Carboplatin

Byline: Dr. Peter Shields

Dr. Peter Shields, director of the Cancer Genetics and Epidemiology Program in the Lombardi Comprehensive Cancer Center at Georgetown University Medical Center, was online Wednesday, Aug. 10, at noon ET to answer your questions about lung cancer.

Shields has published in the field of the molecular epidemiology and genetic risk markers for breast and lung cancer. His clinical area of expertise is in the treatment of nonmalignant hematology, lung and hematologic malignancies. Shields is an expert on use of tobacco products and their relationship to cancer, nicotine replacement therapy, effects of secondhand smoke, and genetic predisposition to tobacco addiction. He has served as a medical expert in high-profile litigation against tobacco companies.

Shields has active funding to study the nicotine addiction and lung cancer risk, and the effects of radiation and smoking interactions for lung cancer risk. He also directs a funded partnership with the University of the District of Columbia focusing on cancer control in minority populations.

The transcript follows.

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Dr. Peter Shields: Hello all, I am here, with a bunch of saved up answers! This is real time, so pardon my spelling and grammar. (I missed that day in elementary school for the basics.)

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Philadelphia, Pa.: My husband -- a complete non-smoker -- was diagnosed with stage IIIb last October. He had a pleurodesis and is now on Tarceva after Carboplatin/ gemcitibine. Will there be any developments in the cure/ live prolonging for people with pleural effusion?

Dr. Peter Shields: I can't give medical advice per se. Sounds like he is getting good care, but best chances (if this is not happening) is to be treated by physicians who do lots of lung cancer. As you know, this is complicated. Right now, I am not aware of a development that will happen quickly, but as above, best to be cared for by someone aware of the particulars.

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Marshall, Va.: Dear Doctor Shields,

Have there been any major advances in lung cancer therapy in the last ten years?

Dr. Peter Shields: Yes and no. Lung cancer remains difficult to treat, almost impossible to cure unless found early. There are newer fancier targeted therapies that help a few people, maybe a lot.

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SW Washington, D.C.: I was a smoker for a couple of years during high school and college, then stopped for more more than 10 years. Unfortunately, back in 2002 I restarted smoking again before stopping (hopefully for the final time) a year ago. Other than not restarting smoking, are there other things I can do to prevent lung cancer?

Dr. Peter Shields: Nicotine addiction is quite daunting. Many smokers dream about smoking 20 years after stopping. You might be one of those, so you need to be careful and avoid the settings that would get you back to smoking (easier said than done). There is no magic bullet that will reduce your risk of lung cancer, other than not resuming smoking. We think that good diet (the type recommended to prevent cancer and heart disease) may help, but the evidence is low and the magnitude of benefit is small compared to not smoking. Ditto for vitamins, and there there have been two large clinical trials that showed the dose of beta-carotene they used increased the risk for lung cancer, so this is a complex topic.

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Washington, D. C.: My aunt was recently told that she has nodules on her lungs. Does this mean that she has lung cancer? She is not saying and we don't want to just come out and ask her. If the probability of her having lung cancer is high we need to approach her about long term planning; i.e. selling her home; moving to assisted living; etc.

Thank you

Dr. Peter Shields: Of course I cannot give medical advice. Nodules may or may not be lung cancer --screening methods today can find tiny nodules that never become lung cancer. On the other hand, she might be trying to protect you. In my experience, you have to figure out your family dynamics -- but directly asking is the best approach. And then being supportive for short term, rather than immediately focusing on long term. Ultimately, each person is entitled to their privacy.

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Washington, D.C.: How safe/healthy is nicotine replacement therapy?

Dr. Peter Shields: Nicotine replacement therapy is substantially safe, especially compared to smoking. We know that if you use NRT the way is is supposed to -- to help you quit and then stop the nicotine, is safe (read manufacturer's labels, there are some complications, but much better than smoking). There as some people who then use NRT for years and years, and unfortunately we do not know if there is a problem with this, because we do not have human studies. So, best to use NRT and then follow the instructions to wean off of that.

