Radiation Oncology/NSCLC/Screening

Screening

• National Lung Screening Trial (2002-2004)
  • 2011 PMID 21714641 Full Text -- "Reduced Lung-Cancer Mortality with Low-Dose Computed Tomographic Screening" (NEJM. 2011 Aug 4;365(5):395-409.)
    • Randomized. 53,454 persons, between 55 and 74 year of age, at high risk for lung cancer, randomly assigned to undergo three annual screenings with either low-dose CT or single-view posteroanterior chest radiography.
    • Outcome: Rate of positive screening tests: 24.2% (low-dose CT) vs. 6.9% (radiography); False positive: 96.4% vs. 94.5%; Diagnosis: 645 cases per 100,000 person-years vs. 572 per 100,000 person-years (rate ratio 1.13, 95%CI: 1.03 to 1.23); 20.0% (SS) relative reduction in mortality from lung cancer with low-dose CT screening.
    • Conclusion: Screening with the use of low-dose CT reduces mortality from lung cancer.
  • 2013 - Incidence -- PMID 24004119 -- "Results of the two incidence screenings in the National Lung Screening Trial." (Aberle DR, N Engl J Med. 2013 Sep 5;369(10):920-31.)
  • 2013 - Initial LDCT -- PMID 23697514 -- "Results of initial low-dose computed tomographic screening for lung cancer." (National Lung Screening Trial Research Team, N Engl J Med. 2013 May 23;368(21):1980-91.)
    • Positive screening test: LDCT 27% vs X-ray 9%; lung cancer diagnosis 1.1% vs 0.7%. Sensitivity and specificity LDCT 94% and 73% vs x-ray 73% and 91%
    • Conclusion: Initial screening result suggest reduction in mortality is achievable

• Multi-Institutional, 2007 PMID 17341709 -- "Computed tomography screening and lung cancer outcomes." (Bach PB, JAMA. 2007 Mar 7;297(9):953-61.)
  • Retrospective. 3246 asymptomatic current or former smokers, annual CT screening, began in 1998. 3 institutions (Milan, Mayo, Moffitt)
  • Outcome: Diagnosis: 144 patients vs. 44 expected (RR 3.2, SS); lung resection 109 vs. expected 11 (RR 10.0, SS); advanced cases 42 vs. expected 33 (NS); deaths 38 vs. expected 39 (NS)
  • Conclusion: Screening increases rate of diagnosis and treatment, but may not reduce death from lung cancer
  • NY Times commentary, -- "How Two Studies on Cancer Screening Led to Two Results" (Welch GH, NY Times, March 13, 2007). Interpretation of these two trials. Significant controversy over this point JCO Comment

• The International Early Lung Cancer Action Program (I-ELCAP) (1993-2005) - PMID 17065637 — "Survival of Patients with Stage I Lung Cancer Detected on CT Screening." Henschke CI et al. NEJM. 2006 Oct 26;355(17):1763-1771.
  • 31,567 pts. Screening annually using low-dose CT.
  • 484 lung cancers detected. 85% had Stage I. Of those Stage I pts, 10-year survival rate was 88% (92% for those who underwent surgical resection).
  • Conclusion: Annual CT screening can detect lung cancer that is curable.
  • Comment: Interpretation of survival data only in those screened positive. Concern about lead-time and length bias, since those patients diagnosed earlier may live longer (longer survival) but have same death rate nonetheless. Not clear who should be screened.

• Dutch Belgian Randomised Lung Cancer Screening Trial (NELSON) (2002 - Ongoing) Registry
  • Randomised trial comparing spiral CT screening vs. observation in high risk individuals for decreasing disease specific mortality.
  • Results expected 2011

Work-Up of Pulmonary Nodules

• Mass General Hospital, 2007 PMID 17544146 -- "Evaluating pulmonary nodules." (Miller JC, J Am Coll Radiol. 2007 Jun;4(6):422-6.)
  • Review. Algorithm described:
  • Compare current study with old study (CXR or CT). If growth, biopsy
  • If no old study, do CT. If benign calcification or fat, no action
  • If nodule on CT:
    • If immunocompromised or fever, consider short (4-6 week) follow up or biopsy
    • If history of malignancy, consider follow-up CT (3, 6, 12 months)
    • Otherwise, look at size:
      • If <=4mm, repeat CT (timing depends on age). If growth, biopsy
      • If 4-8mm, repeat CT (timing depends on age). If growth, biopsy
      • If >8mm, biopsy or PET

• Indiana University, 2006 PMID 16567482 -- "The solitary pulmonary nodule." (Winer-Muram HT, Radiology. 2006 Apr;239(1):34-49.)
  • Review. Solitary pulmonary nodule defined as round/oval opacity <3cm diameter, surrounded by pulmonary parenchyma, not associated with lymphadenopathy, atelectasis, or pneumonia
  • Most lesions: granulomas, hamartomas, or lung cancer
  • Size: nodules approaching 3cm likely malignant, nodules <1cm likely benign
  • Location: RUL most common location of cancer. 70% of lung CA in upper lobes
  • Calcification: typically benign, unless history of bone malignancy
  • Fat: typically benign, unless history of renal cell or liposarcoma
  • Imaging features: consider attenuation, air bronchograms, margin, and cavitation; however, significant overlap in features
  • Growth rate: If no change over 2 years, can consider benign
  • PET: Best test to determine malignancy in lesions >1cm