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Detect Lung Cancer Early: Get a Low-Dose CT Scan

Lung cancer risk is greatest for smokers. Screening is key to catch lung cancer in its earliest stages. Low-dose CT scan is recommended for individuals who are at risk.

Dr. G. Zacharia Reagle discusses lung cancer risk and current screening techniques.
Detect Lung Cancer Early: Get a Low-Dose CT Scan
Zacharia Reagle, DO, FCCP
Dr. Zach Reagle graduated in 1995 with his Bachelor of Science degree and in 2000 with his Master of Science degree from the University of Maryland Baltimore County, MD.  After working as a paramedic for several years he went on to earn his Doctor of Osteopathic Medicine at Touro University College of Osteopathic Medicine in Vallejo, CA in 2008.

Learn more about Dr. Zach Reagle

Prakash Chandran (Host): Today we are going to be talking about lung cancer and early detection screening. Now so many of us are connected to or know someone with this disease and hopefully with the information we learn today; we can catch it early so it can be treated more effectively. I’m joined today by Dr. Zach Reagle a pulmonologist at Sierra Vista. Dr. Reagle, pleasure to have you here. I want to start by learning who is the most at risk for getting lung cancer?

G. Zacharia Reagle, DO, FCCP (Guest): Sure, well thanks for having me. It’s nice to be here today. So, the patients at highest risk for lung cancer are tobacco smokers and there’s definitely a dose response relationship. In other words, the longer – the more somebody has smoked and the longer they have smoked for the risk of developing lung cancer definitely goes up. It is possible for nonsmokers to get lung cancer, but they are the vast minority of lung cancer patients and so those at most risk are smokers.

Prakash: So, I’m curious. When you say smokers, how frequently does one need to smoke in order to be at risk? 

Dr. Reagle: Sure, that’s a great question. So, we kind of measure tobacco smoking in what we, doctors refer to as a pack year and it’s kind of a really – essentially a pack year is most people on average smoke about a pack a day. Some people smoke a little bit less, some people smoke a little bit more. A pack year comes down to for every year that you have smoked a pack a day that’s one pack year. So, for example if somebody smoked one pack a day for 20 years, their tobacco exposure history would be 20 pack years. If they smoked two pack a day for ten years, they would still have 20 pack years and so on. And there’s a fair amount of research that seems to suggest somewhere between 20 and 30 pack years is probably when the risk goes up pretty significantly. That being said, people who have smoked more like 10-15 pack years do still get lung cancers but there’s probably something around between 20-30 pack years that the risk really goes up.

Prakash: Okay, that makes a lot of sense. And what about age, is there a certain age where you are more at risk than other ages?

Dr. Reagle: Yeah, that’s an also good question. Well cancer, any kind of cancer at the end of the day is an abnormal cell growth or cell division and the longer we live and the more our cells have a chance to divide; the greater the chance that there could be a problem in cell division and therefore developing cancer. So, the older you are; the higher the risk is. Every once in a great while people under the age of 55 or 60 do develop lung cancer but most lung cancer patients are going to be over the age of 50 or 55. When you get into the 60s and 70s, and again, most people who are smokers at that age category have been smoking for probably more than 30 pack years so, the longer we live, the higher the risk goes up and again, probably somewhere around over the age of 50 the risk goes up pretty significantly.

Prakash: Okay so if can just reiterate. You are basically saying over the age of 50 especially if you in that 15-20 pack year period, especially if you are still smoking; you are at risk and another thing you also mentioned was sometimes it’s not related to smoking. Can you talk about maybe another reason why you might be susceptible to lung cancer?