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Washington, D.C.: Dr., thank you for taking the time to participate in this forum. I'm a 42-year-old white male who quit smoking almost one year ago, after smoking for 20 years. I'm in excellent health.

There is no history of lung cancer in my family tree although there is a history on both sides of my family lines of smoking. Based on the limited data I've provided would you say that my chances of getting lung cancer will substantially decline each passing year that I continue to not smoke (all other things being equal)? I've heard some say that after five years of not smoking and maintaining good health for some people it's as if they never smoked.

Thanks again for your time.

Dr. Peter Shields: This is an important question. The only known way to reduce one's risk of smoking and, for example, lung cancer, is to quit. An everyone will get benefit no matter what age they quit. Having said that, the data actually shows that the risk of lung cancer in a former smoker is always higher than a never smoker; there always is residual damage that can ultimately transform to cancer. So, your 5 year figure actually is not correct. And the lung cancers still happen 20 years or so later. Some smokers hear this and then figure that there was therefore no point to stop smoking-- but this is untrue. While there is risk that is higher than never smokers, it is much lower than current smokers. So staying smoke free, although maybe challenging at times, is by far the way to be.

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Crystal City, Va.: Dr. Shields,

Thank you for taking my question. I'm 25 and my 52-year-old mom has been a smoker since before I was born. When I was growing up she never smoked in front of me and tried to hide it from me, but I always sort of knew. Now she smokes in front of me, though she still hides it from her parents. She knows I hate that she smokes, that I'm worried for her health, etc. She's a nurse and totally knows the health risks. But she wont' quit. Is there anything I can do? I dread the day when I find out she has cancer or something and rack my brain wondering how I could've prevented it.

Dr. Peter Shields: Unfortunately she is at high risk for lung cancer and other illnesses. Nicotine is highly addictive, and so it is quite difficult to beat. We know that yelling at out loved ones, or making them feel victimized does NOT work. Guilt tripping does not work. Rather, work with them through contemplation to quit, figure out a structure and be supportive. There are lots of options for helping people quit, the goal would be to try to get you mother to consider and try one.

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McLean, Va.: What is the best food or antioxident that will help fight the chances of getting lung cancer?

Dr. Peter Shields: Sorry to say, but this is unknown. My suggestion is having a well rounded diet, fruits and vegetables, and a multivitamin a day. More than that, there is no evidence of benefit, and maybe harm (see other reply about beta-carotene trial). Follow suggestions as put forth by American cancer society or national cancer institute. That is the best we know today.

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Dupont Circle, D.C.: This is probably a dumb question, but could you talk a little about risk factors for lung cancer, aside from smoking? We all know that smoking causes lung cancer, but what other environmental or genetic influences seem to be related to lung cancer? Is it genetic, like breast cancer? Or is it entirely environmental?

Dr. Peter Shields: Not dumb. About 90% is tobacco-related (either from smoking or second hand smoke). There is a familial pattern, but this is rare, and much rarer than breast cancer. Other risk factors are radiation, asbestos, diesel exhaust in heavily exposed workers, and some metals in some occupations. I might be forgetting some, but that is a reasonable list.

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Washington, D.C.: What is included in a cancer test (Blood, stool, etc.)?

Dr. Peter Shields: Depends on the cancer and age. There are specific recommendations for cancer screening that can be found on the Web sites for the American cancer society and the national cancer institute.

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Waldorf, Md.: Should a routine chest X-ray be part of a routine, annual physical? 15-20 years ago, I recall it being ordered often but not in recent years.

Dr. Peter Shields: Easy answer, no. Not even for current smokers. These studies have been done and there is not enough of a benefit. Many physicians still do this, and some might argue the studies are not good enough. There is currently a national trial of over 60,000 current and former smokers looking at CAT scan versus chest X-ray for lung cancer screening. It will take a few years, though, to know their answer.

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Washington, D.C.: I'm a 40 year old male who has smoked for 20 years. I have annual physicals which include (every other year) a chest X-ray.

Over the last year I've experienced an increase in sinus infections (I worked in a "sick building for 7 years before it was "cleaned." I've also had sinus surgery to address the problem.)

