Foster Sylvers , the standout child star of the 1970s family R&B group The Sylvers, has died ... TMZ has learned. Foster's brother, Leon Sylvers III , tells TMZ he died in hospice following a battle with stage 4 pancreatic cancer. More updates will come from their sister, Pat Sylvers . The Sylvers skyrocketed to fame in the '70s with hits like "Fool's Paradise, "Boogie Fever," and "Hot Line." The group had many iterations during their decade in the spotlight ... the above photo shows James ,