JEFFREY BROWN: For decades, warnings about smoking have kept lung cancer in the public eye. This week, the disease and its continuing toll were in the news in a very direct way.
On Sunday, anchorman Peter Jennings died of lung cancer at age 67. Mr. Jennings had said that he'd smoked for many years, quit, but had smoked again in recent years. And yesterday, Dana Reeve, the widow of actor Christopher Reeve announced that she's been diagnosed with lung cancer. Ms. Reeve, who is 44, has never smoked.
Lung cancer remains the leading cancer killer in the world. In the U.S., an estimated 163,000 will die this year, more than the next three most-common cancers: Colon, breast and prostate combined.
Because lung cancer is so difficult to detect early on, the mortality rate is very high. The expected five-year survival rate for all lung cancer patients is just 15 percent.
And for an update on the state of knowledge about lung cancer and its treatment, we're joined by Dr. Mark Clanton, deputy director of Cancer Care Systems at the National Cancer Institute; and Dr. Joan Schiller, an oncologist at the University of Wisconsin and president of the non-profit group Women Against Lung Cancer. Welcome to both of you.
JEFFREY BROWN: Dr. Clanton, let's start very simply. What do we mean by lung cancer?
DR. MARK CLANTON: Well, first of all, cells in our body have a normal life span. They normally stay in a particular place, and they grow at a certain rate.
When lung cancer occurs, it means that cells that are on the lining of the lung, in the substance of the lung, or in the airways that lead to and from the lungs, they live longer, they replicate more quickly and, in fact, when they get past a certain point in terms of their size, they begin to disrupt lung function.
JEFFREY BROWN: And smoking remains the leading cause?
DR. MARK CLANTON: Smoking remains the leading cause. Eighty-five percent to 90 percent of lung cancers are directly related to cigarette smoking.
JEFFREY BROWN: Dr. Schiller, the rates I've seen have gone down in recent -- have gone down for men, but not as much for women. Is this related to smoking patterns?
DR. JOAN SCHILLER: It certainly is. Women started smoking later than men did. Women started smoking primarily in the '60s, and we're just starting to see the impact of that right now.
JEFFREY BROWN: Now, Dr. Schiller we said in our introduction that it's difficult to detect early on. Why is that, and what are the symptoms that people would notice?
DR. JOAN SCHILLER: The reason it's difficult to detect early on is because lung cancer is a relatively asymptomatic disease, meaning that it doesn't cause symptoms until it really presses on something important, like an airway, for example, which would cause shortness of breath or cough, or a blood vessel, which might cause coughing up blood, but there are relatively few nerve endings in the lung so it doesn't cause pain. So it's only until it really gets larger that it starts to cause symptoms.
JEFFREY BROWN: And is it easy for people to know these are the symptoms of lung cancer, or is it confused with other things?
DR. JOAN SCHILLER: Well, unfortunately, shortness of breath, cough, perhaps coughing up blood can be due to other things. The most common example of that is going to be some type of infection, like the common cold.
So for that reason, very often, people can have these symptoms for many weeks before someone thinks to get a chest x-ray. That's particularly important, I think, for non-smokers, because non-smokers can often have these symptoms, and because no one realizes that non-smokers, too, can get lung cancer; these symptoms could continue for a very long time before someone gets a chest x-ray.
JEFFREY BROWN: So Dr. Clanton, the issue becomes how to detect it as early as possible. What is the research into that?
DR. MARK CLANTON: Well, currently, there's a national lung screening trial going on sponsored by the National Cancer Institute. There are 53,000 high-risk people, people who are smokers, were smokers or are current smokers.
And what we're trying to learn there is whether or not we can actually save lives -- reduce the mortality rate from lung cancer by looking at either chest x-ray as one way of detecting it early, or using a more sophisticated technique, called CT scanning.
JEFFREY BROWN: I understand there's some controversy, though, over whether to move toward CT scans.
DR. MARK CLANTON: Well, for example, there are studies that show that CT scans actually can find lung cancers early in some people. So there are physicians who would like to move very quickly to using CT scans today to screen for lung cancer.
However, the real question that the National Lung Cancer Screening Trial is trying to answer is whether or not you can actually save lives or reduce the mortality rate from lung cancer by using CT scanning.
JEFFREY BROWN: Dr. Shilling, what would you add on -- Schiller, I'm sorry, what would you add on this question of early detection and the question of whether to move to a -- something like CT scans?
DR. JOAN SCHILLER: Well, it's certainly a very important question. Clearly, for lung cancer, we need something equivalent of mammograms as for breast cancer, but at this point, I would agree with Dr. Clanton, and that is although the technology is there, we have not yet determined whether or not it can actually save lives.
