June 22, 2020, 12:43 pm News Staff – Nine years ago, the New England Journal of Medicine published the results of the National Lung Screening Trial, which found that screening for lung cancer with low-dose CT reduced lung cancer-specific mortality rates by 20% in individuals at increased risk for the disease.
Over time, many professional health organizations, including the U.S. Preventive Services Task Force, have recommended lung cancer screening with low-dose CT as the standard of care in high-risk individuals based on factors such as age and smoking history.
The AAFP, however, has expressed concerns about the generalizability of the paper's findings in the community setting and, in 2013, concluded that there was not enough evidence to recommend for or against screening those at high risk using this modality.
To address these concerns, a team of researchers in Oregon analyzed more than 6,000 lung cancer screenings performed at a large community health system. The team's findings, published in the May/June issue of Annals of Family Medicine, suggest that under the right conditions, LCS can be performed safely and successfully in a community health care setting, yielding similar diagnosis, intervention and adverse event rates as those seen in the NLST.
The study population consisted of 3,402 patients seen at a multifacility community health system in and around Portland, Ore. Data was collected prospectively over 62 months -- from November 2013 through December 2018 -- and retrospectively analyzed.
Screening was initially performed using NLST eligibility criteria (age 55-74, a history of cigarette smoking of at least 30 pack-years and, if a former smoker, having quit within the past 15 years, no diagnosis of lung cancer, no chest CT in the 18 months preceding enrollment, no hemoptysis, no unexplained weight loss of more than 6.8 kg (15 lb) in the preceding year) and after February 2015, using CMS' eligibility criteria (age 55-77, at least 30 pack-years smoking, smoking cessation within less than 15 years, no cancer symptoms, no concomitant life-threatening illness, medically fit and willing to undergo additional indicated medical management and future LCS).
All patients were screened for lung cancer at baseline, and some patients received as many as seven additional screenings over the study period. Altogether, 6,161 screenings were performed and analyzed.
Five hundred patients in the study population had a result that required further investigation. In most instances, these patients underwent chest CT scan, X-ray, positron emission tomography or ultrasonography.
A total of 176 patients required invasive interventions, with some patients requiring multiple interventions. Although bronchoscopy was the most commonly performed invasive diagnostic procedure, 81 patients underwent surgery, most for a thoracic or extrathoracic malignancy.
A total of 111 malignancies were diagnosed, including 95 lung cancers. Forty-nine percent of lung cancers were detected on initial screening. The most common lung cancer detected was early stage non-small cell cancer, and surgical resection was the preferred treatment.
Twenty-one patients experienced a procedure-related adverse event, including two postsurgical deaths. The most common adverse event, pneumothorax, occurred in 10 patients, six of whom subsequently required a chest tube.
The study authors reported that several data measurements (e.g., true positive or lung cancer diagnosis, intervention frequency, procedure rate, procedure-related adverse event rate and 30-day or surgery-admission mortality) were similar to those observed in the NLST study, as well as those seen in a 2017 study on LCS implementation that was conducted within the Veterans Health Administration.
As with the NLST, the study authors admitted that their results may not be easily generalizable. They noted that the thoracic oncology program involved in the study was staffed by several well-known chest specialists as well as a full-time LCS coordinator, which allowed for a clinical followup rate greater than 99%.
"Without these, we could not have effectively followed and maintained timely interventions or provided thorough results tracking," the authors wrote. "Lack of availability of such resources could be a major limiting factor in the success of an LCS program."
The authors of an accompanying editorial stated that "family medicine has a critical role in increasing the reach of LCS." The specialty, they noted, has led the way in educating patients on smoking cessation and prevention strategies, and the team-based approach found in primary care could serve as "an ideal setting to improve access to LCS," particularly for underserved populations.
The authors also noted, however, that barriers preclude the uptake and delivery of LCS services, and a planned approach is needed to ensure patients receive the optimal benefits of screening. "There is no place like family medicine to realize the ideals of lung cancer control," they wrote, "but the engagement of primary care clinicians and support from payers and funding agencies are needed to catalyze the adoption of LCS."
Chyke Doubeni, M.B.B.S., M.P.H., director of the Center for Health Equity and Community Engagement Research and a senior associate consultant and professor in the Department of Family Medicine at the Mayo Clinic in Rochester, Minn., co-authored the editorial. He told AAFP News that the study highlighted the effectiveness of a collaborative approach, with primary care physicians heavily involved in ensuring patients get the care they need.
