cohort

Britain's own survivor cohort, built on national registration rather than on hospital volunteers, which is why it can follow people for half a century and count deaths that nobody reported. Its central finding is that what kills survivors changes with time: recurrence early, second cancers and heart disease late.

Europe's answer to the American cohorts: thirteen data providers in twelve countries pooled their records to build what its own authors call the largest cohort of children with cancer to date, 83,333 five-year survivors, so that second cancers and heart disease could be counted on a continent that keeps its data in national pieces.

The study that brought survivors back to a hospital and tested them, rather than asking them what was wrong. It found that most of what it found had not been diagnosed: by age 45, on clinical testing, 95.5 per cent of survivors had a chronic health condition and 80.5 per cent had a serious, disabling or life-threatening one.