In this podcast, an expert discusses the latest evidence and evolving guidelines for lung cancer screening, highlighting the benefits of low-dose CT screening, challenges to implementation, and opportunities to improve early detection among individuals at increased risk for lung cancer.
In this episode, Dr Abbie Begnaud discusses the importance of lung cancer screening and evolving strategies to improve early detection among high-risk populations, including:
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Presenter:
Abbie Begnaud, MD, FCCP
Associate Professor of Medicine
University of Minnesota
Pulmonary, Critical Care, Allergy and Sleep Medicine
Program Director, Interventional Pulmonology Fellowship
University of Minnesota Health Lung Cancer Screening Program
Link to full program:
This transcript was automatically generated from the audio recording and may contain inaccuracies, including errors or typographical mistakes.
Advancing the Early Detection of Lung Cancer: Expanding Screening Access, Eligibility, and Awareness
Dr. Abbie Begnaud (M Health Fairview University of Minnesota Medical Center): Annual lung cancer screening is recommended for people in the United States who are known to be at high risk for lung cancer based on a prior smoking history.
Lung cancer screening with low-dose CT has been recommended and covered by insurance since 2013, yet still, we see uptake rates of probably around 20%, just below 20%. That varies by state and varies by age group. Overall, maybe about one in five people who are thought to benefit from lung cancer screening who are eligible for lung cancer screening have received it and are up to date in this country. We can certainly do a lot better than that. When you compare that to other routine cancer screening tests - breast, colon, and cervical.
Annual low-dose CT scan lung cancer screening has been shown to improve mortality. A large clinical trial in the United States showed a 20% reduction in mortality, which many people know, and it is important to know that that study was stopped because 20% was the predetermined mortality reduction. That means it probably underestimated the mortality reduction.
Another large trial called the NELSON trial, which took place in Europe, showed an even more significant reduction in lung cancer mortality. That even varied in different groups as well. Women saw an even greater benefit from lung cancer mortality through annual low-dose CT scan for lung cancer screening.
The way that a mortality benefit happens with lung cancer screening, like with many other screenings, is with a stage shift. The goal is to identify lung cancers when they are small, when they are not symptomatic, when people who are at risk have no signs or symptoms of lung cancer, and they feel fine and healthy, just like with all types of screening. If we can identify a lung cancer at stage 1, where it is very easily treatable, we have many options for treatment and for possibly a cure, we can see much higher survival rates for lung cancer. That is really the goal of lung cancer screening with low-dose CT scan.
In 2021, the United States Preventive Services Task Force updated the guidelines, the recommendations for lung cancer screening. The USPSTF guidelines are important because those drive insurance coverage. That is going to determine who can get screening covered by their insurance plans. Those were widely accepted to be a better set of guidelines, a move in the right direction.
Sometimes we see shifting recommendations, shifting guidelines, and that maybe makes people question the whole process or makes them wonder why are things changing? These guidelines are changed based on recent evidence.
In 2021, they had the addition of the NELSON trial. They also had the addition of some other modelling data, which was more computer estimates of the types of benefits that you could see with lung cancer screening. What they did was they expanded the guidelines in 2021 to lower the age threshold for screening from 55 to 50 years, and to lower the smoking threshold from 30 pack-years to 20 pack-years. Most of these studies included people based on not only age but also the intensity and duration of their smoking history. A pack year is estimated to be the equivalent of smoking a pack of cigarettes a day - 20 cigarettes - for a year. So, 20 pack-years is the equivalent of smoking a pack a day for 20 years.
Newer studies and newer data are showing that younger people with a lighter smoking history will also benefit from lung cancer screening. In some ways, they might benefit even more because these are people who have less of a risk of other types of health conditions, competing mortality from such a long history of cigarette smoking.
The 2021 criteria are widely thought to be a move in the right direction, but many people think they are not the final answer, and that we are going to continue to see changing guideline recommendations on the basis of data that is coming out now from real-world screening data, modelling data. Even the current eligibility criteria probably would only catch about half of people with lung cancer. That means we only have an opportunity to intervene early and get a stage shift on half of people with lung cancer.
