If any part of the headline is 'in quotation marks,' the story is either a vast distortion of the truth, or an outright lie.
If the headline ends in a question mark, the answer is no.
If the headline suggests a major medical breakthrough, the study will be small, the results not statistically significant, or there will simply be no mention of these things.
Addendum: If the headline is written in a publication in the Northwest Territories, hey! Look over there! Something shiny!