When confronted directly delusions tend to integrate the new information into the existing belief system so two examples here would be that maybe the study was flawed or only referring to a specific type of signal or specific type of brain cancer but the more likely option is just deciding that this is more proof that the system as a whole aims to deceive them.
Source: am psych nurse and was trained long ago to never try to talk someone out of a delusion for the exact reason that it tends to just make them stronger (I answered somebody’s question about what to do instead down below if you’re curious).