Randomized controlled trials of the efficacy of lung cancer screening by sputum cytology revisited: a combined mortality analysis from the Johns Hopkins Lung Project and the Memorial Sloan-Kettering Lung Study

Cancer. 2009 Nov 1;115(21):5007-17. doi: 10.1002/cncr.24545.


Background: : Two randomized controlled trials of lung cancer screening initiated in the 1970s, the Johns Hopkins Lung Project and the Memorial Sloan-Kettering Lung Study, compared 1 arm that received annual chest X-ray and 4-monthly sputum cytology (dual-screen) to a second arm that received annual chest X-ray only. Previous publications from these trials reported similar lung cancer mortality between the 2 groups. However, these findings were based on incomplete follow-up, and each trial on its own was underpowered to detect a modest mortality benefit.

Methods: : The authors estimated the efficacy of lung cancer screening with sputum cytology in an intention-to-screen analysis of lung cancer mortality, using combined data from these trials (n = 20,426).

Results: : Over (1/2) of squamous cell lung cancers diagnosed in the dual-screen group were identified by cytology; these cancers tended to be more localized than squamous cancers diagnosed in the X-ray only arm. After 9 years of follow-up, lung cancer mortality was slightly lower in the dual-screen than in the X-ray only arm (rate ratio [RR], 0.88; 95% confidence interval [CI], 0.74-1.05). Reductions were seen for squamous cell cancer deaths (RR, 0.79; 95% CI, 0.54-1.14) and in the heaviest smokers (RR, 0.81; 95% CI, 0.67-1.00). There were also fewer deaths from large cell carcinoma in the dual-screen group, although the reason for this is unclear.

Conclusions: : These data are suggestive of a modest benefit of sputum cytology screening, although we cannot rule out chance as an explanation for these findings. Cancer 2009. (c) 2009 American Cancer Society.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Cytodiagnosis / methods*
  • Early Detection of Cancer*
  • Humans
  • Lung Neoplasms / diagnostic imaging
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology*
  • Male
  • Middle Aged
  • Radiography
  • Sputum / cytology*