Dr. Reagle: Sure. There are people who develop lung cancer who are never smokers or have minimal tobacco exposure history and there’s probably – there’s definitely a genetic component that we don’t I think fully understand at this point in time but is receiving a fair amount of research at this point in time so probably more to come in the future on that. Folks who are never smokers or have minimal tobacco history tend to be females in particular females of East Asian descent are at higher risk of developing lung cancer and again, that’s not necessarily related to tobacco exposure. The good news if you will for those patients is those lung cancers tend to have genetic mutations such as something called the EGFR mutation which is oftentimes can be treated very successfully with a newer class of medications targeted molecular or genetic therapy. But in general, if you are looking at nonsmokers, you are probably looking at females of East Asian descent.

Prakash: Okay. And I’m curious at what point should these at-risk people that you are talking about consider getting checked for lung cancer or when is it may be too late and when do you prefer people come in?

Dr. Reagle: Sure, that’s a good question. So, the problem with lung cancer and probably worth saying that when you look at all types of cancer; lung cancer remains the most fatal cancer for both men and women so, of breast, prostate, colon cancer, all of those are serious problems, but lung cancer is the one that has the highest mortality rate for both men and women. And the reason for that is probably because it doesn’t necessarily create a lot of symptoms until it’s much larger and therefore widely spread. Symptoms of lung cancer when they present can include things like coughing, coughing blood, shortness of breath, unexplained weight loss, some of those kinds of things. People with those symptoms especially people who are over the age of 50 or 60 who have smoked for more than 25 or 30 years probably should get evaluated via their doctor. But you really asked about people who don’t necessarily have symptoms and whether or not there’s a good screening test and this is something that has been looked at in the medical literature for quite some time because in many other cancers like colon cancer for example, we have made a lot of headway in reducing the mortality rate from colon cancer because we find it earlier with like a screening colonoscopy and that kind of thing.

For a long time, chest x-rays were looked at as a potential screening test and even just submitting a sputum or a phlegm sample was looked at and it was not found to be helpful to pick up cancers, lung cancers early. And then in 2011, there was a very famous large trial published in the New England Journal of Medicine called the National Lung Cancer Screening Trial and that was a trial done at multiple sites across the United States where they looked at patients who were between the ages of 55 and 74, who had smoked for at least 30 pack years, so again a pack a day for thirty years or perhaps a pack and a half a day for fifteen years or something like that and were either still smoking or had quit less than 25 years ago. And they found that- and these are asymptomatic patients, patients with no symptoms. That’s the idea behind a screening test.

And they found that utilizing a low-dose CT protocol, they were able to reduce the lung cancer mortality and reduce the overall mortality and that study for about every 320 patients screened; they were able to prevent one premature death with lung cancer. So, from that, many of the guidelines including the Medicare guidelines will cover a lung cancer screening protocol for patients between the ages of 55 and 80 who are again 30 pack years of tobacco exposure and either still smoking or quit less than 15 years ago.

Prakash: Yeah, so it really does sound like when you do express those symptoms, it’s almost too late. You know when you start coughing and the study is fascinating because it shows that people that were not showing any symptoms, they went in there, they were proactive, they got this CT low dose scan done early and they were able to treat it, I’m assuming more effectively. So, talking about this low dose CT scan; tell us a little bit about how it works.

Dr. Reagle: Sure so, it’s a – I mean it’s a CT scan so from the patient’s perspective, you kind of lay down on this tube and this thing runs up and down your chest and it’s over. It doesn’t take terribly long to do and the issue with CT scans is it always has to do with radiation exposure and things like that and we have been able to develop a CT protocol that uses a dramatically less amount of radiation so we have reduced the risks of the screening test and still gives us adequate pictures to be able to look inside the lungs and pick up very small lesions that are not creating any symptoms and might be early cancers. Some cases are early cancers.

Prakash: So is there a difference between a low dose CT scan that you are talking about and a traditional x-ray or MRI because I think when I’m thinking about it I think you go – you lay down and this- you go into this tube of this machine and you are there for a long period of time. Can you talk a little bit about the differences?

