Lung Cancer | Cancer.Net

Lung Cancer Live Chat with Paul A. Bunn, Jr., MD
Wednesday, November 20, 2002, 4:00 - 5:00 PM ET
About Paul A. Bunn, Jr., MD

Dr. Bunn serves as the Grohne/Stapp Chair in Cancer Research at the University of Colorado Cancer Center in Denver. He is Professor of Medicine and Director of the Cancer Center, and also directs the University of Colorado's Specialized Program of Research Excellence (SPORE) in lung cancer. His research focuses on the biology and novel treatment of lung cancer, and his clinical expertise includes lung cancer, lymphomas, and biologic therapy. Dr. Bunn is also a member of the Colorado Tobacco Settlement Research Scientific Advisory Committee, appointed by the governor. Dr. Bunn currently serves as ASCO President for 2002/2003.

Moderator 1: On behalf of the American Society of Clinical Oncology (ASCO), welcome to the Cancer.Net chat on lung cancer, a live question-and-answer session hosted by Paul A. Bunn, Jr., MD. During this hour, Dr. Bunn will answer as many questions as time permits. Some questions may be adapted so Dr. Bunn's answers can help as many people as possible.

Dr. Bunn will begin taking questions at 3:45 PM ET. The chat will begin at 4:00 PM and end at 5:00 PM ET. As you phrase your questions, please keep in mind that Dr. Bunn is unable to give individual medical advice in this setting. In answering questions about specific drugs, Dr. Bunn's comments will be focused on the state of current research and clinical trials on drugs and drug regimens.

This chat is governed by all terms and conditions of the Cancer.Net website.

Good afternoon everyone, and welcome. Thanks for logging on. Dr. Bunn will now begin taking questions.

Raven53: I was a smoker for 20 years and I quit 12 years ago. I am really worried about getting lung cancer. Are there any tests I can ask my doctor for?

Dr. Bunn: There is a national study called the National Lung Screening Trial (NLST) that randomizes subjects to receive an annual spiral CT scan or an annual chest x-ray. You can ask your doctor for the closest site or get the information from the National Cancer Institute.

Dave: I have seen differing opinions concerning adenocarcinoma. Is it or is it not associated with smoking?

Dr. Bunn: Smoking causes 87% of all lung cancer cases, irrespective of the histologic type. Of the 13% that are not smoking related, the majority are adenocarcinomas. Thus, nonsmokers who get lung cancer are mostly likely to get adenocarcinoma, but smoking causes all kinds, including adenocarcinoma.

Suzy: Can chewing tobacco cause lung cancer?

Dr. Bunn: Chewing tobacco is highly related to oral cancers and cancers of the throat. Without any smoking it is unlikely to cause lung cancer. Chewing tobacco can also increase the frequency of other smoking-related cancers such as bladder and kidney cancer.

Guest155: I read recently that the British medical community offered disturbing information about the dangers of smoking marijuana. In particular, incidences of emphysema and lung cancer attributable to marijuana usage. Comment?

Dr. Bunn: It is true that smoking marijuana will cause both lung disease and lung cancer. The risk of lung disease and lung cancer is related to the dose. The more of anything you smoke, the higher the risk of lung disease or lung cancer.

bdkelly: My grandfather died of lung cancer; is it hereditary?

Dr. Bunn: Lung cancer is not directly heritable. However, one can inherit genes that affect susceptibility. During their lifetime, smokers have one in nine chance of developing lung cancer. Undoubtedly, one can inherit genes that make the risk higher or lower for the same amount of tobacco smoke. Unfortunately, we do not have current tests to identify whether an individual has inherited such susceptibility genes.

mona: What is a spiral CT scan and how is it different from an x-ray?

Dr. Bunn: CT scans are x-rays done in three dimensions, whereas chest x-rays are done in two dimensions. Therefore, many more lesions within the lung can be seen on a CT scan compared to a chest x-ray. A spiral CT scan differs from a conventional scan in that the entire test is done within one breath hold. Thus, motion artifact during breathing is minimized. This allows one to see smaller nodules within the lung and reduces x-ray dose and risk.

B_in_VT: Can exposure to pesticides or herbicides cause lung cancer?

