UPDATE 1-Cycling-Cancellara out of Flanders campaign with back injury

(Recasts with injury update) PARIS, March 27 (Reuters) - Fabian Cancellara was ruled out of the Flanders campaign after the triple Tour of Flanders and Paris-Roubaix champion fractured two lower back vertebraes in a crash at the GP E3-Harelbeke on Friday. "X-rays have confirmed the worst: 2 fractures of vertebrae in lower back for Fabian Cancellara means no spring campaign," his Trek Factory Racing team said in their Twitter feed. The Swiss powerhouse was one of several riders to hit the deck early in the cobbled one-day race, which also took out Dutch classics specialist Sebastian Langeveld. Two of cycling's five 'Monument' one-day classics are being held in the Flanders region, with the Tour of Flanders on April 5 and Paris-Roubaix a week later -- both featuring cobbled sections. Cancellara won the Tour of Flanders in 2010, 2013, 2014 and Paris-Roubaix in 2006, 2010, 2013. Another Flanders great, four-times Paris-Roubaix champion and three-times Tour of Flanders winner Tom Boonen has already been ruled out of both races with a shoulder injury. (Reporting by Julien Pretot, editing by Pritha Sarkar)