No, it's not. Cancer is just a form of malfunction of cellular machinery, and as such, can certainly be mitigated or cured at some point. There's already lots of promising research in eliminating it, such as by re-purposing viruses to program the body's immune system to recognize and eliminate the cancerous cells.

It might require artificial intervention, but I believe cancer will be mostly eliminated before too long. And artificial intervention shouldn't be a problem: we have to do this on all our other machines too, we just call it "repair" or "maintenance". There's no such thing as a machine which never needs maintenance from an external source.

Oncology + new genetic tools (just sequencing, not even CRISPR/CAS9) is making amazing progress.

Things that would have been a death sentence 20 years ago now have reasonably hopeful mortality rates.