Lately, these sinus infections have included sore (raw) throats and extreme coughing and phlegm. I'm seeing an ENT as well as a general practitioner both of whom know I smoke. I'm wondering if it is time to press my doctors for a cat scan or additional medical testing like a full body scan to determine if there's more going on than sinus problems. And, yes, I do really want to quit smoking.

Dr. Peter Shields: I can't give medical advice. But I am not aware that scanning other parts of the body will help you with your sinus problem. Sounds like you need to follow-up on your plans to quit smoking. Lots of options out there, and people may have to try more than one to quit long term.

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Washington, D.C.: How does hookah pipe/shisha usage compare with cigarette usage in relation to lung cancer?

Dr. Peter Shields: This information is not known, but we do know that blowing the smoke through water still allows exposure to lots of carcinogens. One would think that unless you use shisha daily, the risk would be lower, but we do not know enough about how the shish might deliver its types of carcinogens.

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Fairfax, Va.: Is nicotine the main trigger of lung cancer?

Dr. Peter Shields: Absolutely not. This is a common misconception among people, including physicians. Tobacco smoke contains thousands of chemicals, and more than 60 known or probable human carcinogens. Nicotine has not been classified as a known or probable carcinogen by any review or regulatory agency that I know of.

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Arlington, Va. : We know that cigarette smoking increases one's chances for lung cancer. How about marijuana smoke? I'd guess it would depend on the frequency, amount, etc.

Dr. Peter Shields: There are some scientists who believe that marijuana delivers more carcinogens than cigarettes. Clearly, it does deliver a lot of carcinogens. This is all burning leaves (tobacco or otherwise). Sort of like sticking your head in a fireplace. But there is no info about relative risk for marijuana or cigarettes that I can say is sufficient to answer this question.

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Chelmsford, Mass.: Dr. Shields:

With Dana Reeves diagnosis of lung cancer, I've read there is a trend of more lung cancer among nonsmoking women, recently. Is there any idea as to why this is happening.

Dr. Peter Shields: There may be some data that nonsmoking women are increasing their risk. But the increase is very small. Most actually do have an exposure to second hand smoke.

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Arlington, Va.: Dr. Shields, my question is about stopping smoking and what help is available? Is there a chance I still may get lung cancer? I am 52 and started smoking when I was 22, my recent X-ray (1 month ago) was clear. Will over the counter therapies help me stop smoking? Thank you for any advice.

Dr. Peter Shields: Several important points. Having a clear x-ray last month is irrelevant to your question. This is not a good screening method and at best, gives you some modicum of assurance that you do not have a large lung cancer at this time. Stopping smoking is critical. There are national quit lines (and for more info go to American Legacy Foundation, National Cancer Institute or American Cancer Society). There are many over the counter options in the form of nicotine replacement therapy, which is proven to work. There are also prescription options that your physician can give. Different ones work for different people, and you might have to try more than one.

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Washington, D.C.: Hello Dr. I just found out that my father has been smoking off and on for many years, though he "quit" smoking all the time over 20 years ago. How at risk is he? Should he be checked for lung cancer?

Dr. Peter Shields: Unfortunately, we do not have good methods for lung cancer screening. Best is to support him to not smoke. See other reply about chest X-rays and cat scans for screening. You will note that the National Cancer Institute Web site has a very informative section on lung cancer screening, and the problems with it.

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Silver Spring, Md.: My mother died last December from a very small inoperable brain tumor in the medulla (spelling?) area that was a metastisis from a previous lung cancer (very early stage removal). For the lung cancer, there was no indication of lymph node invasion (she did not receive chemo) and the subsequent tumor didn't show up on MRIs, spinal taps, CAT scans or PET scans. It was identified via autopsy and due to the location could not be treated. She never smoked ... Is this rare? And, why would her primary cancer 'behave' this way. Thanks

Dr. Peter Shields: This is less common, but unfortunately it happens. Lung cancer is a tough disease. Even though a cancer may be small enough to be operated on, many have already microscopically spread, and it is not known until sometime later.

