Yeah - that's the main problem. It's very treatable, but non-symptomatic, in the early stages. But by the time the symptoms start, your goose is 90% cooked.
But if you find the cancer earlier for some other reason, you have pretty good chances. Heard a story about a guy who had "the best car accident ever". They were worried he might have some internal damage from the seatbelt so they took a scan - discovered his pancreatic cancer and cured it quite easily. If he hadn't had the car accident he would have been a goner about 2 years later.