Screening for Lung Cancer

Australia’s National Lung Cancer Screening Program (NLCSP) commenced on 1 July 2025. It uses low-dose CT (LDCT) to detect lung cancer earlier in people at high risk who do not have symptoms. Lung cancer causes more cancer deaths than any other cancer in Australia.

  1. Who should be screened
    • Eligible people must meet all of the following:
      • age 50–70 years
      • no signs or symptoms suggesting lung cancer
      • currently smoke tobacco cigarettes or quit within the past 10 years
      • smoking history of ≥30 pack-years.
    • Family history, occupational exposure or other lung cancer risk factors do not substitute for the program eligibility criteria.
    • Once enrolled, smoking history eligibility does not need to be reassessed.
    • A participant can therefore remain in the program even when it becomes >10 years since they quit smoking.
    • Participants age out when they turn 71 years.
  2. Pack-years
    • Pack-years = packs smoked per day × years smoked
    • For the program, 1 pack = approximately 20 cigarettes.
    • Examples:
      • 20 cigarettes/day × 30 years = 30 pack-years
      • 40 cigarettes/day × 15 years = 30 pack-years
      • 10 cigarettes/day × 60 years = 30 pack-years.
    • Smoking histories are often approximate; use the patient’s best history and clinical judgement.
    • For expanded detail: Smoking History
  3. Screening test
    • Screening is with low-dose CT chest.
    • Routine screening is approximately every 2 years if no finding requires earlier follow-up.
    • The screening LDCT is free through Medicare for eligible people.
    • MBS 57410 = routine screening LDCT.
    • MBS 57413 = interval LDCT required because of a previous screening finding.
    • These imaging items are mandatory bulk billed.
  4. Symptoms are not screening
    • Do not send symptomatic patients through the screening pathway.
    • Important symptoms include:
      • persistent unexplained cough
      • haemoptysis
      • unexplained shortness of breath
      • other symptoms or signs suspicious for lung cancer.
    • These patients require diagnostic investigation, irrespective of whether they otherwise meet NLCSP eligibility criteria.
  5. Eligibility is not the same as suitability
    • An eligible patient must also be able to undergo LDCT.
    • Screening may need to be deferred or reconsidered if:
      • unable to lie flat for approximately 5 minutes
      • symptomatic respiratory infection within the previous 12 weeks
      • full diagnostic chest CT within the previous 12 months
      • another chest CT is planned for clinical reasons within the next 3 months
      • severe comorbidity means investigation or treatment of a detected cancer would be inappropriate.
    • Suitability may be temporary.
  6. What happens after the LDCT
    • Management follows the NLCSP Nodule Management Protocol.
    • At baseline:
      • very low risk → repeat LDCT in 24 months
      • low risk → 12 months
      • low–moderate risk → 6 months
      • moderate risk → 3 months
      • high / very high risk → respiratory physician or other specialist linked to a lung cancer MDT.
    • Clinically important incidental findings are managed according to the relevant clinical pathway.
  7. Smoking cessation
    • A person does not have to stop smoking to participate in screening.
    • Smoking cessation support should nevertheless be offered throughout the screening pathway.
    • Screening is not a substitute for smoking cessation.
    • For expanded detail: Smoking Cessation Medications
  8. Benefits and harms
    • LDCT can detect lung cancer at an earlier, more treatable stage.
    • Potential harms include:
      • false-positive findings
      • incidental findings
      • additional CT scans
      • invasive investigations
      • radiation exposure
      • overdiagnosis
      • anxiety.
    • This is why the program is targeted to people at sufficiently high risk, rather than offered as general population screening.

The useful exam skeleton is

  • 50–70
  • Asymptomatic
  • Current smoker or quit ≤10 years
  • ≥30 pack-years
  • → LDCT every 2 years
  • Symptoms → diagnose, don’t screen
  • Abnormal LDCT → 12 / 6 / 3 months or respiratory MDT depending on risk
  • And:
  • Pack-years = (cigarettes/day ÷ 20) × years

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