Dr. Bunn: This is not known. It is possible, but if so, it is a small minority of the cases.

zoe: I have not been diagnosed with lung cancer and just had a lung scan that was clear. However, until 15 years ago I was a three-pack-a-day smoker. Would it make sense to get a bronchoscopy or other such test now?

Dr. Bunn: There are no proven effective screening tests. Sputum cytology and annual chest x-rays have been studied but have not been shown to be effective. As discussed above, spiral CT scans are currently being studied. Bronchoscopy would only be indicated if there were symptoms and/or abnormalities on chest x-ray or sputum analysis.

mona: What is the most effective treatment for early stage non-small cell lung cancer?

Dr. Bunn: Lung cancer has four stages, like all cancers. For the purposes of this discussion, I will consider stage I and II to be early stage. Surgery is the mainstay of treatment for stage I and II lung cancer. The role of chemotherapy either before or after surgery is being evaluated in national randomized trials because there is some evidence that it can improve cure rates.

Lisaeze: Are there currently any phase III trials open that look promising for stage IV adenocarcinoma?

Dr. Bunn: There are at least 25 open trials in the United States. One can get a list of these trials from the NCI clinical trials website or from other clinical trials websites. Most of these are evaluating new drugs combined with older established drugs.

B_in_VT: Is there any explanation for why most patients with adenocarcinoma present with multiple tumors throughout both lungs, and others have only one large tumor in one lung with metastatic disease to the lymph nodes and liver?

Dr. Bunn: About one-third of patients have metastasis to an organ outside the lung at the time of diagnosis. This may be in any organ, although sometimes metastases are confined to one or both lungs. This most often occurs with adenocarcinoma or a form of adenocarcinoma called bronchoalveolar carcinoma. This most likely can be attributed to growth factors within the lung that create a fertile soil.

Guest219: I have quickly relapsed extensive stage SCLC after six cycles of etoposide and carboplatin. I am now on single agent irinotecan every three weeks. It has slowed but not arrested the cancer growth. Do you think adding imatinib mesylate (Gleevec) to my regimen would give any advantage? I am c-kit positive.

Dr. Bunn: In this setting, a single trial has not shown imatinib mesylate to be effective. Other clinical trials would be a better option.

B_in_VT: Recent studies using ZD1839 (Iressa) in combination with standard chemotherapy agents have had disappointing results, but what about using ZD1839 as a first-line treatment for NSCLC?

Dr. Bunn: As a single agent, ZD1839 has been studied after one, two, three, or four prior chemotherapy regimens. The response rate is about 15%, no matter how many prior regimens. There are no single agent studies in previously untreated patients, but one would predict the response rate would be 15%. Since chemotherapy produces response rates of 25% to 50% and have been proven to prolong survival, they appear to be the better choice in the first-line setting at the moment. This might change if we could better select who is likely to respond.

Guest18: My mom has stage IV lung cancer. She is experiencing severe pain and the pain pills have many side effects. Are there any alternatives with fewer side effects?

Dr. Bunn: Pain is an extremely distressing symptom for patients and thus all attempts to relieve pain must be tried. There are many pain medicines and one might be better than another for an individual. There are also medications to reduce side effects depending on what drug and what side effect. This should be discussed with your oncologist and/or nurse.

Guest128: Which platinum do you prefer in the treatment of advanced or metastatic NSCLC, cisplatin or carboplatin?

Dr. Bunn: In my opinion, cisplatin and carboplatin are equally efficacious. Carboplatin is more convenient and has fewer side effects and is, therefore, preferred in most instances.

Dave: How much of a risk is long-term exposure to ionizing radiation?

Dr. Bunn: Ionizing radiation can cause lung cancer, but this is extremely rare. Individuals in Japan exposed to atomic bomb exposures had an increase in lung cancer, but the risk of other cancers was higher. Exposures to standard x-rays would rarely, if ever, cause lung cancer.

Karen: My father is reluctant to begin chemotherapy because he is afraid of the side effects (losing his hair and so on). What can be done to prevent those side effects?

Dr. Bunn: The most serious and troubling consequences of chemotherapy can be reduced, but not eliminated by using newer drugs and by appropriate use of medications to reduce side effects. Unfortunately, hair loss is generally not a side effect that can be easily avoided by current drug combinations.

