The holy grail for a screening test is that it discovers more cancers in the screened arm than in the control; that those cancers are of an earlier stage and there is, as a consequence, a stage shift towards lower stage cancers compared with the control group; that the test is acceptable to, basically, healthy individuals with low risks of serious side effects resulting from tests following a positive screen; and that the cost of a life saved, or a quality-adjusted life-year (QALY) is acceptable to the economy of the day.

Published in Thorax there is an end-of-screening report on a Danish CT-based study. They entered 4104 men and women, (of which 45% were women, unusually high) aged between 50 and 70 years, a 20 pack-year smoking history; lung function was recorded but was not used a...