Lung cancer screening requires intensive effort, incidental findings and inappropriate use common
In a clinical demonstration project at eight academic Veterans Health Administration hospitals, researchers looked at percentages of patients who agreed to undergo lung cancer screening, had positive findings on low-dose CT scans, were diagnosed with lung cancer, or had incidental findings.
Implementing a comprehensive lung cancer screening program requires significant clinical effort for as-yet uncertain patient benefit, a study found.
To describe organizational- and patient-level experiences with a lung cancer screening program, researchers created a clinical demonstration project at eight academic Veterans Health Administration (VHA) hospitals. The project provided an implementation guide and support, full-time lung cancer screening coordinators, electronic tools, tracking database, patient education materials, and radiologic and nodule follow-up guidelines.
Researchers looked at percentages of patients who agreed to undergo lung cancer screening, had positive findings on low-dose CT scans (nodules to be tracked or suspicious findings), were diagnosed with lung cancer, or had incidental findings.
The study results were published online Jan. 30 by JAMA Internal Medicine.
There were 93,033 primary care patients assessed. Of the 4,246 patients who met the criteria for lung cancer screening, 2,452 (57.7%) agreed to undergo screening and 2,106 (2,028 men and 78 women; mean age, 64.9 years) underwent screening. Wide variation in processes and patient experiences occurred among the eight sites, the researchers noted.
Of the 2,106 patients screened, 1,257 (59.7%) had nodules; 1,184 (56.2%) required tracking, 42 (2.0%) required further evaluation for findings that were not cancer, and 31 (1.5%) had lung cancer. Incidental findings such as emphysema, other pulmonary abnormalities, and coronary artery calcification were found in 857 patients (40.7%).
The researchers noted that nearly 900,000 people in a population of 6.7 million patients met the criteria for lung cancer screening. “Implementation of lung cancer screening in the VHA will likely lead to large numbers of patients eligible for lung cancer screening and will require substantial clinical effort for both patients and staff,” they concluded.
An editorial called the results “fascinating” due to the low uptake of screening (58%), high rate of incidental findings (41%), and low rate of detection, “and all for a highly resource-intensive program.”
For every 1,000 people screened, the editorial continued, 10 would be diagnosed with potentially curable early-stage lung cancer and five would be diagnosed with incurable, advanced-stage lung cancer. Twenty would undergo unnecessary invasive procedures of bronchoscopy and thoracotomy directly related to the screening, while 550 would experience unnecessary alarm and repeated CT scanning and associated radiation.
“Whether the benefits from this program outweigh the harms, and whether lung cancer screening is a wise investment of considerable resources required for screening and training, remains to be adequately evaluated with robust economic and utility analyses,” the editorial stated. “In the meantime, it is critically important to limit screening to the patients most likely to benefit, in a fully informed, shared-decision manner; it is essential to fully evaluate the potential benefits and known harms before proceeding with lung cancer screening.”
A research letter published in the same issue looked at the use of lung cancer screening in practice, using data from the 2010 and 2015 National Health Interview Survey (NHIS) Cancer Control Module (CCM) to create a study cohort of people 40 years or older. Researchers classified people as high-risk smokers (30 pack-years of smoking history and current smoking or quit date within the last 15 years), low-risk smokers (current or former smokers who did not meet the criteria for high-risk smoker), or never-smokers.
A total of 36,191 individuals told surveyors they had undergone CT for lung cancer screening and 36,209 individuals responded positively to a similar question for chest radiography. The percentage of individuals who received CT scans for lung cancer screening was more than 1.5 times higher in 2015 than in 2010 (2.1% vs. 1.3%; P<0.001). The use of chest radiography for lung cancer screening was not significantly different (2.7% in 2015 vs. 2.5% in 2010; P=0.22). Study authors reported a similar trend among many subgroups stratified by smoking or eligibility status.
The rate of CT scans significantly increased for never-smokers (1.2% vs. 0.8%; P=0.03), low-risk smokers (2.7% vs. 1.5%; P<0.001), and high-risk smokers (5.8% vs. 2.9%; P<0.001). In addition, there were significant increases in the rate of CT screening among high-risk smokers who did not meet the age eligibility criteria and those who met the age eligibility criteria but were not heavy smokers, the authors said. No significant trend in the use of CT was observed for individuals older than age 74 years.
The researchers noted that the increase in the use of CT among individuals who met the eligibility criteria of lung cancer screening was small, suggesting underuse for this established indication, while the increase among noneligible individuals and the continuing use of chest radiography were not in accordance with the latest research.
The editorial, which discussed both studies, agreed. “Analyzing data from the National Health Interview Survey, the authors indicate that many more never-smokers and low-risk smokers than high-risk smokers receive CT for lung cancer screening,” the editorial said. “Low-risk individuals have little or no chance to benefit from the LCS [lung cancer screening] they receive, while high-risk smokers might have a chance to benefit but are undergoing LCS in lower numbers.”