Dr. Reagle:   Sure, so a little bit of it is probably terminology. A chest x-ray is a more traditional x-ray test usually you are standing up and images are taken from a camera. It doesn’t take very long. Oftentimes we get a view from the back looking to your front and then also from the side. An MRI is a magnetic resonance imaging test which takes much longer to do than a chest x-ray or a CT scan and it’s actually interesting you asked because MRIs have not traditionally been used for imaging the lungs very much but they are being looked at in different research protocols and they may be something that we do more in the future. A CT scan is different than both of those in that you are laying down similar to an MRI, but it’s much quicker than an MRI and I think probably easier from the patient’s perspective and it provides us with more detailed images of the inside of your lungs than a chest x-ray for example. In fact, a chest x-ray will sometimes miss, oftentimes can miss very small early cancers just because it’s not as good a picture as a CT scan.

Prakash: Yeah, it sounds much better and more comprehensive than a traditional CT scan, how about any prep work that a patient needs to do. You know like sometimes there is fasting that’s involved or something that the patient has to do 24 hours before. Is there anything like that for this?

Dr. Reagle: Nope. There is no prep work, there is no fasting. In this protocol, we don’t utilize contrast, so there is no problems if you have kidney disease or any issues like that and I think probably the most important thing for patients to understand is that a screening CT scan will pick up things that are noncancerous and sometimes can lead to additional CT scans or even biopsies of lesions that turn out to be benign. One of the interesting things about our lungs is that they are anatomically inside our body but physiologically exposed to environment all the time. So, we certainly can see little small scars or little small things that might look abnormal on the CT scan, that do not turn out to be cancerous. But if you are in that category that we talked about; between the ages of 55 and 80, with a 30-pack year history and either still smoking or have recently quit; the risk benefit ratio overall really favors trying to find a lung cancer early. And so, I tend to support this. But I think it’s important for people to understand that we may find things that end up being benign.

Prakash: Yeah, that does make a lot of sense. So, I just had a question about frequency. So, let’s say that you do fit into that at-risk category patient, do you just get this scan once and then once you detect nothing; you are okay or is this something you should be getting more frequently?

Dr. Reagle: Good, good question. So, right now, we are recommending – right now the recommendation is to do it on an annual basis until you reach that age category of 80 years of age. Now in the event that a screening CT scan was done, and a small lesion was found that kind of meets that category, we say, you know, we are not really sure, we may need to get a follow-up CT scan or something sooner than that to keep an eye on it. But in general, if you pursue a screening CT scan and it’s completely negative then the recommendation will be to redo it the following year.

Prakash: And finally, if a patient is interested in getting a – this low dose CT scan should they just talk to their primary care physician? How do they go about getting this done?

Dr. Reagle: Yeah, that’s a good question. So, I definitely would recommend that they touch base with their primary care physician, talk about their risk of lung cancer, talk about smoking cessation if they are still smoking because one of the misnomers that I want to be sure we don’t perpetuate is people think oh I’ll just get a CT scan. I don’t need to quit smoking. They will find a cancer early on me and that’s not necessarily true. If you are concerned about lung cancer and you want to reduce your risk, quitting tobacco smoking is without a doubt the most important thing you can do. There are medications that can help with that. There are counseling things, cognitive behavioral therapy, different things like that that your primary care doctor should certainly have access to helping you with. But yeah, to answer your question, if you are listening to this and you are thinking heh I’m in that category, then I would definitely approach your primary care doctor and say I’ like to pursue this and they can help get you plugged into the system.

Prakash: Alright, well this has been super informative. It is crazy how many lives smoking and lung cancer have claimed and continue to claim and it’s really good to know about what seems to be a pretty easy and painless way to be proactive with your health especially if you are in that at-risk zone 55 and up for lung cancers. So, Dr. Reagle, thank you so much for being here and for your time today. For a referral to a board-certified physician please call the Sierra Vista Regional Medical Center and Twin Cities Community Hospital Physician Referral Line at 866-966-3680. I’m Prakash Chandran. Thank you so much for listening.