Some nice graphs here hint at what they are doing
It can be seen that the incidence of cancer is going up we also have an aging population and you are increasingly likely to get cancer as you get older. The population has also increased.
So the Tories claim that the NUMBER of cancer deaths has increased and attack the NHS for it.
In fact of course despite the INCREASE in incidence of cancer(caused at least in part by a higher proportion of older people) the PROPORTION of deaths from cancer has decreased.
One thing we need to do on the left is eo get more savvy about stats and expose the way that the Condems lie with statistics.