The Liverpool-set soap ran from 1982 to 2003 and Sweeney played Lindsey Corkhill from 1991 to 2001, before returning for the final episode.
"I don't think it should ever have been decommissioned," the actress told Digital Spy of the show.
"It was groundbreaking drama. You get new controllers who come in who want to make their name and it got dropped, which was such a shame."
Asked if she was proud of her work on the show, Sweeney added: "Oh God yeah, really proud.
"[Creator] Phil Redmond - he was fantastic. His work and the team of writers he had on board, like Jimmy McGovern. And wonderful actors and writers on board. I'm so proud to have been part of it."
Asked if any of her character's storylines will feature in the planned Brookside 30th anniversary DVD, she said: "I hope so, I keep getting tweets about it.
"I really, really hope so. It's a massive part of my life Brookside, and I probably wouldn't be here talking to you if it wasn't for Brookside."
Of reports a few years ago that she may appear in Hollyoaks, Sweeney laughed: "Aye, I read that one, I didn't know about it until I read it!
"Who knows - if it was a nice part and good, gritty role, you never know!"
Claire Sweeney has teamed up with Kenco, the official coffee partner for Macmillan's World's Biggest Coffee Morning, to encourage everyone to sign up for their very own coffee morning on September 28. To register visit Macmillan's Kenco page. Get the Inside Soap magazine on your iPhone or iPad