CONAN: Okay, Dr. Mukherjee
Dr. MUKHERJEE: Well, it's hard for me to comment on the exact shape of a tumor in the brain which looks like a cell phone. I've never seen such a picture. I've certainly seen many pictures of - I've treated several patients with various forms of brain cancer.
And I must say in my perhaps somewhat limited experience, I have never seen a tumor that looks exactly like a cell phone. Perhaps others have. And the second question is: What about this phenomenon? You know, do these contractors know something that we don't, and is this the reason that they're holding their cell phones away?
I mean, I don't have a problem with people holding their cell phones away. That's a matter of personal discretion. If these contractors do know something, I'd love to know it as well.
It turns out what we do know is the material that we have from these -the several trials, not one but multiple, different kinds of trials that I referred to in my piece, and I actually talk about this, some of these trials in my book as well, that's the evidence that we have, and the evidence remains weak and inconclusive that moderate cell phone use in adults is a carcinogen. Now, you know, I said the word moderate, I said adults, because that's where we have the strongest pieces of evidence.
CONAN: George, I suspect you're unconvinced.
GEORGE: Well, yeah, you know, it sounds good. But, you know, seeing is believing. And I must tell you, I have had some rather interesting experiences after using cell phones.
Yeah, I am. You know, and what one of the things is that after having used the cell phone significantly, let's say for a period of, oh, several days, several hours each day, I found that when I pass underneath a, well, fairly normal power line, I was surprised at my sensitivity to it. I was actually able to feel the electromagnetic radiation as I had never felt before. And, you know, that was an astonishing phenomenon to me. And I was wondering if you had any thoughts on that.
Dr. MUKHERJEE: Well, once again, I mean I really, I don't have thoughts about that in particular. I would encourage you to really let the National Institute of Toxicology know about these kinds of sensitivities, because again, if you're feeling something, then it's probably worthwhile studying it in a nonbiased way, you know, turning the power lines on and off and see if this sensitivity really correlates with that. Thus far, as I said, the studies really haven't panned out.
CONAN: We'll have more with Dr. Siddhartha Mukherjee. If you have question for him about what you've heard concerning brains, cancer and cell phones, give us a call, 800-989-8255. It's the TALK OF THE NATION from NPR News.
(Soundbite of music)
CONAN: This is TALK OF THE NATION from NPR News. Im Neal Conan.
It might sound simple to connect a suspected carcinogen to an incidence of cancer like connecting tobacco smoking to lung cancer. But it wasn't in that case, and it's especially not true for the case of cell phones and brain cancer.
Ruling cell phones in or out as carcinogens is important, according to Dr. Siddhartha Mukherjee, who wrote a piece about this for the New York Times magazine, because to label everything potentially carcinogenic is like crying wolf about cancer.
If you have questions about what you've heard concerning cell phones and brain cancer, give us a call, 800-989-8255. Email email@example.com. You can also join the conversation at our website. Go to npr.org, and click on TALK OF THE NATION.
Dr. Mukherjee is with us from our bureau in New York. And let's go next to Calen(ph), Calen with us from Plainville in Connecticut.
CALEN (Caller): Hi. I'd just like your guest, if he knows anything, when I was doing research on my phone a couple years ago, I came across the RS values. And in that research, I saw an interesting image of a scan of an adult head and a scan of a child's head. And the RS frequency in the adult head went about a third into the soft tissue, and the RS frequency into a child went all the way into the middle of his head. So I was wondering if that could have any relation to cancers or tumors in the brain.
Dr. MUKHERJEE: Well, again, the notion of modeling the way radiation penetrates into the head when you use a cell phone has been around for a long time. And it's quite clear to me that, in fact, the old models, much like, in general, old models are not great, and we are refining these models all the time from a scientific perspective, really figuring out what is the depth. And as you're pointing out correctly, a child's skull is very different from an adult's skull.
Now again, what this kind of modeling research shows us is that there's different exposures available or that happen, that occur, in a child's skull versus and adult's skull.
But the meat of the question that you're asking is: Is that, is the difference in that exposure consequential or not? Does it really mean something? It' one thing to say there's a different level of exposure, but there's another - it's quite something else to say that different level of exposure causes cancer.
So just to give you an example, you can change the settings on your light switch to go from dim to extremely bright, but neither of those, although the levels of exposure that you get are vastly different, neither of those, as far as we know, is carcinogenic.
