Early Detection is Key: How CT Screening Can Save Lives from Lung Cancer in Latin America
"Discover how low-dose CT screening and smoking cessation programs are revolutionizing lung cancer prevention in Latin America, offering hope and improving outcomes in a region facing unique challenges."
The importance of detecting diseases early cannot be overstated. While preventing diseases by getting rid of risk factors is key, finding and treating diseases early on while people aren't showing symptoms is also important [1]. There are well-established rules for deciding when it makes sense to screen a population for a particular disease [2]. These rules include making sure that the disease is a big health problem and that it can be treated effectively in specialized centers. It's also important to really understand the disease and to be clear that treating it early is better than treating it after it has become advanced. Plus, screening should be an ongoing effort, not just a one-time event [3].
Fortunately, the results of the National Lung Screening Trial (NLST) [4] showed that lung cancer meets all the requirements for a population screening program. Because of this, it's now accepted as an official policy in the United States and many other developed countries.
In Latin America (LA), many countries are dealing with a shift in the types of diseases they face. Instead of mostly infectious diseases, they're seeing more chronic conditions, like different kinds of cancer. More and more new cancer cases are being found in less developed countries, and it's predicted that over 60% of all new cases will be in these areas by 2030. This is happening because cancer rates are going up and people are expected to live longer around the world [5]. Most of these countries are also seeing lung cancer rates increase. However, there's often a sense of silence around the disease, as if it's something shameful and seen as a death sentence.
Screening Remains Underused
Lung cancer screening uptake has remained low among eligible high-risk adults. In 2015, only 4.5% of at-risk adults aged 55 to 80 had received a CT scan for lung cancer within the previous year. National screening rates were stable from 2019 to 2020, with just under 1 in 15 eligible people screened, while another report found that only 18.2% of eligible individuals received screening. Low-dose CT screening also carries the challenge of false-positive results, reported at 9.6% to 28.9% in baseline rounds and 5.0% to 28.6% in subsequent rounds.
Low-Dose CT and Its Limits
The CDC identifies low-dose computed tomography, or LDCT, as the recommended screening test for lung cancer. The U.S. Preventive Services Task Force recommends annual LDCT screening and advises stopping once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability to undergo curative lung surgery. The American Cancer Society recommends yearly LDCT for adults aged 50 to 80 who currently smoke or formerly smoked. A major limitation is the high rate of nodule detection: one review reported that more than 50% of participants had at least one noncalcified nodule.
From CT Innovation to Mortality Reduction
Interest in CT screening expanded as CT technology improved enough to produce high-quality images during a single breath hold. A major milestone followed in 2011, when results from the National Lung Screening Trial reported that LDCT reduced lung cancer mortality by 20% in high-risk individuals. Screening guidance also considers clinical risk factors such as age and family history. These developments helped establish LDCT as a tool for detecting lung cancer before symptoms appear.
The Double-Edged Sword: Smoking Cessation and Early Detection
It's clear that lung cancer prevention needs to focus on helping people quit smoking. Most developed countries have taken steps to follow the World Health Organization Framework Convention on Tobacco Control (FCTC) [6]. So, controlling tobacco use is a key part of any lung cancer prevention plan. This should include organized actions to make it easier for people to get into effective programs that help them quit smoking for good [7,8].
- Systematic actions: Facilitate access into effective program
- Multidisciplinary approach: Skilled approach is needed for prevention.
Evidence for Earlier Detection
Recent reviews continue to find benefits from LDCT screening in people at high risk of lung cancer. A systematic review reported that the MILD study found a 39% reduction in lung cancer mortality at 10 years compared with no screening, with a reported risk ratio of 0.61 and a 95% confidence interval of 0.39 to 0.95. The National Cancer Institute states that low-dose spiral CT has been shown to reduce the risk of dying from lung cancer in heavy smokers. Evidence from the decade-long National Lung Screening Trial also found that LDCT detected lung cancer better than conventional chest X-rays.
