way to make drug selectively only target cancer

https://phys.org/news/2018-07-x-ray-triggered-nano-bubbles-cancer.html

If a way like this can be developed to make the drug be active only where it is needed (i.e. only in the cancer tissue) then that should eliminate most of the nasty side effects with means we can give a higher dose of the drug and high enough to kill ALL the cancer without making the patient sick so this would be a real cure.

In this case they put the drug in liposomes that only break down to release the drug when exposed to x-rays so that they can then selectively target the cancer with x-rays to make the drug mainly locally be released there which is about where it is needed.

But I cannot help wonder if those same liposomes couldn't be redesigned to respond (by releasing the drug) to some chemical receptor on the cancer cell's surface that isn't on non-cancer cells and thus not only eliminate the need for the x-rays but make it even more selective because using x-rays still inevitably means many non-cancerous cells are inadvertently attacked by being also exposed to those x-rays?
I would think this should make it even better and even work when the cancer has already spread all over the body so to make it completely impractical to target with x-rays.

Originally posted by @humy
But I cannot help wonder if those same liposomes couldn't be redesigned to respond (by releasing the drug) to some chemical receptor on the cancer cell's surface that isn't on non-cancer cells and thus not only eliminate the need for the x-rays but make it even more selective because using x-rays still inevitably means many non-cancerous cells are inadvertentl ...[text shortened]... has already spread all over the body so to make it completely impractical to target with x-rays.

Originally posted by @wildgrass
These are generally referred to as prodrugs. Typically, the are inactive/non-toxic until they undergo an enzymatic conversion into the active drug. In chemotherapy approaches, the goal is to utilize enzymes that are "overexpressed" in cancer cells for targeting and improved pharmacokinetics. Doesn't always work, but the concept is useful at least.

Originally posted by @sonhouse
There is also this: Turmeric.

https://www.sciencealert.com/turmeric-linked-to-helping-with-Alzheimers-cancer-diabetes-arthritis

I think I will follow his advice, even though I am not a great fan of curry....