The title of this article is totally overstating the substance of the article. But essentially MD Anderson researchers propose that clinical trials using drugs meant to break down the pancreatic tumor's stromal barrier failed miserably because the stroma is actually a good thing.
The previous thinking was that the stroma keeps chemotherapy drugs from penetrating to the tumor and that breaking it down would make the chemotherapy more effective. The stroma is 90% of the tumor mass while the cancerous tumor is the inner 10%. So a few trials (Hedgehog inhibitors, for example) were halted early because it was having the opposite effect.
The new proposal from this researcher is that the stroma is actually the body's immune system trying to contain the tumor. And when you take that away, the tumor starts growing faster.
The title implies that all drugs are ineffective, which is not the case. You'd only run into these stroma depletion drugs in a clinical trial.