Lung cancer is a deadly disease. Screening more people is going to be beneficial. That is the data generation that is needed to update the USPSTF guidelines in the near future.
When you are talking about screening for lung cancer, ideally, you would find someone who is at high risk for lung cancer but is otherwise healthy and is not expected to die in the foreseeable future from some other condition; cardiovascular disease, diabetes related complications, etc.
People who are on the younger side of that age range and who have a lower smoking history, and people who are generally healthier, maybe people who do not think of themselves as patients, they are just people out in the world living their lives, they are not experiencing a lot of problems, maybe they are not seeking a lot of medical care. Those are the people who, if we identify a lung cancer early, they are more likely to be able to withstand whatever treatment is needed for lung cancer.
When people are at very high risk of developing lung cancer, let us say you have a person who is much older and has smoked a lot for a long time, and they have other lung conditions, chronic obstructive lung disease. People with lung disease might be likely to die of their lung disease, and they might be unable to sustain the treatment that is recommended for lung cancer. Even though you might screen them and you might find a cancer, you might not be able to get them through treatment for them to experience the longevity and benefit of a lung cancer cure.
Historically, societies have always been pushing the boundaries because they are directly motivated to reduce deaths from cancer. Some of it has to do with extrapolating data from the previous studies, looking at people who once they stopped getting screened, they continued to develop cancers, and also looking at data that shows that even after you quit smoking, your risk of getting lung cancer never goes down to somebody who never smoked. The American Cancer Society, recognizes this. The acknowledgement is that American Cancer Society guidelines do not drive reimbursement, and so they do not really drive change or what people have access to. They advocate for that on the basis of the fact that modelling has shown that even if you quit smoking 16, 17, 20 years ago, if you are still in good health and you still have a life expectancy of at least five to ten years, that identifying a lung cancer early and treating it is going to potentially save your life.
Similarly, the National Comprehensive Cancer Network, their screening guidelines have always been outside of, or pushing the boundaries of what the USPSTF recommended. Even before the USPSTF originally came out with their guidelines, they were recommending a broader range of risk factors besides smoking history.
There are a lot of known risk factors for lung cancer that are not cigarette-smoking related. Occupational exposures are a big one. There is a long list of occupations where people are exposed to a variety of carcinogens that increase their risk for lung cancer. Exposure to radon, an environmental indoor air contaminant in homes, high in certain parts of the country, is thought to be the second leading cause of lung cancer. Family history of lung cancer, especially if you have a family history of lung cancer and a non-smoker and somebody who never smoked, and they have somebody in their family with lung cancer, that is clearly an identifiable risk factor.
The National Comprehensive Cancer Network has always been identifying risk factors for lung cancer, and so someone who has identifiable risk factors should be considered for screening. At the same time, those guidelines are to move the field, push the boundaries. They adopt what we know clinically and what we know scientifically, but they do not rely heavily on, was there a randomized clinical trial that produced high-quality evidence to come up with this, or is this either modelling clinical experience and other sorts of things?
Are other things harmful? Absolutely, they are. Part of it is that people tend to smoke products in a different way. When you want to talk about combustible marijuana, it has been hard to study that for a very long time. It is hard to even know, but clearly, anything that you are lighting on fire, breathing into your lungs, is causing damage. There is different types of damage. I often get asked about hookah pipes.
The way that people smoke those things, even just how they inhale them, how they use them, really does vary over time and by group and by product. It is way more complicated than a smoking pack-year history. There is a lot of interest right now and data to suggest that perhaps instead of the pack-years, we should be just looking at the years smoked. So, more than 20 years smoking because even if somebody smokes five cigarettes a day, ten cigarettes a day, a person who smokes five cigarettes a day can still manage to get as much carcinogenic exposure as somebody who smokes a pack a day, depending on their smoking behavior.