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Falls church, Va.: Why would lung cancer show up after 20 years of smoking cessation (example: Peter Jennings)?

Dr. Peter Shields: Good question. Actually, there are studies of young smokers and 20 year former smokers. You can look at genetic changes in the sputum and see that there is smoking damage that is persistent. So, you get your genes messed up when you are an adolescent smoker (who assumes that they are immortal), and that starts the process. Over the next 20-40 years, the cells have lots of opportunities to get messed up further.

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Baltimore, Md.: Dear Dr. Shields,

While 90% of lung cancer can be correlated with smoking, I recently read a study that less than 10% of smokers get lung cancer. I was wondering if you could address and explain this statistic. Thanks!

Dr. Peter Shields: Your stats are correct. 90% of people who get lung cancer are either smokers, former smokers (the most) or exposed to second hand smoke. Lung cancer is the leading cause of cancer deaths, because it is so difficult to treat. But most people still die of other causes. Most smokers die of smoking related disease -- heart disease, respiratory disease, other cancers, etc. But why only 10% die because of lung cancer, we think is because of genetics. That they were more susceptible to smoking related lung cancer, while other smokers might be more genetically susceptible to heart disease.

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Columbia, Md.: What are some of the other contributing factors to a person contracting lung cancer other than smoking? I've heard that about 15% of people that get lung cancer were never smokers. Do environmental factors such as radon gas, herbacides, or some other pollutant increase the risk of contracting lung cancer. I realize there is a genetic component, but absent of that, what other environmental factors should be considered?

Dr. Peter Shields: See other answer about the other causes of lung cancer. But you remind me to expand on what I meant by radiation, which is a risk factor for lung cancer. This includes radon, nuclear weapons, radiotherapy, and occupational exposure to x-rays in the old days.

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Fairfax, Va.: What's shish?

Dr. Peter Shields: Shisha is a type of tobacco smoked in water pipes or hookas. Used a lot in the middle east, and now popular in some bars in the Washington area.

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Washington, D.C.: Hello Dr. Shields, What are the first symptoms and/or signs of lung cancer?

Dr. Peter Shields: Unfortunately, by the time signs and symptoms happen, it is probably large and inoperable -- cough, shortness of breath, bloody sputum, fatigue, weight loss, chest pain.

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Washington, DC: Hi,

Can you head off a pending anxiety attack and quote some stats on how fast your lungs recover once you quit smoking?

Thanks

Dr. Peter Shields: There is a lot of published data. Stopping smoking at any age is a good thing and reduces your risk compared to if you kept smoking. But, the incidence of lung cancer (the number of people who get lung cancer; analogous to risk) does not revert back to as if you never smoked, just stops the incidence dead in its tracks from increasing. This is complicated. So, continuing to smoke increases incidence a lot more proportionately as you smoke and get older. The curves on a graph separate from each other comparing the risk for a former smoker and a current smoker. Unfortunately, the risk stays not increased (stable) for a former smoker, but when then get to the 60's and 70's, it increases again, but less so than in current lifelong smokers.

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Washington DC: I heard that about 90% of lung cancer cases are found in people that smoke, is this true? If so what accounts for the other 10%, genetics, environmental (asbestos, etc)?

Dr. Peter Shields: I answered this earlier! See if that does not help.

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Washington, DC: I smoked for about 10 years, and quit about four years ago. Am I still at a higher risk of getting lung cancer? Is so, what can I do to minimize the risk, besides continue not to smoke--diet, exercise, other?? Thanks.

Dr. Peter Shields: I answered this earlier! See if that does not help. But, I did forget to mention that exercise also is a recommendation to reduce the risk of cancer in general.

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Gallery Place: Dr. Shields, thanks for joining us today. I have a question re: family history of lung cancer. My grandmother died of lung cancer. She never smoked and she didn't work in an industrial environment that could expose her to carcinogens. I'm worried about my risk of developing lung cancer, given that my grandmother died of the disease even though she was not around environmental factors that could cancer. What does the research say re: genetic predisposition to the disease? Can I do anything do reduce the risk? I don't smoke, but would be interested if I can do more.

