Patrick Dempsey has been on the show since it started and was a part of the original group of five main characters. Other than him, Ellen Pompeo, Sandra Oh, Justin Chambers, Chandra Wilson and James Pickens Jr, the rest of the current cast has been pieced together over the last twelve seasons.
When the show first started back in 2005, there was only nine episodes because it started part way through a season, but the fans flocked to the television sets to check out the new medical drama. By the end of the ninth episode, the show added almost six million viewers. That would continue for the next four to five seasons, but then the show would see a steady decline from there.
Grey’s Anatomy season 12 is set to begin by the end of September of this year. Because of the major cast change, there is no indication as to how many episodes there will be, which leaves fans worried that the show could be cancelled.