If someone is discouraged from smoking by the price of cigarettes, for example, and they do not have the extra disposable income to just pay the full price for a pack of cigarettes, they might make sure that they get every little bit out of each cigarette that they have. They take a few puffs, put the cigarette out, save it for later, and smoke it a bit more. That might be the same as smoking a separate cigarette in each setting.
None of the guidelines right now really in any meaningful way incorporate those other types of smoking exposure that people might have.
Second-hand smoke is another one people ask about. I do not think we have probably enough - it is hard to quantify those things in a clinical trial setting in a way that you can measure them and compare them, but it is clear that all of them contribute to lung cancer and lung disease risk.
When I am seeing a patient, and they say to me, "I smoke 10 or 15 cigarettes a day, and then I also smoke a joint every day or most days," in my mind, I am doing some very rough math to say, "That probably adds up to about a pack a day." There is no objective, black-and-white way that any of the screening guidelines incorporate non-tobacco cigarette smoking.
Clearly there are other risk factors for lung cancer, which are hard to quantify but are definitely identifiable. There are also risk factors for lung cancer that probably we have not totally identified and do not routinely elicit from patients now because certainly in my clinical work and my advocacy work around lung cancer, you meet people who do not have any identifiable risk factors for lung cancer. They never smoked cigarettes, they have no family history, they have no known occupational exposures, and yet here they are in front of you with lung cancer.
Race is really acting as probably an indicator of socioeconomic status, social deprivation. There are some studies which clearly show differences by race in terms of average cigarette smoking and rates of lung cancer. A broad description of that study might be that black Americans and some Native Americans might get lung cancer - Asian Americans might get lung cancer with lower smoking histories. My suspicion is that what that reflects is maybe second-hand smoke exposure, environmental exposure in their personal lives, occupational exposure. I think a lot of these social deprivation factors are probably a better indicator because you might have people who are doing different types of jobs, which are more likely to be exposed to carcinogens, as opposed to a white-collar worker or somebody in an office who is not exposed to various pollutants in their job setting.
The best place to be looking for people who can benefit from screening. Primary care practices, places where patients are coming in, not for lung-related complaints, but maybe coming in for an orthopedic complaint or their routine check-ups, women's health providers or places, urgent care clinics, places again, where people who they do not feel like patients, they are just people living their lives, but they are interacting with a health care entity in a way that they might have a chance to get an opportunity to get screening.
The 50 age range, anybody who is currently smoking at the age of 50 is probably eligible, just based on when people typically start smoking. If you have people who have smoked any time recently in that 50-year-old age range, it is definitely worth thinking about. It is tricky to identify people who are eligible for screening based on the current criteria. Most electronic health records do not really afford an easy way to document the smoking history. It is actually quite time-consuming to get a detailed smoking history from someone. You are really asking them about their whole life story. Again, if someone is around the age of 50 and they smoke now, or they have smoked recently, those are definitely people you would want to be thinking about.
For even people who are older than that, if they have smoked for at least 20 years, it is worth thinking about, for sure. I always ask my patients about other risk factors for lung cancer as well. I know that someone is coming in for a totally unrelated complaint that might not be part of what makes sense to include in that clinical encounter. I ask people about radon. I ask people about their occupational history. I ask them about their family history. Even without all those additional risk factors, if you have someone who has any tobacco smoking history and they are over 50, it is definitely worth thinking about and probably almost leaning towards thinking you are going to screen them unless you have come up with some compelling reason not to.
There are a number of barriers on the patient or screening person perspective. The primary one is, most people who would benefit from lung cancer screening do not know that it is available. They do not know that it exists. Even people who are very proactive about their health care, they are up to date on all of their other recommended cancer screenings, they just have absolutely no idea that lung cancer screening is available. Knowledge is huge.
Some of the other ones are harder to measure and quantify, but are definitely real is the stigma, the fear, the nihilism. Lung cancer is a really scary term. Lung cancer has historically been universally almost fatal disease. Even if people hear lung cancer screening, they are, like, "I do not want to know if I have lung cancer. I do not want to go looking for that. I do not want to find out if I do." Many people, including healthcare providers, mistakenly think that there are no good treatments for lung cancer. Almost every person that I talk to who is being evaluated for lung cancer knows someone who, in their life, some family member or friend, or somebody who was diagnosed with lung cancer and then was dead within a number of months. They will tell me stories like this. I think everyone has this idea in their mind that lung cancer is a very bad thing to get, and if you have it, you are just as soon not knowing.
