Largest-ever lung cancer screening study reveals ways to increase screening outreach

November 22, 2022
computer monitor showing image of a lung cancer scan
Investigators looked at the first million people to be screened for lung cancer in the U.S. to find out who is getting screened - and who isn't. Photo by Marquel Coaxum

Although early cancer detection is known to save lives, many people at risk of lung cancer in the U.S. do not follow the annual screening recommendations, an MUSC Hollings Cancer Center researcher found in a recent study published in the Annals of Internal Medicine.

Lung cancer is the second most common cancer and the primary cause of cancer-related death in the U.S. Often, lung cancer has few or no symptoms until it has spread to other parts of the body, but the disease is more treatable when it is detected early. Approximately 236,000 new lung cancer cases and about 130,000 deaths from lung cancer are expected in 2022.

Hollings lung cancer pulmonologist Gerard Silvestri, M.D., and the American Cancer Society Roundtable on Lung Cancer, a national multidisciplinary team of experts, are working to understand lung cancer screening trends across the general population. Approximately 15 million Americans are now eligible for potentially lifesaving lung cancer screenings with low-dose computer tomography. The U.S. Preventive Services Task Force recommended lung cancer screening in 2013.

Lung cancer screenings are recommended for men and women 50 to 77 years old who currently smoke or who have quit within the last 15 years, with a 20 pack-year history of smoking. A 20 pack-year history means smoking one pack a day for 20 years, two packs a day for 10 years or an increasing number of packs a day over fewer years.

“This study looked at the first million patients entered into the American College of Radiology’s Lung Cancer Screening Registry, which is the only approved registry for lung cancer screening. The first key takeaway is that this is the largest cohort ever looked at from a screening perspective in a nationally representative manner. This is real-world data,” said Silvestri, an international expert in lung cancer and interventional pulmonology.

a man at a desk gestures at a lung scan on a screen 
Dr. Gerard Silvestri emphasized that lung cancer screening is not "one and done." It should be an annual preventive measure. More than half of identified cancers are found on repeat scans, not on the first scan. File photo

Comparing the demographics of the million people in the registry with the estimated 8 million people across the country who were eligible at that time revealed that women were more likely to be screened than men. Although similar numbers of men and women get diagnosed with lung cancer each year, fewer men are getting screened. Silvestri said this might be because women are more attuned to medical screenings than men due to regular cervical and breast cancer screenings.

The study also identified that fewer younger – 55- to 65-year-olds – eligible smokers or former smokers were getting screened than expected. The researchers found that people in the registry were 29% more likely to be above age 65 than the entire eligible population. “The population getting screened may be older because they have uniform health care coverage through Medicare. This suggests that uniform coverage for screening services may be important to consider in the future,” said Silvestri.

"Many people quit smoking, which improves health, but they’re still at risk for lung cancer. We want to make sure that we’re getting the message of screening out there to primary care providers."

Gerard Silvestri, M.D.

A third key finding from this study was that the people in the registry were more likely to be current smokers than expected. This may indicate that former smokers are not getting identified through the electronic health record or by their primary care providers. “This is a significant finding. Many people quit smoking, which improves health, but they’re still at risk for lung cancer. We want to make sure that we’re getting the message of screening out there to primary care providers,” said Silvestri.

Lung cancer screening trials showed that more than half of the identified cancers were picked up on subsequent screens, not the initial screen. However, this study showed that only 22% of people eligible for annual screening came back.

“That is an extraordinarily low number,” said Silvestri. “Lung cancer screening is not a one-and-done procedure. Most people aren’t going to get any benefit from screening if they do not come back during the recommended intervals.”

The MUSC Health Lung Cancer Screening Program sees at least 70% of its participants return each year, thanks to a centralized effort and advanced practice providers who remind patients to attend their annual screenings.

“We are also increasing uptake because we now have six screening sites, not including MUSC’s downtown campus. We're screening in Lancaster, Chester, Florence, Marion, Columbia and Kershaw,” said Silvestri. Primary care doctors may refer people for screening, or individuals can refer themselves for a consultation.

Previously, a trial that enrolled people specifically to study the benefits of lung cancer screening reported an adherence rate of 95% for annual screenings, yet Silvestri’s work revealed a different story once the general population was assessed. This study highlights the importance of reassessing screening implementation in real-world community settings.

It is evident, Silvestri pointed out, that more outreach is needed in the primary care community to reach more former smokers and younger eligible patients. “This study showed us the challenges of reaching men, former smokers and the younger eligible population. The challenge is getting people to come back, something we will make every effort to change in the coming years,” he said.