Lung cancer remains the leading cause of cancer-related deaths. Early detection through low-dose computed tomography (LDCT) screening improves survival, yet guidelines and screening disparities, driven by socioeconomic barriers, provider knowledge gaps, and inconsistent infrastructure, limit its potential. This article examines LDCT screening, challenges, and strategies to improve equitable care and reduce mortality.
Lung cancer is the second most commonly diagnosed cancer in the U.S. and the leading cause of cancer-related death. The overall prognosis remains poor with a 5-year survival rate of just 26%, yet early detection greatly improves the chances of successful treatment. Smoking is the primary risk factor, accounting for roughly 80-90% of cases and increasing the risk of lung cancer by nearly 20 times compared to nonsmokers. Advancing age contributes to risk, with a median age at diagnosis of 70. Other important risk factors include environmental exposures, lung disease, family history of lung cancer, and prior radiation therapy. Recognising these factors is increasingly important as screening guidelines evolve to identify individuals at elevated risk who may not fit traditional criteria.
The United States Preventive Services Taskforce (USPSTF) recommends annual lung cancer screening with low-dose CT (LDCT) for adults aged 50 to 80 who have a 20-pack-year smoking history and currently smoke or quit within the past 15 years. Screening should be discontinued if a person has not smoked for 15 years or has a health condition that limits life expectancy or curative treatment.
Lung cancer screening using LDCT has been shown to reduce mortality in high-risk populations, particularly current and former heavy smokers. The landmark U.S.-based National Lung Screening Trial (NLST) demonstrated a 20% reduction in lung cancer deaths among adults aged 55–74 with a 30-pack-year smoking history. Similarly, the European NELSON trial showed a 24% reduction in mortality after 10 years of follow-up. Other European studies generally support LDCT's ability to detect early-stage cancers, though results on mortality reduction vary due to differences in study size, methodology, and population.
Lung Cancer Screening (LCS) should use an LDCT scanner with specific technical parameters to minimise radiation exposure. For example, a typical LDCT screening involves a radiation dose of less than 1.5 mSv, significantly lower than a standard diagnostic CT. A positive lung cancer screening is identified by solid nodules 5 mm or larger or non-solid nodules 8 mm or larger. Nodules measuring 5 mm or more generally warrant follow-up LDCT in 3 months, while nodules 15 mm or larger require urgent diagnostic evaluation and possible biopsy. Screening is advised annually, balancing early detection benefits with minimising false positives, unnecessary procedures, and radiation risks.
Certain studies have found that screening with LDCT has been associated with a high rate of false positives and potential overdiagnosis, prompting the need for careful evaluation of benefits versus harms. However, LDCT has high sensitivity and reasonable specificity for lung cancer detection. Implementing LDCT screening in high-risk populations has the potential to significantly increase early-stage lung cancer detection, which is crucial for improving treatment outcomes and overall survival rates. Collectively, this body of evidence establishes LDCT as the preferred screening modality for high-risk populations, while ongoing research continues to refine protocols and eligibility.
LDCT remains underutilised as a lung cancer screening tool in the United States, with racial and socioeconomic disparities playing a major role in limiting its reach. The original eligibility criteria for LDCT were derived from studies that predominantly included white males with high socioeconomic status (SES) populations. As a result, these criteria often exclude marginalised groups, such as African American and Hispanic individuals, who are at increased risk for developing lung cancer. While newer guidelines have expanded eligibility by lowering age and pack-year requirements, underrepresented populations still have significantly lower odds of qualifying for screening compared to white individuals.
Even among those who are eligible, critical barriers to implementation persist. Screening uptake remains low due to limited patient awareness, gaps in provider knowledge, stigma, lack of insurance coverage, and logistical barriers to access, factors that disproportionately affect underserved communities. Additionally, evidence shows that adherence to annual lung cancer screening after an initial negative result is lower among Black patients compared to White patients. One study found that socioeconomic status explained nearly 50% of this racial disparity, though it did not fully account for it, underscoring the multifactorial nature of inequities in lung cancer screening.
In terms of the Hispanic population, studies have found that despite being eligible, many Hispanic patients, particularly women, did not receive LDCT screening before their lung cancer diagnosis, highlighting major gaps in implementation. Other barriers, such as language differences, cultural mistrust, and poor access to preventive care, contribute to lower screening rates and later-stage diagnoses among Hispanic and other minority groups.