We know it can pick up small lung cancers earlier; what we don't know is whether that's early enough.
JEFFREY BROWN: Dr. Clanton, I would like to clear up some things that are still confusing to people. For example, in the case of Peter Jennings, as for so many people, they smoked at one time, and then they quit.
Now, when a person quits smoking, to what extent does his or her risk of developing lung cancer go down?
DR. MARK CLANTON: It doesn't matter what stage you stop smoking. Your lung cancer or your risk of getting lung cancer does begin to go down.
And the longer you spend in terms of time between the time you smoked and the time you stopped smoking, your risk continues to go down. The problem is in those people who have smoked a great deal -- a 20-pack-year history, it's clear that the risk never returns to zero --
JEFFREY BROWN: Never goes down to the case of someone who never smoked?
DR. MARK CLANTON: That's exactly correct. So the more you smoked, the less likely it is it will go back to zero. The issue is your risk does go down and continues to go down for as long as you stop smoking.
JEFFREY BROWN: Dr. Schiller, another thing that I think a lot of people wondered about this week was, in the case of Dana Reeve, you mentioned earlier people who develop lung cancer who never smoked. Now, how unusual is that?
DR. JOAN SCHILLER: Well, actually, about 10 to 15 percent of all lung cancers occur in people who have never smoked. And interestingly enough, in the majority of those patients, it tends to occur more commonly in women.
So of all the never-smokers who have gotten lung cancers, the majority of those are women, for reasons that we don't understand yet.
JEFFREY BROWN: Do we know what causes it, even if we don't know exactly why it hits women more?
DR. JOAN SCHILLER: They do not. There are several different hypotheses. So one hypothesis is that women may metabolize the carcinogens found in cigarette smoke differently than do men, in such a fashion that those carcinogens, or cancer-causing substances, tend to hang around longer; that's one hypothesis.
The other thought is that somehow it may be related to the estrogen pathway, somehow estrogen may interact with carcinogens found in cigarette smoke in such a way to put women at a slightly higher risk.
JEFFREY BROWN: What can you add to this about -- of course, we always hear about secondhand smoke. Is that a factor for people who are not smokers?
DR. MARK CLANTON: Absolutely. The two factors are secondhand smoke -- that is, people who don't smoke, who are around others who do -- inhale the same cancer-causing chemicals into their lungs as do smokers.
In fact, in the case of side-stream smoking it's the smoke that comes off the end of the cigarette -- they can actually inhale higher concentrations of those chemicals that cause cancer. So certainly environmental tobacco smoke does cause cancer and can cause lung cancer.
The other issue is there is a colorless, odorless gas called radon that comes up from the soil in some parts of the country, and people exposed to radon gas have a higher risk of lung cancer.
JEFFREY BROWN: All right, now, Dr. Clanton what, about treatment? Someone is diagnosed with lung cancer, what happens?
DR. MARK CLANTON: Well, first of all, there is greater opportunity for success if we find lung cancers when they're localized -- that is, stage one. It's possible to use surgery and also chemotherapy following surgery to treat those people with early lung cancer.
There are also new drugs. A drug called Tarceva, which is very useful in certain people who have certain genetic mutations of their tumors, and also Avastin, which is a drug approved in March of this year, traditionally used for colorectal cancer but is also effective in extending the survival time for some lung cancer patients.
JEFFREY BROWN: Is there, Dr. Schiller, enough research going on, is there enough research money going in to this?
DR. JOAN SCHILLER: No, absolutely not, particularly when you consider the burden that lung cancer puts on Americans each year. As you mentioned in your earlier piece, 160,000 or more Americans will die of lung cancer each year.
More women will die of lung cancer than they will of breast cancer, and yet, relatively speaking, only about one-tenth the amount of federal funding goes into lung cancer per death per year than it does for other types of cancers, such as breast cancer.
JEFFREY BROWN: Dr. Schiller, we just have a short time left, but I wonder if part of that is because of some stigma about lung cancer. We've been told so much about the person almost causes it, the person who smoked causes it.
DR. JOAN SCHILLER: I think that's true, that's one reason. One reason is also the fact that lung cancer is such a high mortality rate that there aren't a lot of patients who survive it who can advocate for it.
You mention the guilt and shame associated with the self-induced disease, and that's true, as well. I don't think it's deserved, given the addictive nature of cigarette smoking.
And lastly, there's a certain neolism out there, on the part of both physicians, as well as the public, that lung cancer is too difficult to treat, and so I think a lot of people are simply not aware of some of the new treatments that have come along lately.
JEFFREY BROWN: All right, Dr. Joan Schiller and Dr. Mark Clanton, thank you both very much.
DR. JOAN SCHILLER: Thank you.
DR. MARK CLANTON: Thank you.