There's quite a few references available here, from a Canadian view:

Cannabis Use and Driving: Knowledge Translation Strategy Recommendations:
http://drugpolicy.ca/wp-content/uploads/2017/02/CDPC_Cannabis-and-Driving_Evidence-Review_FINALV2_March27-2017.pdf

I have hundreds of other 'driving under the influence' studies too if you need, since at least the early 90's - many lengthy government reports and they're all positive, all of them.

Cancer? Here's a small sample for you, I have many, many others if you want?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5054289/