Lung Cancer Q & A

Cancer 101: Cancer Explained

Lung Cancer Q & A

WebMD Live Events Transcript

Lung cancer is the No. 1 cause of cancer deaths for men and women in America. In light of the recent death of news anchor Peter Jennings and the announcement by Christopher Reeve's widow, Dana, WebMD Live invited Peter Shields, MD, from the Lombardi Comprehensive Cancer Center at Georgetown University to answer your questions lung cancer. He was our guest on Aug. 18, 2005.

The opinions expressed herein are the guests' alone and have not been reviewed by a WebMD physician. If you have questions about your health, you should consult your personal physician. This event is meant for informational purposes only.

MODERATOR:
Welcome to WebMD Live. Our guest today is Peter Shields, MD, from the Lombardi Comprehensive Cancer Center at Georgetown University. He is here to answer questions about lung cancer.

Welcome, Dr. Shields. The death of Peter Jennings and the announcement of Dana Reeve's diagnosis has taken a lot of people by surprise, but it really shouldn't.

SHIELDS:
Unfortunately, lung cancer is a pretty common disease; it's the No. 1 cause of death from cancer. There's a whole lot of current smokers out there and several-fold more ex-smokers, all at risk for lung cancer. By and far it is the biggest risk factor. Before smoking lung cancer was a rare disease.

MODERATOR:
How long after quitting does risk go down?

SHIELDS:
Your risk goes down immediately after quitting. What a lot of people don't understand is your risk can never go back to as if you were never a smoker.

There is no question that quitting substantially reduces your risk, compared to continued smoking, and at every age it is a real benefit to quit smoking. But unfortunately, that risk does not go down to as if you never smoked.

MEMBER QUESTION:
How does lung cancer first manifest itself?

SHIELDS:
The way lung cancer can present itself includes:

  • A cough
  • Shortness of breath
  • Weakness and weight loss
  • Sometimes chest pain

Lung cancer remains silent for a long period, and that's when it can be small enough to do something about.

"It's not recommended to have a CAT scan for lung cancer screening, even for smokers."

MEMBER QUESTION:
I am having problems with a nagging cough especially at night, also joint pain. I know X-rays do not show lung cancer until it's too late. Should I have a CAT scan or MRI?

SHIELDS:
Of course I can't give specific medical advice, but you do have risk factors for lung cancer and obviously with a persistent cough you should have quality medical care.

Having said that, at the current time it's not recommended to have a CAT scan for lung cancer screening, even for smokers. But if you're having symptoms related to the lung, then a physician might consider a CAT scan is indicated.

MEMBER QUESTION:
Do chest X-rays detect lung cancer?

SHIELDS:
This is complicated for most people to understand. CAT scans are more sensitive than X-rays, but they also pick up many things that are suggestive of cancer that turn out not to be cancer.

At the current time, we do not know if we are hurting people, because of false positives, more than helping them. There's a large national clinical trial of over 60,000 smokers and ex-smokers so we may know more in a few years.

But at the current time, most of the major organizations who are knowledgeable about cancer screening do not recommend X-rays or CAT scans for smokers.

MODERATOR:
What do they recommend for screening?

SHIELDS:
The clearest recommendation is to stop smoking. That's the only known way to reduce one's risk of lung cancer.

In terms of screening, there is unfortunately no recommendation because we're afraid we're going to be hurting people more than helping them; a workup for a lung cancer lesion seen on X-ray can be substantial. In general we don't recommend screening.

MODERATOR:
Then how is diagnosis done?

SHIELDS:
Most people will have some symptoms, and hopefully the symptoms will be from an early enough lesion that it can be picked up and taken care of.

Part of the problem here is that lung cancers grow so fast that someone could have no evidence of disease by X-ray or CAT scan one year, and the next year they can have a large tumor. So if you were going to do screening, a person would have to do it more than once a year. That's the problem, because we can't be doing X-rays on everyone every month.

Quick GuidePancreatic Cancer Symptoms, Causes, and Treatment

Pancreatic Cancer Symptoms, Causes, and Treatment

MODERATOR:
What role does secondhand smoke play in the development of lung cancer?

