What Are the Chances of Lung Nodules Being Cancer?

Most lung nodules aren't cancerous. It has been noted that fewer than 5 percent of lung nodules turn out to be cancer, i.e., 3 or 4 in 100.
Most lung nodules aren’t cancerous. It has been noted that fewer than 5 percent of lung nodules turn out to be cancer, i.e., 3 or 4 in 100.

Most lung nodules aren’t cancerous. It has been noted that fewer than 5 percent of lung nodules turn out to be cancer, i.e., 3 or 4 in 100. Some of the factors that may increase the likelihood of turning nodules into cancer include

  • Old age
  • Large nodule
  • Past smoker or current smoker
  • Family history of lung cancer
  • Handling asbestos in the past

If a young nonsmoker has a small nodule, it is less likely to be cancer. However, in an older person with a large nodule who recently quit smoking, there are high chances that the nodule will turn out to be cancer. Usually, lung nodules that are 3 cm or bigger are more likely to be cancerous than a small nodule.

If a physician detects lung nodules in an imaging test, they will compare the new scan with a previous one to assess if the nodule has changed its size, shape or appearance. If there are any changes, it’s probably cancerous. Further, the physician may recommend additional testing, such as computed tomography (CT) scan, positron emission tomography (PET) scan bronchoscopy or tissue biopsy to confirm if it’s cancerous.

However, having said all these, it is noted that even in a person with a high risk of lung cancer, most small nodules are not lung cancer.

What happens when a nodule is found on the lung?

If the physician suspects a pulmonary nodule, they will probably recommend additional CT scans to monitor the progression of the nodule. It is known as “active surveillance.” During this period, the physician monitors

  • The growth of nodules: If a nodule is not cancer, it usually doesn’t grow. If the nodule doesn’t enlarge over two years, it is unlikely to be cancer. Most of the time, it is safe to stop monitoring the growth of the nodules if there’s no growth in these two years.
  • Larger nodules: If nodules appear to grow, the physicians may perform close monitoring to determine if it is lung cancer. They will perform a physical examination and may order tests to confirm the diagnosis. Some of the tests include
    • Bronchoscopy, including advanced guided techniques, such as
      • Endobronchial ultrasound (EBUS)
      • Electromagnetic navigational bronchoscopy (ENB)
  • Chest?X-rays?(radiographs)
  • Computed tomography?(CT) scan
  • Fluoroscopy
  • Image-guided sampling techniques that include CT-guided and ultrasound-guided biopsies (fine needle aspiration biopsy or FNA)
  • Magnetic resonance imaging?(MRI)
  • Minimally invasive lung biopsy (thoracoscopic or robotic)
  • Positron emission tomography?(PET)
  • Pulmonary function studies (PFT)

Depending on the features and size of the lung nodule on the CT scan, the physicians may also recommend

  • Observing and repeating X-ray tests if the nodule is probably benign
  • Further imaging, such as a repeat CT scan of the chest or a PET scan
  • Taking a biopsy of the nodule via
    • Bronchoscopy (if the nodule is near one of the airways)
    • A needle biopsy (if the nodule is located near the outside of the lungs)
    • Lung surgery (video-assisted thoracoscopic surgery) if the nodule seems to be cancerous

SLIDESHOW

Lung Cancer: Early Signs, Symptoms, Stages See Slideshow
References
American Thoracic Society. What Is a Lung Nodule? Am J Respir Crit Care Med. 2016; 193: 11-12. https://www.thoracic.org/patients/patient-resources/resources/lung-nodules-online.pdf

Mayo Clinic. Lung Nodules: Can They Be Cancerous? https://www.mayoclinic.org/diseases-conditions/lung-cancer/expert-answers/lung-nodules/faq-20058445

University of Texas Southwestern Medical Center. Pulmonary Nodules and Lung Lesions. https://utswmed.org/conditions-treatments/pulmonary-nodules-and-lung-lesions/