Can you back that up somehow? That doesn't sound at all right to me.
Edit: For the upvote, downvote brigade -- with zero reply so far, but this comment has gone to zero and back to one umpteen times already -- I'm genuinely curious. This isn't some kind of gotcha question.
I have a genetic disorder. I have umpteen relatives who have had cancer. I actually have a serious vested interest in better understanding how this stuff works.
They're less like normal cancers, and more like parasites made of cancerous cells. Moreover, they're not even typical cancer cells -- they're cancer cells which have been dividing (and continuing to mutate) since the disease first came into existence, to the extent that their genetic material has become wildly divergent from that of the host species.
Typical genetic therapies for cancer focus on the hope that enough of the normal apoptotic pathways still exist that the cancer cells can be "convinced" to recognize themselves as cancerous and undergo cell death. In the case of transmissible tumors, though, it's likely that these pathways have been entirely destroyed through selective pressures on the cancer.
I thought I would add that what makes the tasmanian case interesting is that though the body is generally pretty good about detecting and removing foreign cells (including viruses and bacteria), somehow these contagious cancers elude this detection and are allowed to proliferate [1]. It is likely that if the tasmanian devil's immune system were able to detect the intruder cancer cells as coming from another individual, it would eradicate them with ruthless efficiency. Why these cells are able to skirt the host immune system though is a different question.
I mean, I guess it would depend on how you are introducing the gene. How many cells it is getting into.
But if it causes defective cells to suicide, why would it matter where the defect is coming from? I don't think we really have a good handle on what causes cancer. I suspect more cancer is due to some infectious agent than is generally believed and we know genetic variations have significant impact on the immune system and its ability to function at all.
It's cancer. You're trivializing the ultimate source of the problem. If we could ensure universal targeting of cancer cells, we wouldn't need a technically elaborate method of cellular death, like gene modification.
You might as well suggest solving world hunger by just feeding everyone.
No, I'm not. But it's occurred to me that I'm imagining this as treatment for Tasmanian devils that already have tumors. Maybe other people are envisioning it as a preventative measure.
And maybe that's part of the problem in trying to discuss it.
If the cells knew when they were supposed to die, then it wouldn't be cancer.
If the cure is telling the cells when they're supposed to die, then the cells that don't listen survive, ergo the cancer survives.
Which, in the sense of (non-preventitive) treatment, makes it a problem of universal targeting.