Dr. Ella Kazerooni:

Individuals at high risk for lung cancer are eligible for lung cancer screening if they're 50 to 80 years of age and have smoked 20 pack years or more. They either have to be individuals who currently smoke or have smoked sometime in the last 15 years. One pack per day for one year will be considered one pack year. Lung cancer screening discussions are usually initiated by primary care providers with their patients. Most preventative health services, including things like smoking cessation, hypertension screening, are firmly embedded in the preventative health services performed by primary care physicians. So that should be no surprise. But other physicians who see patients who meet the age and pack year history eligibility for lung cancer screening might also refer them for lung cancer screening. It's common for us to have referrals from cardiologists, pulmonary medicine physicians, and our otolaryngologists, for example.

So any physician can refer for lung cancer screening but generally it's initiated by primary care providers. The foundations for the current US Preventative Services Task Force recommendations for lung cancer screening are based on two large randomized controlled trials of individuals who did and did not undergo lung cancer screening. The first of those was performed in the United States known as the National Lung Cancer Screening Trial, which randomized over 50,000 people to chest x-ray versus low-dose lung cancer screening CT. They found a 20% reduction in mortality in individuals who'd been screened for lung cancer using CT. The cancers being detected were also smaller and at an earlier stage. This was filed by the results of the Nelson trial performed in Europe. Similarly, a randomized trial of screening versus no screening, which showed a substantive and significant reduction mortality similar to the National Lung Screening Trial, and suggested that the reduction mortality may be even higher in women.

Compared to the chest X-ray trials generally performed in the 1970s, no mortality reduction was seen with chest x-ray versus no chest x-ray. Now those trials had very different designs with a lot of crossover between the group that did get the screening test, the chest x-ray, and those who were not supposed to get the screening test, no chest x-ray, who might have had chest x-rays as part of their usual care. So the results of those trials are very hard to analyze, but generally are considered not showing significant mortality benefit to be a validity for screening use. With the updated 2021 US Preventative Services Task Force recommendation for lung cancer screening, most of our medical professional societies recommend lung cancer screening for those 50 to 80 year old individuals with a 20 pack year history of smoking or more. Having guidelines and recommendations is one thing, but reaching patients can be challenging. Generally, people talk about breast cancer screening at the soccer field. It's part of community discussions.There's public awareness.

In lung cancer screening there's much less awareness. It's the newer screening test on the block. So it's important that we in the community that firmly believe in lung cancer screening and run lung cancer screening programs reach out and educate not only our referring providers, but also educate the populations that we reach, which may include community health outreach and community engagement. It may mean going into churches and community organizations, reaching people where they live, where they worship, where they have day-to-day access such as the grocery store or the drug store with educational materials. Finding ways to educate the community is critically important. This year we're going to have National Lung Cancer Screening Day for the second year in a row in November, and it's an opportunity to use that as a way to educate in your communities and create media events to increase the visibility of this important lifesaving test.

We also recognize that the electronic health record can be sometimes helpful and sometimes not so helpful in identifying people who are eligible for lung cancer screening. We can certainly find age in the electronic health record, but finding pack years is pretty challenging, and somewhere under half of people who have smoked have pack years documented in the medical record. And even when they do, it can be a struggle. NCQA has kicked off the formation of a HEDIS measure for lung cancer screening, which will work with electronic health record vendors to make sure that EHRs are up to the task to be able to drive a HEDIS measure for lung cancer screening. This is important both structurally for practices that are trying to identify people through their EHRs who are eligible for screening, but also as we work towards a quality measure for lung cancer screening uptake, an important way to change practice.

In a discussion of any cancer screening test it's important to understand the risks and benefits. One that is often brought up in lung cancer screening is that we're using a CT scan, a little bit higher radiation dose than say a chest x-ray or a screening mammogram. It's important to take dose in context of lifelong morbidity and mortality of the individuals who we're screening for example, so individuals who have smoked cigarettes are at risk for many conditions including emphysema, cardiovascular disease including the coronary arteries, heart attacks in the future, and cerebrovascular disease and stroke. So we're screening a patient population that is at risk for many conditions which impact morbidity and mortality already. Lung cancer screening CTs are done with what we call low-dose compared to a typical chest CT done for other reasons. This is done to keep the dose as low as regionally appropriate, the ALARA principle, so that we use the least radiation dose for the task at hand.

This is possible on a CT of the chest compared to CTs of other parts of the body because essentially the lung is a little bit of tissue and a lot of air that you're breathing in and out with every breath, and we need less x-rays to get through that lung to create the picture for us to be able to find early lung cancers then say you would need if you were scanning through the middle of your abdomen or through your brain, through your skull into the brain. So we're able to keep radiation dose very low. We recognize that lung cancer screening is an annual test that could be performed from age 50 to 80, and the patients may also have tests performed in between to evaluate positive abnormalities or lung nodules that warrant further evaluation. So we do pay very careful attention to low radiation dose, which in the patient population where we're asking the question with competing morbidity and mortality concerns is appropriate for the task.

I will say there are considerably lower dose techniques under development. Sometimes we refer to those as ultra low-dose, but we can still create good enough pictures of the lung defined early lung cancer and answer the question with further dose reductions, and many practices are beginning to pursue those already. The successful implementation of lung cancer screening and enrolling eligible individuals and keeping them coming back for their annual screens and follow-up tests can't be separated from the stigma that is associated with cigarette smoking and disease, including lung cancer. Stigma is very real and it may be perpetrated not only in the community, in the public domain, but also in health systems by healthcare providers and staff who work in those systems, not intending to impart harm but doing so in the words that they may choose. It's cognizant to be aware of stigma because we know that stigma with respect to lung cancer care and lung cancer screening can prevent people from coming forward for lung cancer screening and can prevent them from sticking with the important lung cancer care that they need once they're diagnosed.

They may face the stigma at home, as I mentioned, but they may face the stigma by the words we choose. Simply the use of the word smoker as opposed to an individual who smoked is stigmatizing by describing a person by an addictive substance as opposed to describing them as an individual who has a smoking behavior. Stigma contributes to nihilism. In the community in general, we've found through serial behavioral and interviewing studies that people who are at high risk for lung cancer, the very people we're trying to reach, feel nihilism with respect to a lung cancer diagnosis. Sure, we can do a lung cancer screening CT and find it, but is it really going to save their lives? Is it worth coming for screening if they don't think there's any benefit to finding it? We're up against decades where lung cancer has been the leading cause of death in the United States, mostly found at an advanced stage. And when people hear the words lung cancer they think of something that's not curable.

They think of a high likelihood of somebody dying, and if they know anyone who's had lung cancer that has been the general experience. Recent changes in the way we can treat lung cancer at even an advanced stage is adding years of life and adding patients who are now survivors. It's important more than ever that our survivorship community in lung cancer is larger than ever through those advances in treatment and also through early detection such as lung cancer screening. Changing public perception about the disease is important. Recognizing people who are eligible for screening and can come in for that important screening test is important to find it early and once and for all to separate the nihilism of the past created by the lung cancer as we've known it, to the face of lung cancer in the future which is early detection and more treatable cancer.