Full disclosure about cancer screening

Communication about cancer screening is dodgy: benefits are overstated and harms downplayed. Several techniques of persuasion are used. These include using the term “prevention” instead of “early detection,” thereby wrongly suggesting that screening reduces the odds of getting cancer. Reductions in relative, rather than absolute, risk are reported, which wrongly indicate that benefits are large.1 And reporting increases in 5 year survival rates wrongly implies that these correlate with falls in mortality.2 Prasad and colleagues put their finger on another misleading practice: claiming that screening “saves lives” despite the lack of proof that overall mortality is decreased.3

A fall in cancer specific mortality alone cannot prove that lives are saved—the cause of death may be systematically misclassified or screening and subsequent cancer …