Does chemotherapy cause cancer to spread?

Earlier this month, a study was published in Science Translational Medicine that showed how chemotherapy before surgery can stimulate breast cancer invasiveness and invasion under certain circumstances. Not surprisingly, alternative cancer cure mavens everywhere are spinning the study as "proof" that chemotherapy has no benefit and causes only harm (and so you should by their nostrums instead). Unsurprisingly, the actual results are far more nuanced. They do not demonstrate that chemotherapy is ineffective but rather point the way forward to improving chemotherapy regimens. Does chemotherapy cause cancer to spread? David Gorski