SHIELDS:
Secondhand smoke is a clear cause of lung cancer. Every learned and scientific committee and governmental agency who has looked at this has concluded that secondhand smoke causes lung cancer. It's a smaller risk than if you're a smoker, but it is still a real and measurable risk.

About 80% of people with lung cancer have a history of either current or prior smoking, and about 10% of people with lung cancer have a history of being exposed to secondhand smoke, either at home, during childhood, or at the workplace.

MODERATOR:
Peter Jennings was a smoker, but, according to reports, Dana Reeve has never smoked. What are other risk factors for lung cancer besides smoking or secondhand smoke?

"We believe there are some genes that increase a smoker's chance of lung cancer."

SHIELDS:
For Dana Reeve I have not seen information either way about a possible secondhand smoke exposure, for example, from her parents.

There are other known causes of lung cancer that aren't common, but do exist. These include:

  • Radiation (including radiotherapy, asbestos, and radon, which is another form of radiation).
  • Metal exposure in the workplace.
  • Large exposure to diesel exhaust, as happens in some workplaces.

MEMBER QUESTION:
I am a 63-year-old white female whose mother and brother died of lung cancer. Both were heavy smokers and I am a nonsmoker. Do you think that there is a strong genetic link for me?

SHIELDS:
There are some families that have high rates of lung cancer and so there are strong genes that might relate to a high risk of lung cancer, but these are very uncommon. It is quite possible that both of those lung cancers would have happened because of smoking and entirely independent of those genes.

We believe there are some genes that increase a smoker's chance of lung cancer, because only about 1 in 10 smokers actually gets lung cancer. Of course, the other smokers usually die early from other smoking-related disease. We have an idea of what some of those genes might be, but right now these are just research tests -- we don't know yet if there are certain genes that increase the risk from secondhand smoke because those are scientific studies that are much harder to do.

MODERATOR:
Would this member have a risk independent of genetic factors due to secondhand-smoke exposure?

SHIELDS:
The answer could be yes, and it would depend on how much smoking was done around this member. There is a dose-response relationship.

MEMBER QUESTION:
I come from a family with a long history of lung cancer. Other than a periodic chest X-ray, is there anything else I should be doing?

SHIELDS:
Nothing in particular to prevent lung cancer. In general, we recommend good lifestyle habits, things often found as recommendations from many major cancer organizations, which include:

  • Avoiding tobacco smoke exposure
  • Varying your diet
  • Maintaining a healthy weight

But for lung cancer in particular, these things only help a little and there is nothing certain that can prevent a lung cancer if it's going to happen.

MEMBER QUESTION:
Could estrogen be the cause of lung cancer in women who have never smoked?

SHIELDS:
This is a very active research question.

We know that women who have had breast cancer have some increased risk of lung cancer, independent of the estrogen question. We think that there may be some role of estrogens in lung cancer, because of epidemiology patterns, between women and men, however, this has been difficult to prove with good scientific studies.

So the answer today is we don't know.

MEMBER QUESTION:
I have been told that the lung is either the most or one of the most "preferred" organs for metastasized breast cancer. Is that true?

"There are newer targeted therapies that appear more effective than current therapies..."

SHIELDS:
Breast cancer can metastasize to the lung, but unfortunately it can also travel to many other organs, including the bone, liver and brain.

MEMBER QUESTION:
Do early or advanced stages of cancer show any signs in regular full panel blood tests?

SHIELDS:
In general that's not the way we diagnose lung cancer. There may be some abnormalities in blood screening, but it is certainly frequently not a good method.

MEMBER QUESTION:
I was diagnosed with lung cancer 2-and-1/2 years ago. I had a third of my right lung removed and was told by my surgeon he "got it all." How susceptible am I to the cancer returning, or to getting another form of cancer? I have not smoked since my surgery.

SHIELDS:
There are several issues here. The first is that more frequently than not even though a tumor is fully removed surgically, the reality is that there's often small cells that have metastasized. So surgery , even for small lung cancers, does not cure a lot of people.

