Lung cancer screening not being well utilized
Two new studies published in JAMA Internal Medicine found a lack of understanding in appropriate use of lung cancer screening, with one study showing that there was a lack of uptake of lung cancer screening programs despite their established effectiveness, while another study found underuse of effective screening tools and an overuse of CT scans.
“The results of the National Lung Screening Trial (NLST), which found a reduction in mortality from lung cancer of three deaths per 1,000 high-risk individuals screened led to a 2013 U.S. Preventive Services Task Force (USPSTF) recommendation in favor of implementing lung cancer screening with low-dose computed tomography,” Linda S. Kinsinger, MD, MPH, from the Veterans Health Administration National Center for Health Promotion and Disease Prevention, and colleagues wrote. “A process studied in a clinical trial setting, however, may not be directly transferable to real world clinical practice.”
Implementing lung cancer screening in VHA facilities
In Veterans Health Administration (VHA) facilities, implementation of a comprehensive lung cancer screening program required significant clinical effort, yet achieved low uptake and a low rate of lung cancer detection, Kinsinger and colleagues found.
“The [USPSTF] recommends annual lung cancer screening with low-dose computed tomography for current and former heavy smokers aged 55 to 80 years,” they wrote. “There is little published experience regarding implementing this recommendation in clinical practice.”
The researchers conducted a clinical Lung Cancer Screening Demonstration Project (LCSDP) at eight geographically diverse academic VHA hospitals to evaluate organizational- and patient-level experiences with a lung cancer screening program and to determine the number of VHA patients eligible for lung cancer screening. They assessed 93,033 primary care patients and identified 4,246 patients who met criteria for lung cancer screening. Of these 2,106 (2,028 men and 78 women; mean age, 64.9 years) underwent lung cancer screening between Jul. 1, 2013 and Jun. 30, 2015.
Across the study sites, there was a wide variation in processes and patient experiences. A total of 1,257 (59.7%) screened patients had nodules, of whom 1,184 (56.2%) required tracking. Another 42 (2%) required further evaluation but ultimately cancer was not found and 31 (1.5%) had lung cancer. The researchers found that 857 patients (40.7%) had scans that demonstrated a variety of incidental findings such as emphysema, other pulmonary abnormalities and coronary artery calcification.
“The VHA LCSDP found implementing a comprehensive [lung cancer screening] program that followed recommendations to be challenging and complex, requiring new tools and patient care processes for staff as well as dedicated patient coordination,” Kinsinger and colleagues concluded.
“These results will help the VHA plan for broader implementation of such a program across its health care system and may help other groups considering such screening programs to better understand the multiple components involved and the initial clinical effect on patients,” they added.
In an accompanying editorial, Rita F. Redberg, MD, MSc, from the department of medicine at the University of California, San Francisco and Patrick G. O’Malley, MD, MPH, from the division of general internal medicine at the Uniformed Services University, Bethesda, Maryland, wrote that adequate economic and utility evaluations are needed to determine if the lung cancer screening program has benefits that outweigh the harms or is a wise investment.
“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,” they wrote.
Use of CT and chest radiography for lung cancer screening
An increase in intended use of CT scans and a stable use of chest radiography for lung cancer screening from 2010 to 2015 indicated slow uptake and underuse of effective screening tools, while an increase and unintended use of CT scans raised concerns about overuse, Jinhai Huo, PhD, MD, from the department of health services research at the University of Texas MD Anderson Cancer Center, and colleagues found.
The USPSTF lung cancer screening guidelines released after the NLST published its main findings in 2011 may have raised “the public’s awareness of the clinical application of low-dose CT in screening, leading to increased demand for screening not only by individuals who meet the eligibility criteria recommended for [lung cancer screening] but also by those who do not,” they wrote.
The researchers evaluated whether these guidelines affected uptake of CT scans and chest radiography in intended and unintended populations. They analyzed data from the 2010 and 2015 National Health Interview Survey Cancer Control Module detailing whether respondents have undergone CT scans or chest radiography for lung cancer screening, as well as their smoking status and history. Participants were classified into one of three groups: high-risk smokers (current smokers, those who quit smoking within the last 15 years or those with 30 pack-years of smoking history), low-risk smokers (current or former smokers who did not meet high-risk criteria) and never-smokers. The CT question received 36,191 individual responses, while the chest radiography question received 36,209 responses.
Data indicated that in 2015, the proportion of participants who received CT scans for lung cancer screening was more than 1.5 times higher than in 2010 (2.1% vs. 1.3%; P < .001). However, there was no significant difference in the use of chest radiography for lung cancer screening from 2010 to 2015 (2.5% vs. 2.7%, respectively). Among never-smokers (1.2% vs. 0.8%; P = .03), low-risk smokers (2.7% vs. 1.5%; P < .001) and high-risk smokers (5.8% vs. 2.9%; P < .001), there was a significant increase in the rate of CT scans. Similarly, high-risk smokers who did not meet the age eligibility criteria, as well as those who met the age eligibility but were not heavy smokers demonstrated a significant increase in the rate of CT scans. Patients above the age of 74 years did not display a significant trend in the use of CT scans.
“To what extent the increasing use of CT for [lung cancer screening] was driven by recently released guidelines or simply reflected a rising trend of CT use in general needs to be explored in future research,” Huo and colleagues concluded. “[In addition], the use of chest radiography remained stable despite its lack of effectiveness in [lung cancer screening], which may reflect primary care physicians’ knowledge gap regarding the latest scientific discovery in [lung cancer screening].”
In their editorial, Redberg and O'Malley wrote that the findings of Huo and colleagues justify Medicare Evidence Development and Coverage Advisory Committee's concerns about an increase in cancer risk due to unnecessary harmful radiation exposure from CT scans and a high number of additional invasive and risky procedures to investigate many noncancerous nodules. - by Alaina Tedesco
Disclosures: Kinsinger and colleagues report funding from the VHA. Hou and colleagues report receiving support from the Duncan Family Institute, the University of Texas MD Anderson Cancer Center’s Halliburton Employees Foundation and the National Cancer Institute. Redberg reports serving as chair of the Medicare Evidence Development and Coverage Advisory Committee panel for the lung cancer screening discussion. O'Malley reports no relevant financial disclosures.