Benefits Must Be Balanced With Risks
Low-dose CT screening can substantially reduce lung cancer mortality, but it also raises concerns about false positives, follow-up procedures, overdiagnosis, and the practical burden of completing evaluation after an abnormal scan. Reviews of lung cancer screening emphasize that these benefits and harms must be considered together rather than treating screening as risk-free. At the same time, a 2023 narrative review reported that there is currently no epidemiological evidence supporting increased cancer incidence or mortality from the radiation dose used in LDCT screening. This finding addresses radiation risk, but it does not eliminate the other potential harms associated with screening and follow-up.
Comparing Screening Strategies
Low-dose CT is generally positioned as the more sensitive approach for detecting lung cancer early, while conventional chest X-rays are less effective for this purpose. However, comparisons should account for false-positive findings, follow-up requirements, radiation exposure, access to imaging, and the ability of health systems to provide timely diagnosis and treatment. The best strategy therefore depends not only on the screening test itself but also on how reliably the complete care pathway can be delivered.
The Future of Lung Cancer Prevention in Latin America
To tackle this, regional efforts are starting to change things within the public and private healthcare systems. The goal is to improve the quality of care and make primary and secondary prevention for lung cancer better in Brazil. The Brazilian early lung cancer detection program (BRELT1) is the first prevention program in South America with published results in 2016.
The Value of Organized Screening
Expert discussions frame lung cancer screening as potentially highly beneficial when it is widespread and high quality. One model suggests that broad, high-quality screening in the United States could potentially prevent 12,000 lung cancer deaths. The National Lung Screening Trial reported that one in 320 high-risk patients screened with LDCT over five years would avoid a lung cancer death. These estimates support screening while also underscoring the importance of reaching eligible high-risk populations.
Earlier Stages, Longer Survival
Future directions in lung cancer screening focus on improving early detection and making population screening feasible. A 2026 review reports that LDCT detects lung cancer at earlier stages and that population screening was feasible. The same source reports 20-year survival rates of 81% among patients with stage I disease. These findings point toward continued interest in identifying cancer before it advances, although the source does not establish that every screening program will achieve the same outcomes.
Access Determines Impact
Lung cancer remains the leading cause of cancer-related death worldwide, and annual CT screening can detect disease at earlier stages and reduce mortality among high-risk individuals. Yet fewer than 20% of eligible at-risk Americans undergo screening, with Medicaid-insured populations consistently reporting the lowest screening rates across cancers. Risk is concentrated in lower-income populations, making access and care coordination central systemic challenges. In Latin America and elsewhere, the impact of screening will therefore depend not only on imaging capacity but also on whether health systems can connect patients to complete diagnostic and treatment pathways.
Community Support Matters
Real-world implementation depends on more than providing access to a CT scanner. A community outreach case study reported that high-risk patients with a strong smoking history who received low-dose spiral CT screening experienced 15% to 20% lower lung cancer mortality. Case studies from community hospitals and organizations that adopted screening early also offer insight into the barriers and facilitators encountered during implementation. These experiences highlight the importance of community organizations and patient support in helping high-risk people enter and complete the screening process.
We've learned that a good program needs a strong structure and constant feedback between medical and non-medical staff to achieve its goals. BRELT1 started in 2013 to find people at high risk for lung cancer using LDCT screening and a full smoking cessation program. It was created to standardize lung CT screening at our facility. Careful planning, starting with clear goals, has led to focused actions with ways to measure performance, find weak spots, and encourage teamwork between different specialists to use resources better. A big problem in Brazil is the high number of granulomatous diseases, which is common throughout the region.
Latin American countries should work to adapt cancer screening plans to their own situations, taking advantage of the benefits that have already been seen in developed countries using the same methods. With smart strategies, more lives can be saved from lung cancer in Latin America. By combining efforts to help people stop smoking with new technologies, the region can make big progress against this deadly disease.