Could they even treat any cancer besides skin cancer in the 19th century? I remember I once knew a guy said he would prefer to live in the 19th century -- but only with 20th century medical technology.
I'm afraid not. Even tuberculosis which is pretty much a very easily treatable disease nowadays was a death sentence until after WW2 and the advent of penicillin.
Alexander Fleming first discovered the properties of penicillium I believe in 1928, but it would only be in the middle of the war around 1942-1943 that it saw culture and usage as the primordial antibiotic drug.