Screening for lung cancer

There is good reason to believe that screening for lung cancer, by helical CT especially, serves to save lives, although it remains to quantify this effectiveness. The need is to study the distributions of diagnosed cases by stage and size of tumor, specific to particular promising regimens of screening and its associated diagnostics; and it remains to study the durability of the small stage I malignancies detected under CT screening. For the latter, the use of randomized controlled trial is neither ethically admissible nor scientifically necessary.