Unlike drug ads that you find on television, cancer advertisements from hospitals aren’t subjected to the same data-based scrutiny.

And that could be a problem, since they arguably can have more influence on patients than pharmaceutical ads.

Cancer ads play on the emotions of patients, and frequently use words like “highest cure rates” and “lowest risk,” despite having little data to back up the claims.

Patients with cancer, along with their families, are understandable fearful after being diagnosed, so these ads hold powerful sway.

But are high-powered, academic cancer centers better than local hospitals? Not necessarily. Although rarer forms of cancer may be better treated in the city, there is little data suggesting that mortality rates for more common cancers are better at places that have bigger advertising budgets.

As Dartmouth’s evidence guru Gilbert Welch points out, “such ads could persuade people with localized cases of more common diseases like prostate cancer to travel long distances from their families at great expense to obtain treatment that may be as successful, or unsuccessful, as the treatment available much closer to home.”

Indeed.