That is really the huge part. That psychological or knowledge barrier applies to both patients, the general population, as well as healthcare providers. Primary care providers may be unaware of all of the tremendous advances that we have in terms of treatment for lung cancer, early detection through screening, of course, new investigational treatments around blood tests and other types of tests to identify lung cancer. Biopsies are easier, safer, and more effective than ever before. So many treatment options are much better tolerated and much more effective. People with lung cancer are living longer than ever.
For everyone to know that lung cancer is curable and you would not have any symptoms when you first have it, but that is when you want to find it, is a huge barrier to overcome.
Again, I mentioned that a lot of the people who would benefit the most are probably people who are not routinely engaging in preventive care. Maybe they are early middle-aged people, they are working, they are busy with families, they have a smoking history. Maybe they have other risk factors that they do not know about, they are feeling mostly well and healthy. Maybe they are not going in for routine preventive care, so they do not even have a chance to be offered lung cancer screening.
For people who are engaged in screening and they are eligible for screening, there are still logistical barriers. It is a CT scan. Almost always, you have to have the order, and then you have to schedule it, and it happens at another time. Some of those logistical barriers are similar to other types of cancer screening tests.
One thing that is different about lung cancer screening is that you have to have an order from a provider with a shared decision-making visit. For a mammogram, that is not required. A woman can just call and schedule a mammogram without an order from anybody, but for lung cancer screening, you have to have an order. You have to fit together that individual person having the knowledge and the wherewithal to get screened, and then they have to be paired up with a health care provider who also has the knowledge and the motivation to help get them screened. It feels sometimes like matching up those two different components is the hard part.
For a test like a low-dose CT scan, which does administer a small amount of radiation to a person, this is exactly the reason why we do not screen everybody. We do not screen at a population level right now because continual exposure to radiation would likely cause some potential harm over time. That is exactly why we are looking for people who are at a higher risk for lung cancer, who have an identifiable risk factor for lung cancer, because we know that for those people, the benefit of getting screened outweighs the risk.
The amount of radiation that a low-dose CT scan administers to a person when they get the CT scan is about the same amount of radiation that a person who is living in Minnesota gets over the course of an entire year. Another way to characterize it is, it is about the same as seven chest X-rays. Those comparisons give people something that is a little bit more tangible to them and might make it seem like this is not some massive amount of radiation. The CT scans are done using a very low dose of radiation. Honestly, much less radiation than you would get if you went into the emergency department with some pain and you got a diagnostic CT scan.
The VA is really leading the charge when it comes to lung cancer screening. Because of their obligation to people who have served and because of their knowledge, understanding, and study of the types of exposures that veterans have faced. If you are a veteran and you are concerned about lung cancer screening and your lung cancer risk, I would strongly encourage such a person to seek care at their VA.
I am aware of multiple programs at the VA which acknowledge and recognize other risk factors do exist, and so they are really innovating in terms of other risk factors, characterizing toxic exposures through service to ensure that people who are at risk for lung cancer can get screening through the VA. The VA does not have to adhere to USPSTF guidelines; they can choose their own guidelines for screening.
For other people who have never smoked, maybe they work in a job where they are concerned about occupational exposures. That is less of an issue in modern times because of occupational safety regulations in place. The types of occupations that cause risk for lung cancer, the ones that are known to be very high risk - miners and other types of things - they do have some occupational screening programs that are involved with those. A lot of the other occupations that are not as widely characterized to be high risk in the air travel industry, pilots and diesel mechanics, and these people, these are definitely risk factors
I have not seen occupational exposures in people who have never smoked to be an indicator where people are really clamoring to get screened, but I definitely have seen it in people who have never smoked and who have a family member with lung cancer.
