The relationship between smoking and lung cancer

What do cigarette smoking and lung cancer have in common? A lot. MPB’s Karen Brown spoke with Dr. Ralph Vance, a Professor of Medicine in the division of Medical Oncology at the University of Mississippi’s School of Medicine.

Karen: What do the statistics show if you smoke a certain number of years, what the chances are of you getting lung cancer?

Dr. Vance: Smokers are usually smoking a pack a day. That’s an average. After five years, we know if you’ve smoked a pack a day, you’re changing your lung’s tissue, where the exchange of oxygen occurs, permanently. Even if you quit smoking we know it would take another ten years before you would get down to a risk of developing lung cancer of 1.6 where, if you never smoked it would be 1.0. You can reverse the effects but never 100 percent of the effects. And the more you smoke the longer it takes to reverse the effects.

Karen: What percentage of people who have lung cancer have it because of smoking?

Dr. Vance: I would say ninety to ninety-five percent of the people who have lung cancer smoke. We know now that between 5,000 and 10,000 people, a year, develop lung cancer and have never smoked but they’ve been exposed to smoke. If people are smoking in your presence, you’re at risk.

Karen: Are there different stages of diagnosis as with other cancers - stage 1, 2, 3 and 4?

Dr. Vance: Exactly. If you diagnose someone with stage 1, their chances of living five years are astronomically higher than someone who’s diagnosed with stage 4 with metastasis outside the lung.

Karen: What’s the average stage of diagnosis in Mississippi?

Dr. Vance: In Mississippi, it’s stage 3 or stage 4.

Karen: What are the symptoms that present that would cause someone to see their doctor?

Dr. Vance: Some of them are non-specific - weight loss, cough …

Karen: smoker’s cough?

Dr. Vance: It can be a non-productive cough; just a cough. Some people come in and say they have a pain in their leg. They’re not talking about their lung, they’re talking about their leg but they have Metastatic disease from lung to bone. Metastatic disease is the most common way in Mississippi that lung cancer presents.

Karen: What can someone do if they’ve been diagnosed with lung cancer?

Dr. Vance: It depends on the stage. If the size of the primary tumor would allow surgical resection, then that’s the first thing to do. Following that with chemotherapy and radiotherapy would be appropriate. The chemotherapy is because lung cancer often is thought of as a systemic disease. You have a place in your lung but are their microscopic cells in other places like liver or bone or cns [central nervous system]? The theory is to give chemotherapy or radiotherapy to try to prevent the advent of Metastatic disease.

Karen: If someone has been smoking for twenty years, give them a reason to stop because they might think after twenty years, “Well, I’ve smoked this long, it’s not going to help me now.”

Dr. Vance: I can give several reasons. Stopping, even after twenty years, your lungs will get better. You may or may not develop chronic obstructive pulmonary disease (emphysema) from just the cigarette smoking if you stop it. People die of chronic obstructive pulmonary disease often and don’t even have lung cancer but it’s still deadly. Now, we actually have an armament of various things that can be done to help you stop. There is now a block aid for the nicotine receptor in the head that can be given as a pill, while you undergo counseling to help with the frustration and all the things that go along with the habits that are involved with cigarette smoking to try to break those habits. Now, instead of having about 20 percent of people who can really stop we can get more than 60 percent to stop the first time. That, to me, is a huge victory in the process where we’re not fooling the people into saying “You can quit this.” We’re actually giving a little guarantee. “We’re going to help you do this at least 60 percent of the time the first time we try it and if you don’t do it the first time, we can do it again.”