So again, it really boils down to the question: What is the meat of the evidence that, regardless of how one models exposure to a child's skull versus an adult's skull, is there any solid evidence connecting this form of radiation with cancer?
And as I point out in my article, which I would encourage you to read, the evidence ranges not only from human studies but also to animal studies and then finally to cellular studies. And thus far, there appears to be very weak and unconvincing evidence.
Now, that said, there are two major trials that are still out there, two trials, two so-called definitive trials, one from Europe and one from America. And, you know, I hope that that will settle the issue once and for all, but thus far, I would say that the evidence remains pretty negative.
CONAN: Calen, thanks very much.
CALEN: Okay, thanks.
CONAN: You write in your piece that the rarity of the cancer provokes a desperate and often corrosive search for a cause. Why, of all people, did I get an astrocytoma? When patients with brain tumors happen to share a common exposure, in this case cell phones, the line between cause and coincidence begins to blur.
The association does not stand out, nor does it disappear into statistical white noise. Instead, it remains suspended, like some sort of peculiar optical illusion that is blurry to some and all too clear to others.
Dr. MUKHERJEE: Absolutely. So one of the things that I started off thinking about while I was writing this piece, and again some of this is, I've been thinking about this in writing "The Emperor of All Maladies," I began to wonder about how the juxtaposition of cause and cancer are put together.
So as it turns out, if you have a very rare cause and a very rare cancer, then often these two things stand out, like - the analogy I give is it's a little bit like a lunar eclipse.
And so a classical analogy of that is it turns out that in the 19th century, in the 18th and 19th century, chimney sweepers in England were very - had suddenly started developing scrotal cancer, cancer of the scrotum.
Now, chimney sweeping was a relatively rare profession, relatively rare profession, particularly among young adolescents, and the scrotal cancer was an extremely rare form of cancer. And so epidemiologists, most notably, Sir Percival Pott, immediately figured out that the rare and the rare, if you put them together, there must be a relationship.
So that's what happens when you have a rare and rare. The trouble is that when you have a rare cancer and a very common exposure, and that's what's happening, to some extent, with brain cancer and cell phones.
Brain cancer, as I said, are about six to seven cases per 100,000 men and women in America. And cell phone usage is now ranging from 70 to 90 percent, depending on where you are.
And so when one has a very common exposure and a very rare cancer, it's very hard to figure out whether it's cause or a coincidence. It's like saying: Is there a relationship between sitting and cancer? Or is there a relationship between drinking milk and brain cancer?
Well, many people with brain cancer will have had a prior exposure to milk or to sitting. That is not to say that this is not a - this is clearly a very important way to tease out cause and correlation, but it becomes statistically very difficult to do, and that's what I point out in my piece.
CONAN: Let's go next to George(ph) and George with us from Chardon in Iowa.
GEORGE (Caller): Yeah, I saw an article in my alumni magazine from the University of California at Berkeley, where the University of California School of Public Health had gone back and looked at all the various studies on this issue, and they found that when they sorted out the studies that had been funded by the telephone companies, that the preponderance of the studies show that there was a connection. And when they looked at those telephone studies that were funded by the telephone companies, there were obvious flaws in the methodology.
Dr. MUKHERJEE: Well, I tried, again, in my piece, to identify the sources of funding for various studies. And as you can imagine, that's an extremely difficult thing to do because many people don't declare their funding.
On a side note, I'd just like to tell you very clearly: I have no funding - my funding sources are quite publicly known for my laboratory. I have no sources of funding from the cell phone industry. In fact, I'm quite annoyed at the amount of money that they seem to charge me every month.
(Soundbite of laughter)
CONAN: Like the rest of us, yeah.
Dr. MUKHERJEE: Just a side note. And what I tried to do is I tried to use studies where such sources of funding were at least somewhat moderately known. And I really leaned upon the National Cancer Institute to guide me in this. And if you look up the National Cancer Institute website, which I encourage you to do, at www.nci.org, that is the National Cancer Institute, which is, as far as I know, one of the least biased institutes in the United States, does extremely important work.
The message in the National Cancer Institute is, having looked at several studies, that there has not been any convincing link. And I tried to follow their - the studies that they had followed through and tried to, again, identify the sources of funding for the various studies and the various companies. And where they were possible, I tried to declare them.
