both p=0·003). The 20-year risk
of cancer death (1634 deaths
in 12 659
patients in three trials) remained lower in the aspirin groups than in the control groups (all solid cancers, HR 0·80, 0·72—0·88, p<0·0001; gastrointestinal cancers, 0·65, 0·54—0·78, p<0·0001), and benefit increased (interaction p=0·01) with scheduled duration of trial treatment (≥7·5 years: all solid cancers, 0·69, 0·54—0·88, p=0·003; gastrointestinal cancers, 0·41, 0·26—0·66, p=0·0001).