There is actually some truth to that. Cures for some types of previously incurable cancers were approved by the FDA in Trumps first year (2017)- the so called CAR-T therapies. They were mostly for blood cancers, but there are more coming for both solid and blood. So yeah, Trump's term(s) will be the turning point on the war on cancer.
And don’t forget the “Right To Try” bill he signed. People who decide to use that could end up saving countless lives due to research they’ll be involved in.