Screening that reduces cancer mortality serves as a foundational element of impactful care for certain cancers. That said, harms related to screening deserve our attention—overdiagnoses; diagnostic odysseys that may be invasive, expensive, or even unintentionally harmful; overtreatment of diagnosed cases that may never have harmed the individual; and diagnoses of patients who die with, rather than of, a cancer that never merited attention, much less intervention. However, an article by Mulshine et al (reported in the Annals of the American Thoracic Society and summarized in this issue of The ASCO Post) reminds us that cancer screening may also lead to potential benefits from the early identification of ancillary diagnoses not linked to the screened cancer per se.1 For example, lung cancer screening may identify other health threats that benefit from earlier, presymptomatic detection.
Potential Benefits
The authors noted two large trials of lung cancer screening—I-ELCAP (International Early Lung Cancer Action Program)2 and NLST (National Lung Screening Trial3)—involving individuals at high risk for lung cancer because of a combination of age and a substantial and recent history of tobacco use (ie, current or former smoker). In these studies, a diagnosis of emphysema was made in 23.8% and 31% of participants in I-ELCAP and NLST, respectively, with the vast majority, 76.5% and 82%, having had no recorded history of that condition. Thus, lung cancer screening frequently promoted a new diagnosis of emphysema in those with no prior clinical diagnosis or apparent awareness of the disease.
The report also proposed a compendium of potential benefits that may result from such an early diagnosis. Of note, the authors theorized that participants and their physicians may be personally and impactfully motivated in any number of ways to change their behavior by taking the following steps:
1) Undergoing tobacco cessation treatment
2) Seeking more sensitive and specific quantitation of tobacco’s adverse impact on lung function
3) Pursuing nonpharmacologic interventions to mitigate or delay common respiratory symptoms through improved exercise or respiratory conditioning
4) Considering preventive vaccines or earlier treatment of respiratory infections to reduce their likelihood and severity
5) Adhering to the future lung cancer screening schedule with greater fidelity.
Challenges Linked to Tobacco Exposure
I concur with the assessments of Mulshine et al regarding the wide range of potential benefits of lung cancer screening for patients diagnosed with presymptomatic emphysema; however, proving that they result in actual patient benefits through careful study will be important. Although there are numerous approaches to help patients deal with the onerous symptoms of advanced emphysema—shortness of breath, mucus-producing cough, wheezing, chest tightness—this life-threatening respiratory illness is most often caused by tobacco exposure.
As such, the most impactful treatment of presymptomatic emphysema would be to eliminate continued exposure to tobacco. Would such a diagnosis motivate smokers to quit tobacco use with greater commitment and success? Would it motivate providers to prioritize the treatment of nicotine addiction as more of a critical, life-threatening disease entirely worthy of their time, attention, and commitment, rather than see it as a patient’s self-imposed “bad habit” that is futile to address?
“Lung cancer screening may identify other health threats that benefit from earlier, presymptomatic detection.”— Ernest Hawk, MD, MPH
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Helping individuals to recognize and overcome their addiction to nicotine is extremely challenging despite a plethora of evidence-based interventions, clinical guidelines, and the growing availability of certified tobacco-treatment specialists. Although data suggest that most smokers desire to stop smoking, their attempts to quit are so commonly unsuccessful that a nicotine addiction is now most commonly and accurately characterized as a chronic, relapsing condition; thus, in essence, this underscores a smoker’s frequent inability to quit when and as intended.
And, currently, we do a poor job of convincing smokers of the critical importance of quitting smoking. For example, success rates of self-quit attempts typically average less than 5%, national quitline services report quit rates of up to 29%, and most smokers require multiple quit attempts before succeeding. Data suggest that physicians may unintentionally contribute to poor rates of success through the following factors:
1) Their frustration with patients harboring respiratory disease who continue to smoke, possibly diminishing physicians’ enthusiasm for the delivery of evidence-based treatment
2) Their limited knowledge of and negative thoughts about cessation treatments
3) Money/time issues and failure to view, much less prioritize, tobacco (or more specifically, nicotine) addiction as a disease.4
How Can Clinicians Do Better?
We can do much better, and there’s clearly an urgent and important need to do so; early identification of emphysema by lung cancer screening may present a critical stimulus to succeed. Presymptomatic emphysema, if more commonly identified and diagnosed, may stimulate more health-care professionals and smokers to urgently initiate and more enthusiastically commit to successful tobacco cessation. In this way, they would realize its profound benefits to reduce the risk of emphysema progression, lung cancer, and a host of other substantial health risks that result from tobacco, including serious cardiovascular events.
