14 blood proteins may signal lung cancer risk years before diagnosis

Lung cancer can progress for years without producing obvious symptoms, making the search for ways to spot the disease, or its risks, at an early stage one of medical research’s key priorities. An international study published in the scientific journal Cell now highlights a possibility that remains under investigation: a combination of 14 proteins found in blood may be linked to a greater risk of developing lung cancer years before the illness is diagnosed.

Researchers examined blood samples from more than 48,000 people, using artificial intelligence and sophisticated protein-analysis techniques to identify patterns connected with the tumour developing later. This so-called protein signature was also assessed across different datasets, including groups of people who had never smoked.

The finding is not yet a blood test for cancer detection

Despite the encouraging findings, the research does not mean that a blood test is already available to diagnose lung cancer years before it develops. The study identifies a potential association between certain proteins and the future risk of the disease, but further validation stages are needed before it can be used routinely in clinical practice.

According to infectious disease specialist Dr Evaldo Stanislau, coordinator of the Medicine course at São Judas University, whose Medicine course forms part of Inspirali, the ecosystem responsible for managing 15 medical schools across different regions of Brazil, the finding offers an important prospect for the future of early detection.

“It's important to stress that this is research pointing towards a promising route, rather than a test currently available to diagnose lung cancer in clinical practice. The study shows that blood could potentially be used to identify biological signs associated with an increased risk of the disease before it is diagnosed through conventional methods,” he explains.

Should future research confirm these results, a tool of this kind could help identify people more likely to develop the disease and enable more personalised monitoring strategies.

Lung cancer can also affect people who have never smoked

Smoking remains the leading risk factor for lung cancer, but it is not the only one. People who have never smoked can also develop the disease, underlining the importance of investigating other factors linked to its onset.

Based on data presented by Dr Stanislau, the risk of having lung cancer by the age of 75 reaches almost 20% among smokers, compared with around 5% among former smokers and approximately 1% among people who have never smoked. Even within this last group, cases account for between 15% and 20% of lung cancer diagnoses worldwide.

“Lung cancer is not a disease exclusive to people who smoke. Smoking is undoubtedly the main risk factor, but other elements are involved, including exposure to pollution, substances present in certain workplaces, family history and some lung diseases. That is why prevention and monitoring need to be considered more broadly,” says Stanislau.

White August highlights lung cancer prevention

The discovery comes during White August, an awareness campaign focused on lung cancer. The initiative aims to improve understanding of risk factors, prevention, symptoms, diagnosis and treatment.

As the disease can remain silent during part of its progression, paying attention to warning signs is equally important. A persistent cough, shortness of breath, chest pain, hoarseness, tiredness, unexplained weight loss and blood in phlegm are changes that should be assessed by a healthcare professional.

This does not mean, however, that any of these symptoms necessarily indicates cancer. They may be caused by a range of other conditions, but if they persist they should be investigated.

Who should undergo lung cancer screening?

At present, lung cancer screening is not recommended indiscriminately for the entire population. People with a significant smoking history or other risk factors may be advised to have specific monitoring, including imaging tests, depending on medical assessment.

The new research into blood proteins is still far from replacing these approaches. Before it can become part of routine clinical care, the signature identified by researchers must undergo additional studies confirming that it can predict disease risk safely and accurately.

How can the risk of lung cancer be reduced?

While new detection methods are being studied, established measures remain essential for reducing the likelihood of developing the disease:

• Do not smoke: smoking is the main risk factor for lung cancer, and giving up cigarettes progressively lowers the risks associated with tobacco use.
• Avoid cigarette smoke: exposure to second-hand smoke is also associated with an increased risk.
• Use protection at work: professionals exposed to asbestos, silica, arsenic, benzene, cadmium, chromium and nickel should follow recommended occupational protection measures.
• Reduce exposure to pollution: long-term exposure to air pollution is linked to respiratory problems and may contribute to lung disease.
• Maintain medical follow-up: people with a smoking history, lung disease or other risk factors should discuss the need for monitoring and tests with a healthcare professional.
• Investigate persistent symptoms: coughing, shortness of breath, hoarseness or blood in phlegm, among other signs, should be assessed.

For the specialist, developing new detection methods does not lessen the importance of established prevention strategies.

“The best approach is still to reduce risk factors. Stopping smoking, avoiding exposure to cigarette smoke, using protective equipment in workplaces containing potentially harmful substances and maintaining medical follow-up are measures that can make a difference. White August is an important opportunity to remember that prevention and information also save lives,” he emphasises.

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