B_in_VT: I am a 36-year-old female lifetime nonsmoker recently diagnosed with stage IV adenocarcinoma. I have never had exposure to asbestos or radon or worked in an industrial setting, and there is no family history of lung cancer. Where do I look for a cause of this illness?

Dr. Bunn: It is unlikely that the cause will be determined. If you wanted, you could determine radon levels in the home in which you grew up as a child.

Alisa: How dangerous is it to have CT, brain, bone, and PET scans every four months?

Dr. Bunn: Since having all these scans every four months is not indicated, it is not known how dangerous this is.

Guest219: What is the best phase III clinical trial available now for relapsed, metastatic SCLC?

Dr. Bunn: Clinical trials are done to find an answer. If we knew the answer, it wouldn't be a clinical trial. Therefore, it is impossible to say whether one clinical trial is better than another. The only way to make progress in the treatment of SCLC or any cancer is through clinical trials.

Dave: Is it common for rib pain/discomfort to continue for months or years following a thoracotomy?

Dr. Bunn: Yes. This is a very troubling side effect for a significant minority of patients. Consultation with a pain specialist would be recommended.

Elad: Spiral CT can now reveal lung lesions much smaller than those seen with chest x-rays. Do we know how small a lesion would need to be for its removal to result in a likely cure if the tumor had not shed cells?

Dr. Bunn: About 50% of the United States smoking population will have one or more small nodules on a spiral CT scan. The vast majority of these are not lung cancer. In the small percentage that is lung cancers, surgical resection will cure the majority, but not all. Approximately 170,000 people are diagnosed each year.

bdkelly: Please describe the differences between small cell lung cancer and lung carcinoid tumor. I know they have a few similarities.

Dr. Bunn: Some tumors in the lung have neuroendocrine properties. These include carcinoids, small cell carcinomas, and large cell carcinomas with neuroendocrine features. Although these tumors share neuroendocrine properties, they have very different biologic and clinical manifestations and are treated differently. Carcinoids grow slowly and metastasize much less frequently and are therefore usually cured by surgical resection.

Raven53: I have breast cancer and my doctor now says I have cancer in my lung. Does this mean I have lung cancer?

Dr. Bunn: I cannot determine from the information provided. Having breast cancer spread to the lung would be more common than having two cancers. But it is possible that there are two cancers. Your doctor should determine which it is before proceeding, because the treatments would be different.

Guest128: In ECOG 1594, do you think second-line treatment altered one-year survival? If so, what other endpoints are important?

Dr. Bunn: It is impossible to know whether second-line treatment influenced results in ECOG 1594. There is evidence that second-line therapy with docetaxel can improve survival.

Suzy: What is your opinion of vitamin A derivatives for treating lung cancer?

Dr. Bunn: The answer to this is not known. But, there are clinical studies determining if a retinoid vitamin A derivative given with chemotherapy will improve results compared to chemotherapy alone. Thus, the answer to this question will be known in a few years.

Mike2: What are the symptoms of lung cancer? My Dad, a smoker of 34 years, has a cough and will not go to see a doctor.

Dr. Bunn: Cough, change in cough, change in the material that one coughs up are frequent symptoms in chronic lung disease as well as lung cancer. There are many other symptoms in lung cancer patients. Certainly a smoker with new symptoms should be highly encouraged to visit his or her physician.

jamesp: Is there any evidence that women are more susceptible to lung cancer? If so, why?

Dr. Bunn: This is not known for sure. There is some suggestive evidence that women might be slightly more susceptible although this is not proven. Theories about this revolve around the effects of estrogens and gene expression differences in males and females.

zoe: I had a CT scan that found no cancer, but it did find some emphysema. Is there any correlation? Are other tests indicated?

Dr. Bunn: There is a small increased risk of lung cancer in smokers with air flow obstruction, but no other tests would be indicated at the moment.

Shetland: How soon after a person begins smoking does the risk of getting lung cancer begin?

Dr. Bunn: Thirty seconds.

B_in_VT: Is there any correlation between the size of tumors and/or spread of the disease that indicates how long someone has had adenocarcinoma?