The second question here is susceptibility to a second cancer. First of all, with the smoking history and having shown the right combination of factors to get one lung cancer, it's certainly possible to get another lung cancer or another smoking-related cancer, such as in the oral cavity or esophagus.

MEMBER QUESTION:
What is involved in treating lung cancer besides removal of the tumor(s)?

SHIELDS:
You can only get surgery when the tumor appears to be limited to one part of the lung. But the actual treatment plan is decided by several things:

  • Type of lung cancer
  • Size
  • Whether it has metastasized

The treatment plan could include:

Quick GuidePancreatic Cancer Symptoms, Causes, and Treatment

Pancreatic Cancer Symptoms, Causes, and Treatment

MODERATOR:
What can you tell us about current clinical trials?

SHIELDS:
There are many clinical trials that are ongoing. There are newer targeted therapies that appear more effective than current therapies. But for lung cancer, the treatments remain less successful than more successful, and I think for people with lung cancer they really should be looking for the best quality treatment with doctors that have access to newer drugs.

MEMBER QUESTION:
I need to quit smoking! What do you suggest?

SHIELDS:
There are a number of effective ways of quitting smoking. There are national "quit lines" -- telephone lines that someone can call to figure out what might be best for them. There's both over-the-counter treatments, especially nicotine replacement types of therapy, and there's prescription medications.

We don't have good predictions for which would work for one person, so sometimes smokers have to try different ones.

MODERATOR:
And for those of you trying to quit who would like support, please be sure to visit our Smoking Cessation Support Group message board on WebMD.

MEMBER QUESTION:
Is nicotine replacement OK or does it pose a risk as well?

SHIELDS:
There is no question that nicotine replacement therapy helps a lot of people quit. And it actually gives you less nicotine than cigarettes, so using it reduces your nicotine exposure. When used as directed by the manufacturer as a method to quit, we believe this is safe. Side effects are minimal, and for most people, nonexistent.

What we don't know yet is if it's safe when people who use nicotine replacement therapy for years and years.

"There's more than 4,000 chemicals in cigarette smoke."

MEMBER QUESTION:
What is it in the cigarettes that causes cancer?

SHIELDS:
There's more than 4,000 chemicals in cigarette smoke; at least 60 of them are known to be or probably are human carcinogens.

So there are a lot of chemicals in cigarette smoke that are causing lung cancers. Some people falsely believe that it is the nicotine in cigarette smoke that causes cancer. But in fact, that is not the case.

MEMBER QUESTION:
I'll be 48 in October. I quit smoking in January of this year. What are my chances of still contracting lung cancer down the road? There is no history of lung cancer in my family, only uterine cancer in a maternal aunt.

SHIELDS:
The most important thing for you to do is to remain smoke-free. The chances of getting lung cancer are a lot less by remaining smoke-free.

However, the risk will reduce the most over the next 5 to 10 years. Unfortunately, the risk won't go back to what it was before you ever smoked.

MEMBER QUESTION:
Since there is no benefit at all from cigarettes, why do you think cigarettes haven't been made illegal? We don't allow heroin and yet more people die from tobacco!

SHIELDS:
In some ways, comparing it to heroin makes this a rhetorical question. In fact, in the early 1900s, the tobacco industry was extremely effective in protecting their industry through many types of federal legislation.

Many government agencies, for example, the Food and Drug Administration, are not allowed to regulate tobacco. One would think that our culture is antitobacco, but I would ask the rhetorical question, if that were true, why hasn't it been banned?

So then the next question is, how is it that we accept tobacco? I think part of the answer lies in the perception that smoking is sexy, that going to smoke-filled bars is fun, or part of the mystique of going out, and I would put forth that many of these images have been driven by tobacco company money and advertising.

This is an industry that spends a lot of money protecting itself, and making a product that is inherently dangerous, when used as intended.

MODERATOR:
And while federal regulations prohibit regulating tobacco, other government sectors have spent years and millions suing tobacco companies.