CONAN: But George raises a point that a lot of people raise, because obviously the economic stakes in this are huge. And we do have an outstanding example of not-so-recent history - of recent history, rather - where, again with enormous economic consequences, the tobacco industry tried to hush-up all the studies that linked smoking to cancer.
Dr. MUKHERJEE: Absolutely, and it's very important to remember that, because - and again, very clearly pointed out both in the book and in the article - the tobacco industry has had an epic role in suppressing the evidence.
The one difference that I would mark out between tobacco and lung cancer and several other forms of cancer, in comparison to cell phones and brain cancer, is that despite the efforts of the tobacco industry, the human studies were highly convincing.
So there was a - as the rates of smoking increased, the rates of lung cancer and other cancers increased coincidentally. Human studies that were more experimental - in other words, if you asked lung cancer patients if they had prior smoking and compared them to control patients, again highly, highly suggestive.
Animal experiments, including very famous rabbit experiments done in the 1930s and 1920s by several scientists, again, clearly showed that if you painted tar from tobacco onto animals, they would get cancer. And in fact, subsequently, much more detailed analysis on human tissues and various other tissues have clearly showed that tobacco is a carcinogen.
Now, if you use that kind of standard, thus far - as I said there are some definitive trials pending - but thus far, cell phones have not met even one of these standards, I would say.
CONAN: George, thanks for the call.
GEORGE: Yeah, I wish he would check out that study from the School of Public Health at the University of California because it came out after his book was published.
CONAN: Before this article, though.
GEORGE: Well, I don't - yeah, but then he needs to look at that study, because I don't...
Dr. MUKHERJEE: I will look at the study. And I would encourage you to look at the School of Public Health of the University of California because it came out after his book was published.
CONAN: Before this article, though?
GEORGE: Well, I don't - yeah. But then he needs to look at that study because I don't (unintelligible).
Dr. MUKHERJEE: I will look at the study, and I would encourage you to look at the National Cancer Institute website.
CONAN: Okay. Thanks, George.
Let's see - we go next to - this is Carl. Carl(ph) with us from Minneapolis.
CARL (Caller): Hi. Can you hear me?
CONAN: Yes. You're on the air. Go ahead.
CARL: Hi. I was diagnosed with a brain (unintelligible) in December, and I just returned from radiation treatment at Mass. General Hospital, and I was...
CONAN: I'm sorry to hear about the bad news, Carl.
CARL: Oh, that's fine. One, the issue of cell phones came up in my diagnosis. A friend of mine (unintelligible) the information from an agency called the Environmental Work Improvement showed radiation output from various cell phones. And my phone was really quite high, so I got a new cell phone, and that has low radiation levels. And I'm wondering what Dr. Mukherjee thinks of requiring cell phone manufacturers to publish radiation levels on their phones and what the current discussion is on requiring this kind of information?
Dr. MUKHERJEE: I would very much encourage cell phone companies to publish the radiation exposure from the phone. Number one, it gives consumers appropriate choice. Number two, actually, it allows scientists to do better experiments. It allows epidemiologists to do the kinds of experiments, more refined kind of experiments that allow us to better understand this phenomenon. So I'm very much for it.
I also point out that I'm very much for, as best possible within the realms of privacy allowing epidemiologists and researchers to have access to real-time phone data, so that, you know, one doesn't have to rely on memory to figure out whether you, one, whether some patients have used a lot of phone time or some patients have used very little phone time because memory can be very biased and very selective.
CONAN: Does - has these - has the cell phone industry, the manufacturers of the phones, have they been transparent throughout this process?
Dr. MUKHERJEE: Well, it's - I think one has to begin, again, given the example of tobacco, one has to begin with the - one has to begin with suspicion and only work backwards to non-suspicion. I think that transparency would be, for any large industry, would be a little bit of a stretch.
(Soundbite of laughter)
Dr. MUKHERJEE: I don't think there's been a lot of transparency in many industries regarding exposure, but that said, scientists have found methods to expose, for instance, mice and rats to very long doses of radiation simulated or simulating the kind radiation that cell phones emit. And thus far, all those experiments have primarily been negative as well.
There was one major experiment that was reported on cells as positive, but that experiment has now been - it's been charged that that experiment is fraudulent, so we don't know whether that experiment was really true or not.