Dr. Peter Shields: There are some families with lots of lung cancer, but not yours if it is only one member (a grandmother). So, I would not be concerned if you are ok in avoiding smoke -- smoking and second hand smoke. Otherwise, I answered this earlier about prevention! See if that does not help.

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McLean, Va.: My husband does not smoke and never has but he grew up in a house with both parents smoking around him. How significantly does that increase his risk of lung cancer?

Dr. Peter Shields: Depending on the level of smoking, this type of exposure is considered to place him at increased risk of lung cancer. On average, the studies say about 1.4-fold risk, or 40% increased. This is compared to active smoking, which is 10 to 20-fold risk.

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Washington, D.C.: Are my chances of getting lung cancer higher than others? I'm a 46 year-old-woman who has never smoked but grew up in a household where both parents smoked until I was 20 years old. My father was a pipe insulator and died of mesothelioma in 1984. I'm worried about all the second hand smoke and possible asbestos I was exposed to as a child.

Dr. Peter Shields: I answered this earlier! See if that does not help about the smoking. Bystander asbestos and the mesothelioma risk has been documented, as you indicate. But, for asbestos and lung cancer risk requires a much higher dose, so I would not consider your circumstance as an asbestos-related risk.

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Alexandria, Va.: What other cancers can be linked to smoking besides lung cancer?

Dr. Peter Shields: Lots -- off the top of my head-- oral cavity, throat, esophagus, brain, leukemia, pancreas, stomach, colon, liver, and maybe breast (I think so, but other scientists do not). As of today, probably not lymphomas and myelomas.

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Arlington, Va.: How likely is it for someone who has never smoked, to get lung cancer via second hand smoke? A lot of my friends smoke. Thanks.

Dr. Peter Shields: Depends on dose. The risk from friends is less quantified, but we know that restaurant workers, bartenders, children of smokers and spouses of smokers are at increased risk.

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Washington, D.C.: Dr. Shields, Thanks for taking questions! I'm a former smoker (smoked for nine years, I'm in my mid-twenties and quit within the last year), in addition to staying away from cigarettes and watching the diet, can exercise help to decrease the risk of lung cancer?

Dr. Peter Shields: I answered this earlier! See if that does not help.

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Washington, D.C.: What are some symptoms I should look out for and bring to my Dr.'s attention if I want to catch lung cancer early?

Dr. Peter Shields: I answered this earlier! See if that does not help.

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Washington, D.C.: What is the approximate lung cancer risk for smoking no more than 1 cigarette per day, and and on some days, say 3 per week, not smoking at all? Thank you.

Dr. Peter Shields: Depends on the number of years smoked, but there are some models that show a cig/day for 20 years still have an increased risk, but less than 1.5 to 2-fold.

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Washington, D.C.: How do you develop lung cancer and not be a smoker?

Dr. Peter Shields: I answered this earlier! See if that does not help. But most cases are from inhaling second hand smoke.

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Washington, D.C.: In your research, have you found any links to marijuana smoking and lung cancer?

Dr. Peter Shields: I answered this earlier! See if that does not help.

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Washington, D.C.: What is the cancer rate of those who abuse marijuana wrapped in cigar paper?

Dr. Peter Shields: I answered this earlier! See if that does not help. Same answer for cigar paper.

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Cheltenham, Md.: Why when people are diagnosed with lung cancer, do they only live 6 months or less?

Dr. Peter Shields: It is a very fast growing, aggressive tumor. The genetics that drive the tumor to grow big and spread are complex. The genetics also make it resistant to treatments. We think this is because lung cancer develops after exposure to all those carcinogens in smoke. Lots of opportunities to mess up the genes in many ways.