Dr. Bunn: There is no way to know given a single point in time or one set of x-rays. Many patients in retrospect have lesions that can be observed on prior x-rays. Given serial assessments over time, one can give some estimates as to the time the cancer began, which is usually one to ten years previously.

steve: My last PET scan revealed two hot spots, one is an active 4 cm tumor in my upper left lung, and on the supraclavicular node immediately above it. Would you consider surgery to be a possible option here?

Dr. Bunn: Staging is the most important aspect of determining treatment. In this case, the staging has not been completed by the PET scan. If the supraclavicular node is palpable, a needle aspirate should be done. If positive, surgery would not be indicated.

Mike2: As a parent, what are the best methods I can use to keep my kids from smoking?

Dr. Bunn: This is a critically important but difficult question to answer. Education about dangers of disease many years in the future is important, but clearly not sufficient. The best advice at the moment is serious discussions and communication between you and your children.

mona: How effective is surgery for SCLC?

Dr. Bunn: Surgery is only effective in any form of lung cancer when the tumor can be removed entirely by the surgical procedure. Because small cell lung cancer usually has spread to regional lymph nodes or metastatic sites, surgical therapy is not useful in the vast majority of cases. In those uncommon situations where there are no lymph node metastases, surgery followed by chemotherapy is indicated for SCLC patients.

zoe: My internist recently told me that the incidence of lung cancer among former smokers is only 2%. This seems very low, but he is a full professor of medicine. Could you clarify the statistic?

Dr. Bunn: The statistic cited is incorrect. In the United States just under 50% of all new lung cancer cases are in former smokers. The risk of lung cancer in former smokers declines over time, but never reaches that of a nonsmoker even after twenty years.

Alisa: I have been cancer-free for two years (from stage IIB adenocarcinoma). How often should I get CT scans and how often should I be getting PET scans?

Dr. Bunn: You should not be getting PET scans. It is not known whether you should be getting spiral CT scans or how often. Certainly this should not be more than every six months at the moment and should not be more often than every year after four years.

Guest219: Because SCLC is so easily metastatic, why hasn't there been more interest in antiangiogenesis treatments?

Dr. Bunn: There has been incredible interest in antiangiogenic therapies. Unfortunately, early trials have not been extremely promising. Therefore, progress has been slowed. But this remains an important target.

B_in_VT: Without having a brain scan, can I be sure that I have no brain metastasis? Are there any symptoms of brain and/or bone metastasis?

Dr. Bunn: The majority of brain and bone metastases are symptomatic. But, about 20% of SCLC and 5% of NSCLC patients will have asymptomatic brain metastases.

Dave: Do you consider support groups to be beneficial for survival/well being?

Dr. Bunn: Both survival and quality of life are critically important for all of us. At present there is no evidence that support groups improve survival but may improve quality.

tatiana: How do I find support groups for people with cancer? I don't live close to a large city.

Dr. Bunn: It would be reasonable to try several websites that would include the website of your nearest comprehensive cancer center, the ASCO website (Cancer.Net), or the American Cancer Society website.

Kurt: What do SCLC and NSCLC stand for?

Dr. Bunn: SCLC stands for small cell lung cancer. NSCLC stands for non-small cell lung cancer. Within the NSCLC group are three histologic types called adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. The differences are determined by a pathologist looking at a tissue biopsy under the microscope.

Kurt: I smoked when my kids were little. Could they get lung cancer?

Dr. Bunn: About 3% of lung cancers are caused by passive tobacco exposure, which generally comes from multiple sources but does include exposure to parents smoking.

Suzy: In your opinion, what is the best method or drug to use to quit smoking?

Dr. Bunn: Nicotine replacement therapy is the cornerstone. Additional therapy with bupropion SR (Zyban) can help increase quit rates. You should discuss this with your physician.

Moderator 1: The chat is now ending. We hope this discussion has been valuable, and we regret not being able to answer every question.

More information is available in Cancer.Net's lung cancer section.

SAVE THE DATES: Cancer.Net's December chat, 'coping with cancer during the holidays,' is scheduled for December 3, 2002, from 4:00 - 5:00 PM ET. The chat will be co-hosted by Diane Blum, MSW, Executive Director of Cancer Care, Inc., and Deane L. Wolcott, MD, President of the American Psychosocial Oncology Society.

The chat room is now closed. Thanks again for joining us.