Catching America's Top Cancer Killer
May 27, 2021
Image by Natalia Saltybaeva, et al licensed under CC BY 4.0
Lung cancer kills more Americans every year than breast, colon and prostate cancers combined. A screening test could prevent tens of thousands of those deaths, but it presents complex risks and barriers.
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The Basics: Lung Cancer and Early Detection
Although lung cancer mortality has improved as smoking has steadily declined and treatments have advanced, the disease still kills more than 130,000 people in the U.S. every year. One big reason lung cancer has remained so lethal is that more than 75% of cases are diagnosed after the disease has spread, when survival rates are much lower.
For decades, while other cancers were being caught early with tests like mammograms and colonoscopies, lung cancer lacked an equivalent early detection tool. That changed in 2011, when a massive 53,000-patient randomized controlled trial confirmed that screening patients with a type of chest imaging known as a low-dose CT scan reduced lung cancer mortality by 20% compared to screening patients with a standard chest X-ray. The trial, known as the National Lung Screening Trial (NLST), also highlighted screening’s risks including false positives and clinical complications.
In 2013, the United States Preventive Services Task Force (USPSTF) officially recommended annual CT lung scans as a no-cost preventive service for people between 55 and 80 years old with a history of heavy smoking. Medicare adopted similar coverage criteria in 2015.
In March 2021, the USPSTF recommended expanding screening to people over 50 and those with shorter smoking histories. The changes nearly double the number of people eligible from about 8 to 15 million. Medicare is still deciding whether to cover the newly eligible, and Medicaid coverage varies by state.
The Risks of Lung Cancer Screening
While the upside of screening sounds simple — reducing lung cancer deaths by 20% — it is complicated by an array of risks and unknowns that accompany the test.
Medicare had enough concerns about those risks that they added unprecedented guardrails to their 2015 decision to cover lung cancer screening. Those guardrails included requiring that providers document proof of a “shared decision making” conversation with patients about the test’s risks and benefits, and that every scan be submitted to a national registry for safety and quality monitoring.
The major risks of lung cancer screening fall largely into the following five buckets. Some remain more speculative than others because Medicare has only covered lung cancer screening for five years and outcomes data are still being gathered and analyzed.
False Positives
In the NLST, the large screening study, about 1 in 4 patients had a positive scan. But just 4% of positive scans turned out to be lung cancer — the other 96% were false alarms caused by benign spots like scar tissue.
Complications
The process of confirming whether a suspicious finding is cancerous can require invasive procedures that come with increased risk, especially in older and sicker patients. Of those NLST patients with a false-positive scan, nearly 1 in 10 suffered a complication from an invasive follow-up procedure.
Overdiagnosis
Some cancers found through screening are unlikely to actually harm people, leading to unnecessary and expensive treatments. Science's understanding of which cancers can be safely left alone is rapidly evolving so estimates of so-called overdiagnosed lung cancers vary widely, from 3% to 67%.
Quality Concerns
Other studies raise questions about whether all hospitals and clinics, especially those with fewer resources and specialists, are able to screen, diagnose and treat patients at the same level of quality seen in the NLST. For example, one study found a nearly 25% complication rate among community providers performing the invasive procedures needed to confirm a lung cancer diagnosis.
Risk Assessment Challenges
Even among people who meet screening criteria, the test's risks and benefits vary widely based on individualized factors, like smoking history and comorbidities, that can be hard for providers and patients to assess. Doctors under pressure for time or revenue could refer patients more likely to be harmed than helped by the test.
Bonus Audio! Balancing the Risks and Benefits
Studies show providers struggle to effectively communicate the risks of medical interventions and sometimes omit them altogether. Click the audio player to hear a screening decision-making conversation we recorded between Memorial Sloan Kettering adult nurse practitioner Lisa Carter-Harris and a patient.
Some providers use interactive tools or visuals like the one below to help patients understand the risks and benefits of screening. The particular graphic seen here, published in Interpreting Health Benefits and Risks by Andy Lazris and Erik Rifkin, illustrates for every 1,000 people scanned, the expected number of lung cancer deaths prevented (3.5) vs. false-positives found (233).
Screening Barriers and Solutions
1) Access to Care
In general, lung cancer screening poses more barriers than other cancer screens, for example, because it must be done yearly and with a high-tech CT scanner. Lung cancer screening is also one of very few cancer screening tests to target people with a certain behavior (smoking) as opposed to just their age and/or gender.
Smoking, which causes between 80 and 90% of lung cancers, is much more common among society’s most vulnerable groups, including those with less education, less income and less health insurance.
¹Original analysis of 2015 National Health and Information Survey data based on 2013 USPSTF screening criteria done for Tradeoffs by Rafael Meza, PhD. ²Current Cigarette Smoking Among Adults in the United States, CDC.
These social inequities combine to make accessing health care burdensome, especially for a preventive test that may not seem urgent and could lead to expensive follow-up testing and treatment. Researchers have also identified racial and geographic disparities in who receives lung cancer screening.
Solutions:
Because so many people who smoke are uninsured, expanding insurance coverage to those populations would likely improve access to screening (and cancer outcomes overall). Medicaid coverage of screening could also be made more consistent across states.
Some health systems are piloting ways to make cancer screening more accessible for patients that do not have regular access to primary care or the time to return for multiple visits. For example, the screening program at Temple University Hospital uses a one-stop shop model, where patients get screened, receive their results, and schedule any necessary follow-up scans or procedures in a single visit.
