[Someone]

I read it as 0.8% of all deaths, not of only the deaths caused by cancer. I think that is the most logical reading.

If that's correct, I get at that 4% this way: according to https://www.cancer.org/content/dam/cancer-org/research/cance..., about 20% of all deaths are caused by cancer.

If, of that 20%, 0.8% is caused by alcohol-induced cancer, 4% of all deaths caused by cancer are caused by alcohol-induced cancer.