CONAN: Carl, we wish you the best of luck with your treatment.
Dr. MUKHERJEE: Same here. I truly wish you the best of luck.
CARL: Thank you very much.
CONAN: We're talking with Dr. Siddartha Mukherjee, assistant professor in medicine in medical oncology at Columbia University, a practicing physician. He wrote the article "Do Cell Phones Cause Brain Cancer" that appeared in Sunday's New York Times Magazine; yesterday, got the Pulitzer Prize for "Emperor of All Maladies: A Biography of Cancer." You're listening to TALK OF THE NATION from NPR News.
And let's see if we can go next to - this is Julia. Julia with us from Medical Lake in Michigan.
JULIA (Caller): I'm in Washington state, by the way.
JULIA: Hi. Dr. Mukherjee, what a pleasure to talk to you. Congratulations on earning the Pulitzer Prize. I loved your book. It was a very personal experience, and I - it resonated very deeply with me.
Dr. MUKHERJEE: Thank you so much.
JULIA: So thank you so much for your work. My question today is about when you ask such a specific question about cell phones and brain cancer, and you come up and you do your detective work and you identify, no, it doesn't look like it's going to have quite an effect, and you understand these malignancies in the adult brain. Can you take that information what you understand about the physiology of brain tumor and make it applicable to what we understand in brain tumors in children and vice versa? Can we learn from kids and apply that to the treatment in adults?
Dr. MUKHERJEE: Well, it's a very important question. Now, the human trials that I talked about, the trials in which we looked at the incidents or use of cell phones have really been on adults. So it's hard to extrapolate the human data into children. There's certainly various toxins - I won't talk about carcinogens in particular. There's certainly various toxins that we know of which are specifically toxic to certain stages of development and are not toxic later in development. Absolutely many examples of this.
Now, that said, the animal data and the cellular data, the data on cells - whether cells change genes or whether genes mutate, or whether animals develop cancer - those data actually have been tried on very young animals. In fact, there was an experiment that was done with animals who were treated with a chemical to prime them to have brain tumors in utero, and then, cell phone - not cell phone but radiation similar to cell phones was applied. And there was no increase in cancer.
So, if from those animal data, we can extrapolate a little bit into children, but really, these studies that I've talked about have not looked at cell phone use in children.
Now, obviously, part of the reason was that in the past, cell phones were not being used by children to a large extent. This is a relatively recent phenomenon, although I'm told, in fact, children are - some people tell me and again the studies are pending. Some people tell me now children now using less cell phones because they're texting so much.
I don't know what the exact studies are going to show in terms of actual usage relative to the parts of the head that are being used.
But the quick answer to the question is we - the retrospective studies and the human studies have all been really performed on adults. These studies on cellular - the cellular material and the studies on animals to some extent have been done on fetal or very young animals, and certainly, the cells are cells.
CONAN: Julia, thanks very much.
JULIA: Thank you.
CONAN: And John is among those who have emailed to correct that the NCI website is cancer.gov, not...
Dr. MUKHERJEE: (Unintelligible)...
CONAN: ...cancer.org, of course.
Dr. MUKHERJEE: ...absolutely right.
CONAN: And a lot of questions on this, just little time though. Does the radiation danger from phones only occur when they are active with a call? Do they emit radiation when simply on? I carry my phone in my pocket all day. Am I radiating hip or groin simply by having the phone in my pocket?
Dr. MUKHERJEE: Yes. To some extent, there is radiation that occurs during - when the cell phone is on, even the not so-active position. And there are some data on this you can - that you can log in to an informational website on cell phones which - and there are several available, and they would tell you exactly to what extent we - what we know about this radiation exposure.
CONAN: Dr. Mukherjee, again, congratulations on the Pulitzer Prize yesterday.
Dr. MUKHERJEE: Thank you so much. It's been a real pleasure.
CONAN: Siddartha Mukherjee, assistant professor of medicine in medical oncology at Columbia University. He wrote "Do Cell Phones Cause Brain Cancer" in The New York Times Magazine and yesterday, as we mentioned, won the Pulitzer Prize for "The Emperor of All Maladies: A Biography of Cancer."
Coming up next, Peter Lovenheim joins us. He realized he really didn't know his neighbors and came up with an eccentric experiment. Stay with us. It's the TALK OF THE NATION from NPR News.