Right now, the best test that we have for screening is a CT scan. It does give you radiation, and it probably just does not make sense to screen people who have one non-smoking additional risk factor for lung cancer screening.
The problem is not with doing one scan. Someone comes to me like this, and we can say, "Okay, we will do one scan." Now the question is, if that scan is clear, then what do you do? You really do not want to sign that person up for an annual CT scan every year. There have been scenarios where someone has come to me, and I will say, "Okay, we will do one scan, but if that one is clear, now we are in a scenario of uncertainty." I will say the type of lung cancer that people who have not smoked get usually is a very slow-growing lung cancer. Probably an annual scan would not be the answer. It might be every few years, every three or four or five, but again, now we are just making stuff up. We do not have a lot of great data to support those people.
The first thing I tell them is, make sure that about the risk factors that you can control and you can do something about. If you have not tested your home for radon, make sure you do that. If you are not paying attention to things like outdoor air quality, make sure you do that."
Air pollution and outdoor air quality is almost certainly going to be more recognized as a risk factor for lung cancer. It is definitely known to contribute to lung cancer risk, but it is still hard to quantify how and who is at risk for that due to outdoor air exposure. I basically say to people, "Take care of your body, be a good advocate for your health control, the risk factors that you might not be thinking about, which you do have some control over now, and by all means, pay attention to symptoms." Once we are talking about symptoms, we are not talking about screening anymore.
For somebody who has a family history of lung cancer and no other risk factors, I will say to them, "Listen, make sure that you pay attention to your body. If you start to notice a cough that does not go away, do not allow yourself to be dismissed by health care providers." I have heard more stories of this than I care to count, where someone is young, and they are healthy, and they do not smoke, and the health care providers who take care of them think, "This person could never have lung cancer. It must be reflux. It must be post-nasal drainage. It must be a virus or allergies."
If someone has a cough or respiratory symptoms that do not go away, they do need to be evaluated because we are definitely seeing, people who are diagnosed with lung cancer now do not have any smoking history. We definitely need to be on the lookout. I do not think we are at the point where we can screen those people because the CT scan is just not the best option for screening somebody who is pretty low risk.
Smoking cessation is a very important part of screening. I really try to hold in both of my hands, on the one hand, compassion and empathy for older adults who have tried and unsuccessfully been able to quit smoking. Those people still deserve care, and they still deserve screening, and they still deserve the chance to identify a lung cancer early. Also, at the same time, people who are undergoing screening really deserve as much support as they are willing to accept, and compassion and help to quit smoking, because quitting smoking is really the way to maximize the bang from lung cancer screening. It improves mortality from a wide variety of diseases, not just lung cancer.
Even if someone is still smoking, they deserve screening, and they deserve the opportunity to find their lung cancer early. It is never too late to quit. Even if you have a lung cancer, it is never too late to quit smoking because you will respond to treatment better and have less of a chance of recurrence. Smoking cessation is always something that needs to be a part of this conversation.
The benefits from screening are pretty clear to me. At the same time, things like overdiagnosis, things like false positives, things like incidental findings, those all can be advantages where you find something that you were not even looking for that you can improve someone's health, but they do have to be managed judiciously.
Ideally, screening would happen in a place where there are experts who can manage the findings. Lung cancer screening does have a high false positive rate. What that means is that a lot of the nodules that are detected will not be a lung cancer. That would be considered a false positive. So, in a place where they are judiciously managing those nodules, the person would maybe get a subsequent imaging. If it is stable, nothing would happen. The place where you can get into maximizing the harms of screening is places where they are either not paying close enough attention to findings on screening, so things get missed or fall through the cracks, or places where they are going overboard with managing findings, which are known to be common and probably benign.
It is probably hard to give an answer for how to do that, how to know if the place that you are referring a person is doing screening in a quality way. A multidisciplinary tumor board, having surgeons, having radiologists, having lung specialists is a good one.
Alot of integrated health care systems do a good job with screening and are capable of managing the findings in a way that you will get more benefit from screening than you will a potential harm.