The study results are "colonoscopies do not lead to a reduction in colon cancer mortality". Reporting that isn't misleading that's what the study says.

Basically in the treated group of 1103 of every 10,000 people died. And in the control group 1104 of every 10,000 people died.

So to summarize the study. Inviting someone to a colonoscopy reduces their risk of getting colon cancer by 22 basis points. Their risk of dying from colon cancer by 3 basis points, and their risk of dying of any cause by 1 basis point.

With the actual risk reduction being up to 5x this assuming it's a 20% difference in the rate of getting colonoscopies which is driving the difference.

But this makes metformin look good because it drives a much larger overall reduction in risk.