2) Stigma and Lack of Awareness
Estimates vary, but multiple studies have found just roughly half of primary care providers are aware of the USPSTF lung screening guidelines. Surveys of eligible patients have also found between 38% and 59% are unaware of screening. Some of that lack of awareness is likely due to the newness of the test and its more complex eligibility criteria related to smoking history.
Experts also believe a related challenge is the unique stigma that surrounds lung cancer. Research shows that fear of being stigmatized by medical professionals leads patients who smoke to delay care for lung cancer symptoms. Advocacy groups say societal stigma around lung cancer has also made it harder to recruit corporate partners, secure celebrity endorsements and generally raise awareness about screening on a national level.
Solutions:
Researchers are testing a range of interventions, from simple print-out reminders for providers to YouTube videos for patients, to improve awareness of lung cancer screening. The National Lung Cancer Roundtable, a public-private coalition convened by the American Cancer Society, hosted its first national summit on lung cancer stigma in 2020.
Tradeoffs
In addition to the risk-benefit tradeoffs that come with every individual patient’s screening decision, there are larger tradeoffs for various health care stakeholders.
Policymakers
Federal and state policymakers must decide how to divvy up limited dollars among different kinds of cancers and different strategies to decrease deaths from those cancers, including prevention, screening and treatment. When it comes to lung cancer in particular, tobacco control policies and programs are an outsized priority.
Public Payers
State Medicaid agencies and Medicare are still deciding whether to follow the USPSTF and expand coverage of screenings for more people while facing stretched budgets. One 2015 estimate projected lung cancer screening would cost Medicare nearly $7 billion over five years, but cost-effectiveness analyses vary widely depending on eligibility criteria, uptake and implementation.
Providers
Hospitals must also decide whether to dedicate limited resources to establishing a screening program, and individual primary care providers must decide if and how a nuanced discussion of screening's benefits and risks fits into their often packed patient visits.
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Episode Resources
Research and Reporting on Lung Cancer Screening:
Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement (US Preventive Services Task Force; JAMA; 3/9/2021)
Yearly Lung Cancer Scans Are Advised for People 50 and Over With Shorter Smoking Histories (Denise Grady, New York Times, 3/9/2021)
Screening for Lung Cancer With Low-Dose Computed Tomography: Updated Evidence Report and Systematic Review (Daniel E. Jonas, Daniel S. Reuland, Shivani M. Reddy, et al; JAMA; 3/9/2021)
Evaluation of the Benefits and Harms of Lung Cancer Screening With Low-Dose Computed Tomography: Modeling Study for the US Preventive Services Task Force (Rafael Meza, Jihyoun Jeon, Iakovos Toumazis, et al; JAMA; 3/9/2021)
Addressing Disparities in Lung Cancer Screening Eligibility and Healthcare Access (M. Patricia Rivera, Hormuzd A. Katki, Nichole T. Tanner, et al; American Journal of Respiratory and Critical Care Medicine; 10/1/2020)
What happens when the doctor blames you for your own cancer? (Monica Bhargava, Washington Post, 1/11/2019)
Implementation of Lung Cancer Screening in the Veterans Health Administration (Linda S. Kinsinger, Charles Anderson, Jane Kim, et al; JAMA Internal Medicine; 1/30/2017)
On Medicare and Assessing the Value of Lung Cancer Screening (Paula Span, New York Times, 5/8/2015)
Why Some Doctors Hesitate To Screen Smokers For Lung Cancer (Anders Kelto, NPR, 4/13/2015)
Cost-Effectiveness of CT Screening in the National Lung Screening Trial (William C. Black, Ilana F. Gareen, Samir S. Soneji, et al; New England Journal of Medicine; 11/6/2014)
Reduced Lung-Cancer Mortality with Low-Dose Computed Tomographic Screening (The National Lung Screening Trial Research Team, New England Journal of Medicine, 8/4/2011)
Principles of Cancer Screening: Lessons from History and Study Design Issues (Jennifer M. Croswell, David F. Ransohoff and Barnett S. Kramer; Seminars in Oncology; 6/2010)
Episode Credits
Guests:
Otis Brawley, MD, Professor of Oncology, Johns Hopkins University School of Medicine
Lisa Carter-Harris, PhD, APRN, Behavioral Scientist and Adult Nurse Practitioner, Memorial Sloan Kettering Cancer Center
Cherie Erkmen, MD, Professor of Thoracic Surgery and Director, Lung Cancer Screening Program, Temple University
Ella Kazerooni, MD, Professor of Radiology, University of Michigan
Ida Pittman, lung cancer patient, Temple University Hospital
Helena Price, Ida’s cousin and health care advocate
Gerard Silvestri, MD, Professor of Pulmonology, Medical University of South Carolina
The Tradeoffs theme song was composed by Ty Citerman, with additional music this episode by Blue Dot Sessions and Epidemic Sound.
This episode was produced by Leslie Walker and mixed by Andrew Parrella.
Special thanks to Rafael Meza, Stacey Fedewa and Adam Yoffe.
Additional thanks to:
Laurie Fenton, Emily Eyres, Kristine Chin, Paul Pinsky, Efren Flores, Samir Soneji, Steven Woloshin, Dusty Donaldson, Tina Shih, Evan Walker and our stellar staff!