This is 100% correct. We have a vast array of mechanical means to kill tumors, but very few pass the extra test of preventing therapy induced metastasis or other significantly detrimental damage. We're approaching a point where combination products may start to be viable, but that's "approaching" in the sense that the technology is just now becoming viable for further testing. We're nowhere near marketing of "nano tech" solutions (as many silicon valley types like to claim/dream up).

Edit: An addendum is that one of the biggest revelations these days isn't in treatment, but in the ability to track abnormal cell features. If you can target cancerous cells for uptake of specific elements/molecules, you can far more easily deal with larger growths well before their malignancy spreads further. This, however, only works for well defined tumors. Once you get into things like lymphomas, you're in a very different ballpark.