actually, tumors are being immunosurveilled constantly, and when the immune system identifies those cells, it tries very hard to eliminate them. The immune system doesn't know or care that the cells are "foreign", just that the cells have properties, or tags that correlate with properties, that make those cells dangerous.

While I generally agree there will be no single silver bullet technology by which we "cure all cancer" in a general way with little to no side effects, I think it's not inconcievable that improving our ability to identify potentially damaging our cells will contribute a lot to keeping people cancer-free.

And while I also generally agree that cancer is inextricably intertwined with tissue growth, as an existence "proof", cancer has never been observed in naked mole rats; this observation alone is significant.