Danh Pham, MD
A total 1.9% of more than 7.6 million current and former heavy smokers in the United States underwent lung cancer screening in 2016, suggesting that it remains inadequate despite recommendations from the United States Preventive Services Task Force (USPSTF), according to an analysis presented ahead of the 2018 ASCO Annual Meeting.
Current USPSTF recommendations, released in 2013, call for annual low-dose CT scans in patients ages 55 to 80 years who are current or former heavy smokers, determined by smoking ≥30 cigarette-pack years. ASCO and the American College of Chest Physicians issued a joint guideline in 2012 with similar opinions. Moreover, the Centers for Medicare and Medicaid Services (CMS) expanded Medicare coverage for low-dose CT scans for lung cancer screening.
“Despite the time since implementation and the potential to prevent thousands of lung cancer deaths every year, annual low-dose CT scanning is only at 1.9% nationally, which remains inadequate following these USPSTF recommendations, especially when it compares to other known screenings in cancer,” said lead study author Danh Pham, MD, a medical oncologist of James Graham Brown Cancer Center at the University of Louisville, during a presscast prior to the meeting.
Current data provided estimates of lung cancer screening since US execution, leading to Pham’s et al statistical analysis, which is the first assessment of lung cancer screening rates since those guidelines were issued and subsequent insurance coverage.
In the study, researchers used data from the 2016 American College of Radiology’s Lung Cancer Screening Registry of people who received low-dose CT scans across the radiographic screening sites. These data were then compared with findings from the 2015 National Health Interview Survey, which estimates the number of eligible smokers to be screened, as per the USPSTF recommendations. Moreover, data were compared between 4 US census regions of Northeast, West, Midwest, and South; the analysis excluded those without a history of lung cancer and patients with missing data.
Overall, results showed that while a total 1796 screening centers could have screened 7,612,975 current and former heavy smokers, only 141,260 people underwent low-dose CT scans, leading to a 1.9% national screening rate. Screening rates were calculated by dividing the number of low-dose CT scans by the number of eligible smokers for screening as per the standard recommendations.
Data showed that the Northeast had the highest screening rate at 3.5% (40,105 scans) followed by the Midwest at 1.9% (38,931). The Northeast and Midwest regions had 404 and 497 screening sites, as well as 1,152,141 and 2,020,045 eligible smokers, respectively.
Moreover, the South region had 663 accredited screening sites, the largest of the 4 regions, and the highest number of smokers eligible for screening (3,072,095). However, the screening rate here was 1.6% (47,966), determined to be the second-lowest screening rate in the country.
In the West, findings showed that this region had the lowest number of accredited screening sites (232), as well as the lowest screening rate at 1.0%. This region had 1,368,694 eligible smokers and 14,080 were screened.
“This ultimately begs the question on the root of the disparity: are physicians not referring enough, perhaps?” asked Pham. “Or, are eligible patients not wanting screening—even if they knew a test was available? Controversy, unfortunately, exists amongst providers…while patients at risk for lung cancer also perhaps lack the adequate awareness of the benefits of screening.”
Additionally, 85% of the current smokers who did have low-dose CT scans were offered smoking cessation resources. There was not a significant difference when compared across census regions.
The authors noted that it remains unclear why the lung cancer screening rate is significantly less than that of other cancer screening modalities. For example, Pham said, approximately 65% of women ≥40 years had a mammogram in 2015.
“It’s still speculation at this point, but lung cancer is particularly unique in that there may be a stigma associated with screening, in that [lung] cancer is attributed to modifiable risk factors through heavy smoking,” Pham explained. “The at-risk population may be deterred from wanting screening if diagnosing cancer will result in confirming a poor lifestyle choice.”
Preliminary findings of 2017 lung cancer screening rates show a small uptick across all census regions. Forward-thinking initiatives, said Pham, include awareness programs and mandatory lung cancer screening as a national quality measure. Effective screening can prevent 12,000 premature lung cancer deaths annually, he concluded.
“Regardless of whatever the reason, this ultimately is a call to action in everyone’s part to increase the much-needed screening, whether it’s through increasing awareness or conducting additional research to urgently increase the screening of the number one cancer killer in America.”