David Cameron is no doubt aware that the exclusion of certain information is necessary when attempting to discredit a political opponent with emotive verse on sensitive subjects.

“What Gordon Brown is not telling you about the situation with cancer, cancer drugs and cancer outcomes is, after all the things he’s talked about, all the money that’s gone in, our death rate from cancer is actually worse than Bulgaria’s.” This was what he said during the first leaders’ debate. But what Cameron didn’t mention was what he himself was ‘not telling you’.

The reference to cancer deaths in Bulgaria and the UK made by Cameron is actually correct (according to Eurostat figures, Bulgaria’s death rate from cancer was 170 per 100,000 people in 2007, the UK’s 178). What is unclear is why Cameron implies a direct correlation between these deaths and government money. I may have missed something but the reason there are masses of cancer researchers and institutes and still no cure for cancer or miracle drug is because it is a wildly complex disease which can not be simply extinguished by healthcare money or drugs.

Cameron should have added that cancer is affected by cigarette smoke, alcohol consumption, sun exposure, diet, exercise, the level of exposure to certain chemicals in the direct environment, genes and also that there are other potential but controversial causes such as pesticides, deodorants, acrylamide, artificial sweeteners and hair dyes. In addition to this, ‘Cancer’ is really a group of 200 diseases which are likely to require different treatments. This information is publicly available on the Cancer Research UK website. It is extremely difficult to define whether the higher UK death number can be attributed to one, a few, a combination or all of these.

But Cameron’s insinuation that lower cancer deaths in Bulgaria mean they have better healthcare and therefore a better Government would be a little diluted if he took the trouble to mention all this in a debate.