Even more interesting are drug holidays: cancer becomes resistant to drug A by evolving a new clone that uses some other metabolic pathway unaffected by the drug but is less efficient. Stop drug A, the first more efficient clone takes over again. Give drug A again and there is no resistance for a while.
[1] https://www.oncode.nl/news/one-two-punchmethod-published-in-...
> deploying phages can cause the bacteria to evolve in response, and that evolution sometimes involves switching from being antibiotic-resistant to being sensitive to antibiotics.
There's a few big stories like this. Chances are, in the next 25 years you may find yourself being treated with phages.
For that reason it seems wrong to think about cancer as “developing” resistances - I don’t believe that cancer is something that evolves/mutates.
https://en.m.wikipedia.org/wiki/Somatic_evolution_in_cancer#...
Resistance is a neat thing.
I remember (and I'm sure someone will reply with a link to it, since I can't find it) reading a story about a fellow with a very seriously antibiotic resistant bacteria infecting his chest. It resisted everything they had. Researchers found a phage that would attack that specific bacteria- but alas, the bacteria became resistant to the phage as well!
Fortunately, the bacteria had limited dimensions in which to change. The changes needed to become resistant to the phage made it no longer resistant to at least one of the antibiotics. It could not have its cake and eat it to. With both attacks against the bacteria ongoing, it was defeated.
What I'm implying with all this is that yes, the cancer may become resistant to this therapy in question but in doing so it may be forced to become less dangerous, or less resistant to other forms of attack. It does not change merely from "not resistant" to "resistant" but from "form A, which is not resistant" to "form B, which is resistant", and "form B" may have a lot of other consequences.