Lung cancer screening in the United States remains underutilized, with only about 20 percent of eligible individuals receiving recommended low-dose CT scans despite their proven effectiveness in detecting early-stage disease when treatment outcomes are more favorable. Current guidelines from the U.S. Preventive Services Task Force (USPSTF) advise annual screening for adults aged 50 to 80 who have a smoking history equivalent to a pack a day for 20 years and who currently smoke or quit within the past 15 years.

This screening criterion, based largely on randomized controlled trials involving heavy smokers in the United States and Europe, has significantly reduced lung cancer mortality in those populations. However, roughly half of lung cancer cases in the U.S. occur in individuals who do not meet these parameters. This includes a significant portion of Black Americans, with only about 63 percent of Black men and 50 percent of Black women diagnosed with lung cancer falling within the current screening guidelines. Many in these groups tend to have a lighter daily smoking history but over a longer duration.

A substantial challenge is the detection of lung cancer among non-smokers, who account for approximately one in seven lung cancer cases nationally. Among these, certain demographics—such as women, people of Asian descent, and those with a family history of lung cancer—appear to be at elevated risk. In Asian countries, particularly Taiwan, lung cancer is increasingly found in non-smokers, prompting national screening initiatives that include individuals with family histories or other risk factors like secondhand smoke exposure. These efforts have identified lung cancers at rates similar to those observed in heavy smokers in U.S. trials.

In contrast, there is no established national screening program targeting non-smokers in the United States, though smaller studies are underway focusing on high-risk groups such as younger Asian American women and those with strong family histories. Experts emphasize the need for randomized controlled trials assessing the benefits and risks of expanding screening to broader populations with lower or no smoking history. The potential harms of screening, including false-positive results, anxiety, additional imaging, and occasional unnecessary procedures, must be carefully balanced against the goal of reducing lung cancer mortality.

Ongoing research is exploring biological markers and imaging advances to better identify individuals at elevated risk. For instance, a recent British study highlighted a blood-based protein signature linked to increased lung cancer risk, while U.S. researchers have developed predictive algorithms that assess future cancer risk based on a single CT scan. Combining these emerging tools with traditional risk factors could enhance screening precision, allowing for more tailored approaches that extend beyond smoking history.

Clinicians and researchers agree that integrating demographic data, family history, and novel biomarkers will be crucial in refining lung cancer screening strategies. Such developments promise to broaden detection efforts while minimizing unnecessary interventions, potentially saving thousands of lives annually.