Lung Cancer Screening: Challenges and Opportunities

Lung cancer remains the leading cause of cancer death in the United States, with more than half of all cases (57 percent) being diagnosed at a late stage with an average five-year survival rate of 22.6 percent^1. However, there are signs of progress, with the rate of new cases going down 9 percent nationally and an increase in the five-year survival rate by 13.1 percent over the past five years². This is likely due to reduced smoking rates, increased radon testing, more stringent air pollution regulations, and improvements in treatment¹. However, the implementation of lung cancer screening to detect the deadly disease at an earlier stage has undoubtedly played a role in these gains, as well.

In 2011, the National Lung Screening Trial reported a 20-percent relative reduction in lung cancer amongst adults who smoked heavily and received low-dose CT (LDCT) annual screening compared to those who received annual chest radiographs². Based on this evidence, the United States Preventive Services Task Force recommended annual lung cancer screening (LCS) with LDCT for high-risk adults (defined as 55-to-80-year-old persons who have a 30-plus pack year smoking history and quit less than 15 years ago).

Insurance companies and Medicare/Medicaid began to cover LCS in 2014-2015. Despite these guidelines and financial reimbursement, patient and physician uptake to the guideline has been slow. Less than 4 percent of eligible adults received screenings in 2015, and that figure had a marginal increase to 5.7 percent in 2020². However even with the lagging adoption, early diagnosis rates have increased 33 percent over the past five years². Of all cases, 23 percent are caught at an early stage, which has a much higher five-year survival rate at 59 percent².

Why have the rates for LCS with LDCT remained low? There are many potential factors at play, such as healthcare providers not collecting a sufficiently detailed smoking history to identify eligible patients, smokers being a demographic with a predisposition to have less contact with primary care providers (PCP), PCPs not recommending screening due to lack of time and other priorities, lack of insurance incentivization, high rate of false positives on LDCT, perhaps even the perception that smoking is a lifestyle choice and that resources should not be spent on this population.

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As for the argument of the unacceptable number of false positives, there is, indeed, a 20-percent rate of over-diagnosis of lung cancer, which is consistent with the rate of over-diagnosis in breast cancer³. However, it also prevents one death for every 250 screens, which far exceeds the number needed to treat (NNT) of 2,000 for screening mammography⁴. According to one meta-analysis of annual LCS with LDCT, all-cause mortality was not reduced in a significant manner, which is reassuring that the increased amount of screening and over-diagnosis of lung cancer did not increase other causes of mortality⁵.

What can we do to increase adherence to this useful screening tool? Many possible obstacles can be targeted, such as using clinical navigators to assist patients in following up appropriately, implementing algorithms to better identify eligible patients by using existing electronic health care data. There are two reports that attempted to increase it in two different manners, one more clinically, one involving more of the community.

In the first scenario, within the Kaiser Northern California system, they implemented a reporting system in 2015 that standardized radiology reports of pulmonary findings with tags. Tags that were indicative of lung cancer were automatically forwarded to a coordinator who sent a list of cases to a triage physician. The physician, then, either sent the case to a multidisciplinary committee or the patient's primary care physician (PCP) with management recommendations.

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The committee was composed of a care coordinator, pulmonologist, thoracic surgeon, and often a radiologist and oncologist, and the group met weekly to discuss cases. They would, then, either manage the case or send recommendations to the PCP. From the data that was collected pre- and post-implementation from nearly 100,000 patients, they found that lung cancer was detected at the early stage 26 percent of the time pre-intervention, and 30 percent of the time post-intervention.

The intervention was associated with a 24-percent increase in odds of early-stage lung cancer diagnosis within 120 days, with a quicker time to surgical intervention (46 days vs 41 days) without biopsies. It appears that standardization of the radiologic reporting coupled with the multi-disciplinary committee increased the rate of detection of early-stage cancer which ultimately leads to improved long-term outcomes³.

The other instance is the state Kentucky which has one of the highest LCS rates in the country. Kentucky has expanded the Medicaid program, which removes the need for preauthorization for LCS. The government supports the cause with the governor publicly committing to reduce lung cancer mortality. In 2013, the Kentucky Lung Cancer Education Awareness Detection Survivorship Collaborative was created and implemented two LCS projects.

The first one educated hundreds of PCPs on lung cancer prevention, early detection, treatment, and survivorship. The second project gave feedback to LCS programs on how to best deliver screening and engage healthcare providers. Due to this combined effort from the community with government support, Kentucky has the third highest screening rate in the nation, leading to more lung cancer survivors. They have provided a framework for other states with high lung cancer burdens to follow².

As evidence continues to grow that LDCT is an effective tool at increasing lung cancer survivorship – and awareness increases amongst the public – LCS rates will likely increase in the following years. However, there is still much work to be done to achieve the rates that would benefit the most vulnerable populations.

As demonstrated by these two cases, there are issues that can be improved at every level of the system – educating patients about the benefits of annual LDCT, promoting the value of LCS to PCPs, standardization of lung cancer findings and templates within an electronic medical record, improved coordination of care, and further research into how to refine screening populations and screening modalities. With widespread adoption by healthcare providers, this intervention will surely improve both the longevity and quality-of-life for increased numbers of at-risk individuals who receive the diagnosis of lung cancer.

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References:

1. State of Lung Cancer 2020 Report (Rep.). (2020, November 17). Retrieved https://www.lung.org/getmedia/381ca407-a4e9-4069-b24b-195811f29a00/solc-2020-report-final.pdf

2. Stacey A Fedewa, PhD, Ella A Kazerooni, MD, MS, Jamie L Studts, PhD, Robert A Smith, PhD, Priti Bandi, PhD, Ann Goding Sauer, MSPH, Megan Cotter, MPH, Helmneh M Sineshaw, MD, MPH, Ahmedin Jemal, DVM, PhD, Gerard A Silvestri, MD, MS, State Variation in Low-Dose Computed Tomography Scanning for Lung Cancer Screening in the United States, JNCI: Journal of the National Cancer Institute, 2020;, djaa170, https://doi.org/10.1093/jnci/djaa170

3. Urbania, T. H., Dusendang, J. R., Herrinton, L. J., Alexeeff, S., Corley, D. A., Ely, S., . . . Sakoda, L. C. (2020). Standardized reporting and management of suspicious findings on chest ct imaging is associated with improved lung cancer diagnosis in an observational study. Chest, 158(5), 2211-2220. doi:10.1016/j.chest.2020.05.595

4. Gøtzsche, P. C., & Nielsen, M. (2006). Screening for breast cancer with mammography. The Cochrane database of systematic reviews, (4), CD001877. https://doi.org/10.1002/14651858.CD001877.pub2

5. Ebell, M. H., Bentivegna, M., & Hulme, C. (2020). Cancer-Specific mortality, all-cause mortality, and overdiagnosis in lung cancer Screening Trials: A meta-analysis. The Annals of Family Medicine, 18(6), 545-552. doi:10.1370/afm.2582