In the U.S. there are about 600,000 cancer deaths per year. World-wide -- about 10 million, according to the WHO.
Drug overdose deaths in the U.S. -- about 60,000-70,000, with declines starting to be seen after a couple of decades of increases. If you include other 'medication related' deaths (allergic reactions, interactions, etc.) and non-OD deaths related to illicit drug use (i.e. a heart attack due to meth or coke) it would be a bit higher, but still FAR below the number of cancer deaths.