"The study showed that community-based primary care physicians do very well on performing or managing the LCS process in collaboration with subspecialty teams," Doubeni said. "In this study, they were able to achieve comparable outcomes as the clinical trials. This is a really exciting study and we need more studies like this to demonstrate family physicians' abilities in managing complex care processes and achieve similar outcomes as major clinical trials."
Overall, Doubeni thought family physicians should be encouraged about the findings.
"The results are important because they raise hope in our ability to safely make the series of interventions involved in LCS available to all eligible patients in our practices and improve health for all Americans, most of whom receive care in family medicine practices."
Doubeni noted that he shared the Academy's concerns about applying the results of clinical trials without considering differences in the quality and interpretation of low-dose CT scans and the quality of treatment available to patients.
"Although the evidence base for LCS has expanded, that concern remains valid," Doubeni said. "In communities without the type of subspecialty expertise to manage patients with abnormal low-dose CT scans, avoidable differences in the care received can unfavorably tip the balance of harms and benefits.
"What that means for me is that we should provide every community access to the resources and expertise needed for each eligible person to realize the full benefit for screening for this devastating cancer irrespective of socioeconomic status."
Doubeni also noted that the USPSTF already recommends LCS for certain individuals at increased risk, which makes it imperative for family physicians to work with clinicians in other specialties to manage their patients' care.
"Family physicians know their patients best and are well-placed to assess their eligibility for LCS, provide smoking cessation counseling, provide shared decision-making, and order screening for those who meet criteria and are healthy enough to undergo treatment if positive," said Doubeni. "It is important to identify subspecialists with the expertise to medically and surgically manage abnormal scans to reduce false-positives and achieve a low surgical mortality rate."
Finally, Doubeni emphasized that although he is a member of the USPSTF, he was responding as an individual family physician and not as a member of the task force.
Sarah Coles, M.D., of Phoenix, a member of the AAFP's Commission on Health of the Public and Science, focused on how the study's findings translated to family physicians working in the community.
"While interesting, this study does not put to rest the debate about LCS in community primary care settings," she told AAFP News. "This study aimed to support that the NLST was indeed generalizable to the community setting. However, there are multiple concerns that draw that conclusion into question."
Coles noted that the Annals study was conducted in a large integrated health system in which patients had access to highly specialized care. Suspicious findings on imaging were reviewed by a multidisciplinary team that included specialists in surgery, pulmonology, oncology, radiology and pathology, who then provided recommendations to referring primary care physicians. She also pointed to that fact that, as the authors themselves noted, the LCS program had a full-time coordinator who assisted with tracking results and patient follow-up.
"It is unlikely that many community sites would have access to these extensive resources and may have different results in that more representative setting," Coles said. "Additionally, the study lacked diversity, does not report how many patients declined screening (and does not) provide long-term outcomes."
To Coles, the take-home message was clear: More research is necessary.
"Studies should be conducted through a primary care lens and should also consider how screening, follow-up and management are implemented in routine primary care," she stated.
Coles also said the results will not change her personal approach to screening.
"This study is another piece in the puzzle as we evaluate the safety and efficacy of low-dose (CT) LCS in higher risk populations. In my opinion, however, it alone does not alter my practice," said Coles. "I will continue to participate in shared decision-making with my patients regarding LCS, with a thorough discussion of risks, including overdiagnosis, need for repeat imaging or invasive diagnostic procedures, incidental findings, false positives and additional radiation exposure. These risks must be weighed against the potential benefits as well as the patient's values and goals."
Noting that the USPSTF is in the process of updating its recommendation, Coles said the Commission on Health of the Public and Science will review the task force's recommendation, once finalized, as well as its supporting evidence.
Specifically, she explained, "The commission will evaluate strengths and weaknesses of the evidence, potential benefits and harms of screening, and the impact on health equity. The commission may also seek input from the Science Advisory Panel, an advisory work group consisting of family physicians with expertise in evidence review, research and methodology.
"Based on best available evidence, the commission then recommends to the AAFP Board of Directors (whether) to continue or amend the AAFP recommendation on LCS. If the Board agrees, the AAFP will update its recommendation on the website and provide members a clear explanation of their rationale.
"It is key to look at the body of evidence as a whole to avoid bias and guide recommendations on the best available evidence," Coles concluded.