State-Level Lung Cancer Screening Rates Do Not Align with Lung Cancer Burden

The first population-based study of lung cancer screening found that state-level screening rates were not aligned with disease burden, with the exception of Kentucky, which has supported comprehensive efforts to implement lung cancer screening.¹

“The increasing but low utilization of lung cancer screening reflects both ongoing efforts to screening eligible adults, and the many challenges to do so,” Stacey A. Fedewa, MPH, PhD, said in a press release.² “Kentucky, which has supported screening implementation efforts, is unique as its screening rates are over twice the national average and four times that of other high lung cancer burden states like West Virginia and Arkansas.”

The report, published in JNCI: The Journal of the National Cancer Institute, indicates that deliberate efforts from various stakeholders are needed to boost lung cancer screening rates among eligible adults with a heavy smoking history, a group facing multiple barriers to lung cancer screening and cancer care.

To capture screening events, investigators utilized the American College of Radiology’s Lung Cancer Screening Registry (LCSR). Specifically, population-based surveys, US Census, and cancer registry data were used to estimate the number of eligible adults and lung cancer mortality.

Nationally, the screening rate was found to remain steady between 2016 (3.3%; 95% CI, 3.3%-3.7%) and 2017 (3.4%; 95% CI, 3.4%-3.9%), increasing to 5.0% (95% CI, 5.0-5.7) in 2018 (2018 vs 2016 screening rate ratio [SRR] = 1.52; 95%CI, 1.51-1.62).

“Medicare and most commercial insurers began covering [lung cancer screening] in 2015, likely contributing to increased utilization since reimbursement and cost is a frequently cited barrier among providers and patients,” the study authors noted. “We did not observe measurable increases until 2018, possibly due to the lag between insurance coverage and scaling up [lung cancer screening] in health systems.”

On the state level, in 2018 it was also found that several Southern states with a high lung-cancer burden, such as Mississippi, West Virginia, and Arkansas, had relatively low screening rates (<4%) among eligible adults, while several Northeastern states with a lower lung cancer burden, such as Massachusetts, Vermont, and New Hampshire, had the highest screening rates (12.5%-15.2%).

However, the exception to the above observations was Kentucky, which had the nation’s highest lung cancer mortality rate and one of the highest screening rates (13.7%).

Additionally, the study also found that compared to the national average, lung cancer screening rates were about 20% lower in states with a high proportion of uninsured adults who smoked and 40% lower in states with a relatively low number of lung cancer screening facilities. This suggests that there may be critical gaps in access to lung cancer screening.

According to sociodemographic factors, screening rates were positively correlated with the proportion of smokers who were female and negatively correlated with smokers who were Hispanic. Overall, the results showed that states with adults who smoked and are Hispanic had a significantly lower screening rate ratio than the national average.

“Even with a physician recommendation, [lung cancer screening] may be particularly hard to increase because of individual-level barriers, such as competing health and financial demands, unique values and beliefs among adults who smoke,” the authors explained. “Beliefs about screening may also vary by sociodemographic factors. Women may be more likely to benefit from screening and adhere to [lung cancer screening] guidelines.”

Importantly, this study was not without limitations, including that researchers assumed a uniform probability that a person was eligible for lung cancer screening given that they smoked cigarettes, recognizing that smoking duration and intensity may vary by state and the National Health Interview Survey estimate used in the study could be limited by small sample sizes. Moreover, the national number deemed eligible in the study approximated those of previous studies.

“Despite these limitations, our study has many strengths,” wrote the authors. “It provides the first population-based state-level screening data for all 50 states as well as a framework to do so as current state-based survey tools (i.e., [Behavioral Risk Factor Surveillance System]) do not ask questions on [low-dose computed tomography] in all states. These data are needed to inform state-level policy and lung cancer implementation efforts.”

References:

1. Fedewa SA, Kazerooni EA, Studts JL, et al. State Variation in Low-Dose CT Scanning for Lung Cancer Screening in the United States. JNCI: The Journal of the National Cancer Institute. doi: 10.1093/jnci/djaa170

2. First Population-Based Study Finds State-Level Lung Cancer Screening Rates Not Aligned With Lung Cancer Burden in the U.S. [news release]. Published November 12, 2020. Accessed November 12, 2020. http://pressroom.cancer.org/LDCTScanLCS