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Arlington, Va.: Dear Dr. Shields --

I have a friend who is a pack-a-day smoker. I know that she won't quit until she gets to her own point of readiness. But I'm wondering about my level of risk from being around her when she smokes? She'll smoke in the car (windows down) when we're driving, and often to keep her company I'll sit outside on the porch with her while she smokes. And when we go out, like last night, I sit next to her at a table while she smoke 5 or 7 cigarettes in 3 hour period. How much damage is this doing to me? I'm a complete non-smoker except for my exposure to her.

Thanks,

Dr. Peter Shields: I answered this earlier! See if that does not help. You can guess the relative doses -- in a car with windows rolled up is worse than outdoors!

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Silver Spring, Md.: Dr. Shields, Anyway to know that if Jennings had not started back smoking on Sept. 11, 2001 he would have developed lung cancer this year. Also, does the occurrence of lung cancer take a long time?

Dr. Peter Shields: No way to know, and maybe. See other discussions about risks of lung cancer in former smokers. Most people get lung cancer in late 50's, 60's, and 70's, so it takes 20-40 years or more to develop.

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Silver Spring, Md.: We have a low level of radon present in our basement, discovered by doing a home test ordered online. Does having any radon present significantly increase our risk of lung cancer? We are non-smokers, but the recent attention given to lung cancer makes me wonder if we should take action or if its paranoia. Thanks.

Dr. Peter Shields: Presumably you got the info from the environmental protection agency web site. The best we can do is to calculate the doses in persons with high level radon exposure and extrapolate back to decide what level would be acceptable for the rest of us. Their exposure levels are pretty conservative, meaning they want to protect people. But their risk estimates still consider that someone might get lung cancer, say 1 in a million people. At that level of exposure, it would not make me paranoid.

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Fairfax, Va.: If younger women who are non-smokers are getting lung cancer how can I protect myself?

Dr. Peter Shields: I answered this earlier more generally! See if that does not help.

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Evanston, Ill.: My father died of lung cancer at 58, and I am an ex-smoker now in my early 50s. For the last few years I've had an annual low-dose spiral CT scan. Do we yet know if early detection by this means will increase my chances of survival, and if so by how much?

Dr. Peter Shields: As mentioned earlier, there is a 60,000 person study going on in the US to answer this. It will be several years more before good info is known. At the present time, there is insufficient data to say that people should get screened by CAT scans on a routine basis (although some studies suggest such). There are potential risks that might outweigh the benefits, including lots of surgery for false-positives. At least we should have better info in several years.

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Washington, D.C.: How safe/healthy is nicotine replacement therapy?

Dr. Peter Shields: I answered this earlier! See if that does not help.

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Washington, D.C.: Just a comment. Smokers who want to quit can get help by calling the national quitline number 1-800-QUITNOW (1-800-784-8669) or by going to www.smokefree.gov

Getting help greatly increases the odds of success.

-- Danny, Campaign for Tobacco-Free Kids

Dr. Peter Shields: Thanks!

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Washington, D.C.: Dr. Shields, Good afternoon. Do you think publicity surrounding Dana Reeve and other non-smokers who are afflicted with lung cancer will help lead Congress to increase funding for lung cancer research?

Dr. Peter Shields: One can only hope. There are lots of people who cannot quit because nicotine is incredibly addictive, maybe the most addictive drug around (in the form of smoke -- there is less nicotine in nicotine replacement therapy). And there are lots of people who figured out how to stop smoking, and are still at risk for lung cancer, so we can'f forget them. Unfortunately we victimize the smoker and conclude it is their fault. But, given the addictive nature, and the fact that most smokers begin during adolescence (when kids think that they are immortal and can stop anytime), we need better strategies, or the rate of new smokers will continue to be the same or almost the same as quitters.

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Baltimore, Md.: Is there such thing as a "pre" cancer test....In other words, is there an exam that can gauge your propensity to get cancer?

Dr. Peter Shields: I answered this earlier! See if that does not help.

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Arlington, Va.: How great a risk is daily exposure to diesel particulate matter, such as the type and amount we are exposed to while driving behind school buses?

Dr. Peter Shields: This is all about dose. Heavy worker exposure increases risk, but this is probably not for the general population.

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Dr. Peter Shields: OK all, hands cramping. Bye.

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