SHIELDS:
This is an interesting dilemma, because we do have some federal agencies, such as the National Institutes of Health and the Department of Health and Human Services, who want people to stop smoking, and at the same time, the U.S. Department of Agriculture is conducting research or in other ways helping the tobacco industry.

We have agencies like the Alcohol, Tobacco and Firearms agency which has yet a different perspective, and yet at the same time, there's no question that tobacco smoking is the major preventable cause of death as we measure it in heart disease, cancer, respiratory illness, and others.

If there was a consistent governmental approach for this product as there are for other consumer products, I think the approach might be very different.

"For as many adults who quit, there is an equal or almost equal number of kids who become regular smokers."

MEMBER QUESTION:
Can smoking marijuana also cause lung cancer? What about pipes and cigars?

SHIELDS:
Certainly cigar smoking causes lung cancer. There's less available studies of pipe smokers. For marijuana, we also don't have the studies to say either way, but there are some researchers who think the risk of cancer from marijuana smoking may be higher because marijuana cigarettes -- which are unfiltered and burn differently -- may deliver higher levels of carcinogens.

MODERATOR:
What can we do to keep children from beginning to smoke?

SHIELDS:
This is one of our biggest problems. Because for as many adults who quit, there is an equal or almost equal number of kids who become regular smokers.

Part of the problem is the image of smoking being sexy and adult-like; part of the problem is adolescent rebellion. And for some young women, they see smoking a way as keeping their weight down.

Quick GuidePancreatic Cancer Symptoms, Causes, and Treatment

Pancreatic Cancer Symptoms, Causes, and Treatment

But the real problem here is that most adolescents think they are immortal, that they won't become addicted, that they can stop any time, and they won't grow up with smoking-related problems. We know that this is not true. We know that there are some effective ways of preventing smoking initiation, and we need a lot of research to figure out better how to prevent initiation.

For example, an antismoking commercial to an adult may appear effective, yet focus groups among kids will show it's not effective. Some of the effective advertising can be the counter-marketing campaigns about tobacco companies, showing how kids have been manipulated by the tobacco companies -- this can cause the kids to rebel against the tobacco companies.

Other effective campaigns are showing how you can lose loved ones, like the ad by the Marlboro man's brother talking about how he lost his brother. On the other hand, some humorous commercials, like a camel making fun of the Joe Camel ads, were not effective. Why? Because kids did not understand that if this is a serious topic, why were we joking?

This is a serious challenge. When you look at the advertising campaigns of one of the tobacco companies trying to prevent youth smoking they look good, but in scientific studies they are at least not effective and maybe even promote smoking compared with advertising campaigns by nontobacco companies.

MODERATOR:
How do we know so much about the tobacco companies' marketing practices?

SHIELDS:
Because of the law suits that have happened over the last several years, the tobacco companies have been required to put their internal documents on the web. This means you can go to web sites such as www.tobaccodocuments.org and see the actual internal memorandum, internal studies, internal research and their opinions.

They have research showing that cigarettes were addictive and cause cancer many, many years before they admitted this publicly. They also have research showing that ever since they started marketing light cigarettes they knew light cigarettes were not healthier or safer. And yet you can see how they continued to market these light cigarettes because their profits went up when people smoked them because they needed the same nicotine. This meant people smoked more cigarettes per day, which meant the tobacco companies were enjoying their profits and not disclosing the realities.

MODERATOR:
What is the future of lung cancer treatment?

SHIELDS:
The future has to be in better-targeted therapies. Our technologies for designing drugs are getting better and better, so ultimately lung cancer will be controllable if not preventable.

But it's a big challenge, because these are tumors that are formed by many carcinogens in tobacco smoke, so genetically they're very complex. We have a lot of challenges ahead.

MODERATOR:
Dr. Shields, do you have any final comments for us?

SHIELDS:
Thanks for this opportunity and remember to not smoke.



©1996-2005 WebMD Inc. All rights reserved.

Subscribe to MedicineNet's Cancer Report Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

Reviewed on 9/22/2005

Health Solutions From Our Sponsors