July 8, 2024
July 8, 2024

How to Diagnose Lung Cancer Early

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How to Diagnose Lung Cancer Early

Lung cancer is one of the world's most prevalent types of cancer and is the most common cause of cancer-related death. There are many causes of lung cancer, such as smoking, occupational exposure to carcinogens, and genetic predisposition. While treatments for lung cancer continue to improve, early detection remains an incredibly important factor in determining survival rates.

Localized (early-stage) non-small cell lung cancer (NSCLC) and small cell lung cancer (SLC) have 5-year survival rates of 65 and 30 percent, respectively. However, late-stage cancers that have metastasized carry respective 5-year survival rates of just 9 and 3 percent. Thus, early diagnosis can have a profound impact on the chances of surviving lung cancer.

High-risk individuals, particularly those with a history of smoking, are encouraged to adhere to screening guidelines, including annual low-dose computed tomography (LDCT) scans, to improve early detection. Recognizing early symptoms, such as persistent cough, chest pain, and shortness of breath, is crucial. Furthermore, enhancing patient education and ensuring primary care physicians are well-informed about screening protocols can improve early diagnosis and treatment outcomes. This article provides a comprehensive guide on early detection methods for lung cancer, incorporating the latest research and recommendations for strengthening screening uptake.

Risk Factors and Screening Eligibility

Lung cancer can arise for many reasons. A primary risk is inhalation of airborne carcinogens that interact directly with our lung tissue.

Identifying High-Risk Individuals

While a significant proportion of lung cancers are attributable to genetic factors, environmental risk factors include smoking tobacco, exposure to radon, and exposure to occupational hazards like asbestos. History and intensity of smoking (number of packs) are specifically used to determine eligibility for lung cancer screening.

To aid with early detection, high-risk individuals should commit to regular check-ups with their healthcare provider. Furthermore, those still smoking should seek support for reducing their intake or quitting altogether.

Screening Guidelines and Recommendations

Screening guidelines help primary care providers determine their patients' risk status and refer them for screening where necessary. As we’ve seen, there are many environmental and genetic risks for lung cancer. However, most guidelines focus on age and history of smoking to evaluate the need for screening.

American Cancer Society (ACS): The ACS recommends annual screening for individuals aged between 50 and 80 who have a history of smoking and have smoked one pack a day for twenty years or equivalent pack-years (e.g., two packs a day for ten years).  

US Preventive Services Task Force (USPSTF): The USPSTF recommends similar guidelines to the ACS but excludes people who have quit smoking for longer than 15 years.

Diagnostic Tools and Techniques 

Fortunately, several methods are available for effective lung cancer diagnosis, and some are particularly useful for diagnosing rare tumor types and helping determine clinical stage characteristics.


This technique uses relatively low amounts of radiation to take detailed images of the lungs. A primary benefit of LDCT is that it can detect lung cancer early, improving survival rates and reducing the incidence of late-stage disease. One clinical trial found that LDCT reduced mortality rates by 20 percent. However, it also has a high false positive rate, which limits its effectiveness in some cases.

Advanced Imaging and Diagnostic Procedures

Though LDCT is the primary screening method for lung cancer, other methods are helpful in certain cases.

Magnetic Resonance Imaging (MRI)

This method generates detailed images of the lungs, helping to detect tumors, determine their size, and assess their spread. Different types of MRI, such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI, provide additional information about the tumor's characteristics and blood supply.

Ultrasound (UC)

This technique uses sound waves to create images of the chest, helping to detect and guide biopsies of tumors near the chest wall. UC can complement LDCT as a means of monitoring specific types of lung cancer, such as bronchogenic carcinoma.

These additional screening methods are especially useful if initial screening results are inconclusive and have particular uses in diagnosing specific types of lung cancer. For instance, MRIs can help diagnose rare tumors like malignant pleural mesotheliomas and assess local invasion. In addition to helping diagnose bronchogenic carcinoma, UC techniques can help with tumor staging by assessing lymph node involvement.

Clinical Symptoms and Early Warning Signs

Several symptoms may indicate the presence of lung cancer. Being aware of these signs is crucial if you are at high risk of developing the disease. For those with chronic lung illness, it is essential to be extra vigilant, as many symptoms of chronic illness overlap with lung cancer.

Recognizing Early Symptoms

Catching lung cancer early can significantly improve survival rates. Therefore, it’s crucial to know the early signs of the disease. These include: 

  • Persistent cough
  • Chest pain
  • Shortness of breath
  • Unexplained weight loss
  • Loss of appetite
  • Fatigue
  • Coughing up blood

Consider booking a consultation with a healthcare professional if you experience these symptoms, particularly if you are at high risk.

It’s important to note that you may only experience a few of these symptoms because they vary significantly across individuals. A large study from China found a huge variation in symptoms in individuals with lung cancer, with only 17.9 percent experiencing chest pain and 4.8 percent experiencing fatigue. You may experience no symptoms, as early-stage lung cancers are mainly asymptomatic.

Patient Education and Awareness

Patient education is vital in improving screening to help with the early detection of lung cancers. Many barriers prevent patients from seeking screening services, such as distrust of the healthcare system, fears about a positive diagnosis, and the associated financial burden. Many patients may be unaware of symptoms or not understand the importance of early detection. Overcoming these issues is essential to improving engagement with screening programs.

Healthcare professionals play a central role in educating the public about the importance of early detection. Methods for improving lines of communication include: 

  • Hosting community awareness events.
  • Replacing phrases like “lung cancer screening” with “lung health check”.
  • Using electronic alerts as reminders to discuss lung cancer screening programs.

Role of Primary Care Physician

Primary care physicians are critical for assessing early signs of lung cancer and referring patients to screening programs. However, some physicians may not be aware of screening guidelines and are hesitant about using risk prediction software. Importantly, patients using personalized risk prediction software had increased awareness of and engagement with screening programs. These findings highlight the importance of continuing education and training for primary care providers, especially in understanding and integrating the latest screening guidelines.

How to Diagnose Lung Cancer Early: Summary

Lung cancer is a leading cause of cancer-related deaths, driven by factors such as smoking, exposure to other carcinogens, and genetic predispositions. Early detection through screening is crucial, as it dramatically improves survival rates by allowing tumors to be detected before they spread. High-risk individuals, particularly smokers, should adhere to screening guidelines, with annual LDCT scans recommended by health organizations like the ACS. Recognizing early symptoms, including persistent cough, chest pain, and shortness of breath, is essential. Furthermore, enhancing patient education and ensuring primary care physicians are well-informed about screening protocols are vital for promoting early detection. Ultimately, early screening can save lives by identifying the disease at a more treatable stage.

You can determine your risk for various types of cancer, including lung cancer, by using Ezra's risk calculator. In just a few minutes, you can identify if you are at high risk for any type of cancer. With Ezra, you can opt for an LDCT scan to screen for potential lung cancer, which is a quick process of only five minutes.