Lung cancer is the leading cause of cancer deaths in the United States, largely because most patients with lung cancer are diagnosed at advanced stages of the disease. Despite this, until now it wasn’t known if lung cancer screening would be effective in identifying early-stage patients in the general population.
New research from Michigan State University has found that using low-dose computed tomography, or LDCT, for lung cancer screening has led to a significant decrease in advanced lung cancer in the U.S.
The research was presented by Maxwell Akanbi, a clinical instructor at the MSU College of Human Medicine in his third year of residency at McLaren Flint Hospital in Michigan, at the American Society of Clinical Oncology national meeting and also published in the Journal of Clinical Oncology.
“Our study was to evaluate the effectiveness of lung cancer screening in the U.S. general population,” Akanbi said. “Our results showed that the incidence of advanced lung cancer actually decreased in the U.S. population following the rollout of lung cancer screening. This was particularly significant in minority populations.”
To assess the impact of screening, Akanbi and colleagues calculated the age-adjusted incidence of advanced lung cancer before LDCT screening was covered by insurance for this patient group (2004 to 2014) and after it was covered (2015 to 2018).
The researchers analyzed SEER data, which is data collected and published on cancer, for 400,343 adults ages 55 to 80 who were diagnosed with regional or metastatic lung cancer from 2004 to 2018. Slightly more than half of the patients were men (54.9%). Most were non-Hispanic White (76.1%) and lived in metropolitan counties (83.7%).
The researchers found a significant decline in the age-adjusted incidence of advanced lung cancer after LDCT screening was adopted. The incidence declined by three cases per 100,000 people per year from 2015 to 2018 relative to 2004 to 2014. There was a significant decrease in advanced lung cancer incidence for both women and men, but the decrease was greater for women.
Non-Hispanic Black patients had the greatest decrease in advanced lung cancer incidence when patients were analyzed by race and ethnicity. The incidence declined by five cases per 100,000 people per year for non-Hispanic Black patients, three per 100,000 for non-Hispanic White patients, two per 100,000 for Hispanic patients, and two per 100,000 for non-Hispanic Asian/Pacific Islander patients.
Patients living in non-metropolitan areas had a greater decline in advanced lung cancer incidence when compared with metropolitan dwellers. The incidence declined by seven cases per 100,000 people per year for non-metropolitan patients and three cases per 100,000 for metropolitan patients.
“The results are encouraging because there have been concerns that lung cancer screening may not be very effective in minority populations because of limited access to screening facilities,” Akanbi said. “While this is encouraging, the work is not yet done.
“Our end goal is to make sure there’s a reduction in lung cancer mortality. There are still barriers between screening and mortality, so the next stage of our study will be to see whether this reduction in the incidence of advanced lung cancer actually translates to a reduction in lung cancer mortality.”