Here is one example of how we can do better. Rather than accept success rates of 5% to 10% for a given self-quit attempt, Cinciripini et al combined nicotine replacement therapy with intentional motivational training and behavioral counseling to create a cessation program. It was remarkably effective for smokers with cancer—9-month cessation rates averaged 44% across a cohort of patients with a variety of cancer diagnoses.5 In 2017, such reports prompted the National Cancer Institute to fund the development and replication of dedicated tobacco treatment programs in many of our nation’s cancer centers.
Motivating Others to Support Smoking Cessation
In addition to the many questions framed around how to motivate individuals and providers in lung cancer screening programs, other important questions relate to the ability of presymptomatic emphysema diagnoses identified through lung cancer screening to motivate smokers’ family and friends to assist and support those smokers to successfully quit tobacco and reduce or eliminate their nicotine dependence. In a 2021 report, a validated lung cancer natural-history model showed that adding a one-time tobacco cessation intervention with only 15% effectiveness to lung cancer screening would increase life-years to a level equivalent to screening 100% (vs 30%) of the population.6 Such data highlight the potential population-level impact of greater attention to tobacco cessation. These and other lung cancer screening data might also convince governmental policymakers and commercial insurers to prioritize tobacco cessation treatment more consistently and substantively. This would not only improve participants’ health and wellness, but it would also address the dramatically destructive effects related to smoking far beyond emphysema or lung cancer alone. However, first, we must demonstrate these potential benefits are achievable in the real world, rather than only in theory or in a modeled virtual space.
Cautious Optimism
We should proceed with enthusiasm but also with caution. Identifying subclinical and presymptomatic stages of a disease should not necessarily label individuals as ill, nor prompt the immediate delivery of a treatment in advance of the signs or symptoms of disease. However, subclinical and presymptomatic signs of disease should also not be clinically ignored. Most often, they should be considered as sentry signals, indicating a disease process has begun, which may merit patients’ and providers’ attention to further prioritize actions that are likely, if not proven, to slow or halt disease progression while also maximizing those actions’ safe delivery. For individuals diagnosed with presymptomatic emphysema, tobacco treatment clearly serves as an ideal example of an intervention that portends exceptional benefits and essentially no harms; therefore, it should be vigorously pursued.
Cancer screening tests, such as low-dose computed tomography for lung cancer, may result in unintended harms as well as benefits. Early identification and treatment of presymptomatic emphysema identified through lung cancer screening should strongly and urgently emphasize tobacco treatment with a goal of cessation. I anticipate that future research will demonstrate the ability of lung cancer screening to motivate providers, patients, caregivers, insurers, and others to more quickly, effectively, and efficiently prompt reconsideration and prioritization of tobacco cessation as an essential component of high-quality medical care. Hopefully, the realized benefits of that choice will additionally prompt broader attention and investment by the public and providers in other areas of cancer prevention, risk reduction, and early detection—which promise so much to our vision of improving cancer risks, care, and outcomes at the population level.
DISCLOSURE: Dr. Hawk reported employment by The University of Texas MD Anderson Cancer Center; has received grant support from the National Cancer Institute and Cancer Prevention and Research Institute of Texas; has received salary support from the Boone Pickens Distinguished Chair for Early Prevention of Cancer; and has received honoraria from service on the Project ECHO Cancer Advisory Board as well as the External Scientific Advisory Boards of several NCI-designated cancer centers.
REFERENCES
1. Mulshine JL, Aldigé CR, Ambrose LF, et al: Emphysema detection in the course of lung cancer screening: Optimizing a rare opportunity to impact population health. Ann Am Thorac Soc 20:499-503, 2023.
2. Steiger D, Siddiqi MF, Yip R, et al: The importance of low-dose CT screening to identify emphysema in asymptomatic participants with and without a prior diagnosis of COPD. Clin Imaging 78:136-141, 2021.
3. Pinsky PF, Lynch DA, Gierada DS: Incidental findings on low-dose CT scan lung cancer screenings and deaths from respiratory diseases. Chest 161:1092-1100, 2022.
4. van Eerd EAM, Risør MB, Spigt M, et al: Why do physicians lack engagement with smoking cessation treatment in their COPD patients? A multinational qualitative study. NPJ Prim Care Respir Med 27:41, 2017.
5. Cinciripini PM, Karam-Hage M, Kypriotakis G, et al: Association of a comprehensive smoking cessation program with smoking abstinence among patients with cancer. JAMA Netw Open 2:e1912251, 2019.
6. Meza R, Cao P, Jeon J, et al: Impact of joint lung cancer screening and cessation interventions under the new recommendations of the U.S. Preventive Services Task Force. J Thorac Oncol 17:160-166, 2022.
Acknowledgment: Dr. Hawk extends his appreciation for editorial assistance provided by Stephanie Martch.
Dr. Hawk is Vice President and Head of the Division of Cancer Prevention and Population Sciences at The University of Texas MD Anderson Cancer Center, Houston.
