"It's a relief but only because these things take a while," Cane added. "Things have gone back and forth but to have it locked in and not have to worry about that sort of thing for the next four years is pretty cool. I'm looking forward to sticking around.
"The decision around wanting to stay in New Zealand and play for the teams I love was an easy one. Without beating around the bush getting the best deal that you can for you."
Cane has also captained the All Blacks twice, against Namibia at the 2015 World Cup and to another victory against Italy in Rome last year.
Listen: Sam Cane on the Devlin Radio Show
"I've grown into a leadership role at the Chiefs and also within the All Blacks. You've got a lot more say and I've got a pretty strong drive to see these teams successful when you're in a spot like that within a team. You've got a big say on how that team performs."
Cane has suffered a number of head knocks during his career, the latest while playing for the Chiefs against the Bulls in April, and was frank about his concern about multiple concussions.
"I'd be lying if I said it didn't worry me and I've certainly had my fair share. I've been fortunate though that none have put me out for a long period of time. I'm not taking that for granted. You only need one in the wrong spot...sometimes guys don't even have a history of it and be out for a wee while.
"It's certainly scary when you see two or three of your mates every year really really struggling with it."