Lung cancer screening
Lung cancer screening with low-dose CT (LDCT) is an imaging strategy that is beginning to be adopted for high-risk patients in some health systems. Lung cancer is the most common cause of cancer death worldwide, and there is accumulating higher level evidence that a mortality benefit exists with the screening of carefully selected patients.
A Lung-RADS screening classification exists for the purpose of standardizing follow up and management.
On this page:
Screening guidelines
American Lung Association low-dose CT lung cancer screening recommendations (based on National Lung Screening Trial criteria):
- current or former smokers with at least a 30 pack-year history of smoking
- 55-74 years of age
- no history of lung cancer
Other recommendations:
- smoking cessation must be emphasized for patients who are being screened
- imaging screening programs should be associated with multidisciplinary centers that can care for patients who need follow-up
- screening should not be mandatory, but the patient may choose it after a discussion of risks and benefits
Advantages to screening
- detection of lung cancers at an early stage leads to a better outcome (~52% 5-year mortality with stage I and 5% 5-year mortality at stage IV)
- potential to decrease mortality
- may have a positive effect in promoting smoking cessation (controversial)
Disadvantages to screening
- a high false positive rate, requiring interventions, which has the potential to increase screening cost and morbidity on a population level
- ionizing radiation from CT has the potential to increase radiation-induced cancer on a population level
- possible "overdiagnosis" (the cancers found and treated may not effectively decrease the patient's mortality)
- may have a negative effect in promoting smoking cessation (controversial)
Evidence
National lung screening trial
- randomized controlled trial 3
- n = 53,454
- 55-74 years of age
- former or current smokers with over 30 pack-year history
- slightly healthier study cohort than U.S. population overall
- three rounds of annual screening
- positive if at least one noncalcified nodule >= 4 mm
- nodules stable over three screening sessions considered benign
- chest radiograph screening exam used as a control
Results
- low-dose CT detected more nodules than radiograph and greater than twice the diagnosis of stage IA
- ~20% relative reduction in lung cancer mortality in the LDCT arm [95% CI, 6.8-26.7%]
- absolute risk reduction in lung cancer death by 3-4:1000 individuals screened
- ~6.7% reduction in all-cause mortality [95% CI, 1.2-13.6%]
- overall, 320 screened to save one life (mammography 1:465-601)
As with any screening program, the population-level benefits must be greater than the risks. There is increasing evidence that low-dose lung cancer screening benefits outweigh the risks at this time for selected patient groups. There is continued debate over the cost-effectiveness of screening, but it may be cost-effective if limited to the study population or selected subgroups of the study population.
Further studies will refine lung cancer screening strategy, including a possible volume-based nodule assessment rather than single longest dimension assessment.
Related Radiopaedia articles
Chest
- imaging techniques
-
chest x-ray
-
approach
- adult
- pediatric
- neonatal
-
airspace opacification
- differential diagnoses of airspace opacification
- lobar consolidation
-
atelectasis
- mechanism-based
- morphology-based
- lobar lung collapse
- chest x-ray in the exam setting
- cardiomediastinal contour
- chest radiograph zones
- tracheal air column
- fissures
- normal chest x-ray appearance of the diaphragm
- nipple shadow
-
lines and stripes
- anterior junction line
- posterior junction line
- right paratracheal stripe
- left paratracheal stripe
- posterior tracheal stripe/tracheo-esophageal stripe
- posterior wall of bronchus intermedius
- right paraspinal line
- left paraspinal line
- aortic-pulmonary stripe
- aortopulmonary window
- azygo-esophageal recess
- spaces
- signs
- air bronchogram
- big rib sign
- Chang sign
- Chen sign
- coin lesion
- continuous diaphragm sign
- dense hilum sign
- double contour sign
- egg-on-a-string sign
- extrapleural sign
- finger in glove sign
- flat waist sign
- Fleischner sign
- ginkgo leaf sign
- Golden S sign
- Hampton hump
- haystack sign
- hilum convergence sign
- hilum overlay sign
- Hoffman-Rigler sign
- holly leaf sign
- incomplete border sign
- juxtaphrenic peak sign
- Kirklin sign
- medial stripe sign
- melting ice cube sign
- more black sign
- Naclerio V sign
- Palla sign
- pericardial fat tag sign
- Shmoo sign
- silhouette sign
- snowman sign
- spinnaker sign
- steeple sign
- straight left heart border sign
- third mogul sign
- tram-track sign
- walking man sign
- water bottle sign
- wave sign
- Westermark sign
-
approach
- HRCT
-
chest x-ray
- airways
- bronchitis
- small airways disease
-
bronchiectasis
- broncho-arterial ratio
- related conditions
- differentials by distribution
- narrowing
-
tracheal stenosis
- diffuse tracheal narrowing (differential)
-
bronchial stenosis
- diffuse airway narrowing (differential)
-
tracheal stenosis
- diverticula
- pulmonary edema
-
interstitial lung disease (ILD)
- drug-induced interstitial lung disease
-
hypersensitivity pneumonitis
- acute hypersensitivity pneumonitis
- subacute hypersensitivity pneumonitis
- chronic hypersensitivity pneumonitis
- etiology
- bird fancier's lung: pigeon fancier's lung
- farmer's lung
- cheese workers' lung
- bagassosis
- mushroom worker’s lung
- malt worker’s lung
- maple bark disease
- hot tub lung
- wine maker’s lung
- woodsman’s disease
- thatched roof lung
- tobacco grower’s lung
- potato riddler’s lung
- summer-type pneumonitis
- dry rot lung
- machine operator’s lung
- humidifier lung
- shower curtain disease
- furrier’s lung
- miller’s lung
- lycoperdonosis
- saxophone lung
-
idiopathic interstitial pneumonia (mnemonic)
- acute interstitial pneumonia (AIP)
- cryptogenic organizing pneumonia (COP)
- desquamative interstitial pneumonia (DIP)
- non-specific interstitial pneumonia (NSIP)
- idiopathic pleuroparenchymal fibroelastosis
- lymphoid interstitial pneumonia (LIP)
- respiratory bronchiolitis–associated interstitial lung disease (RB-ILD)
- usual interstitial pneumonia / idiopathic pulmonary fibrosis (UIP/IPF)
-
pneumoconioses
- fibrotic
- non-fibrotic
-
lung cancer
-
non-small-cell lung cancer
-
adenocarcinoma
- pre-invasive tumors
- minimally invasive tumors
- invasive tumors
- variants of invasive carcinoma
- described imaging features
- adenosquamous carcinoma
- large cell carcinoma
- primary sarcomatoid carcinoma of the lung
- squamous cell carcinoma
- salivary gland-type tumors
-
adenocarcinoma
- pulmonary neuroendocrine tumors
- preinvasive lesions
-
lung cancer invasion patterns
- tumor spread through air spaces (STAS)
- presence of non-lepidic patterns such as acinar, papillary, solid, or micropapillary
- myofibroblastic stroma associated with invasive tumor cells
- pleural invasion
- vascular invasion
- tumors by location
- benign neoplasms
- pulmonary metastases
- lung cancer screening
- lung cancer staging
-
non-small-cell lung cancer