Is it somewhat true that about 1 in 3 people will get cancer sometime in their lives?

Just plain true: If you count little cancers that are not especially aggressive, it is higher. We cure a majority of even the bad ones nowadays, about 2/3. Cancer is hundreds of diseases and is inevitable as the genome becomes destabilized with the ongoing exposure to background mutagens. You can lower your risk in various ways and catch many tumors early.