In addition to disparities in SES and race, inconsistent screening infrastructure, such as limited availability of trained staff, incomplete referral processes, and lack of centralised systems, further hinders equitable access. Across healthcare settings, particularly in safety-net clinics, primary care providers often report uncertainty about eligibility and low rates of LDCT ordering, exacerbated by the absence of electronic medical record (EMR) prompts and high rates of patient refusal.
Complicating matters further, low health literacy significantly impacts patients' understanding and engagement with lung cancer screening. Studies show that approximately one-third of patients at urban, low-income centers have low health literacy. Yet, most online educational materials exceed the recommended reading level, making them inaccessible to many. Low health literacy is associated with poorer health outcomes across chronic diseases and contributes to reduced use of preventive services, greater difficulty managing illnesses, and higher mortality.
These findings highlight that disparities in lung cancer screening stem from a complex interplay of eligibility criteria, healthcare system limitations, and socioeconomic factors. Improving screening rates will require addressing these multifactorial issues across individual, provider, and system levels.
The true measure of a successful lung cancer screening program is its ability to meaningfully engage and impact the communities it aims to serve. Program effectiveness should be assessed by key outcomes such as screening uptake rates, the stage at which cancers are diagnosed, adherence to annual follow-up, and reductions in lung cancer mortality. High screening uptake, in particular, is not just a metric, it is foundational to achieving earlier diagnosis, more effective treatment, and improved survival.
Successful implementation models offer valuable lessons. For example, the Liverpool Lung Health Check program in the UK achieved a screening uptake of 40% among high-risk, underserved populations in its first round, substantially higher than typical participation rates in similar cohorts, by deploying mobile scanning units and issuing targeted invitations.
Looking forward, guidelines should consider expanding beyond the current criteria that focus primarily on age and smoking history. Incorporating additional risk factors, including family history, occupational exposures, and pre-existing lung conditions, could help identify more individuals at heightened risk and improve the inclusiveness and effectiveness of screening programs.
However, broader guidelines alone are insufficient unless accompanied by solutions that address deeper systemic barriers. Educational and awareness campaigns must tackle persistent obstacles such as stigma, mistrust of the healthcare system, and low health literacy, especially in underserved communities. Notably, illustrated, low-literacy patient brochures and community workshops have been shown to increase screening participation in urban, low-income settings. Other effective educational strategies include culturally tailored messaging, community-based information sessions, and partnerships with local leaders to build trust.
Additionally, strengthening primary care capacity is essential. Targeted training for providers, the implementation of EMR alerts to identify eligible patients, and the deployment of patient navigators are all evidence-based strategies that have demonstrated significant improvements in screening uptake. Integrating these interventions into routine practice can help ensure that more eligible patients are identified, engaged, and retained throughout the screening process.
Lung cancer screening using low-dose computed tomography (LDCT) has proven to reduce mortality, yet it remains significantly underutilised, particularly in communities that could benefit the most. To effectively reduce lung cancer mortality, healthcare leaders must prioritise addressing socioeconomic and infrastructural barriers that contribute to disparities in screening access.
Specific policy actions recommended include expanding insurance coverage and reimbursement for screening to reduce financial barriers, establishing centralised registries and electronic medical record prompts to streamline patient identification, and developing targeted community outreach programs modeled after successful initiatives. This program demonstrated significantly improved screening uptake among underserved populations through culturally sensitive education and ease of access.
Widespread adoption of these measures could substantially reduce lung cancer mortality nationwide and diminish longstanding disparities. Hospital administrators, public health leaders, and community-based organisations must take coordinated action to champion these efforts. As research advances and new technologies emerge, continued vigilance and adaptability will be required to ensure lung cancer screening programs remain effective and equitable for all populations.
Jeffrey Velotta, MD, FACS, is a thoracic surgeon and Clinical Professor at Kaiser Permanente Bernard J. Tyson School of Medicine. His clinical and research interests focus on innovative techniques and regionalisation pathways for lung and esophageal cancer. His most recent research aims to improve lung cancer screening uptake among Asian Americans and to identify key factors contributing to the rising incidence of lung cancer in non-smoking Asian women.
Diego Martinez Mendiola is a UCSF medical student with a focus on surgical oncology and improving access to cancer care. He has managed pediatric hematology trials at UCSF Benioff Children’s Hospital, Oakland and led global health projects in Vietnam and Ghana. He is also an advocate for Latino health equity and mentorship through national initiatives.
Shreya Guha is a second-year medical student at California Northstate University College of Medicine. Her research interests include advancements in patient-centered care, narrative medicine, and studying surgical outcomes in vulnerable and underserved populations.
