What do studies tell us about screening vs. non-screening?

International ELCAP NEJM 2006

• Catch cancers at earlier stage, involving 32,000 patients. Took patients who were smokers and gave them CT screening for lung cancer 
• 31, 567 of those patients that were diagnosed with lung cancer, and a very high percentage had stage I cancer, which is the very early stage
  • 88%-10 year survival in stage 1 cancer 

Take thousand people get screening and thousand don’t screening and see who does better and follow them for 10 years to see how many people are alive from the groups. The only way to definitively prove that staging works. Hopefully if staging works maybe 90% the patients are alive and maybe 80% not screened alive. 10 percent difference made by the screening. No study has done that yet and not come close to that.

It is known that a low-dose CT scan of the chest can reduce deaths from lung cancer by as much as 20%